Interpreting the CBC. Robert Miller PA Assistant Professor of Clinical Pediatrics and Family Medicine USC Keck School of Medicine Retired

Transcription

1 Interpreting the CBC Robert Miller PA Assistant Professor of Clinical Pediatrics and Family Medicine USC Keck School of Medicine Retired

2 The CBC 3 Cell Lines RBCs WBCs Platelets Assess general health Make a diagnosis Monitor a diagnosis Monitor treatment Normal RBCs RBC Morphology

3 Red Cell Line (Adult values, Medscape) RBC M cells/mcl (M), (F) Hgb g/dl (M), (F) Hct 40%-52% (M), 36%-47% (F) MCV fl MCH pg/ml MCHC g/dl Reticulocyte % RDW % RBC Morphology Anisocytosis Poikliocytosis Spherocytosis Target cells Microcytosis Macrocytosis Schistocytes Fragmented cells Hypochromasia Polychromasia Sickle cells RBC Morphology Anisocytosis: excess variation in size (High RDW, iron def., many others) Poikilocytosis: excess variation in shape (Hemolytic disorders, nutritional def., others)

4 RBC Morphology Microcytosis: small cells (MCV < 80) (Iron def., hemoglobinopathy, chronic disease) Macrocytosis: large cells (MCV > 100) (Megaloblastic, alcohol, liver dis., retics) RBC Morphology RBC Morphology Hypochromasia: pale cells (Iron def., anemia of chronic dis., others) Polychromasia: blue tinge to cytoplasm indicating a young cell (young reticulocyte)

5 RBC Morphology Iron Deficiency Anemia RBC Morphology Associated With Hemolysis Spherocytes: spherical cells Target cells: target appearance with hemoglobin concentration in center Sickle cells: crescent shape

6 RBC Morphology Target Cells & Spherocytes in Hemoglobinopathy Sickled Cells

7 RBC Morphology Schistocytes: fragmented cells (DIC, MAHA, TTP, HUS, cardiac valves, etc) Howell-Jolly body: blue spot of DNA remnants (Asplenic, hyposplenism) Agglutination: RBC clumping (Antibodies - usually IgM, mycoplasma, mono) Schistocytes Peter Maslak, ASH Image Bank 2013; Copyright 2013 American Society of Hematology. Copyright restrictions may apply. Howell Jolly Body Howell-Jolly body No Spleen? Nucleated RBC Why?

8 Cold Agglutinin / Agglutination RBC Morphology RBC - Reticulocytes Immature cells characterized by a network of filaments and granules

9 Copyright 2011 American Society of Hematology. Copyright restrictions may apply. Nucleated red blood cell Peter Maslak, ASH Image Bank 2011; Reticulocytes Young RBCs, N = 1 % (.5-1.5) Index of erythropoetic activity Increased following : treatment of anemia blood loss hemolysis Corrected Retic For Degree of Anemia Retic % X Pt. Hct. = corrected retic normal (45) 6 % X 30 = 4 % % X 15 = 4 % 45

10 Double Correction for Retic? Reticulocyte production index (RPI) First correct for degree of anemia A second correction graph is for the degree of prematurely released reticulocytes. Slide will show polychromasia (polychromatophilic macrocytes) RBC Morphology - RPI Hematocrit (%) Retic maturation correction and below % X 30 = 4 % = 2.7% RBC Morphology The Indices MCV: mean cell volume ( fl) MCH: mean cell hemoglobin MCHC: mean cell hgb concentration

11 Anemias: Think About The Retic If caused by a nutritional deficiency (like iron / B12 / folate) will probably have a low retic until the nutrient is provided to increase RBC production If caused by RBC loss (bleeding or hemolysis) will probably have a high retic compensating for the low hgb/hct because it has the nutrients & ability to increase RBC production Hemolytic Anemia Hgb / Hct (low or falling) Retic (increased)? RBC loss = bleeding / hemolysis? Recent Rx for anemia Anemia... Diagnosis 1) The patient has an anemia and RBCs are: Microcytic Normocytic Macrocytic 2) The retic count is higher or lower than expected High - blood loss / hemolysis? Low - nutritional deficiency?

12 RBC Size Common Anemias Microcytic Normocytic Macrocytic Iron deficiency Bleeding (acute) Megaloblastic Thalassemia Hemolysis Alcoholism (Lead) Aplastic anemia Medications Liver desease Anemia of Anemia of chronic disease chronic disease vwd Glanzmann s Thrombasthenia Bernard Soulier Syndrome GP IIb/III a Fibrinogen Afibrinogenemia A representation of normal platelet responses and the congenital disorders of platelet function Deficiency of Platelet Coagulant Activities Reproduced with permission from: Rao AK. Am J Med Sci. Platelets... Evaluation Number Morphology Function

13 Platelet Production Thrombopoietin stimulates platelet production Megakaryocyte stays in the marrow Platelet development, by OpenStax College CBC Platelet... Evaluation Platelet count ( K) Mean platelet volume (MPV) Morphology (uncommon) Platelets. Peter Maslak, ASH Image Bank 2011; Copyright 2011 American Society of Hematology. Copyright restrictions may apply.

14 Platelet Morphology Mean platelet volume (MPV) (normal MPV fl Large platelets Giant platelets Defective granulation (grey platelet syndrome0 Giant platelet. Peter Maslak, ASH Image Bank 2011; Copyright 2011 American Society of Hematology. Copyright restrictions may apply. RBC, Platelet, Leukocyte Electron micrograph facility, NCI at Fredrick

15 Platelets Platelet size can be of diagnostic significance when associated with thrombocytopenia Thrombocytopenia caused by bone marrow failure may have a low or normal MCV Thrombocytopenia caused by peripheral destruction (eg. ITP) usually have higher MCV Platelets Peripheral destruction of platelets (like in ITP) is associated with a higher MPV because the increased production of new, young platelets are typically a little larger and more active This possibly explains how many patients do OK with even very low platelet counts TWBC & Differential Total leukocytes: x 10 9 /L Neutrophils: % Lymphocytes: % Monocytes: 2 10 % Eosinophils: 1 6 % Basophils: 1 2 %

16 Macrocytes / Hypersgmented Poly Lymphoblast

17 Normal Bone Marrow Atypical Lymphocytes Neutropenic Disorders Quantitative Disorders Accelerated Destruction Maldestribution Decreased Production

18 Neutropenia Neutropenia: Count Absolute Neutophil ANC <1500 cell/mm 3 Severe Neutropenia: ANC < 500 cells/mm 3 Severe Neutropenia Studies have shown: Severe neutropenia (ANC < 500) may result with 40% of patients developing febrile neutropenia within a 4 day period Absolute Neutrophil Count (ANC) ANC calculation Total WBC x % Total Neutrophils Example: Total WBC = 5000/mm 3 Band Neutrophils = 5% Segmented Neutrophils = 55% ANC = 5,000 x 60% = 3,000

19 Captain Morgan