Hematology and Hemostasis: Exam 2

PIVKA

Proteins induced by vitamin K deficiency or antagonists; the nonfunctional precursor forms of vitamin-K-dependent coagulation factors.

What is hemolysis?

Defined as the rupture or destruction of red blood cells. Hemolysis of a sample can be caused by improper collection or certain pathologic conditions (like in hemolytic anemia)

Which blood cell has the greatest specific gravity?

Erythrocytes (RBC's)

Buffy coat

a thin light colored layer of white blood cells and platelets than lie between a top layer of plasma and red blood cells

A Packed Cell Volume (PCV) test evaluates what percentage of whole blood contains ____________

Erythrocytes (RBC's)

What is a blood smear test used for?

Performing differential white blood cell counts, estimating platelet numbers, and looking at the morphologic features of WBCs, RBCs, and platelets

When performing a blood smear on a sample from a non-anemic patient the spreader slide should be held at a ______ degree angle

30 degree

A low neutrophil count indicates

autoimmune issues, nutritional deficiencies, cancer (leukemia, lymphoma, myelofibrosis), viral or bacterial infections, & medication side effects (usually from chemo)

Low lymphocyte levels usually suggest a patient is

stressed or using corticosteroid class drugs

A low Basophil count indicates

acute infection, severe allergies, hyperthyroidism, & medication side effects

Which leukocytes are involved in allergic reactions and parasitic infections?

Eosinophils and Basophils

absolute value is calculated by:

multiplying the total WBC count by the percentage of each cell type

Which type of WBC is the most abundant WBC in the peripheral blood of most mammals?

Neutrophil

Which type of WBC is the largest WBC in peripheral blood?

Monocyte

A CBC uses which color top collection tube?

Purple (EDTA)

A blood chemistry panel uses which color top collection tube?

Green (Heparin)

Which color top blood collection tube would be used for coagulation tests?

Blue (Citrate)

Mean Corpuscular Volume (MCV) is an indicator of the _______ of the average RBC

Size

Plasma with a cloudy appearance is characterized as _________

lipemic (fatty)

Plasma with a red tinge is characterized as ____________

Hemolyzed

Which species normally has yellow colored plasma?

Horses

Which cell gives rise to all blood cells?

The pluripotent hematopoietic stem cell (HSC)

Erythropoiesis

Production of RBC that occurs in red bone marrow (adult animals) and in the liver and spleen (fetuses). Erythropoietin is released from the kidney when oxygen levels are low. Stages of maturation are Rubriblast, Protubicyte, Basophilic reticulocyte, Polychromatophilic reticulocyte, Metarubicyte, and Reticulocyte

Rubriblast

The most immature stage of red blood cell development. Contains one or more nuclei and a basophilic cytoplasm.

Prorubicyte

Second stage of RBC maturation. These cells are smaller than Rubriblasts and have a denser cytoplasm with no visible nucleus

Metarubicyte

Smallest cell in the RBC maturation series. These cells have a condenses nucleus and a red cytoplasm. These cells cannot divide. Hemoglobin formation finishes in this stage.

Thrombopoesis

Platelet formation. Controlled by the release of thrombopoietin primarily from the liver, sometimes the kidney. Stages of maturation are Megakaryoblast, Promegakaryocyte, and Megakaryocyte. These cells become so large that the cytoplasm extends into sinuses and is sheared off to create proplatelets which fragment into platelets

Which organ is the primary producer of the cytokine controlling thrombopoiesis?

Liver

Megakaryocyte

Last stage of thrombopoiesis. These cells have several nuclear lobes and a cytoplasm with reddish granules. Cytoplasm is sheared off by bone marrow sinuses to become platelets

Granulopoesis happens in the:

Bone marrow

Which stages of granulocytes are in the proliferation pool?

Myeloblasts, Promyelocyte, and Myelocytes

Which stages of granulocytes are in the maturation pool?

Metamyelocytes and Band cells

Band/stab cells

Last stage of immaturity before becoming a mature granulocyte. These white blood cells have a horseshoe shaped nucleus

Myelocyte

Third stage of Granulopoesis. Myelocytes come from promyelocytes and develop into metamyelocytes. Cells in this stage are small in size and begin the production of granules

Monopoiesis

Production of monocyes. Stages of maturation are Monoblasts, Promonocytes, and Monocytes. Monocytes may become macrophage cells if they interact with certain cytokines

Lymphopoiesis

Production of lymphocytes. Maturation happens in the thymus (T-lymphocytes), bone marrow and other lymphoid tissues (NK lymphocytes), bone marrow, Peyer's patches, and the bursa of fabricius (B-lymphocytes)

-pneia

ending used when blood has a decreased number of cells

Neutropenia

a decreased number of neutrophils

-philia or -cytosis

increased number of cells in the blood

Left-shift

An increase in the number of immature neutrophils in response to disease

Leukemia

Neoplastic cells in the blood or bone marrow

Packed Cell Volume

(AKA hematocrit if done by an analyzer) volume percentage of erythrocytes present in a sample of centrifuged blood

A red ring on a microhematocrit tube indicates:

The tube is heparinized

A blue ring on a microhematocrit tube indicates:

The tube has been untreated

What should you do when reading a PCV result?

Line up the top of the clay plug with the 0 line and read below the buffy coat

A below normal PCV result indicates

anemia or an inadequate amount of blood to anticoagulant in the collection tube

Sodium fluoride

Additive in collection tubes used for preserving blood glucose. This anticoagulant should not be used with enzymatic tests

A well hydrated animal with a 50% PCV should yield a sample that is

50% cells and 50% fluid. A 10ml sample yields 5 ml of fluid

Order of draw for collection tubes

Blue, red, tiger top, green/tan, purple, and grey

Polycthemia/Erythrocytosis

An increase in the number of RBCs in blood

Impedance analyzers

Electronic cell counters that use the impedance method (pass a current of electricity between electrodes separated by a glass tube with a small opening) and count cells in size ranges

Impedance analyzers classify cells based on:

Size

Quantitative Buffy Coat System

A type of hematology analyzer that uses centrifugation and staining to provide a count. Provides a hematocrit value and estimates for WBC and platelet concentration. Main disadvantage in abnormalities in WBC may be undetected unless a blood smear is manually done

Quantitative buffy coat analyzers provide _____________ cell counts

estimated (NOT actual) cell counts

Laser-Based flow Cytometer Analyzer

A kind of analyzer that uses a focused laser to evaluate the size and density of cells. Results are based on the way light scatters when it hits cells. These analyzers can provide erythrocyte indices, EDW, and platelet parameters

Erythrocyte indices are used to diagnose

Different types of anemia

Nonregenerative anemia

Bone marrow is not responding to the need for more RBC production because of bone marrow issues, kidney dz, etc

How do you calculate the Mean Corpuscular Volume (MCV) of a blood sample?

Divide the PCV by 6 to get the RBC concentration ----> divide the PCV by the RBC concentration ----> multiply this number by 10 to get the final value (unit is Femtoliters or fL)

How do you calculate the Mean Corpuscular Hemoglobin (MCH) of a blood sample?

Divide the PCV by 6 to get the RBC concentration ---> divide the PCV by 3 to get the hemoglobin conc ---> divide the hemoglobin conc value by the RBC conc value ---> multiply this number by 10 to get the final value (unit is Pictograms or pg)

How do you calculate the Mean Corpuscular Hemoglobin Concentration (MCHC) of a blood sample?

Divide the PCV value by 3 to get the hemoglobin concentration ---> multiply this number by 100 to get the final value (unit is in grams per deciliter or g/dl)

Erythrocyte indices

Used to classify anemias. This test provides an objective measure of the size and average hemoglobin concentration by comparing the sample to morphologic features

Mean corpuscular volume (MCV) uses the unit

Femtoliters or fL

Mean corpuscular hemoglobin (MCH) uses the unit

Pictograms or pg

Mean corpuscular hemoglobin concentration (MCHC) uses the unit

grams per deciliter or g/dl

Hemocytometers

gridded slide under microscope. Cells can be counted in a known area, and that number can be estimated to find the full volume of a blood sample

An increased PCV result is commonly due to _________________

dehydration

Normal PCV range for dogs

37-55%

Normal PCV range for cats

30-45%

Normal PCV range for horses

32-57%

Normal PCV range for cattle

24-42%

Methemoglobin

Occurs naturally in RBC and in plasma but can be converted into hemoglobin for oxygen delivery

What is the drawing order for blood collection tubes?

Blue (citrate), red, tiger top, green/tan (Heparin), purple (EDTA), and grey/white (Oxalates/Sodium flouride)

Poikilocytes

abnormally shaped erythrocytes

Leukemoid response

Mistaken for leukemia because this condition causes higher than normal leukocyte levels. Usually caused by inflammatory disease

Granules are characteristic of a _________ granulocyte

mature

Schistocytes

fragmented red blood cells formed because of shearing

Blood samples can be frozen. (T/F)

False! Blood samples that cannot be viewed immediately should be refrigerated, not frozen. Freezing can cause lysis of blood cells

Disadvantages to heparin

It interferes with the staining of erythrocytes (meaning it cannot be used for blood smears) and can cause clumping of WBC, clumping of platelets, and interferes with WBC morphology (meaning it shouldn't be used for CBC's)

Disadvantages to EDTA

Causes blood cells to shrink if the tube is underfilled and the anticoagulant to blood ratio is off.

Acanthocytes (Spur cells)

Spiculated RBCs with a few unevenly distributed surface projections. These cells are seen in patients with altered lipid metabolism (dogs with hemangiosarcoma, cats with hepatic lipidosis, etc

Echinocytes (Burr cells)

Spiculated RBC with numerous short, evenly spaced, blunt to sharp surface projections of uniform shape and size. Seen in dogs with lymphosarcoma, after exercise in horses, and in healthy pigs. Also occur after snake bites in dogs or because of prolonged sample storage

Drepanocytes

Sickle shaped cells of angora goats and sheep. Thought to be an in vitro phenomenon caused by high oxygen tension

Keratocytes (Helmet cells)

Presence of these cells is associated with hemangiosarcoma, neoplasia, hepatic diseases, and anemia. May appear to have vacuoles. Caused by intravascular trauma

Spherocytes

Darkly staining RBC with reduced or no central pallor. Not easily identified in species other than dogs. These cells suggest the immune mediated destruction of RBC's which results in hemolytic anemia.

Leptocytes

Characterized by increased membrane surface area relative to cell volume- cells may take a variety of shapes.

Codocytes (Target cells)

Leptocytes with a central area of pigment surrounded by a clear area and then a dense ring of peripheral cytoplasm. May be seen in normal smears but can be associated with anemia, liver dz, and some inherited disorders

Stomatocytes

Folded lepatocyte cells that hae a transverse raised fold that extends across the center of the cell as well as a clear pale region in the center of the cell

Basophilic stippling

Small dark blue inclusions within RBC's. Observed in Wright stained cells and represents residual RNA. Common in immature RBC's in ruminants, occasionally in cats in a response to anemia, and characteristic of lead poisoning

Howell-Jolly bodies

Basophilic nuclear remnants seen in young erythrocytes during the response to anemia. Increased numbers indicates spleen disorders

Bone marrow samples can be described as:

acellular (aplasia), hypercellular (hyperplasia), & hypocellular (hypoplasia)

Which species rarely releases reticulocytes into circulating blood?

Horses

Normocytic anemia is associated with

secondary to acute or chronic disorders

Macrocytic anemia (large red blood cells) is associated with

a temporary increase in response to regenerative anemia

Microcytic anemia (small red blood cells) is associated with

Iron deficiency

Hypochromatic anemia

Anemia where red blood cells have a smaller amount of hemoglobin so they stain a lighter color. Associated with iron deficiency or newly released reticulocytes

Normochromic anemia

Anemia where red blood cells have a normal level of hemoglobin. Cells stain red in color

Iron deficient anemia

Associated with nutritional issues or chronic blood loss. Characterized by microcytic RBC's and a low MCHC value

Production disorders

Disorder where erythropoiesis is reduced or defective. Erythrocytes are normocytic

hemolytic anemia

characterized by an inadequate number of circulating red blood cells due to the premature destruction of red blood cells by the spleen

Wright stains and Wright-Giemsa stains are ______________________ type stains

Romanowsky