Hematology and Coagulation Quiz

Hematopoiesis and Blood Cell Formation

• Hematopoiesis is the process of blood cell formation, primarily occurring in the bone marrow in adults.
• Hematopoietic stem cells (HSCs) differentiate into myeloid and lymphoid lineages.
• Myeloid progenitors create erythrocytes (red blood cells), thrombocytes (platelets), and various leukocytes (white blood cells)
• Lymphoid progenitors create lymphocytes (B cells, T cells, and natural killer cells).
• Erythropoietin (EPO), primarily produced by the kidneys, stimulates erythropoiesis (red blood cell production). Low oxygen triggers EPO release.
• Thrombopoietin regulates platelet production (thrombopoiesis).
• Colony-stimulating factors (CSFs) stimulate blood cell growth and differentiation.
• Reticulocytes are immature red blood cells released into the bloodstream; their number indicates bone marrow activity. Increased reticulocytes suggest heightened RBC production.
• Advanced concepts include intricate signaling pathways, transcription factors, and epigenetic modifications that regulate hematopoiesis.

Hematologic Organs and Their Functions

• Bone marrow is the main site of hematopoiesis in adults, containing hematopoietic stem cells and supporting stromal cells.
• Kidneys produce erythropoietin, crucial for red blood cell production.
• The liver creates prothrombin and other clotting factors; stores iron as ferritin.
• The spleen filters blood, removes damaged red blood cells, breaks down hemoglobin, stores platelets, and plays a role in immune responses.
• Advanced concepts involve intricate interactions between hematopoietic cells and the bone marrow microenvironment; the spleen's role in immune surveillance and red blood cell homeostasis.

Hematology Laboratory Tests

• Complete Blood Count (CBC) is a comprehensive blood test.
  • Red Blood Cell (RBC) Count: Number of circulating RBCs. Normal range varies by sex and age.
  • Hemoglobin (Hb): The oxygen-carrying protein in RBCs. Normal range varies by sex and age.
  • Hematocrit (Hct): Percentage of blood volume occupied by RBCs. Normal range varies by sex and age.
  • White Blood Cell (WBC) Count: Number of circulating WBCs. Normal range is typically 5,000-10,000/μL. Specific WBC types are also counted.
  • Platelet Count: Number of circulating platelets. Normal range is typically 150,000-450,000/μL.
• Peripheral Blood Smear: A microscopic examination of a blood sample to assess cell morphology (shape and size).

Red Blood Cell Disorders: Anemias

• Anemia is a condition of insufficient red blood cells or hemoglobin, reducing oxygen-carrying capacity.
• Iron deficiency anemia results from insufficient iron intake, impaired absorption, or excessive blood loss, causing small red blood cells.
• Vitamin B12 deficiency anemia (Pernicious Anemia) is due to vitamin B12 deficiency often from the lack of intrinsic factor, resulting in enlarged red blood cells.
• Aplastic anemia is bone marrow failure, resulting in a deficiency of all blood cell types.
• Sickle cell disease is an inherited disorder where abnormal hemoglobin causes red blood cells to sickle, causing vaso-occlusion and hemolysis.
• Thalassemia is an inherited disorder causing reduced or absent globin chain synthesis, leading to abnormal hemoglobin and anemia.

White Blood Cell Disorders

• Leukopenia is a decrease in white blood cell count.
• Neutropenia is a decrease in neutrophil count, a type of white blood cell crucial for fighting infections.
• Infectious Mononucleosis ("Mono") is an EBV (Epstein-Barr virus) infection with lymphocyte increase.
• Leukemia is a group of cancers involving uncontrolled proliferation of abnormal white blood cells. Types include acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), and chronic myeloid leukemia (CML).

Platelet Disorders and Coagulation Disorders

• Idiopathic Thrombocytopenic Purpura (ITP) is an autoimmune disorder decreasing platelet count, causing easy bruising, petechia, purpura, and bleeding.
• Thrombotic Thrombocytopenic Purpura (TTP) is a rare disorder with microthrombi formation, thrombocytopenia, and symptoms including thrombocytopenia, microangiopathic hemolytic anemia, fever, and neurologic symptoms.
• Hemophilia A is a deficiency of factor VIII causing excessive bleeding, especially after injury or surgery. Replaced by factor VIII therapy.
• Hemophilia B (Christmas Disease) is a deficiency of factor IX causing excessive bleeding, similar to Hemophilia A, replaced by factor IX therapy.
• Von Willebrand Disease involves a deficiency or dysfunction of von Willebrand factor (vWF), affecting platelet adhesion. Treated with desmopressin or vWF replacement therapy.

Bone Marrow Biopsy

• Examination of bone marrow tissue to assess hematopoiesis and detect abnormalities

Advanced Concepts

• Limitations and potential sources of error in hematologic tests
• Interpreting CBC results in the context of clinical findings
• The limitations and potential sources of error in hematologic tests. Interpretation of CBC results considering appropriate clinical findings.
• Interplay of coagulation factors and inhibitors
• The pathophysiology of inherited and acquired coagulation disorders
• Molecular subtypes and prognostic factors for lymphoma and multiple myeloma
• Role of targeted therapies in treating these cancers.
• Intricate regulation of the coagulation cascade. Roles of anticoagulants and thrombolytics in managing bleeding and thrombotic disorders.