CCCS6 CBC and Anemia PDF

Clinical chemistry case study Complete blood count Megaloblastic anemia Hemolytic anemias G6PD deficiency case Iron deficiency anemia Beta Thalassemia Complete blood count The complete blood count (CBC) is one of the most commonly ordered blood tes...

Clinical chemistry case study Complete blood count Megaloblastic anemia Hemolytic anemias G6PD deficiency case Iron deficiency anemia Beta Thalassemia Complete blood count The complete blood count (CBC) is one of the most commonly ordered blood tests. The complete blood count is the calculation of cells and cell fragments suspended in the plasma. These calculations are generally determined by special machines that analyze the different components of blood A major portion of the complete blood count is the measure of the concentration of white blood cells, red blood cells, and platelets in the blood. CBC is ordered when there are clinical findings indicating disorders that affect blood cells. For example: Infection, Inflammation, Parameters of CBC The complete blood count, or CBC, lists a number of many important values. Typically, it includes the following: 1. White blood cell count (WBC or leukocyte count) 2. WBC differential count 3. Red blood cell count (RBC or erythrocyte count) 4. Hematocrit (Hct) 5. Hemoglobin (Hb) 6. Mean corpuscular volume (MCV) 7. Mean corpuscular hemoglobin (MCH) 8. Mean corpuscular hemoglobin concentration (MCHC) 9. Red cell distribution width (RDW) 10.Platelet count 11.Mean Platelet Volume (MPV) White blood cells count (WBCs) and WBCs differential White blood cell (WBC) count is a count of the total number of white blood cells in a person's sample of blood. The normal number of WBCs in the blood is 4,500-11,000 WBC/mL. WBCs Differential: May or may not be included as part of the panel of tests. It identifies and counts the number of the various types of white blood cells present. Neutrophils 40-75% of WBCs. Lymphocytes 20-45% of WBCs. Eosinophils 1-6% of WBCs. Monocytes 2-10% of WBCs. Basophils 0-1% of WBCs. Leukopenia and leukocytosis Leukopenia caused by : Bone marrow disorders or damage Autoimmune conditions such as rheumatoid arthritis and systemic lupus erthrymatosus (SLE) Severe infections (sepsis) Lymphoma or other cancer that spread to the bone marrow Diseases of immune system (e.g., HIV) Leukocytosis caused by : Infection, most commonly bacterial Inflammation Leukemia, Myeloproliferative disorders Allergies, asthma Tissue death (trauma, burns, heart attack)  Platelet count (RBCs) A normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. Possible Causes of Possible Causes of Thrombocytosis: Thrombocytopenia: “Reactive” thrombocytosis Spurious lab result caused by related to acute trauma, surgery, platelet clumping, idiopathic blood loss, iron deficiency, or immune-mediated chronic infections, inflammatory thrombocytopenia (ITP), diseases including rheumatoid medications, viral infection, arthritis and ulcerative colitis, leukemia, sepsis, splenectomy hypersplenism Mean Platelet Volume (MPV) “Young” platelets, recently released from the bone marrow, are typically slightly larger In an individual with thrombocytopenia: Increased MPV indicates normal bone marrow response Decreased or low normal MPV may indicate impaired bone marrow response  Erythrocyte count (RBCs) Red blood cell (RBC) count is a count of the actual number of red blood cells in a person's sample of blood. Normal RBC range is: Male: 4.7 to 6.1 million cells per microliter (cells/mL) Female: 4.2 to 5.4 million cells/mL Hemoglobin Concentration and Hematocrit (Hct): Hemoglobin Concentration (Hb) : measures the amount of hemoglobin in whole blood expressed in grams per deciliter. normal values: 13.0-18.0 g/dL in adult males 11.5-16.5 g/dL in adult, non-pregnant females. Hematocrit (Hct): the volume of RBCs compared to the total blood volume (RBCs + plasma). Other name for the hematocrit is packed cell volume (PCV) normal values (Hct): 42-52% in adult males 37-47% in adult females. Hematocrit Red Blood Cell Indices Red blood cell indices are calculations that provide information on the physical characteristics of the RBCs: Mean corpuscular volume (MCV) is a measurement of the average size of RBCs. Mean corpuscular hemoglobin (MCH) is a calculation of the average amount of hemoglobin inside a red blood cell. Mean corpuscular hemoglobin concentration (MCHC) is a calculation of the average percentage of hemoglobin inside a red cell. Red cell distribution width (RDW), which may be included in a CBC, is a calculation of the variation in the size of RBCs. Mean Corpuscular Volume (MCV) The MCV indicates the average volume of the red blood cells. (Normal: 80~97 fl) If the MCV is less than 80 fl, the RBCs are smaller than normal (microcytic); this may be caused by iron deficiency anemia or thalassemia, for example. If the MCV is greater than 97 fl, the RBCs are larger than normal (macrocytic), this may be seen in anemia caused by vitamin B 12 or folate deficiency. If the MCV is within the normal range, the RBCs are normocytic Mean Corpuscular Hemoglobin Concentration (MCHC) Indicates the average concentration of Hemoglobin in one RBC. Normal value = 32 - 36 g/dl An MCHC below 32 g/dL indicates hypochromia, which is seen in conditions such as iron deficiency anemia and thalassemia. An MCHC above 36 g/dL indicates hyperchromia which is seen in conditions where the hemoglobin is more concentrated inside the red cells as seen in hereditary and acquired RBC membrane disorders (e.g. hereditary spherocytosis and autoimmune hemolytic anemia) RBCs with a normal MCHC are termed Mean Corpuscular Hemoglobin (MCH) The MCH indicates the average quantity (mass) of hemoglobin in the red blood cells. (quantity of Hb present in one RBC) Normal value for the MCH : 27~31 pg An MCH lower than 27 pg is found in microcytic anemia and also with normocytic, hypochromic RBCs. An elevated MCH occurs in macrocytic anemia and in some cases of spherocytosis in which hyperchromia may be present (in spherocytosis MCHC will be also high). Red cell distribution width (RDW) Red Cell Distribution Width (RDW) measures the variability in the size of red blood cells. Two measurements: RDW-coefficient of variation (RDW- CV): Normal range: 11.5-14.5% RDW- standard deviation (RDW-SD): 40.0 - 55.0 fL. High RDW indicates high variability in RBC sizes On a peripheral blood smear the sample with high RDW will show “anisocytosis” (see next slide) Descriptive Terms Used on Peripheral Smears Anisocytosis: marked variation in RBC sizes (visual counterpart of increased RDW) Poikilocytosis: marked variation in the shape of RBCs Hypochromia or hypochromasia: RBCs are paler than normal because they contain less hemoglobin (visual counterpart of decreased MCHC) Macrocytosis: increased number of large RBCs (visual counterpart of increased MCV) Microcytosis: increased number of small RBCs (visual counterpart of decreased MCV) Anisocytosis Poikilocytosis Reticulocyte Count Reticulocytes are “young” red blood cells that were recently released from the bone marrow. Normally, reticulocytes comprise 0.5 - 2.5% of all red blood cells. (Note: this is a % of total RBCs not Increased an absolute count) reticulocytes (reticulocytosis) is a normal response to blood loss or anemia. Since reticulocytes are larger, the MCV (and RDW) may be elevated. The combination of anemia with a low or normal reticulocyte count indicates that the bone marrow is unable to respond normally, either due to lack of essential ingredients (iron deficiency, vitamin B12 An example of Complete Blood Count (CBC) Anemia Reduction in one or more of the major RBC measurements:, Hb, Hct, RBC Count: All factors are dependent on the RBC mass and the plasma volume According to World Health Organization criteria, anemia is defined as Hb < 130 g/L ( 100 fl ( normal 82-98 fl) unless a cause of microcytosis is also present (e.g., iron deficiency or thalassemia trait) MCH: increased MCHC: normal Reticulocytopenia and low Reticulocyte Index (corrected reticulocyte count) Total WBC count – normal / low Platelet count – normal/ low Pancytopenia, especially if anemia is sever. Hemolytic Anemia Anemia that result from increased destruction of RBCs with a reduction of the circulating life-span (Normal: 110- 120 days) – Hemolysis