VTT 234- Hematology Study Guide

Stomatocytes

"Happy Face" Results from membrane defects May be present in hemolytic anemia

Target Cells

"Leptocytes", "Codocytes" Possess an excess of cell membrane in relation to the amount of hemoglobin. Often observed in liver disease.

Acanthocytes (RBC)

Also called spur cells, are spherical cells with blunt-tipped or club-shaped spicules of different lengths projecting from their surface at irregular intervals. Major morphologic feature in dogs with hemangiosarcoma (often accompanied by regenerative anemia). Also seen in some dogs and cats with liver disease and dogs with iron deficiency.

RBC Size

Anisocytosis- variation in red cell size Macrocytosis- large red cells (increaseMCV) Microcytosis- small red cells (decrease MCV)

Keratocytes

Formed from physical or chemical injury to red cells. "Helmut" shape, crescent moon, blister cells. Can be seen with liver disease in cats such as hepatic lipidosis. Can occur secondary to: Oxidative damage Iron deficiency

GTT

Green; contents are lithium heparin(anticoagulant) -purpose: blood gas & chemistries

Feline normal values (PCV & HG)

HCT (PCV): 30-45% Hemoglobin: 8-15 g/dl

Canine normal values(PCV & HG)

HCT (PCV): 37-55% Hemoglobin: 12-18g/dl

spherocytes

One of the most important shapes to recognize. -Decreased surface : volume ratio -Lack central pallor -Marked spherocytosis strongly suggests IMHA. -Spherocytes may also be seen with: Heinz Body Anemia Zinc toxicosis Post Blood Transfusion

Evaluating protein (in plasma)

Purposes: -Hydration status -Inflammatory status (d/t fibrinogen) -Liver, kidney, & GI function -Neonates tend to have lower than normal total proteins. (Underdeveloped immune system) -Geriatrics tend to have higher than normal total proteins. ( water retention)

RTT

Red; Nothing; -Purpose: chemistries, urine, drug monitoring

SST

Serum separator aka tiger top & marble top; contents are gel wax (to lower cell usage of glucose) -purpose: chemistries & function tests

Echinocytes (RBC)

Spiculated RBC's. Projections may be sharp or blunt, are usually numerous, and evenly spaced around circumference of cell. The spicules are uniform in size. Causes of echinocyte formation: Artifact: aging blood or excessive exposure to EDTA. Natural: observed in dogs with renal disease or rattlesnake envenomation.

The differential *

The percentage of each cell type you count is termed the relative differential count. The absolute differential is obtained by multiplying the percentage of each cell type by the total WBC count to get the number of each type of leukocyte per microliter. Example 10.59 x 10^9 g/l is total WBC If you observed 75% neutrophils (relative neutrophils) 10.59 x 0.75 = 7.94 x 10^9 g/dl (absolute neutrophil count)

ACT

activated clotting time; contents diatomaceous earth (diatoms=little sea creatures) -purpose: stimulates clotting, coagulation studies

BTT

blue; contents are sodium citrate (anticoagulant) -purpose:coagulation studies

Basophilic stippling

erythrocyte inclusion -Feature of regenerative anemia. Most of the stippling is seen in young red cells. It can also occur in the absence of anemia in animals with lead poisoning.

Heinz bodies

erythrocyte inclusion; -Oxidation of hemoglobin causes the hemoglobin molecule to distort. Results in the formation of intracellular inclusions called Heinz bodies. Morphologic appearance depends on what they are stained with: When stained with dif quik, they appear as a rounded protrusion ("Peppermint Patty" nose) on the red cell membrane. With New Methylene Blue (NMB), they appear as a dark blue inclusion & are more easily visualized.

Howell-Jolly bodies

erythrocyte inclusion; -Small fragments of non-functional nucleus which was not extruded as the cell left the bone marrow. Appear as a single, small, pale blue, perfectly round inclusion. Their numbers increase in regenerative anemias. In normal cats and in any species with compromised or absent splenic function (corticosteroids, splenectomy), low numbers can be seen in the peripheral blood despite the absence of anemia.

Monocyte (WBC)

function is phagocytosis

GTT (Grey)

grey; oxylate (anticoagulant) -purpose: glucose studies

Pokilocytes

irregular shaped rbc's

LTT

lavender; contents are heparin EDTA(anticoagulant) -purpose: CBC's

MCH

mean cell hemoglobin -The average weight of hemoglobin in an individual cell. -Calculation: -Hb x 10 ¸ rbc (0.00) = ______pg (picograms) -Normal values: -Canine :19-23pg -Feline: 13-17pg

MCHC

mean cell hemoglobin concentration; -The average concentration of hemoglobin (color) in an individual red cell. (Also the ratio of weight of Hb to % of RBCs) -This value allows the red cells to be classified as: -Normochromic -Hypochromic -Hyperchromic -Calculation- -Hb ¸ PCV x 100 = _______g/dl -Normal values: -canine: 32-36g/dl -feline: 30-36g/dl

MCV

mean corpuscular (Cell) volume, The average volume (size) of an individual rbc. This value allows the red cells to be classified as: -Normocytic- normal size -Microcytosis- smaller than normal cells. -Macrocytosis- larger than normal cells. -Calculation: -PCV x 10 ¸ rbc (0.00) = _______fl -Normal Values: -Canine: 62-77fl -Feline: 39-55fl

Polychromasia (RBC)

morphology color; -Variety of cell colors -Corresponds to -aggregate -reticulocytes. A good indication of a -regenerative response. -Confirm with a reticulocyte count. -Expect a slightly increased MCV & a slightly decreased MCHC when marked

Normochromic (RBC)

morphology color; Good Red Edges and Central Pallor Dogs exhibit central pallor (bi-concavity) Cats exhibit only slight central pallor

Hyperchromic (RBC)

morphology color; RBC that contains excessive amounts of red hemoglobin pigment.

Hypochromic (RBC)

morphology color; pale red cells due to low hemoglobin content. Iron deficiency is the most common cause.

PCV

packed cell volume (hematocrit); -PCV is performed manually ; HCT is automated -Hematocrit (or PCV) is measured by using a microhematocrit tube filled with blood. - -Once a hematocrit is obtained, a hemoglobin can be calculated. - -Divide the hematocrit by 3 to obtain a hemoglobin measurement.

Maturation of RBCs

pluriopotential stem cell is found in bone marrow turns into a RBC then into a rubriblast. Then prorubricyte a smaller nucleus, then rubricyte, metarubricyte, lastly into polychromatophil or reticulocyte

Neutrophil (WBC)

production : inflammation & stress function: pahgocytosis &inflammatory mediator

Eosinophil (WBC)

production: allergies & parasites function: hypersensitivity & antiparasitic

Basophil (WBC)

production: antigens & antibodies function: anaphylaxis & heparin & histamine release

Lymphocyte (WBC)

production: viruses function: immunity

Schizocytes

small fragments of rbc's formed by intravascular trauma. -Results from cell membrane damage during circulation -Results from vascular disorders (DIC), or heartworm disease.