HEMA 1-4

• Hematology is the study of blood cells through staining, counting, analyzing, and recording the appearance, phenotype, and genotype of all types of cells
• The purpose of hematology is to predict, detect, and diagnose blood diseases and systemic diseases affecting blood cells
• Hematology is also used to select and monitor therapy for diseases
• Qualitative analysis in hematology focuses on morphology, such as through a Peripheral Blood Smear, while quantitative analysis involves counting, like in a Complete Blood Count (CBC) and Differential Count
• Blood functions include transporting oxygen (Hgb) from lungs to tissues, clearing carbon dioxide (Hgb) from tissues to lungs, transporting biomolecules, delivering waste to the liver and kidneys, providing coagulation enzymes (platelets), and protecting vessels from trauma and hemostasis
• Blood has an average volume of 5 liters and consists of plasma (transporting and nourishing blood cells) and cells (RBC - erythrocytes, WBC - leukocytes, Platelets - thrombocytes)
• Historical figures in hematology include Athanasius Kircher, Anton van Leeuwenhoek, Giulio Bizzozero, and James Homer Wright
• Prefixes in hematology terminology include meanings like lack, without, red, iron, blood, white, large, small, and many others
• Hematologic procedures involve a Complete Blood Count (CBC) which enumerates cellular elements, quantitates hemoglobin, and describes cell appearance, including RBC, WBC, and Platelet parameters
• Red Blood Cells are anucleate, biconcave, discoid cells filled with a reddish protein, produced in the bone marrow, and are measured in volume to detect anemia or polycythemia
• Hemoglobin is a protein inside RBCs, measured using reagents like potassium cyanide and potassium ferricyanide, and its concentration is determined spectrophotometrically
• Hematocrit is the ratio of packed RBC volume to whole blood volume, determined by centrifugation, and excludes the Buffy Coat which contains WBCs and platelets
• RBC indices like MCV, MCHC, MCH, and RDW reflect RBC diameter, staining intensity, hemoglobin mass, and variation in RBC volume, respectively
• White Blood Cells include granulocytes (Neutrophils, Eosinophils, Basophils) and agranulocytes (Lymphocytes, Monocytes), which are produced in bone marrow or lymphoid tissue and are crucial for protection from infection and injury
• Differential Count of WBCs includes percentages of Neutrophils, Lymphocytes, Eosinophils, Basophils, and Monocytes, each with specific functions and characteristics
• Platelets, or thrombocytes, are fragments from megakaryocytes, maintain blood vessel integrity, and are crucial for clot formation and hemostasis
• Hematologic procedures also involve Blood Film Examination, which allows for the examination of abnormalities in blood cells and estimation of WBC and platelet counts
• Other hematologic procedures include Coagulation studies, Bone Marrow examination, Flow cytometry immunophenotyping, Cytogenetic analysis, and Molecular diagnosis assays
• Specimen collection for hematologic testing involves equipment like tourniquets, collection tubes with additives like clot activators, anticoagulants, antiglycolytic agents, and separator gel
• Clot activators accelerate the clotting process, anticoagulants prevent blood clotting, and EDTA is used to maintain normal morphology of blood cells
• Overall, hematology involves the study of blood cells, their functions, abnormalities, and diagnostic procedures to predict, detect, and manage various blood and systemic diseases
• Heparin binds to antithrombin in plasma and inhibits thrombin and activated factor X
• EDTA maintains normal morphology of blood cells and prevents distortions
• EDTA + calcium forms insoluble calcium salt
• Dry additives include K2 EDTA or Na2 EDTA, while the liquid additive is K3 EDTA
• EDTA is the coagulant of choice for cell counting and sizing
• EDTA results in less shrinkage of RBCs and less of an increase in cell volume on standing
• Sodium Citrate reacts with EDTA + calcium to form insoluble calcium salt
• Sodium Citrate is available in 3.2% and 3.8% concentrations
• Sodium Citrate is used as an anticoagulant for aPTT, PT testing, and Westergren ESR
• Due to dilution of anticoagulant to blood, sodium citrate is generally unacceptable for most other hematology tests
• Heparin inactivates the blood-clotting factor thrombin & factor Xa
• Heparin is an in vitro and in vivo anticoagulant
• Heparin coats capillary blood collection tubes
• Heparin is inappropriate as an anticoagulant for many hematology tests, such as Wright-stained blood smears
• Oxalate distorts cell morphology, causing RBCs to become crenated
• Vacuoles appear in granulocytes when exposed to oxalate
• Bizarre forms of lymphocytes and monocytes appear rapidly when treated with oxalate
• Sodium fluoride is an antiglycolytic agent that inhibits the metabolism of glucose by blood cells
• Anticoagulated plasma with sodium fluoride can be immediately centrifuged to obtain plasma