HEMA CIULLA

• Whole blood


  Includes erythrocytes, leukocytes, platelets, and plasma
• Buffy coat


  Small white layer of cells lying between the packed red blood cells and the plasma
• Plasma


  Liquid portion of unclotted blood
• Serum


  Fluid that remains after coagulation has occurred and a clot has formed
• Plasma composition

  • 90% water
  • Proteins
  • Enzymes
  • Hormones
  • Lipids
  • Salts
• Plasma appearance


  Hazy and pale yellow (contains all coagulation proteins)
• Serum appearance


  Clear and straw colored (lacks fibrinogen group coagulation proteins)
• Hematology terminology prefixes/suffixes


  • a-
  • -blast
  • -chromic
  • -cyte
  • dys-
  • -emia
  • ferro-
  • hyper-
  • hypo-
  • iso-
  • macro-
  • mega-
  • micro-
  • myelo-
  • normo-
  • -oid
  • -osis
  • pan-
  • -penia
  • -plasia
  • -poiesis
  • poly-
  • pro-
  • thrombo-
  • without
• Formed elements and sizes

  • Thrombocytes (platelets) - 2-4 μm
  • Erythrocytes (RBCs) - 6-8 μm
  • Normal lymphocytes - 6-9 μm
  • Reactive lymphocytes - 10-22 μm
  • Basophils - 10-15 μm
  • Segmented neutrophils - 10-15 μm
  • Band neutrophils - 10-15 μm
  • Eosinophils - 12-16 μm
  • Monocytes - 12-20 μm
• Homeostasis


  Body's tendency to move toward physiological stability
• Conditions for in vitro testing of blood and body fluids

  • Osmotic concentration (0.85% sodium chloride, isotonic)
  • pH reference range (venous 7.36-7.41, arterial 7.38-7.44)
  • Temperature (37.0°C)
• MCV (mean corpuscular volume)


  Indicator of the average/mean volume of erythrocytes (RBCs)
• Conditions affecting MCV


  • Increased in megaloblastic anemia, hemolytic anemia with reticulocytosis, liver disease, and normal newborn
  • Decreased in iron deficiency anemia, thalassemia, sideroblastic anemia, and lead poisoning
• MCH (mean corpuscular hemoglobin)


  Indicator of the average weight of hemoglobin in individual RBCs
• Conditions affecting MCH


  • Increased in macrocytic anemia
  • Decreased in microcytic, hypochromic anemia
• MCHC (mean corpuscular hemoglobin concentration)


  Measure of the average concentration of hemoglobin in grams per deciliter
• MCHC ranges


  • 32-37 g/dL indicates normochromic RBCs
  • Less than 32 g/dL indicates hypochromic RBCs (iron deficiency, thalassemia)
  • Greater than 37 g/dL indicates possible error or spherocytes
• RDW (RBC distribution width)


  Determined from the RBC histogram, increased proportional to the degree of anisocytosis (variation in size)
• Conditions with high RDW

  • Post-transfusion
  • Post-treatment (e.g. iron, B12, or folic acid therapy)
  • Idiopathic sideroblastic anemia
  • Presence of two concurrent deficiencies (iron and folic acid)
• Hematocrit


  Percentage of RBCs in a given volume of whole blood
• Hematocrit reference ranges


  • Males: 41-53% (0.41-0.53 L/L)
  • Females: 36-46% (0.36-0.46 L/L)
• Hemoglobin


  • Reference range for males: 13.5-17.5 g/dL (135-175 g/L)
  • Reference range for females: 12.0-16.0 g/dL (120-160 g/L)
• Platelets


  Reference range: 150-450 x 10^9/L (150,000-450,000/μL)
• MPV (mean platelet volume)


  Analogous to the MCV for erythrocytes, reference range 6.8-10.2 fL
• Relative count


  Amount of a cell type in relation to other blood components
• Absolute count


  Actual number of each cell type without respect to other blood components
• Wright's stain


  Most commonly used routine peripheral blood smear stain, contains methylene blue and eosin
• Causes of poor Wright's stain


  • Buffer or stain below pH 6.4 (RBCs too red, WBC nuclei poorly stained)
  • Buffer or stain above pH 6.8 (RBCs and WBC nuclei too blue)
  • Excess buffer
  • Decreased staining time
  • Increased washing time
  • Thin smear
  • Expired stains
  • Poor washing
  • Thick smear
  • Increased protein
  • Heparinized blood sample
• Prussian blue stain


  Stains iron granules in RBCs, histiocytes, and urine epithelial cells
• New methylene blue


  Stains RNA in reticulocytes, measure of bone marrow erythropoiesis
• Neutral red with brilliant cresyl green


  Stains Heinz bodies, clinical disorders associated include G6PD deficiency and unstable hemoglobin disorders
• Hematopoiesis


  Production and differentiation of blood cells
• Intrauterine hematopoiesis phases


  • Mesoblastic (yolk sac) phase
  • Hepatic (liver) phase
  • Myeloid/medullary phase
• Bone marrow cellularity


  • Normocellular - 30-70% hematopoietic cells
  • Hypercellular/hyperplastic - >70% hematopoietic cells
  • Hypocellular/hypoplastic - <30% hematopoietic cells
  • Aplastic - Few or no hematopoietic cells
• 1. E (myeloid:erythroid) ratio


  Ratio of granulocytes and precursors to nucleated erythroid precursors, normal range 3:1 to 4:1
• Stem cell theory


  Hematopoiesis involves pluripotential stem cells that develop into committed progenitor cells and finally mature blood cells
• Committed progenitor cells and their mature cell types


  • CFU-MEG - Thrombocytes
  • CFU-GM, CFU-M, CFU-G - Monocytes, Neutrophils
  • BFU-E - Erythrocytes
  • CFU-Eo - Eosinophils
  • CFU-Ba - Basophils
• Primary lymphoid tissue


  • Bone marrow - Site of pre-B cell differentiation
  • Thymus - Site of pre-T cell differentiation
• Secondary lymphoid tissue


  • Lymph nodes
  • Spleen
  • Gut-associated tissue (Peyer's patches)
• Leukocytes


  Classified as phagocytes (granulocytes, monocytes) or immunocytes (lymphocytes, plasma cells, monocytes)