Introduction to CBC and Blood Smear Interpretation Thanyaphong Na Nakorn, MD, PhD Division of Hematology Department of Medicine Chulalongkorn University 1 Complete blood count z z z z z The most common test used in clinical medicine Determine type and severity of blood cell abnormalities Nowadays, CBC is fully automated and highly reproducible. Correct interpretation of automated CBC can reduce rate of unnecessary blood smear examination Provide useful information for provisional diagnosis of RBC and WBC diseases 2 1 Component of automated CBC Hb, Hct, Hct, z Blood count basic parameters: Hb, platlet. RBC, WBC, platlet. z Red cell indices: MCV, MCH, MCHC, RDW z WBC differentials z Cytogram or Scattergram z Reticulocyte count 3 Basic principles of automated blood cell analyzer z z Electrical impedance: Coulter Counter , CellCell-Dyn® Dyn® Optical impedance and light scatter: TechniconTechnicon-H series z VCS (volume, conductivity, light scatter) technology BeckmanBeckman-Coulter VCS, MAXM, STKS 4 2 Coulter Technology • Cell count and size can be measured by electrical impedance ©J.Paul Robinson ©J.Paul Robinson 5 Hydrodynamic Focusing Sheath fluid Laminar Coaxial Flow The Bernoulli Effect Direction of flow Velocity Gradient Viscous drag along walls. Lower pressure Particles move to low pressure area 6 3 Technicon Technology 7 VCS Technology 8 4 Instrument Coulter STKS Methodology features Impedance, conductivity, laser technology Coulter GENGEN-S Impedance, flow cytometry, cytometry, conductivity, laser light scatter (reticulocyte analysis) Sysmex SESE-9000 Direct current (resistance to cell volume); radioradio-frequency (cell density, size) Cobas Argos 55-diff (Roche) Impedance, light absorption (halogen light source) Technicon H-3 (Bayer) Cytochemistry, Cytochemistry, flow technology (reticulocyte analysis) Advia 120 (Bayer) Cytochemistry, Cytochemistry, flow technology (reticulocyte analysis) Cell Dyn 4000 (Abbott) Impedance, laser light scatter 9 Red cell parameters z Direct Measurement z (RBC (RBC)) Erythrocyte Concentration (RBC) x 1066/ml Mean Corpuscular Volume (MCV) (MCV Femtolitre (fl) (MCV)) (Hb (Hb)) Gram/decilitre (g/dl) Hemoglobin (Hb) Gram/decilitre Indirect Measurement (Hct) Hct) = RBC x MCV/10 Hematocrit (Hct) % (MCH (MCH)) = HB x 10 / RBC RBC (pg) Mean Corpuscular Hemoglobin (MCH) (MCHC Hemoglobin Concentration Concentration (MCHC) (MCHC)) Mean Corpuscular Hemoglobin = Hb/Hct x 100 (g/dl) (RDW Red Cell Distribution Width (RDW) (RDW)) % % 10 5 RBC size and MCV 11 Red Cell Distribution Width RBC x 106/ml 20th percentile 80th percentile RDW 75 RDW = 80 85 80th percentile - 20th percentile 80th percentile + 20th percentile 90 X constant 12 6 three-part differentials WBC: three-part CellCell-Dyn 1700CS 13 Five-part differentials WBC: Five-part ¾ Neutrophil Monocyte ¾ Lymphocyte Nφ Eo ¾ Monocyte ¾ ¾ Eosinophil ¾ ¾ Basophil ¾ lymphocyte Baso Coulter VCS 14 7 Six-part differentials WBC: Six-part Peroxidase channel ¾ Neutrophil ¾ ¾ Lymphocyte ¾ ¾ Monocyte ¾ Eosinophil ¾ Basophil ¾ Large Unstained Cell (LUC) Technicon*H2 Technicon*H2 15 Six-part differentials WBC: Six-part Basophil/lobularity channel ¾ ¾ Additional parameters in TechniconTechnicon-H analyzer analyzer Technicon-H 1. 1. Mean peroxidase activity index (MPXI) 2. Lobularity Index (LI) Technicon*H2 Technicon*H2 16 8 Platelet parameters z z Platelet count z z Mean Platelet Volume (MPV) z z Platelet Distribution Width (PDW) z z Plateletcrit (Pct) 17 Reticulocyte count z z z z z z nonnon-nucleated RBC Reticulocyte = non-nucleated with polyribosomal RNA as stained by supravital stain (new methylene blue or brilliant cresyl blue) Polychromasia underestimates reticulocytes Three methods of reticulocyte enumeration Manual count on slide per 1,000 RBC Automated CBC with counter (Coulter reticulocyte counter VCS, Cell-Dyne CellCell-Dyne 4000, TechniconTechniconH3) Flow cytometry with fluorescent dyes 18 9 Coulter™ Report from Coulter™ 19 Technicon-H™ Report from Technicon-H™ 20 10 21 Clinical Utility of automated CBC z Differential diagnosis of RBC disorders Microcytic RBC z Use WBC differential cytogram to guide WBC morphology and phenotypes 22 11 What is your diagnosis? WBC RBC Hb HCT MCV MCH MCHC RDW HDW PLT 5.00 3.56 6.0 21.0 59.0 17.0 28.8 19.4 4.02 427 x103/µL x106/µL g/dL % fL pg g/dL % g/dL x103/µL 23 Differential diagnosis of anemia using MCV and RDW Low MCV Normal MCV High MCV Thalassemia trait Heterozygous HbE, HbE, HbC, HbC, etc. RDW <15 Anemia of chronic disease (ACD) ACD Heterozygous HbS, HbS, HbCS, HbCS, HbE, HbE, etc. Hereditary spherocytosis Acute hemorrhage Aplastic anemia MDS Myeloma Liver disease Hyperthyroidism Iron deficiency anemia Thalassemia intermedia Sideroblastic anemia RDW >15 Severe ACD RBC fragmentation Early or combined nutritional deficiency Myelodysplasia Myelophthisis Sickle cell anemia or Homozygous HbCS B12 deficiency Folate deficiency AIHA Drugs: HU, ARV, AZA, etc. 24 12 Factors known to cause spurious laboratory results in hematology analyzers. Parameter RBCs Hb MCV MCHC RDW WBCs Platelets Spuriously increased Spuriously decreased WBC >50 000/mm3 Clotting hyperlipidemia, hyperlipidemia, hyperbilirubinemia Clotting Cold agglutinins, hyperglycemia, WBC >50 000/mm3 Cryoglobulins Hyperlipidemia, Hyperlipidemia, cold agglutinins Post transfusion Nucleated red cells, platelet clumps, unlysed red cells, cryoglobulins WBC >50 000/mm3 WBC fragmentation, severe microcytosis, microcytosis, cryoglobulins Clotting Satellitism, Satellitism, clumping 25 Basic Principles for Blood Smear Interpretation z z z z Assess quality of smears Specimen preparation & staining Estimate cell numbers RBC: evenly dispersed with minimal intercellular space 10-20/LPF WBC: 10-20/LPF 7-20/OF Platelets: 7-20/OF Determine predominant cell populations Carefully examine cellular morphology 26 13 RBC disorders z z Hypochromic microcytic anemia Iron deficiency anemia Thalassemia and hemoglobinopathy Macrocytic anemia Megaloblastic anemia NonNon-megaloblastic macrocytic anemia Non-megaloblastic Hemolytic anemia Immune hemolytic anemia: AIHA, DHTR Microangiopathic hemolytic anemia (MAHA) Genzymopathies: G-6-PD G-6-PD deficiency Red cell enzymopathies: spherocytosis, RBC membrane defects: spherocytosis, ovalocytosis, elliptocytosis, elliptocytosis, stomatocytosis ovalocytosis, RBC inclusion bodies and parasites z z z z z z 27 Area of blood film examination 28 14 RBC Size and MCV 29 30 15 31 32 16 33 34 17 35 36 18 37 38 19 39 40 20 41 42 21 43 44 22 45 46 23 47 48 24 49 50 25 51 52 26 53 54 27 55 56 28 57 58 29 59 60 30 61 62 31 63 64 32 65 66 33 WBC disorders Leukopenia neutropenia: bone marrow failure, with absolute neutropenia: agranulocytosis with atypical lymphocytes: viral infection, chronic lymphoproliferative disorders with immature myeloid cells: acute leukemia, MDS or myelopthisis z Leukocytosis z leukocytosis: leukemoid reaction Reactive leukocytosis: Acute leukemia: AML vs. ALL disorders Chronic myeloproliferative disorders lymphoproliferative disorders disorders Chronic lymphoproliferative z Leukoerythroblastosis z z z 67 68 34 69 70 35 71 72 36 73 74 37 75 76 38 77 78 39 79 80 40 81 82 41 Platelet disorders z z Quantitative disorders nonnon-immune Isolated thrombocytopenia: Immune vs. non-immune Thrombocytopenia associated associated with with other other hematologic Thrombocytopenia abnormalities Thrombocytosis z z Qualitative disorders (megathrombocytes Giant platelets (megathrombocytes) (megathrombocytes)) Platelet inclusion or granule abnormality Bizarre in shape and size megakaryoblasts Megakaryocytes or megakaryoblasts 83 84 42 85 86 43 87 88 44 89 90 45 91 92 46 93 47
© Copyright 2026 Paperzz