Hematology Quiz
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Questions and Answers

Which of the following terms refers specifically to a type of immune cell precursor?

  • Thrombocyte
  • Erythrocyte
  • Committed Lymphoid Progenitor (correct)
  • Granulocyte

    • What does the abbreviation 'GM' stand for in the context of blood cell types?

  • Granulocyte Monocyte (correct)
  • Giant Monocyte
  • Granulocyte Macrophage
  • Granulocyte Marker

    • What is the role of CFU-GM in hematopoiesis?

  • It regulates lymphocyte maturation.
  • It contributes to the formation of red blood cells.
  • It represents a committed progenitor for megakaryocyte development.
  • It is involved in the differentiation of myeloid lineages. (correct)

    • Which of the following molecules is primarily responsible for stimulating platelet production?

    <p>Thrombopoietin</p> Signup and view all the answers

    During prenatal hematopoiesis, which location is primarily responsible for blood cell production before birth?

    <p>Yolk Sac</p> Signup and view all the answers

    What do the terms 'GEMM' and 'CFU' represent in hematopoiesis?

    <p>Granulocyte, Erythrocyte, Monocyte, Megakaryocyte and Colony Forming Unit</p> Signup and view all the answers

    Which growth factor is specifically associated with the regulation of erythropoiesis?

    <p>EPO</p> Signup and view all the answers

    What does the term 'metarubricyte' refer to in the context of blood cell maturation?

    <p>An intermediate stage in erythroid development</p> Signup and view all the answers

    Which cell type is derived from a megakaryocyte?

    <p>Platelet</p> Signup and view all the answers

    Which of the following components is crucial for the synthesis of protoporphyrin?

    <p>Precursors</p> Signup and view all the answers

    Which of the following cell types originates from committed progenitors in the myeloid lineage?

    <p>Platelets</p> Signup and view all the answers

    Which immune cells are referred to as NK and T cells?

    <p>Natural Killer and T cell</p> Signup and view all the answers

    Which of the following describes the role of IL-3 in hematopoiesis?

    <p>It promotes the proliferation of multiple progenitor cell types.</p> Signup and view all the answers

    What role does Interleukin (IL) serve in the immune response?

    <p>Cell signaling during immune response</p> Signup and view all the answers

    Which cell type is directly associated with the formation of platelets?

    <p>Megakaryocyte</p> Signup and view all the answers

    Which stage of myeloid lineage development occurs after the promyelocyte stage?

    <p>Myelocyte</p> Signup and view all the answers

    What is the first heme precursor in the synthesis pathway mentioned?

    <p>Delta-aminolevulinic acid</p> Signup and view all the answers

    What could lead to the excessive formation of porphyrins?

    <p>Blockage of any enzymatic step in heme synthesis</p> Signup and view all the answers

    Which compound comes after porphobitinogen in the heme synthesis pathway?

    <p>Uroporphyrinogen</p> Signup and view all the answers

    Which intermediate is formed directly before heme in the synthesis process?

    <p>Protoporphyrin</p> Signup and view all the answers

    What is the final product of the heme synthesis pathway?

    <p>Heme</p> Signup and view all the answers

    In the context of porphyrias, what aspect of heme synthesis is critical?

    <p>Maintaining all enzymatic steps functionally intact</p> Signup and view all the answers

    What percentage of Hemoglobin F (Hgb F) is typically present in a newborn?

    <p>60-90%</p> Signup and view all the answers

    Which anticoagulant is noted for its ability to chelate calcium?

    <p>EDTA</p> Signup and view all the answers

    What is the main hemoglobin type present in adults?

    <p>Hgb A</p> Signup and view all the answers

    What characterizes the urine of individuals with porphyrias?

    <p>Red or port wine colored urine</p> Signup and view all the answers

    Which embryonic hemoglobin chain is represented by Gower II?

    <p>α2ε2</p> Signup and view all the answers

    Which of the following statements about iron storage is incorrect?

    <p>Excess iron is always eliminated from the body effectively.</p> Signup and view all the answers

    What type of hemoglobin is almost entirely absent in adults?

    <p>Hgb F</p> Signup and view all the answers

    What type of symptoms are associated with acute intermittent porphyria (AIP)?

    <p>Neuropsychiatric symptoms</p> Signup and view all the answers

    Which hemoglobin chain composition corresponds to Portland hemoglobin?

    <p>ε2γ2</p> Signup and view all the answers

    Which precursor is commonly associated with cutaneous symptoms in porphyrias?

    <p>Uroporphyrin (UR)</p> Signup and view all the answers

    What is the function of Heparin in laboratory procedures?

    <p>Anti-thrombin agent</p> Signup and view all the answers

    Which condition is characterized by excessive iron accumulation that leads to organ damage?

    <p>Hemochromatosis</p> Signup and view all the answers

    Which of the following statements about globin synthesis is accurate?

    <p>Embryonic hemoglobins include Gower I and II.</p> Signup and view all the answers

    What is the primary role of ferritin in the body?

    <p>Store iron in a soluble form</p> Signup and view all the answers

    Which precursor is involved in the earliest stage of heme synthesis?

    <p>Delta-aminolevulinic acid</p> Signup and view all the answers

    Which of the following is NOT a symptom of porphyria?

    <p>Frequent headaches</p> Signup and view all the answers

    What could lead to a stain appearing too blue during a leukocyte differential?

    <p>Using a buffer with a high pH</p> Signup and view all the answers

    Which leukocyte is most commonly increased in cases of bacterial infections?

    <p>Neutrophil</p> Signup and view all the answers

    How is the absolute value of leukocytes calculated?

    <p>Relative value (%) x Total WBC count</p> Signup and view all the answers

    In which condition might an increase of monocytes be significant?

    <p>Malignancies</p> Signup and view all the answers

    What is indicated by a significant increase in eosinophils?

    <p>Allergies and Parasites</p> Signup and view all the answers

    What effect does a prolonged washing step have on staining results?

    <p>Stain may appear lighter</p> Signup and view all the answers

    What can cause discrepancies in the 'Rule of Three' when considering the correlation of Hb, Hct, and RBC?

    <p>The presence of abnormal red blood cells</p> Signup and view all the answers

    What is the expected normal range for hemoglobin in adults?

    <p>14 ± 2 g/dl</p> Signup and view all the answers

    What condition may require a warm sample and a rerun for accurate results?

    <p>Cold agglutinin disease</p> Signup and view all the answers

    Which of the following is NOT a potential reason for discrepancies in the Rule of Three?

    <p>Normal platelet counts</p> Signup and view all the answers

    What is the normal range for red blood cells (RBC) in millions per microliter in adults?

    <p>4.5 ± 0.7 x 10^6/µL</p> Signup and view all the answers

    Which measure is typically correlated using the Rule of Three?

    <p>Hb, Hct, and RBC</p> Signup and view all the answers

    When can a warm sample not resolve issues such as abnormal red blood cells?

    <p>Cold agglutinins are present</p> Signup and view all the answers

    What is the normal platelet count range per microliter of blood?

    <p>150,000 - 400,000/µL</p> Signup and view all the answers

    What is the reference range for a male's WBC count?

    <p>5,000 - 10,000/ul</p> Signup and view all the answers

    How is the total volume counted when assessing WBCs?

    <p>Length x width x depth of squares counted</p> Signup and view all the answers

    What is the total volume counted for a WBC assessment when all 9 squares are counted?

    <p>0.9 mm³</p> Signup and view all the answers

    How many squares should be counted for platelet counts?

    <p>25 squares in the center</p> Signup and view all the answers

    What is a common source of error in blood cell counting?

    <p>High white blood cell count</p> Signup and view all the answers

    What is the female reference range for hematocrit levels?

    <p>42 ± 5%</p> Signup and view all the answers

    What formula is used to calculate the total number of cells counted?

    <h1>cells counted x total volume x dilution factor</h1> Signup and view all the answers

    What dimension corresponds to the depth when calculating the total volume in cell counting?

    <p>0.1 mm</p> Signup and view all the answers

    What is the MCV range characteristic of microcytic cells?

    <p>MCV &lt; 80</p> Signup and view all the answers

    Which cell shape is associated with hereditary stomatocytosis?

    <p>Stomatocyte</p> Signup and view all the answers

    What do Howell-Jolly bodies indicate in a blood smear?

    <p>Disturbed erythropoiesis</p> Signup and view all the answers

    Which condition is characterized by the presence of schistocytes?

    <p>Disseminated Intravascular Coagulation (DIC)</p> Signup and view all the answers

    What MCHC value indicates a hypochromic condition?

    <p>MCHC &lt; 32 g/dL</p> Signup and view all the answers

    Which cell shape is often seen in cases of hemolytic processes?

    <p>Spherocyte</p> Signup and view all the answers

    What does basophilic stippling in red blood cells indicate?

    <p>Thalassemia</p> Signup and view all the answers

    Which red blood cell shape is primarily seen in megaloblastic anemia?

    <p>Macroovalocyte</p> Signup and view all the answers

    What indicates an increase in the variation of cell sizes, termed anisocytosis?

    <p>RDW &gt; 14.5</p> Signup and view all the answers

    Which abnormal red cell shape is associated with hereditary elliptocytosis?

    <p>Elliptocyte</p> Signup and view all the answers

    What is a likely cause of elevated platelet size in a blood sample?

    <p>Bernard-Soulier syndrome</p> Signup and view all the answers

    Which method is suggested for checking platelet counts when low levels are observed?

    <p>Check for clumping on a feather edge of the slide</p> Signup and view all the answers

    What correction is necessary when nucleated red cells are present in the blood sample?

    <p>Recalculate white cell count</p> Signup and view all the answers

    Which of the following conditions is associated with 'satelitism' in a blood sample?

    <p>Myeloproliferative disorders</p> Signup and view all the answers

    What describes the shape of healthy red blood cells?

    <p>Biconcave disk</p> Signup and view all the answers

    What is a key indicator of hemoglobin C in a blood smear?

    <p>Bar-shaped crystals</p> Signup and view all the answers

    Which formula is correct for calculating the corrected white blood cell count in the presence of nucleated red cells?

    <p>wbc count x 100 / (100 + # nrbcs)</p> Signup and view all the answers

    What type of platelet morphology may indicate myeloproliferative disorders?

    <p>Giant platelets</p> Signup and view all the answers

    What is the primary constituent of Howell-Jolly bodies?

    <p>DNA</p> Signup and view all the answers

    Which stain is commonly used to identify Basophilic Stippling?

    <p>New Methylene Blue</p> Signup and view all the answers

    What condition is indicated by the presence of Howell-Jolly bodies?

    <p>Hemolytic Anemias</p> Signup and view all the answers

    In which type of anemia is Basophilic Stippling most commonly associated?

    <p>Thalassemia</p> Signup and view all the answers

    What is the function of Wright stain in relation to red cell inclusions?

    <p>To identify abnormal cellular structures</p> Signup and view all the answers

    Which of the following inclusions is specifically associated with G6PD deficiency?

    <p>Heinz Bodies</p> Signup and view all the answers

    What is the primary confirmatory stain used to identify Siderotic Granules?

    <p>Prussian Blue</p> Signup and view all the answers

    Which abnormal blood cell inclusion is a remnant of the mitotic spindle?

    <p>Cabot Ring</p> Signup and view all the answers

    In which condition might you observe abnormal red blood cell (RBC) shapes?

    <p>Cold Agglutinin Disease</p> Signup and view all the answers

    Which staining method is noted to be ineffective in visualizing Heinz Bodies?

    <p>Wright Stain</p> Signup and view all the answers

    Which parasite is primarily associated with malaria?

    <p>Plasmodium</p> Signup and view all the answers

    Which abnormal RBC inclusion is linked to unstable hemoglobins?

    <p>Heinz Bodies</p> Signup and view all the answers

    What type of anemia is characterized by megaloblasts in the bone marrow?

    <p>Megaloblastic Anemia</p> Signup and view all the answers

    What is the normal range for hematocrit (Hct) in adults?

    <p>42 ± 5%</p> Signup and view all the answers

    What might cause discrepancies in the correlation of hemoglobin, hematocrit, and red blood cells?

    <p>Clotted sample</p> Signup and view all the answers

    How is the reticulocyte count useful in clinical practice?

    <p>Monitors erythropoiesis</p> Signup and view all the answers

    Using the Rule of Three, what should the expected hemoglobin value be if the hematocrit is measured at 45%?

    <p>15 g/dL</p> Signup and view all the answers

    Which of these factors would NOT typically be considered when analyzing discrepancies in the Rule of Three?

    <p>Dehydration status</p> Signup and view all the answers

    What is the expected normal range for red blood cells (RBC) in millions per microliter in adults?

    <p>4.5 ± 0.7</p> Signup and view all the answers

    Which staining method is used for reticulocyte counts?

    <p>New methylene blue</p> Signup and view all the answers

    Which of the following abnormalities could indicate a need to check hemoglobin levels separately from RBC and Hct using the Rule of Three?

    <p>Sickle cell anemia</p> Signup and view all the answers

    What does a corrected reticulocyte count of 2.0% indicate concerning the hematocrit level?

    <p>It indicates a proportionate adjustment based on low hemoglobin levels.</p> Signup and view all the answers

    Given a hemoglobin level of $3.0 imes 10^6/µL$ and a reticulocyte count of 3.6%, how is the absolute reticulocyte count calculated?

    <p>By multiplying the RBC count with the reticulocyte percentage.</p> Signup and view all the answers

    What does an RPI value of 1.0 suggest about the reticulocyte production in response to anemia?

    <p>There is insufficient erythropoietic response to the anemia.</p> Signup and view all the answers

    How is the relative reticulocyte percentage related to the overall reticulocyte and RBC count?

    <p>It is calculated as the number of reticulocytes divided by total RBC count.</p> Signup and view all the answers

    When analyzing reticulocyte counts, what is a primary consideration in differentiating between relative and absolute values?

    <p>Absolute values are less influenced by changes in RBC mass.</p> Signup and view all the answers

    What implication does a reticulocyte count of 3.6% have for a patient with anemia?

    <p>It reflects possible iron deficiency and ineffective erythropoiesis.</p> Signup and view all the answers

    What does an erythrocyte sedimentation rate of 0-20 mm in females indicate?

    <p>Normal inflammatory response</p> Signup and view all the answers

    Which of the following factors could lead to an increased erythrocyte sedimentation rate?

    <p>Increased plasma proteins</p> Signup and view all the answers

    In the context of reticulocyte production index (RPI), what does a value greater than 2 imply?

    <p>Adequate bone marrow response to anemia</p> Signup and view all the answers

    What is indicated by a corrected reticulocyte count that is significantly low?

    <p>Inadequate bone marrow response to anemia</p> Signup and view all the answers

    Which clinical scenario is most likely associated with a reticulocyte percentage of 0.5 - 1.5%?

    <p>Normal erythropoiesis</p> Signup and view all the answers

    What could result in a decreased erythrocyte sedimentation rate?

    <p>Increased anticoagulants</p> Signup and view all the answers

    Which of the following best describes a significant source of error when measuring the erythrocyte sedimentation rate?

    <p>Improper specimen collection technique</p> Signup and view all the answers

    In which condition might reticulocyte count be notably high?

    <p>Post-acute blood loss</p> Signup and view all the answers

    What is the normal myeloid to erythroid (M:E) ratio in healthy bone marrow?

    <p>3:1 - 4:1</p> Signup and view all the answers

    What clinical condition is associated with a 'dry' tap during bone marrow aspiration?

    <p>Aplastic anemia</p> Signup and view all the answers

    In hemoglobin electrophoresis, which hemoglobin type migrates the fastest?

    <p>Hemoglobin A</p> Signup and view all the answers

    Which of the following is a potential interpretation of an increased M:E ratio?

    <p>Myeloid hyperplasia</p> Signup and view all the answers

    At which pH level is hemoglobin electrophoresis typically performed?

    <p>8.6</p> Signup and view all the answers

    What does a low myeloid to erythroid (M:E) ratio indicate?

    <p>Erythroid hyperplasia</p> Signup and view all the answers

    Which of the following hemoglobins migrates slower in electrophoresis?

    <p>Hemoglobin S</p> Signup and view all the answers

    Which factor could explain myeloid hyperplasia in a bone marrow examination?

    <p>Acute myeloid leukemia</p> Signup and view all the answers

    What is a characteristic finding in SC disease regarding crystal appearance?

    <p>Hand in glove or Washington monument shape</p> Signup and view all the answers

    Which of the following is an indicator of Hemoglobin C disease in homozygous individuals?

    <p>Presence of Hb H inclusions</p> Signup and view all the answers

    How can Hemoglobin C be differentiated from other hemoglobin types during electrophoresis?

    <p>It migrates with A2 and E</p> Signup and view all the answers

    What hemoglobin type is primarily absent in alpha thalassemia?

    <p>Hb A</p> Signup and view all the answers

    What is the typical blood morphology associated with alpha thalassemia?

    <p>Microcytic, hypochromic anemia</p> Signup and view all the answers

    What defines the conditions present at birth in homozygous individuals with Hemoglobin C?

    <p>Presence of Hb Bart's</p> Signup and view all the answers

    Which feature is indicative of decreased production of alpha chains in relation to thalassemia?

    <p>Microcytic anemia</p> Signup and view all the answers

    What kind of inclusions are typically observed in conditions associated with Hemoglobin H?

    <p>Heinz bodies</p> Signup and view all the answers

    What is the expected cellular composition ratio for a sample utilizing a 50% cells:50% fat ratio?

    <p>50% cells:50% fat</p> Signup and view all the answers

    Which hemoglobin variant is characterized by a structural mutation involving valine at the 6th position of the beta chain?

    <p>Hemoglobin S</p> Signup and view all the answers

    What effect does a reducing agent like Sodium dithionite have on Hemoglobin S during testing?

    <p>It causes Hemoglobin S to precipitate, producing turbidity.</p> Signup and view all the answers

    At which pH does Hemoglobin S generally migrate in relation to the Hemoglobin D variant?

    <p>pH 8.6</p> Signup and view all the answers

    What type of anemia is typically associated with homozygous sickle cell disease?

    <p>Chronic hemolytic anemia</p> Signup and view all the answers

    Which group of individuals typically has Hemoglobin D, which migrates with Hemoglobin S during testing?

    <p>East Indian individuals</p> Signup and view all the answers

    What is the main purpose of performing an overall evaluation of cellularity using a biopsy?

    <p>To analyze cell morphology and cellularity.</p> Signup and view all the answers

    Which statement accurately describes the migration behavior of hemoglobin variants during electrophoresis at a defined pH?

    <p>Hemoglobin S and Hemoglobin D migrate together at pH 8.6.</p> Signup and view all the answers

    What condition results from having three deleted alpha genes?

    <p>Hemoglobin H disease</p> Signup and view all the answers

    Which type of anemia is primarily associated with a problem in globin production?

    <p>Thalassemias</p> Signup and view all the answers

    Which condition is characterized by a defect in red blood cell membranes leading to spherocytes?

    <p>Hereditary spherocytosis</p> Signup and view all the answers

    What is a common cause of megaloblastic anemia?

    <p>B12 deficiency</p> Signup and view all the answers

    Which of these conditions does NOT result from a problem with hemoglobin structure?

    <p>Transfusion reaction</p> Signup and view all the answers

    Chronic renal disease is a type of anemia classified under which category?

    <p>Production loss</p> Signup and view all the answers

    Which external factor can contribute to hemolytic anemia?

    <p>Physical trauma</p> Signup and view all the answers

    Which of the following describes an anemia due to ineffective erythropoiesis?

    <p>Megaloblastic anemia</p> Signup and view all the answers

    Which condition is associated with increased levels of methylmalonic acid (MMA)?

    <p>B12 Deficiency</p> Signup and view all the answers

    How is hereditary spherocytosis characterized in the context of blood smears?

    <p>Presence of spherocytes</p> Signup and view all the answers

    What blood features are indicative of folate deficiency?

    <p>Increased reticulocyte count and oval macrocytes</p> Signup and view all the answers

    In which condition would you expect to find cold agglutinin antibodies?

    <p>Cold agglutinin disease</p> Signup and view all the answers

    Which type of anemia is associated with anti-intrinsic factor antibodies?

    <p>Pernicious Anemia</p> Signup and view all the answers

    Which laboratory finding is expected in lead poisoning?

    <p>Basophilic stippling of red blood cells</p> Signup and view all the answers

    What is primarily indicated by the presence of Hh C crystals in hemoglobin C disease?

    <p>Bar-shaped crystals and target cells</p> Signup and view all the answers

    In sickle cell disease, what unique crystal formation is observed?

    <p>Washington monument crystals</p> Signup and view all the answers

    What is a common feature of homozygous hemoglobin C disease?

    <p>Mild chronic anemia</p> Signup and view all the answers

    In the context of alpha thalassemia, what does a deletion of four alpha genes usually lead to?

    <p>Hydrops fetalis</p> Signup and view all the answers

    What laboratory finding is associated with iron deficiency anemia?

    <p>Increased Total Iron Binding Capacity (TIBC)</p> Signup and view all the answers

    How is hemoglobin C confirmed in laboratory testing?

    <p>Electrophoresis</p> Signup and view all the answers

    Which condition is characterized by three deleted alpha genes?

    <p>Hemoglobin H disease</p> Signup and view all the answers

    Which condition is associated with a hypocellular bone marrow and pancytopenia?

    <p>Aplastic Anemia</p> Signup and view all the answers

    What formation is typically observed in the blood smear of patients with Hb H disease?

    <p>Hemoglobin H inclusions</p> Signup and view all the answers

    What type of anemia is primarily associated with the absence or reduced production of beta chains?

    <p>Beta thalassemia</p> Signup and view all the answers

    What laboratory finding is definitive for diagnosing hemoglobin defects?

    <p>Poikilocytes on Smear</p> Signup and view all the answers

    Which type of anemia is categorized as microcytic and hypochromic?

    <p>Iron deficiency anemia</p> Signup and view all the answers

    What is the primary characteristic of microcytic, hypochromic anemia related to thalassemia?

    <p>Decreased hemoglobin concentration</p> Signup and view all the answers

    Which type of anemia involves normal bone marrow and an increased reticulocyte count?

    <p>Acute Blood Loss</p> Signup and view all the answers

    In which type of hemolytic anemia would you expect a normal mean corpuscular volume (MCV)?

    <p>Chronic disease anemia</p> Signup and view all the answers

    What is commonly observed in patients with chronic renal disease affecting red blood cell production?

    <p>Decreased Bone Marrow Activity</p> Signup and view all the answers

    Which of the following anemias is characterized by apoptosis of erythroid precursors in the bone marrow?

    <p>Aplastic anemia</p> Signup and view all the answers

    What type of blood cell morphology is indicative of a hemoglobinopathy?

    <p>Sickle Cells</p> Signup and view all the answers

    What type of anemia is most likely to occur as a result of a vitamin B12 deficiency?

    <p>Megaloblastic anemia</p> Signup and view all the answers

    Which of the following lab findings is not typically associated with hemolytic anemias?

    <p>Normal Bone Marrow</p> Signup and view all the answers

    Which anemia is associated with hereditary conditions affecting the RBC membrane?

    <p>Hereditary spherocytosis</p> Signup and view all the answers

    What lab finding is typically observed in megaloblastic anemia due to folate deficiency?

    <p>Increased mean cell volume (MCV)</p> Signup and view all the answers

    Which type of hemoglobinopathy is characterized by Hb S?

    <p>Sickle cell disease</p> Signup and view all the answers

    What finding distinguishes chronic disease anemia from iron deficiency anemia?

    <p>Increased serum ferritin</p> Signup and view all the answers

    What is identified as a hallmark for Hairy Cell Leukemia (HCL)?

    <p>Tartrate-Resistant Acid Phosphatase (TRAP)</p> Signup and view all the answers

    Which of the following indicates a typical characteristic of Gaucher disease?

    <p>Accumulation of glucocerebroside</p> Signup and view all the answers

    Which cell surface markers are associated with myeloid lineage leukemias?

    <p>CD13, CD33</p> Signup and view all the answers

    Which cell type would most likely show a positive result for non-specific esterase?

    <p>Monocytic leukemias</p> Signup and view all the answers

    The presence of Auer rods is primarily associated with which type of leukemia?

    <p>Acute Myeloid Leukemia</p> Signup and view all the answers

    The common leukocyte antigen (CD45) is expressed on which of the following?

    <p>All leukocytes</p> Signup and view all the answers

    Which marker is specifically used to identify T-lineage cells?

    <p>CD3</p> Signup and view all the answers

    In Niemann-Pick disease, which histological finding is typically observed?

    <p>Globular or foamy cytoplasm in macrophages</p> Signup and view all the answers

    Which type of myelodysplastic syndrome is characterized by 20% plasma cells in peripheral circulation?

    <p>Refractory Anemia (RA)</p> Signup and view all the answers

    What does a positive result for Prussian Blue staining indicate?

    <p>Iron overload</p> Signup and view all the answers

    Which marker is associated with leukocytes in the context of their alkaline phosphatase levels?

    <p>Leukemoid Reaction</p> Signup and view all the answers

    Which myeloproliferative disease is primarily indicated by the presence of myeloblasts with minimal maturation?

    <p>Acute Myeloid Leukemia (AML)</p> Signup and view all the answers

    What is indicated by the presence of myeloblasts without differentiation?

    <p>Acute Myeloid Leukemia (AML)</p> Signup and view all the answers

    What type of anemia is specifically indicated by the presence of a significant number of plasmacytic cells?

    <p>Refractory Anemia (RA)</p> Signup and view all the answers

    What characteristic is associated with Alder-Reilly syndrome?

    <p>Large Azurophilic Granules</p> Signup and view all the answers

    Which condition is related to a defect in lysosomal fusion?

    <p>Chediak-Higashi Syndrome</p> Signup and view all the answers

    What is a characteristic feature of May-Hegglin anomaly?

    <p>Giant Platelets</p> Signup and view all the answers

    Which of the following conditions is linked to a higher susceptibility to infections?

    <p>Chediak-Higashi Syndrome</p> Signup and view all the answers

    Which genetic alteration is associated with acute myeloid leukemia (AML) with a t(8;21) inversion?

    <p>Recurrent Chromosomal Abnormalities</p> Signup and view all the answers

    What is the primary symptom of Pelger-Huet anomaly?

    <p>Hyposegmented Polymorphonuclear Cells</p> Signup and view all the answers

    In which AML subtype might dysplasia be observed?

    <p>Therapy-Related AML</p> Signup and view all the answers

    Which condition can lead to 'ghost cells' upon acid elution?

    <p>Fetal Hemoglobin Resistance</p> Signup and view all the answers

    Which test is most specific and sensitive for detecting the absence of GPI Anchor Proteins?

    <p>FLAER Test</p> Signup and view all the answers

    What is the purpose of the Kleihauer-Betke Acid Elution test?

    <p>To evaluate resistance of fetal hemoglobin to acid</p> Signup and view all the answers

    Which test evaluates the formation of Heinz bodies within hemoglobin due to oxidizing agents?

    <p>Heinz Body Prep</p> Signup and view all the answers

    What does the Sickle Cell Screen primarily test for?

    <p>Reduced solubility of deoxygenated Hemoglobin S</p> Signup and view all the answers

    Which antibody type is associated with the Donath Landsteiner Test?

    <p>IgG Ab</p> Signup and view all the answers

    Which test is used to determine the presence of cold autoantibodies in hemolytic anemia?

    <p>Cold Agglutinin Titer</p> Signup and view all the answers

    What measuring process is entirely different from the assessment of the presence of cold agglutinins?

    <p>Hemoglobin Electrophoresis</p> Signup and view all the answers

    Which condition is primarily indicated by the FLAER Test?

    <p>Paroxysmal Nocturnal Hemoglobinuria</p> Signup and view all the answers

    What is the patient's white count if 0.02 ml of blood was diluted with 1.98 ml of ammonium oxalate and an average of 50 cells was counted?

    <p>5,000/µL</p> Signup and view all the answers

    Which M:E ratio is considered normal for an adult?

    <p>1:1.5</p> Signup and view all the answers

    Which disease is most compatible with positive findings for CD10, CD19, CD22, and negative for CD13 and CD33 in a flow cytometry study?

    <p>Acute Lymphoblastic Leukemia (ALL)</p> Signup and view all the answers

    Which laboratory manual test is most likely affected by a 4 ml EDTA tube containing only approximately 1 ml of whole blood?

    <p>Peripheral blood smear</p> Signup and view all the answers

    Which cytogenetic abnormality is specifically diagnostic of acute promyelocytic leukemia?

    <p>t(15;17)</p> Signup and view all the answers

    What is the typical M:E ratio observed in conditions of anemia?

    <p>3:1</p> Signup and view all the answers

    Which of the following cell lines does NOT give rise to plasma cells?

    <p>Megakaryocytic</p> Signup and view all the answers

    In a bone marrow differential, which percentage of blasts would typically raise a suspicion for acute leukemia?

    <p>20%</p> Signup and view all the answers

    What does an RDW greater than 14.5% combined with decreased iron and increased TIBC suggest?

    <p>Iron deficiency anemia</p> Signup and view all the answers

    In thalassemia minor, which of the following is likely not to be observed?

    <p>Severe anemia</p> Signup and view all the answers

    What would characterize a condition indicated by giant platelets and increased TIBC?

    <p>Bernard-Soulier syndrome</p> Signup and view all the answers

    Which option correctly describes Rb AS in terms of solubility testing?

    <p>Positive solubility test with migration to the C position</p> Signup and view all the answers

    What hematological change would underfilling lead to regarding sed rate?

    <p>Falsely decreased sedimentation rate</p> Signup and view all the answers

    Which hematological condition is characterized by the presence of siderotic granules?

    <p>Sideroblastic anemia</p> Signup and view all the answers

    What does a positive solubility test for Hb C indicate?

    <p>Hemoglobin C disease</p> Signup and view all the answers

    What is the expected normal range for the M:E ratio in hematological evaluations?

    <p>3:1 to 4:1</p> Signup and view all the answers

    What is the most likely interpretation of the laboratory results indicating a hemoglobin level of 6 g/dl, an MCV of 114 fl, and oval macrocytes on Wright stain?

    <p>Pernicious anemia</p> Signup and view all the answers

    Which condition is most likely associated with decreased synthesis of globin chains?

    <p>Beta-thalassemia</p> Signup and view all the answers

    In the case of a 72-year-old adult female with hemoglobin at 11.2 g/dl and an MCV of 128 fl, what additional test would help clarify the diagnosis?

    <p>Reticulocyte count</p> Signup and view all the answers

    What is the most appropriate follow-up action for a laboratory result showing numerous flagged values with no evidence of clots in the sample?

    <p>Warm the sample to 37°C and rerun</p> Signup and view all the answers

    Based on the results of MCH of 39 pg, MCHC of 34 g/dl, and RDW of 18.5%, what could be a probable diagnosis?

    <p>Pernicious anemia</p> Signup and view all the answers

    What condition may be indicated by a reticulocyte count of 1.2% in the presence of macrocytic anemia?

    <p>Bone marrow suppression</p> Signup and view all the answers

    What finding from the blood results is least consistent with folate deficiency?

    <p>Elevated MCHC</p> Signup and view all the answers

    From the provided blood results, which option suggests a more severe underlying condition?

    <p>Positive anti-intrinsic factor antibodies</p> Signup and view all the answers

    What is the dilution factor when using a 1:100 dilution for manual cell counts?

    <p>100</p> Signup and view all the answers

    In which condition might Rouleaux formation be observed due to increased plasma proteins?

    <p>Plasma cell myeloma</p> Signup and view all the answers

    How can the volume factor be eliminated in a manual cell count calculation?

    <p>By adding a fixed number of counted cells</p> Signup and view all the answers

    Which of the following options is NOT affected by lipemia when measured?

    <p>Platelet count</p> Signup and view all the answers

    Which of the following calculations results in 5,500/mm3 for cell counts?

    <p>55 x 100</p> Signup and view all the answers

    What is the expected outcome regarding serum viscosity in cases of plasma cell myeloma?

    <p>Increased viscosity and decreased albumin:globulin ratio</p> Signup and view all the answers

    Which condition is NOT associated with disturbed erythropoiesis?

    <p>Polycythemia vera</p> Signup and view all the answers

    Which component of the manual cell count formula is not directly influenced by the total volume?

    <p>Number of cells counted</p> Signup and view all the answers

    Which compound is primarily responsible for iron storage in the body?

    <p>Hemosiderin</p> Signup and view all the answers

    In a patient with iron deficiency anemia, which laboratory result would most likely be observed?

    <p>Low serum iron</p> Signup and view all the answers

    What hematological characteristic is typical of the May-Hegglin anomaly?

    <p>Presence of Dohle bodies</p> Signup and view all the answers

    In the context of hemoglobin electrophoresis, which variant is characterized by an abnormal banding pattern seen in the S region?

    <p>HbS</p> Signup and view all the answers

    What would be the most appropriate interpretation of an MCV of 74 fl in a 32-year-old female?

    <p>Microcytic anemia</p> Signup and view all the answers

    Which of the following conditions is characterized by a failure of granulocyte development past the 'band' stage?

    <p>Chronic granulomatous disease</p> Signup and view all the answers

    Which laboratory result is consistent with a diagnosis of anemia of chronic inflammation?

    <p>High serum ferritin</p> Signup and view all the answers

    What is the expected result of the TIBC test in a patient with iron deficiency anemia?

    <p>Increased TIBC</p> Signup and view all the answers

    What is the primary function of platelets at an injury site?

    <p>Initial arrest of bleeding and formation of a platelet plug</p> Signup and view all the answers

    What percentage of platelets is distributed in the peripheral blood?

    <p>70%</p> Signup and view all the answers

    What is the normal life span of platelets in circulation?

    <p>9-12 days</p> Signup and view all the answers

    Which molecule is formed from arachidonic acid in platelets and plays a role in their function?

    <p>Thromboxane A2</p> Signup and view all the answers

    What role does prostacyclin play in the coagulation process?

    <p>Inhibits platelet aggregation</p> Signup and view all the answers

    In which location do platelets primarily adhere and aggregate following an injury?

    <p>Injury site</p> Signup and view all the answers

    What is the reference range for platelet count in millimeters cubed?

    <p>150,000 - 400,000/mm3</p> Signup and view all the answers

    What product is released by platelets that facilitates the assembly of the fibrin clot?

    <p>Fibrinogen</p> Signup and view all the answers

    What initiates the process of platelet adhesion during hemostasis?

    <p>Exposure of von Willebrand factor</p> Signup and view all the answers

    What role does ADP play in the aggregation phase of platelet function?

    <p>It stimulates shape change in other platelets.</p> Signup and view all the answers

    Which of the following factors is known to bind to the platelet surface and is essential for the assembly of coagulation factor complexes?

    <p>Factor V</p> Signup and view all the answers

    In the context of platelet aggregation, what is indicated by the transformation from a disc shape to a sphere shape?

    <p>Enhancement of surface area for receptor exposure</p> Signup and view all the answers

    What occurs as a result of weak stimuli during platelet aggregation?

    <p>Short-lived aggregates that are reversible</p> Signup and view all the answers

    What common characteristic do Hemophilia A and B share in relation to platelet function?

    <p>They affect the binding of Factor VIII and IXa complexes.</p> Signup and view all the answers

    During platelet activation, how does the shape of platelets change?

    <p>From disc to sphere to pseudopods</p> Signup and view all the answers

    What is the function of the glycoprotein IIb/IIIa complex in platelet aggregation?

    <p>It links platelets by binding fibrinogen.</p> Signup and view all the answers

    Which coagulation factor is primarily not found in the serum due to consumption during clotting?

    <p>Factor I</p> Signup and view all the answers

    What role do factors III, V, and VIII play in coagulation?

    <p>They act as cofactors.</p> Signup and view all the answers

    Which of the following factors is categorized as a serine protease?

    <p>Factor VII</p> Signup and view all the answers

    What characteristic distinguishes coagulation factors from much of the other proteins?

    <p>They are noted by Roman numerals.</p> Signup and view all the answers

    Which factor is solely categorized as a transamidase involved in the coagulation cascade?

    <p>Factor XIII</p> Signup and view all the answers

    In the context of plasma coagulation factors, what does factor HMWK stand for?

    <p>High molecular weight kininogen</p> Signup and view all the answers

    Factors I, V, VIII, and XIII are categorized under which type of proteins?

    <p>Fibrinogen proteins</p> Signup and view all the answers

    Which condition is most likely to elevate fibrinogen levels in the serum?

    <p>Acute infections</p> Signup and view all the answers

    What group of factors is activated by the intrinsic pathway of coagulation?

    <p>Factors XI, XII, PK, and HMWK</p> Signup and view all the answers

    Which coagulation factor is directly involved in the activation of Factor X alongside Factor VII?

    <p>Factor IX</p> Signup and view all the answers

    Which of the following statements is true regarding the vitamin K dependency of coagulation factors?

    <p>Factors VII, IX, and X are all vitamin K dependent.</p> Signup and view all the answers

    In the contact activation pathway of coagulation, which component is NOT considered a contact protein?

    <p>Factor VII</p> Signup and view all the answers

    What role does calcium play in the activation of coagulation factors?

    <p>Calcium is a cofactor that binds Factor VIII and Factor IX.</p> Signup and view all the answers

    Which factor is NOT consumed during the clotting process?

    <p>Factor XIII</p> Signup and view all the answers

    Which pathway becomes activated primarily through tissue factor or tissue thromboplastin?

    <p>Extrinsic pathway</p> Signup and view all the answers

    Which class of coagulation factors does NOT include vitamin K-dependent proteins?

    <p>Contact proteins</p> Signup and view all the answers

    What is the primary function of plasmin in the clotting process?

    <p>To cleave fibrin strands into soluble fragments</p> Signup and view all the answers

    What type of fragments does plasmin produce from the fibrin strands?

    <p>Soluble fragments of fibrin</p> Signup and view all the answers

    What are D-dimers specifically associated with in the clotting process?

    <p>Cross-linked fibrin degradation products</p> Signup and view all the answers

    Which process results in the cleavage of fibrinogen to produce fibrin?

    <p>Fibrinogenolysis</p> Signup and view all the answers

    What happens during the process of fibrinolysis?

    <p>Fibrin is degraded to soluble fragments</p> Signup and view all the answers

    What factor plays a crucial role in the intrinsic pathway of coagulation?

    <p>Collagen</p> Signup and view all the answers

    Which component is specifically activated by the contact pathway during coagulation?

    <p>Factor XII</p> Signup and view all the answers

    What is the relationship between thrombin and fibrin?

    <p>Thrombin converts fibrinogen into fibrin</p> Signup and view all the answers

    Which anticoagulant primarily targets the intrinsic pathway of the coagulation cascade?

    <p>Heparin</p> Signup and view all the answers

    What role does calcium (ca++) play in the activation of prothrombin?

    <p>It is essential for the conversion of prothrombin to thrombin</p> Signup and view all the answers

    What type of fragments can result from the breakdown of unclotted fibrinogen?

    <p>Fibrin degradation products</p> Signup and view all the answers

    What is the role of tissue plasminogen activator (TPA) in the fibrinolytic system?

    <p>To convert plasminogen to plasmin</p> Signup and view all the answers

    Which factor is NOT involved in the extrinsic pathway of coagulation?

    <p>Factor IX</p> Signup and view all the answers

    What monitoring method is typically used to assess therapeutic levels of heparin?

    <p>Activated partial thromboplastin time (APTT)</p> Signup and view all the answers

    Which ion is critical for the activation of several coagulation factors in the cascade?

    <p>Calcium</p> Signup and view all the answers

    What is the main function of high molecular weight kininogen (HMWK) in the coagulation cascade?

    <p>To act as a cofactor for Factor XI</p> Signup and view all the answers

    What is the primary function of tissue plasminogen activator inhibitor (TPAI)?

    <p>To stop the activation of Factors V and VII</p> Signup and view all the answers

    How does heparan sulfate contribute to the regulation of coagulation?

    <p>By binding and inactivating activated serine proteases</p> Signup and view all the answers

    What does excessive and inappropriate fibrinolysis commonly indicate?

    <p>Disseminated intravascular coagulation (DIC)</p> Signup and view all the answers

    What role does endothelial cell thrombomodulin play in the coagulation process?

    <p>Inactivates Factors V and VIII when bound to Protein C</p> Signup and view all the answers

    Which mechanism prevents fibrinogenolysis when active plasmin escapes the clot area?

    <p>Inhibition by Alpha-2 plasmin inhibitor</p> Signup and view all the answers

    What might be a consequence of liver disease concerning fibrinolytic regulation?

    <p>Accumulation of inhibitors and unregulated clotting</p> Signup and view all the answers

    What interaction does a tissue plasminogen activator have with coagulation factors?

    <p>It activates plasminogen to plasmin</p> Signup and view all the answers

    What is a primary role of activated Protein C in the coagulation process?

    <p>Inactivates Factors V and VIII</p> Signup and view all the answers

    Which coagulation factors are excluded from the APTT test?

    <p>Factor VII and XIII</p> Signup and view all the answers

    What is the therapeutic goal for heparin therapy as a ratio to 'normal' range?

    <p>1.5-2.5 times</p> Signup and view all the answers

    What effect do hemolyzed samples have on platelet aggregation studies?

    <p>They should not be used for studies</p> Signup and view all the answers

    What is the reference range for fibrinogen levels in mg/dL?

    <p>200-400 mg/dL</p> Signup and view all the answers

    What type of samples may obscure changes in optical density during coagulation studies?

    <p>Lipemic samples</p> Signup and view all the answers

    Which activator is NOT used in coagulation studies?

    <p>Silica</p> Signup and view all the answers

    Which coagulation test does NOT measure defects in intrinsic or extrinsic pathways?

    <p>Thrombin time</p> Signup and view all the answers

    During which therapy is the APTT primarily monitored?

    <p>Heparin therapy</p> Signup and view all the answers

    What condition is characterized by rapid dissolution of clot indicating fibrinolytic activity?

    <p>Disseminated Intravascular Coagulation</p> Signup and view all the answers

    Which of the following factors affects platelet aggregation?

    <p>Fibrinogen levels</p> Signup and view all the answers

    What is the reference range for normal bleeding time?

    <p>&lt; 20 seconds</p> Signup and view all the answers

    Which in vitro aggregating agent is NOT commonly used in platelet function assays?

    <p>Arachidonic acid</p> Signup and view all the answers

    What is the therapeutic goal for the International Normalized Ratio (INR) in anticoagulant therapy?

    <p>2.0 - 3.5</p> Signup and view all the answers

    What does the platelet function assay (PFA test) primarily measure?

    <p>Platelet function</p> Signup and view all the answers

    What is the consequence of Glanzmann Thrombasthenia on clot retraction?

    <p>Inhibited clot retraction</p> Signup and view all the answers

    Which of the following factors does the Prothrombin Time (PT) test specifically monitor?

    <p>Vitamin K dependent factors</p> Signup and view all the answers

    Which anticoagulant is used to collect blood samples for coagulation tests due to its role in preventing clotting?

    <p>Sodium citrate</p> Signup and view all the answers

    Which in vivo aggregating agent is NOT part of the standard panel for platelet function assessment?

    <p>Prothrombin</p> Signup and view all the answers

    In which condition is the bleeding time replaced by the Platelet Function Assay (PFA)?

    <p>Severe platelet disorder</p> Signup and view all the answers

    What does the Activated Partial Thromboplastin Time (APTT) test primarily evaluate?

    <p>Intrinsic pathway factors</p> Signup and view all the answers

    What is the acceptable reference range for Prothrombin Time (PT) in seconds?

    <p>&lt; 13 seconds</p> Signup and view all the answers

    Which reagent is primarily used for the Prothrombin Time (PT) test?

    <p>Tissue thromboplastin</p> Signup and view all the answers

    What is the effect of using glass ware over plastic tubes for blood specimen collection?

    <p>Enhances platelet aggregation</p> Signup and view all the answers

    Which factors are measured by the Prothrombin Time (PT) test?

    <p>I, II, V, VII, and X</p> Signup and view all the answers

    What is the primary factor deficiency found in Hemophilia B?

    <p>Deficiency of Factor IX</p> Signup and view all the answers

    Which inheritance pattern is associated with Hemophilia B?

    <p>Sex-linked recessive</p> Signup and view all the answers

    In Hemophilia C, what is the factor deficiency that causes bleeding problems?

    <p>Factor XI</p> Signup and view all the answers

    Which type of patients is most commonly affected by Hemophilia C?

    <p>Ashkenazi Jews</p> Signup and view all the answers

    What is the purpose of APTT mixing studies in the context of bleeding disorders?

    <p>To differentiate factor deficiency from inhibitor presence</p> Signup and view all the answers

    Which of the following statements correctly describes von Willebrand Disease?

    <p>It involves abnormalities in platelet function.</p> Signup and view all the answers

    What is the typical inheritance pattern of Hemophilia A?

    <p>Sex-linked recessive.</p> Signup and view all the answers

    What is the main factor targeted by lupus anticoagulants in autoimmune disorders?

    <p>Phospholipids.</p> Signup and view all the answers

    Which laboratory method is utilized to confirm the presence of lupus anticoagulants?

    <p>Platelet neutralization techniques.</p> Signup and view all the answers

    What percentage of lupus erythromatosis cases are associated with the presence of lupus anticoagulants?

    <p>5-10%.</p> Signup and view all the answers

    Which of the following is NOT a common scenario in which lupus anticoagulants might be present?

    <p>Cirrhosis.</p> Signup and view all the answers

    How is spontaneous bleeding into joints primarily characterized in individuals with Hemophilia A?

    <p>As recurrent hemarthrosis.</p> Signup and view all the answers

    What is a consequence of vitamin K deficiency in terms of blood coagulation factors?

    <p>Functional deficiency of Factors II, VII, IX, and X</p> Signup and view all the answers

    Which of the following conditions would likely lead to vitamin K deficiency?

    <p>Regular use of broad-spectrum antibiotics</p> Signup and view all the answers

    What method is used to detect Factor XIII deficiency?

    <p>5M urea test</p> Signup and view all the answers

    Which statement about von Willebrand Factor (vWF) is correct?

    <p>vWF deficiency leads to platelet adhesion defects.</p> Signup and view all the answers

    What can be used to treat conditions associated with a deficiency in von Willebrand Factor?

    <p>Cryoprecipitate or DDAVP</p> Signup and view all the answers

    Which of the following is true regarding the inheritance pattern of Compound deficiencies such as Factor XIII?

    <p>It follows an autosomal recessive pattern.</p> Signup and view all the answers

    Which condition is primarily associated with thrombosis due to microcirculation occlusion?

    <p>Antiphospholipid syndrome</p> Signup and view all the answers

    What type of antibodies are commonly involved in Antiphospholipid syndrome?

    <p>Anticardiolipin antibodies</p> Signup and view all the answers

    Which of the following events are typically driven by platelets?

    <p>Arterial events associated with atherosclerosis</p> Signup and view all the answers

    What mutation is specifically linked to an increased risk of thrombosis in Antiphospholipid syndrome?

    <p>Prothrombin mutation at position 20210</p> Signup and view all the answers

    Which of the following laboratory findings is commonly seen in patients with Antiphospholipid syndrome?

    <p>High levels of D-dimer</p> Signup and view all the answers

    Which of the following statements is true regarding the general population and prothrombin mutation?

    <p>1-2% of the general population are heterozygotes.</p> Signup and view all the answers

    What is the primary function of Antithrombin in the coagulation process?

    <p>Inhibits active serine protease factors</p> Signup and view all the answers

    How does Low Molecular Weight Heparin (LMWH) primarily exert its anticoagulant effect?

    <p>Inhibiting Factor Xa</p> Signup and view all the answers

    What is the effect of Aspirin on platelet function?

    <p>Permanently inhibits cyclo-oxygenase</p> Signup and view all the answers

    Which of the following anticoagulants requires monitoring through the APTT response curve?

    <p>Unfractionated Heparin</p> Signup and view all the answers

    What vitamin does Warfarin inhibit in its anticoagulant action?

    <p>Vitamin K</p> Signup and view all the answers

    Which of the following platelet inhibitors acts permanently until platelet replacement occurs?

    <p>Aspirin</p> Signup and view all the answers

    Which type of anticoagulant primarily targets vitamin K dependent factors?

    <p>Warfarin</p> Signup and view all the answers

    What distinguishes Glycoprotein IIb/IIIa receptor inhibitors from other platelet inhibitors?

    <p>They target a specific platelet receptor.</p> Signup and view all the answers

    What is the role of Protein S in the coagulation process?

    <p>Co-factor for Protein C</p> Signup and view all the answers

    Which factor deficiency is most pronounced in liver disease?

    <p>Factor VII</p> Signup and view all the answers

    What effect does Factor V Leiden mutation have on coagulation?

    <p>Resists the action of Protein C/S</p> Signup and view all the answers

    What laboratory finding is expected in secondary fibrinolysis compared to primary fibrinolysis?

    <p>Positive D-dimer</p> Signup and view all the answers

    Which of the following statements regarding Protein C is correct?

    <p>It requires Vitamin K for synthesis</p> Signup and view all the answers

    What is a common test to assess the function of Protein C?

    <p>Activated Protein C Resistance Test</p> Signup and view all the answers

    How does a deficiency in Protein S affect coagulation?

    <p>Results in excessive clot formation</p> Signup and view all the answers

    Which laboratory finding indicates DIC (Disseminated Intravascular Coagulation) in patients?

    <p>Presence of RBC fragments</p> Signup and view all the answers

    What is expected to be observed when performing an APTT on a patient undergoing high-dose warfarin therapy?

    <p>Prolonged due to multiple factor deficiencies</p> Signup and view all the answers

    Which condition is characterized by abnormal PFA results and the presence of giant platelets?

    <p>Bernard-Soulier syndrome</p> Signup and view all the answers

    In a patient with a prolonged APTT of 53 seconds, what could potentially be the diagnosis?

    <p>Vitamin K deficiency</p> Signup and view all the answers

    What would most likely indicate the presence of schistocytes on a blood smear?

    <p>All of the above</p> Signup and view all the answers

    Comparing the effects of anticoagulants, which requires monitoring with the anti-factor Xa assay?

    <p>Factor Xa inhibitors</p> Signup and view all the answers

    Which factor is most likely deficient in a patient with a major bleeding disorder and an unexpectedly normal PT?

    <p>Factor XI</p> Signup and view all the answers

    Which anticoagulant is recognized for its lack of requirement for routine monitoring?

    <p>Dabigatran</p> Signup and view all the answers

    What laboratory result is likely to indicate secondary fibrinolysis in a patient?

    <p>Increased d-dimer levels</p> Signup and view all the answers

    What is the primary mechanism by which aspirin functions as a platelet inhibitor?

    <p>Destroying cyclo-oxygenase</p> Signup and view all the answers

    Which of the following anticoagulants requires monitoring through the PT/INR?

    <p>Warfarin</p> Signup and view all the answers

    What unique quality distinguishes low molecular weight heparin from unfractionated heparin?

    <p>It provides a more predictable response</p> Signup and view all the answers

    Which statement about glycoprotein IIb/IIIa receptor inhibitors is accurate?

    <p>They are not permanent inhibitors</p> Signup and view all the answers

    Which testing method is typically used to monitor patients on unfractionated heparin?

    <p>APTT</p> Signup and view all the answers

    What is a characteristic feature of factor Xa inhibitors like Rivaroxaban and Apixaban?

    <p>They do not usually require monitoring</p> Signup and view all the answers

    Which anticoagulant's mechanism is based on inhibiting the production of functional factors II, VII, IX, and X?

    <p>Warfarin</p> Signup and view all the answers

    What is the common property shared by glycoprotein IIb/IIIa receptor inhibitors?

    <p>They are usually effective in acute situations</p> Signup and view all the answers

    What laboratory result would likely be expected from a patient undergoing high-dose warfarin therapy with evidence of bleeding?

    <p>Increased PT and APTT with positive d-dimer</p> Signup and view all the answers

    Which condition is best characterized by abnormal platelet function indicated by abnormal PFA results and giant platelets?

    <p>Bernard-Soulier syndrome</p> Signup and view all the answers

    In a case where a child has a prolonged Prothrombin Time but a normal APTT, which condition is most likely responsible?

    <p>Congenital factor VII deficiency</p> Signup and view all the answers

    What is the most likely explanation of a prolonged APTT that remains prolonged after mixing with normal plasma?

    <p>The presence of an inhibitor or other anticoagulant</p> Signup and view all the answers

    What could explain the laboratory finding of schistocytes on a blood smear in a patient experiencing bleeding?

    <p>Thrombotic microangiopathy</p> Signup and view all the answers

    Which of the following laboratory findings would most likely be present in a patient with primary fibrinolysis?

    <p>Prolonged PT and APTT with normal platelet count</p> Signup and view all the answers

    Which of the following would likely lead to increased APTT results while mixing with normal plasma still reveals prolonged APTT?

    <p>Vitamin K deficiency leading to multiple factor deficiencies</p> Signup and view all the answers

    What finding is most consistent with secondary fibrinolysis, particularly in the context of a hypercoagulable state?

    <p>Elevated PT with increased fibrin degradation products</p> Signup and view all the answers

    Which factor deficiencies are monitored by the prothrombin time test in patients on warfarin therapy?

    <p>Factors II, VII, IX, and X</p> Signup and view all the answers

    What is the primary characteristic that differentiates Factor V Leiden from typical coagulation abnormalities?

    <p>Presence of a strong anticoagulant or inhibitor</p> Signup and view all the answers

    Which statement accurately describes the role of antibiotics in a child's likelihood of hemophilia B?

    <p>Repeated courses of antibiotics can disrupt vitamin K producing organisms.</p> Signup and view all the answers

    What laboratory result is typically not associated with primary fibrinolysis?

    <p>Prolonged prothrombin time</p> Signup and view all the answers

    Which condition might present with a prolonged bleeding time despite normal platelet morphology?

    <p>Platelet Function Disorders</p> Signup and view all the answers

    A 1:1 mixing study that remains abnormal in a patient suggests which of the following?

    <p>The presence of a coagulopathy inhibitor</p> Signup and view all the answers

    Which statement is true about thrombocytopenia associated with certain conditions?

    <p>It is characterized by small sized platelets.</p> Signup and view all the answers

    What is a common misconception regarding the inheritance pattern of congenital deficiencies of coagulation factors?

    <p>Congenital deficiencies are always autosomal recessive</p> Signup and view all the answers

    Study Notes

    Hematopoiesis Overview

    • Prenatal hematopoiesis occurs in early embryo development, shifting to adult hematopoiesis after birth.
    • Hematopoiesis is the formation of blood cellular components, primarily in the bone marrow.

    Hematopoietic Stem Cells

    • Hematopoietic stem cells differentiate into various blood cell lineages.
    • Essential subtypes include:
      • CFU-GEMM: Committed progenitors for granulocytes, erythrocytes, megakaryocytes, and monocytes.
      • CLP: Committed lymphoid progenitor leading to lymphocytes.

    Growth Factors

    • Key growth factors involved in hematopoiesis include:
      • GM-CSF, IL-3, and EPO (Erythropoietin).
      • TPO (Thrombopoietin) plays a vital role in megakaryocyte maturation.

    Blood Cell Maturation Stages

    • Stages include:
      • Rubriblast to reticulocyte (erythrocyte)
      • Myeloblast to segmented neutrophil (granulocyte)
      • Monoblast to monocyte
      • Lymphoblast to B/T lymphocytes
    • Reticulocyte is an immature form of an erythrocyte, indicative of erythropoiesis.

    Hemoglobin and Heme Synthesis

    • Heme synthesis requires iron and protoporphyrin.
    • Iron transport proteins include transferrin and ferritin; excess iron stored as hemosiderin.

    Porphyrias

    • Conditions caused by enzyme deficiencies in heme synthesis leading to accumulation of heme precursors.
    • Symptoms depend on the stage of precursor buildup:
      • Early: Neuropsychiatric symptoms (e.g., acute intermittent porphyria).
      • Late: Cutaneous symptoms (e.g., photosensitivity).

    Heme Precursor Sequence

    • Includes: Delta-aminolevulinic acid → Porphobilinogen → Uroporphyrinogen → Coproporphyrinogen → Protoporphyrin → Heme.

    Globin Synthesis

    • Distinct hemoglobin types are produced during different life stages:
      • Newborns mainly produce Hgb F (fetal hemoglobin).
      • Adult hemoglobin consists primarily of Hgb A.
    • Chromosomes 16 and 11 house various globin chain genes critical to hemoglobin formation.

    Hemoglobin Laboratory Procedures

    • Common anticoagulants used in laboratory settings:
      • EDTA (chelator of Ca²⁺).
      • Heparin (an anti-thrombin agent).

    Sources of Error

    • Cold agglutinins and high WBC count can lead to inaccuracies in blood tests.
    • Hemoglobin staining issues:
      • Too blue indicates a basic stain or prolonged staining.
      • Too red signifies an acidic stain or prolonged washing.

    Calculations

    • WBC formula:
      • (# cells counted × dilution factor) / total volume
    • Total volume is calculated as length × width × depth of the square.
    • For WBC counting, all 9 squares are considered, resulting in a total volume of 0.9 mm³.
    • Reference range for WBC: 5,000 - 10,000/µL.

    Leukocyte Differential

    • Normal relative values are typically provided in accompanying charts.
    • Absolute values calculation involves multiplying relative value (%) by the total WBC count.
    • Example: If total WBC count is 6,000/µL, calculations adjust to determine specific leukocyte types.

    Significance of Increased Leukocytes

    • Neutrophils: Elevated during bacterial infections.
    • Lymphocytes: Increased with viral infections.
    • Monocytes: Associated with TB, syphilis, and malignancies.
    • Eosinophils: High in allergies and parasitic infections.
    • Basophils: Linked to immediate hypersensitivity reactions.

    Platelet Evaluation

    • Evaluate all 25 center squares for platelets.
    • Check for platelet clumping and satellite cells, especially in EDTA samples.
    • Evaluate platelet size; large platelets indicate Bernard-Soulier syndrome, May-Hegglin anomaly, or stress.

    Nucleated Red Cells

    • Correct white cell count when nucleated red cells are present using the formula:
      • Corrected WBC count = (WBC count × 100) / (100 + # nRBCs).

    Red Cell Morphology

    • Size classifications:
      • Normocytic: MCV 80-100 µm³.
      • Microcytic: MCV < 80 µm³.
      • Macrocytic: MCV > 100 µm³.
    • Anisocytosis indicates size variation (RDW > 14.5).
    • Color classifications:
      • Normochromic: MCHC 32-36 g/dL.
      • Hypochromic: MCHC < 32.

    Abnormal Red Cell Shapes

    • Abnormal shapes can indicate various conditions:
      • Sickle cells are seen in sickle cell disease.
      • Target cells are associated with thalassemias and hemoglobinopathies.

    Red Cell Inclusions

    • Howell-Jolly bodies, indicative of disturbed erythropoiesis.
    • Basophilic stippling often seen in thalassemia and megaloblastic anemia.

    Rule of Three

    • Correlates hemoglobin (Hb), hematocrit (Hct), and red blood cell (RBC) counts:
      • Hb x 3 = Hct ± 3%.
      • RBC × 3 = Hb ± 0.5.
    • If discrepancies arise, consider potential causes such as clotted samples or cold agglutinin interference.

    Reference Ranges

    • Hemoglobin: Male 14 ± 2 g/dL, Female 16 ± 2 g/dL.
    • Hematocrit: Male 47 ± 5%, Female 42 ± 5%.
    • WBC: 5,000 - 10,000/µL.
    • Platelets: 150,000 - 400,000/µL.

    Red Cell Inclusions

    • Howell-Jolly Bodies: Composed of DNA; identified with Wright or New Methylene Blue stains; indicate disturbed erythropoiesis, hemolytic anemias, megaloblastic anemia, and post-splenectomy.
    • Basophilic Stippling: Composed of RNA; detected with Wright or New Methylene Blue stains; associated with thalassemia and lead poisoning.
    • Pappenheimer Bodies: Contain iron; detected with Wright stain; indicate sideroblastic anemia and hemoglobinopathies; confirmed with Prussian Blue stain for siderotic granules.
    • Heinz Bodies: Composed of denatured and precipitated hemoglobin; identified using supravital stains like Brilliant Cresyl Blue or New Methylene Blue; associated with G6PD deficiency, thalassemia, and unstable hemoglobins.
    • Cabot Rings: Composed of remnants of mitotic spindle; identified with Wright stain; relate to megaloblastic anemia.
    • Parasites: Include organisms like malaria, Babesia, and trypanosomes; identified using Wright stain; indicate parasitic infections.

    Rule of Three

    • Correlates hemoglobin (Hb), hematocrit (Hct), and red blood cell (RBC) count:
      • Normal hemoglobin: 14 ± 2 g/dL for females, 16 ± 2 g/dL for males.
      • Normal hematocrit: 42 ± 5% for females, 47 ± 5% for males.
      • Normal RBC count: 4.5 ± 0.7 million/µL for females, 5.3 ± 0.8 million/µL for males.
    • If the rule doesn’t fit, consider potential issues such as clotted samples, cold agglutination, lipemic samples, abnormal hemoglobin types, or abnormal red cell morphology.

    Reticulocyte Count

    • Uses supra vital stains to assess living red cells; common stains include New Methylene Blue and Brilliant Cresyl Blue.
    • Monitors erythropoiesis and is calculated as follows:
      • Percentage of reticulocytes = number of reticulocytes in 1000 RBCs × 10
      • Absolute reticulocyte count = total RBC count × percentage of reticulocytes
      • Corrected reticulocyte count = (% retics × patient Hct) / 45
    • Reticulocyte Production Index (RPI) calculates the bone marrow response to anemia; RPI > 2 indicates adequate response, < 2 indicates inadequate response.

    Erythrocyte Sedimentation Rate (ESR)

    • Measures the rate of red blood cell sedimentation through plasma.
    • Reference ranges:
      • Female: 0-20 mm/hr
      • Male: 0-15 mm/hr
    • Clinical correlation: Increased ESR can indicate the presence of inflammation due to elevated plasma proteins (e.g., fibrinogen, globulin).
    • Sources of error in ESR measurement include tube tilting, prolonged standing, excessive temperature changes, and excess EDTA.

    Example Calculations

    • Reticulocyte count example: 36 reticulocytes counted = 3.6% reticulocyte count.
    • Corrected reticulocyte count example: 3.6% × 25% Hct = 2.0% corrected count.
    • Absolute reticulocyte count: 3.0 million/µL × 0.036 = 108,000/µL.
    • RPI example: 2.0% = 1.0 (adjusted for maturing time).

    Effects of Therapy on Reticulocyte Count

    • Distinction between relative and absolute reticulocyte counts is important in assessing response to therapy in anemia.

    Special Hematology Overview

    • Bone marrow preps include assessing megakaryocytes and myeloid:erythroid ratios, vital for diagnosing conditions such as aplastic anemia and leukemias.
    • Reference range for megakaryocytes is 5 per low power field (lpf).
    • Normal myeloid:erythroid ratio is 3:1 to 4:1; deviations indicate various pathologies (e.g., myeloid hyperplasia, erythroid hyperplasia).

    Clinical Correlations in Bone Marrow

    • A "dry" tap may indicate aplastic anemia or myelofibrosis.
    • Myeloid to erythroid (M:E) ratio assists in the diagnosis of conditions like hemolytic anemia.
    • Overall cellularity evaluation requires biopsy; typical cellularity ratio is 50% cells to 50% fat.

    Hemoglobin Electrophoresis

    • Hemoglobin forms migrate differently based on the pH of the medium: Cellulose acetate (pH 8.6) and Citrate agar (pH 6.2).
    • At pH 8.6, hemoglobin C crawls, S is slow, and Hf is fast, with A accelerating.
    • Hemoglobin S exhibits abnormal characteristics in sickle cell trait (heterozygous) versus sickle cell disease (homozygous).

    Hemoglobinopathies Overview

    • Hemoglobin S mutation replaces Glutamic Acid with Valine at the 6th position of the beta chain; associated with severe chronic hemolytic anemia in homozygous individuals.
    • Hemoglobin C mutation substitutes Glutamic Acid with Lysine, causing mild anemia in homozygotes.

    Thalassemias

    • Alpha thalassemia involves decreased production of alpha chains, leading to microcytic, hypochromic anemia.
    • Beta thalassemia is associated with absent or reduced beta chain production; typical trait exhibits microcytic anemia.
    • Hemoglobin H disease arises from three deleted alpha genes, producing characteristic inclusions and complications.

    Classification of Anemias

    • Anemia classified based on causes, including iron deficiency, hemolytic disease, and chronic disease.
    • Normocytic anemia occurs when hemoglobin and hematocrit levels are normal despite the presence of anemia.
    • Megaloblastic anemias commonly arise from Vitamin B12 or folate deficiencies.

    Key Concepts in Red Cell Disease States

    • Hemolytic disease may present in newborns due to maternal antibodies.
    • Sickle cell disease can be confirmed through turbidity in sickle dex tests and electrophoresis.
    • Variants such as Hb E and Hb D are associated with different demographics and clinical presentations.

    Important Remember Usages

    • Recognize the migration of hemoglobin variants for proper diagnosis.
    • Use specific media and pH for accurate identification of hemoglobin types during electrophoresis.
    • Understand the clinical significance of specific tests and their interpretations to aid in diagnosing hematological disorders.

    Hemoglobin C and Anemia

    • Hemoglobin C disease is characterized by chronic hemolytic anemia.
    • Heterozygous individuals are typically asymptomatic.
    • Homozygous individuals experience mild chronic anemia and have Hb Bart's at birth.
    • Presence of Hb H inclusions (Heinz bodies) may occur.
    • Hemoglobin C crystals are described as "bar-shaped" and target cells may also be present.
    • In sickle cell disease (SC disease), crystals appear as "hand in glove" or "Washington monument."
    • Confirmation of HbC status can be performed through electrophoresis:
      • Cellulose acetate shows migration with A2, E, O, and Harlem.
      • Citrate agar allows separation from other hemoglobins.

    Thalassemia and Chain Production

    • Alpha Thalassemia involves decreased or absent production of alpha chains.
    • Characterized by microcytic, hypochromic anemia with variations in hemoglobin types:
      • Silent carriers exhibit normal complete blood counts (CBC).
      • Two gene deletions lead to mild anemia.
      • Three gene deletions result in Hemoglobin H disease, potentially leading to hydrops fetalis in severe cases.
    • Beta Thalassemia results from opposite effects, with absent or reduced beta chains.

    Classification of Anemias

    • Anemia is classified based on hemoglobin (Hb) & hematocrit (Hct), and mean corpuscular volume (MCV):
      • Normocytic Anemia: Normal size or production issues (e.g., hemoglobinopathies like Hb-S, Hb-C).
      • Microcytic Anemia: Commonly caused by iron deficiency, with increased total iron-binding capacity (TIBC).
      • Macrocytic Anemia: Often linked to vitamin deficiencies (B12 or Folate), with characteristic bone marrow findings.

    Types of Anemia and Key Laboratory Findings

    • Microcytic/Hypochromic Anemia:

      • Iron Deficiency: Low ferritin, high TIBC, low saturation.
      • Chronic Disease: Normal ferritin levels, increased serum iron with low TIBC.
      • Thalassemia Trait: Normal serum iron and TIBC, low A2 and F levels.

    • Macrocytic Anemia:

      • B12 Deficiency: High B12 with oval macrocytes, hypersegmented polys, and positive intrinsic factor antibodies.
      • Folate Deficiency: Elevated folate levels, oval macrocytes, and hypersegmented polys.

    • Normocytic/Normochromic Anemia:

      • Antibody-Mediated: Elevated bilirubin, positive direct antiglobulin test (DAT).
      • Membrane Defects: Presence of spherocytes or elliptocytes, correlating with hereditary spherocytosis or elliptocytosis.
      • Enzyme Deficiencies: Notable findings in G6PD deficiency include Heinz bodies.

    General Knowledge on Anemia

    • Aplastic anemia is associated with hypocellular bone marrow and may present as a "dry tap" on aspiration.
    • Acute blood loss typically shows a normal bone marrow with reticulocyte increase.
    • Chronic renal disease reflects reduced erythropoietin (EPO) levels affecting red blood cell production.
    • Hemoglobinopathies require specific tests like hemoglobin electrophoresis for definitive diagnosis.

    Inspirational Note

    • Trust your perceptions; they are often more accurate than believed.

    Special Tests

    • FLAER Test: Assesses absence of GPI anchor proteins; highly specific for CD 55 and CD 59, useful for diagnosing Paroxysmal Nocturnal Hemoglobinuria (PNH).
    • Flow Cytometry: Evaluates deficiency of CD 55 and CD 59 on red blood cells and granulocytes; less sensitive than FLAER for PNH.
    • Heinz Body Preparation: Detects the effect of oxidizing agents on hemoglobin, revealing precipitated globin chains; relevant for G6PD deficiency and unstable hemoglobins triggered by oxidants.
    • Sickle Cell Screen: Tests for reduced solubility of deoxygenated HbS; utilizes reducing agent Na Dithionate to identify sickle cell disease.
    • Kleihauer-Betke Acid Elution: Identifies fetal hemoglobin's resistance to acid elution, indicating fetal-maternal hemorrhage; fetal cells stain pink, while adult cells appear ghost-like.
    • Hemoglobin Electrophoresis: Analyzes migration of various hemoglobins; helpful in diagnosing suspected hemoglobinopathies.
    • Cold Agglutinin Titer: Detects cold autoantibodies; associated with cold autoimmune hemolytic anemia.
    • Donath Landsteiner Test: Identifies biphasic DL antibody; relevant for paroxysmal cold hemoglobinuria.

    Hereditary Conditions

    • Alder-Reilly Anomaly: Presence of large azurophilic granules; associated with mucopolysaccharide disorders like Hunter and Hurler syndromes.
    • Chediak-Higashi Syndrome: Characterized by large lysosomes; results in albinism and increased susceptibility to infections.
    • May-Hegglin Anomaly: Appears as large platelets and Dohle bodies in leukocytes; does not affect leukocyte function.
    • Pelger-Huët Anomaly: Demonstrates hyposegmented polys but retains normal function.

    Myeloproliferative Diseases

    • Myelodysplastic Syndromes (MDS): Neoplastic disorders marked by cytopenias and abnormal bone marrow differentiation; includes refractory anemia with plasma cells observable in circulation.

    Special Cytochemical Stains / Inclusions / Markers

    • Prussian Blue Stain: Indicates iron presence; pertinent in diagnosing sideroblastic anemia and iron overload conditions.
    • LAP Stain: Assess leukocyte alkaline phosphatase levels; elevated in leukemoid reactions and polycythemia vera.
    • Peroxidase/Sudan Black Stain: Identifies myeloperoxidase/lipid presence; positive in myeloid precursors, negative in lymphoid precursors.
    • Non-Specific Esterase: Marks monocyte precursors; positive in monocytic leukemias.
    • TRAP Stain: Used for diagnosing hairy cell leukemia by identifying tartrate-resistant acid phosphatase.
    • Auer Rods: Presence indicates acute myeloid leukemia; formed by granule fusion.
    • CD Markers: Key indicators for leukemic lineages; e.g., CD13 and CD33 for myeloid, CD10 and CD19 for B-lineage.

    Lysosome and Lipid Storage Disorders

    • Gaucher Disease: Results in glucocerebroside accumulation; identified by bone marrow macrophages having a striated appearance.
    • Niemann-Pick Disease: Characterized by sphingomyelin accumulation; exhibits foamy cytoplasm in bone marrow macrophages and sea-blue histiocytes.

    Iron Storage and Anemia

    • Major iron storage compounds include hemosiderin and ferritin; siderotic granules and transferrin serve different roles.
    • Anemia of chronic inflammation shows low serum ferritin, low serum iron, and increased TIBC.
    • MCV and MCH values help interpret types of anemia; low values suggest microcytic anemia.

    Hemoglobin Electrophoresis and Interpretation

    • A patient with a negative dithionite solubility test shows bands in A and S regions, indicating possible HbAS or HbAE.
    • Interpretation of hemoglobin results is vital for diagnosing disorders like thalassemia and sickle cell disease.
    • In adults, normal M:E ratios range from 3:1 to 4:1, indicating expected ratios of myeloid to erythroid cells in the bone marrow.

    White Blood Cell Count and Differential Diagnosis

    • Hematological evaluation of elevated WBC with neutrophilia suggests possible bacterial sepsis or acute myelogenous leukemia.
    • The calculation for manual WBC count: (cells counted x dilution factor) gives total WBC count.

    Bone Marrow Analysis and Flow Cytometry

    • Flow cytometry identifying CD markers aids in diagnosing leukemias, such as positive CD10, CD19, and negative CD13 in acute lymphoblastic leukemia.
    • Differential counts of blasts can support diagnosis and characterize certain leukemias.

    Laboratory Sample Handling and Effects

    • Inadequate blood sample volume in EDTA tubes can alter test results due to excessive EDTA leading to false interpretations.
    • Rouleaux formation can indicate elevated monoclonal immunoglobulin, often associated with plasma cell myeloma.

    Diagnostics in Leukemia

    • t(15;17) translocation is specifically diagnostic for acute promyelocytic leukemia (APL).
    • Presence of toxic granulation and Dohle bodies in neutrophils points towards acute leukemia cases.

    Additional Hematological Concepts

    • Iron studies show distinct patterns; low ferritin and increased TIBC signify iron deficiency anemia, while reduced ferritin and normal or high TIBC indicate anemia of chronic disease.
    • Deterioration in reticulocyte production implicates failure in red blood cell synthesis, essential for anemia diagnosis.

    Key Figures

    • Serum ferritin normal range is 20-250 ng/ml; low values necessitate further investigation for iron deficiency.
    • Serum folate levels and intrinsic factor antibodies are critical in diagnosing pernicious anemia.

    Platelet Production

    • Produced from megakaryocytes.
    • 30% of platelets are stored in the spleen; 70% circulate in peripheral blood.
    • Normal reference range: 150,000 - 400,000 platelets/mm³.
    • Platelet lifespan is approximately 9-12 days.

    Platelet Functions

    • Primary role is to stop bleeding by forming a platelet plug at injury sites.
    • Adhesion involves glycoprotein lb binding to exposed collagen and requires von Willebrand's factor.
    • Aggregation leads to secretion of ADP and other granule components, including Factor V and fibrinogen.

    Platelet Plug Formation

    • Platelet plug is localized to the injury site, preventing excessive bleeding.
    • Secretion of arachidonic acid is converted into thromboxane A2, promoting platelet activation.
    • Adjacent endothelial cells convert arachidonic acid into prostacyclin, which inhibits platelet aggregation.

    Fibrin Clot Assembly

    • Platelets release critical components for fibrin clot assembly: fibrinogen, Factor V, and Factor VIII.
    • Fibrinogen binds to platelet surfaces during aggregation, linking them together.
    • Factor VIII is associated with von Willebrand factor on the platelet surface.

    Platelet Shape Change

    • Platelets undergo a shape change from disc to sphere upon activation.
    • This change exposes phospholipids critical for assembling factor complexes, historically referred to as Platelet Factor 3.

    Hemophilia Connection

    • Binding of Factor VIII and IXa complex is calcium-dependent; deficiencies in these factors (Hemophilia A and B) present similarly clinically.

    Summary of Platelet Interaction

    • Fibrinogen binding mediates initial, reversible aggregation phase due to weak stimuli.
    • Platelet interactions are crucial in hemostasis, with GP IIb/IIIa inhibitors blocking platelet aggregation pathways.

    Fibrinogen Proteins

    • Fibrinogen and related factors include I, V, VIII, and XIII.
    • Consumed during the clotting process, thus absent in serum.
    • Increased levels observed during acute phase reactions such as pregnancy and inflammation.

    Functions of Plasma Coagulation Factors

    • Substrate: Factor I (fibrinogen) is the primary substrate for clot formation.
    • Cofactors: Factors III, V, and VIII enhance enzymatic reactions.
    • Enzymes:
      • Serine proteases (factors II, VII, IX, X, XI, XII) cleave peptide bonds.
      • Transamidase is associated with Factor XIII.

    Characteristics of Coagulation Proteins

    • Coagulation Groups: Categorized as contact factors (XI, XII, prekallikrein (PK), HMWK), prothrombin factors (II, VII, IX, X), and fibrinogen factors (I, V, VIII, XIII).
    • Vitamin K Dependency: Prothrombin factors are vitamin K dependent; fibrinogen factors are not.

    Coagulation Cascade

    • Intrinsic Pathway: Activated by collagen and HMWK, monitored by APTT (Activated Partial Thromboplastin Time).
    • Extrinsic Pathway: Triggered by tissue factor, monitored by PT (Prothrombin Time).

    Fibrinolytic System

    • Initiated intrinsically via collagen or extrinsically via tissue plasminogen activator (TPA).
    • Activates plasminogen to form plasmin, which then cleaves fibrin into soluble fragments.
    • D-dimer is a specific marker from crosslinked clot degradation.

    Regulation and Inhibition

    • TPA can be inhibited by tissue plasminogen activator inhibitor (TPAI), stopping over-activation.
    • Plasmin activity is inhibited by Alpha-2 Plasmin Inhibitor to prevent excessive fibrinogenolysis.
    • Excessive fibrinolysis is prevalent in disseminated intravascular coagulation (DIC) and liver disease, where regulatory mechanisms are compromised.

    Other Functions of Thrombin

    • Enhances factors V and VIII, recruits platelets, and activates endothelial cell thrombomodulin, which inactivates factors V and VIII.
    • Feedback mechanism that potentiates clot stabilization and enhancement of platelet aggregation.

    Clotbusters and Hemostatic Function Tests

    • Streptokinase, Urokinase, and Tissue plasminogen activator are commercial "clotbusters" used to dissolve blood clots.

    Prothrombin Time (PT)

    • Screens for extrinsic and common coagulation pathways.
    • Measures factors I (Fibrinogen), II (Prothrombin), V, VII, and X.
    • Monitors oral anticoagulants like warfarin and coumarin.
    • Uses tissue thromboplastin and CaCl2 as reagents.
    • Sensitive to Vitamin K dependent factors; INR calculation required.
    • Standard reference range is under 13 seconds; therapeutic goal is an INR of 2.0 to 3.5.

    Activated Partial Thromboplastin Time (APTT)

    • Screens for intrinsic and common pathways of coagulation.
    • Measures all factors except VII and XIII.
    • Commonly used to monitor heparin therapy.
    • Reference range is 20-40 seconds, with a therapeutic goal of 1.5-2.5 times normal range.

    Fibrinogen Assay

    • Quantitative measurement of Fibrinogen (Factor I).
    • Reference range is 200-400 mg/dL.

    Thrombin Time (TT)

    • Does not assess defects in intrinsic/extrinsic pathways.
    • Useful for evaluating fibrinogen levels.

    Platelet Aggregation

    • Essential for platelet adhesion and aggregation during hemostasis.
    • Affected by fibrinogen levels and presence of antithrombotics.
    • Reference range is ≤ 20 seconds.

    Bleeding Time and Platelet Function Assays

    • Historically measured platelet function but has largely been replaced by Platelet Function Assay (PFA).
    • PFA assesses platelet function against collagen, ADP, and epinephrine; sensitive to aspirin, von Willebrand disease, and ADP receptor issues.

    Clot Retraction

    • Evaluates platelet function and fibrinogen levels.
    • Important for understanding clot stability and retraction ability.

    Important Test Information

    • Use sodium citrate (3.2%) for specimen collection to maintain appropriate calcium levels.
    • Preservation of appropriate anticoagulant to blood ratios is critical; recommended ratio is 9:1.
    • Hemolyzed samples should not be used for platelet aggregation studies due to interference from red blood cells.
    • Lipemic samples may obscure changes in optical density during testing.

    Acquired Disorders

    • Inhibitors often involve IgG antibodies targeting specific factors or phospholipids.
    • Lupus anticoagulant (LA) is an inhibitor directed against phospholipids, associated with conditions like Lupus Erythematosus (5-10% prevalence), as well as malignancies and infections.
    • Screening for LA utilizes low concentration phospholipid reagents, featuring tests like DRVV1.
    • Confirmation of LA presence is done via platelet neutralization techniques.

    Inherited Disorders

    • Hemophilia A is characterized by a deficiency of Factor VIII, inherited as a sex-linked recessive trait predominantly in males, leading to spontaneous bleeding in joints; treated with Factor VIII concentrates.
    • Hemophilia B results from a deficiency of Factor IX, also sex-linked and similar in clinical presentation to Hemophilia A; managed with Factor IX concentrates.
    • Hemophilia C involves a deficiency of Factor XI, presenting as incomplete autosomal recessive inheritance, with variable clinical severity, especially prevalent in Ashkenazi Jews. Confirmed through APTT mixing studies.
    • von Willebrand Disease features a primary defect in von Willebrand Factor (vWF), crucial for platelet binding. It leads to secondary Factor VIII deficiency and manifests as a platelet adhesion defect; treated with cryoprecipitate or DDAVP.
    • Factor XIII deficiency, inherited in an autosomal recessive manner, is not detected by standard coagulation tests but results in significant bleeding and poor wound healing, confirmed using the 5M urea test.

    Vitamin K Deficiency

    • Causes functional deficiency of coagulation factors II, VII, IX, and X due to lack of vitamin K, which is sourced from diet and gut bacteria.
    • Deficiency may arise from poor diet or extensive antibiotic use, and similar effects are seen in patients on warfarin therapy.

    Fibrinolysis and Protein C

    • Fibrinolysis involves the breakdown of fibrin in blood clots, where Protein C plays a critical role.
    • Protein C is a vitamin K dependent serine protease, activated by thrombomodulin on endothelial cells.
    • Protein C requires Protein S as a cofactor to inactivate coagulation factors V and VIII.

    Key Factors in Liver Disease

    • Liver disease can cause deficiencies in coagulation factors I, II, V, VII, IX, and X, with Factor VII deficiency being the most prominent.
    • Thrombin formation can be affected, leading to increased risk of thrombotic events.
    • Elevated levels of fibrinogen degradation products (FDP) can indicate fibrinolysis.

    Disseminated Intravascular Coagulation (DIC)

    • DIC is a secondary condition often caused by sepsis, obstetric complications, or infections.
    • Characterized by thrombotic occlusions in microcirculation, producing RBC fragments and consumption of platelets.
    • High levels of D-dimer are indicative of DIC.

    Thrombotic Diseases

    • Arterial events driven by platelets can stem from atherosclerosis or prosthetic heart devices.
    • Venous events can occur due to blood flow problems or clot inhibitor deficiencies, with antithrombin being a key factor.
    • Prothrombin mutation (20210) affects approximately 1-2% of the population, increasing thrombotic risk.

    Antiphospholipid Syndrome

    • Characterized by the presence of antibodies such as anticardiolipin antibodies, lupus anticoagulant, and specific antibodies like beta-2-glycoprotein.

    Anticoagulant Therapy

    • Platelet inhibitors include:

      • Aspirin, which permanently inhibits cyclo-oxygenase in platelets.
      • Clopidogrel (Plavix™), which blocks the ADP receptor permanently.
      • Glycoprotein IIb/IIIa inhibitors (like Abciximab) that provide temporary inhibition.

    • Oral anticoagulants include:

      • Warfarin, which prevents the production of vitamin K dependent factors, requiring INR monitoring.
      • Factor Xa inhibitors (Rivaroxaban and Apixaban) that generally do not require monitoring.
      • Dabigatran, a thrombin inhibitor that also requires no monitoring.

    Laboratory Assessment Questions

    • High-dose warfarin therapy typically shows prolonged PT with APTT potentially normal due to factor VII sensitivity.
    • Abnormal PFA results and presence of giant platelets may indicate Bernard-Soulier syndrome.
    • Prolonged APTT in children can prompt further diagnostic considerations for underlying coagulopathy.

    Anticoagulant Therapy Overview

    • Anticoagulants are crucial in preventing blood clots, with multiple types used based on mechanism and patient needs.

    Parenteral Anticoagulants

    • Heparin (unfractionated)

      • Functions by inhibiting serine protease factors via Antithrombin.
      • Monitoring typically done through Activated Partial Thromboplastin Time (APTT) and can also use anti-factor Xa assays for assessment.

    • Low Molecular Weight Heparin (LMWH)

      • Specifically targets Factor Xa.
      • Provides a more predictable response compared to unfractionated heparin and generally doesn't require frequent monitoring.

    Oral Anticoagulants

    • Warfarin

      • Inhibits Vitamin K, preventing synthesis of functional Factors II, VII, IX, and X.
      • Requires regular monitoring via Prothrombin Time/International Normalized Ratio (PT/INR).

    • Thrombin Inhibitors (Dabigatran)

      • Do not usually require monitoring.

    • Factor Xa Inhibitors (Rivaroxaban, Apixaban)

      • Typically do not require monitoring.

    Clinical Cases and Diagnostic Questions

    • High-dose warfarin therapy affects PT; APTT results are expected to be prolonged due to multiple factor deficiencies.

    • Abnormal Platelet Function Assay (PFA) with giant platelets indicates conditions such as Bernard-Soulier syndrome, Glanzmann thrombasthenia, von Willebrand disease, or Wiskott-Aldrich syndrome.

    • A child with prolonged PT and APTT likely experiences Vitamin K deficiency, often due to antibiotic treatment impairing gut bacteria.

    • A prolonged APTT that normalizes upon mixing with normal plasma indicates the presence of an inhibitor or anticoagulant.

    Answers to Sample Questions

    • The reason for prolonged APTT in high-dose warfarin therapy is due to deficiencies in coagulation factors.

    • Dilutional mixing studies that remain abnormal suggest a strong anticoagulant or specific inhibitor present.

    • Diagnosis of coagulation disorders requires understanding of underlying conditions and their presentations, such as interpreting schistocytes and D-dimer levels in conjunction with bleeding profiles.

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    Related Documents

    Hematology PDF - Prenatal and Adult Hematopoiesis
    Blood Cell Counts PDF
    Red Cell Inclusions PDF
    Special Hematology PDF
    Anemia Types and Key Lab Findings PDF
    Special Tests PDF
    Hematology Sample Questions PDF
    Coagulation PDF
    Plasma Coagulation Factors PDF
    Routine Tests of Hemostatic Function
    Hemostasis Disorders Past Paper
    Fibrinolysis - Medical Notes
    Anticoagulant Therapy PDF

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