Presentation on theme: "MLAB Hematology Keri Brophy-Martinez"— Presentation transcript:
1 MLAB 1415- Hematology Keri Brophy-Martinez AnemiaPart One
2 AnemiaAnemia is the inability of the blood to supply the tissue with adequate oxygen for proper metabolic function.Clinically, anemia is defined as a decrease in the normal concentration of hemoglobin or erythrocytes.Anemia is not a disease, but an expression of an underlying disorder or disease.
3 Development of Anemia Anemia occurs if: Erythrocyte loss or destruction exceeds the maximum capacity of bone marrow erythrocyte production ORBone marrow erythrocyte production is impaired or abnormal
4 Causes of anemia Acute blood loss (hemorrhage) Accelerated destruction of RBC’s (immune or non-immune)Nutritional deficiency (iron, folate or B12)Bone marrow replacement (e.g. cancer)InfectionToxicityHematopoietic stem cell arrest or damageHereditary or acquired defect
5 Anemia Classifications FunctionalUses absolute and corrected retic count, RPI, and serum iron for classificationTypesSurvival Defects(Increased Destruction)Proliferation Defects(Decreased production)Maturation Defects
6 Anemia Classifications MorphologicUses erythrocyte indices (MCV) for classificationTypesMacrocytic, NormochromicCauses: Folate or B12 deficiency, liver disease, alcoholismNormocytic, NormochromicCauses: bone marrow failure, hemolytic anemia, chronic renal failure, leukemia, metastatic malignancyMicrocytic,HypochromicMost common anemiaCauses: iron deficiency, sideroblastic anemia, thalassemia, chronic diseases
8 Diagnosis of anemia Clinical history Physical signs such as pallor, fatigue, weakness and shortness of breathLaboratory testsCBCExamination of the blood smearReticulocyte - measures effective erythropoiesisBone marrow examinationIron studies - iron, total iron-binding capacity (TIBC), ferritinVitamin B12 and folateErythropoietin level
11 Parameters of the CBC (complete blood count) Red Blood Count or RBCHemoglobinHematocritNote: the approximate relationship of the hemoglobin to the hematocrit is 1:3. This may vary with the cause of the anemia and the effect on the RBC indices, especially the MCV.RBC indicesMCV - mean cell volumeNormal: fL (femtoliters)Measured directly on automated cell countersUsed to classify RBCs as normocytic, microcytic or macrocyticIndicates the average volume of the red cellsCalculation: Hct x 10RBC
12 RBC Indices con’t MCH - mean cell hemoglobin weight Normal: pgA measurement of the hemoglobin content in RBC’sCalculation: Hgb x 10RBCMCHC - mean cell hemoglobin concentrationNormal: %Used to classify RBCs as normochromic, or hypochromicA measure of the concentration of hemoglobin in the average RBCCalculation: Hgb x 100Hct
13 Parameters of the CBC (complete blood count) RDW -Red Cell Distribution WidthCalculated index used to identify anisocytosisNormal: %Calculation: Standard deviation of MCV x100Mean MCV
14 Reticulocyte Adult reference range: 0.5 - 2.5% Useful in determining the response to the anemia and the potential of the bone marrow to manufacture RBC’s. Expressed as a percentage of the RBC’s.When anemia is present, it is helpful to correct the retic using the patient’s hematocrit in order to assess appropriate bone marrow responseA supravital stain called New Methylene Blue is used to stain reticulocytes. On a Wright’s stained smear, reticulocytes appear as bluish red cells. The term used for retics on Wright’s stain is polychromasia.Corrected retic% = retic % X Patient hctNormal hct* based on age and sex[*Normal female hct = 42%][*Normal male hct = 45%]
15 Reticulocyte maturation time in days RPI = corrected retic Prematurely released retics remain in the blood and take from ½ to 1 ½ days longer to mature. This will cause even the “corrected” retic to be elevated, so a calculation must be performed to correct for this situation to obtain the reticulocyte production index (RPI). A maturation time table is used for this calculation.Indicator of the adequacy of the bone marrow response in anemiaRPI>2: good bone marrow responseRPI<2: inadequate responseRPI = corrected reticmaturation time in days
16 Adult Reference Ranges Red Blood CellsMale: x 106 /µlFemale: x 106 /µlHemoglobinMale: g/dlFemale: g/dlHematocritMale: %Female: %MCVfLMCH28-34 pgMCHC32-36 %Reticulocyte%RDW%
17 ReferencesHarmening, D. M. (2009). Clinical Hematology and Fundamentals of Hemostasis. Philadelphia: F.A Davis.McKenzie, S. B., & Williams, J. L. (2010). Clinical Laboratory Hematology . Upper Saddle River: Pearson Education, Inc.