MLAB 1415- Hematology Keri Brophy-Martinez Introduction to Hematology

Terms Hematology Study of formed cellular blood elements: the white blood cells, red blood cells and platelets Hemostasis Arrest of bleeding by the formation of a barrier to blood loss Maintenance of an adequate number of cells to carry out the functions of the organism Hematopoiesis Dynamic formation and development of blood cells, normally in the bone marrow Process responsible for the replacement of circulating blood cells

Functions of the Hematology lab Confirm a physician’s clinical impression of a possible hematological disorder Establish a diagnosis or rule out a diagnosis Detect an unsuspected disorder Monitor the effects of radiation or chemotherapy

Blood Composition Plasma: 55% Constituents of Plasma Water (92%) Solutes(8%) Albumins Globulins Fibrinogen Others ( electrolytes, hormones, vitamins, lipids, salts, enzymes and carbohydrates)

Functions of Plasma Transport medium for nutrients & metabolites Immune Defense Coagulation

Blood Composition Cellular Elements Leukocytes: 1% White Blood Cell= WBC Granulocytes- fight infection Lymphocytes- cellular and humoral immunity Monocytes- phagocytosis of foreign substances and dead or dying cells Platelets: 1% Thrombocytes Help to maintain hemostasis by plugging capillaries and forming clots Actually a fragment of cytoplasm from megakaryocyte Erythrocytes: 43% Red Blood Cell= RBC Transports oxygen (O2) to tissues and excrete carbon dioxide (CO2) from tissues RBC’s do not have a nucleus

A Erythrocytes (RBCs) B&H Lymphocytes C&E Segmented neutrophil D Eosinophil F Monocyte G Platelets I Neutrophilic band J Basophil

proteins, albumins, globulins, fibrinogen, electrolytes, hormones, nutrients, and respiratory gases 55% 45%

Blood Composition Plasma: liquid portion of blood from an anticoagulated tubes Serum: liquid portion of blood from a clotted specimen

Reference ranges Differ according to age, race, sex and geographic location Established by individual facilities in order to account for patient population Refer to inside covers of textbook to review various reference ranges

Overview: Laboratory testing Complete Blood Count= CBC Indications: fatigue, weakness, infection, inflammation, bruising, bleeding Quantifies the white blood cells (WBC), red blood cells (RBC) , hemoglobin, hematocrit and platelets. Calculates the RBC indices WBC Differential: enumeration of the types of WBC’s, RBC morphology, platelets I

Sample & Storage Requirements Whole blood, non-hemolized Avoid clots Anticoagulant of choice K2 or K3 EDTA (ethylene diamine tetracetate) Purpose of the anticoagulant is to prevent clotting of specimen Storage Room temperature- up to 1 day 4oC- to preserve sample longer, but may induce cold agglutination

Changes in Aging EDTA Samples Erythrocyte Changes Neutrophil Changes Hypochromic Smudge/basket cells Schistocytes Cytoplasm rupture Elliptocytes Pyknotic nuclei Spherocytes Loss of granulation Crenated Cytoplasmic vacuoles Loss of nuclear shape, chromatin

Observations from Aged EDTA

Affect of Hemolysis on CBC Parameters WBC Probably unaffected RBC Falsely low due to RBC lysis and/or RBC fragments not be counted as RBCs HGB Reportable- accurate measurement relies on RBCs being completely lysed HCT Falsely low- calculated with an invalid MCV and falsely low RBC MCV Invalid falsely low or high depending on the degree of hemolysis. May be falsely low if RBC fragments cause smaller pulses to be produced in the RBC aperature or falsely high if fragmented RBCs fall below the RBC threshold and are not counted. MCH Invalid- calculated with a falsely low RBC MCHC Invalid- calculated with a falsely low HCT RDW Falsely high due to RBC fragments increasing the CV of the RBC histogram PLT Falsely high due to RBC fragments being incorrectly counted as platelets

References McKenzie, Shirlyn B., and J. Lynne. Williams. "Chapter 21." Introduction. Clinical Laboratory Hematology. Boston: Pearson, 2010. Print Rodak, Bernadette F., Fritsma, George, and Elaine Keohane. "Chapter 35." Myelodysplastic Syndrome. Hematology Clinical Principles and Applications. St. Louis: Elsevier, 2012. Print Teshima, D. Y. (2017, July). EDTA in transit: Degenerative changes in blood cell morphology. MLO, 49(7), 12-14.