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90 terms

Clin Path Exam 1

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What are the 3 major physical abnormalities of plasma in a PCV tube?
lipemia, hemolysis, anemia, remember yellow plasma is normal in ruminants due to diet
How many platelets should you count on a blood film in the high power (1000X) field?
6-10
What do macroplatelets look like? Are they diagnostic?
They approach or pass the length of an RBC, they suggest accelerated platelet regeneration in DOGS but not cats
Red top serum collection tube?
no anticoagulant, want the blood to clot so serum can be harvested
Lavender top blood collection tube?
contains EDTA, used for blood collection for hematological studies, most consistently preserves morphologic features
Green top blood collection tube?
heparin tube, used for blood undergoing biochemical tests, esp. whole blood that may be exposed to other chemical anticoagulants
Blue top blood collection tube?
sodium citrate, blood samples used for coagulation biochemistry determinations
Sure sep tube?
red and black top, no anticoagulant but contains gel to separate packed cells during centrifugation
Gray top blood collection tube?
fluoride, not an anticoagulant but prevents RBCs from metabolizing glucose during transport of whole blood
What are the storage procedures for blood?
- what happens at room temp?
- what happens if frozen?
- what happens if blood:anticoagulant ratio is off?
- how/when do you store serum?
analyze for CBC within 1 hour, otherwise make blood film for later; blood in EDTA does not store well; blood cells swell at room temperature; blood cells lyse if frozen; underfilled EDTA tube will throw off ratio of blood:anticoagulant and RBCs shrink; refrigerate serum if not used right away because of glucose metabolism, freeze if not using for within 24-48 hours
What is a young neutrophil called?
metamyelocyte
What is unique about the cow neutrophil?
the cytoplasmic granules are often orange/pink
What unique about the cow lymphocyte?
ruminants have larger sized lymphocytes, may have granular cytoplasms
Describe the appearance of a reactive lymphocyte.
reactive lymphocytes have basophilic cytoplasm and irregular shaped nucleus
How can you distinguish a monocyte from a neutrophil?
- the chromatin of a monocyte's nucleus is usually less condensed than the neutrophil's chromatin
- the monocyte is usually larger than the neutrophil
- the monocyte is usually more "grayish" compared to the neutrophil
- fine light purple cytoplasmic granules are normal in the monocyte
Which WBC is the most often misidentified?
the monocyte
Describe the canine eosinophil.
variable size and number, some as large as RBCs, some granules wash out during staining and leave an empty vacuole (common in the greyhound)
When you report a differential leukocyte concentration, what are the units?
cells per uL
Where does production of granulocytes occur:
- in the adult?
- in the patient with chronic inflammation?
- in the young animals?
- adult: bone marrow
- inflammed: bone marrow, spleen, liver, lymph node
- young: bone marrow and spleen
What is the GM stem cell and what does it differentiate into?
GM stem cell = granulocyte-monocyte stem cell
differentiates to blood granulocytes which include neutrophils, eosinophils, basophils; and monocytes.
What are the 6 "life stages" of a neutrophil and their distinguishing characteristics?
1. myeloblast - committed to granulocyte prod.
2. progranulocyte - see primary azurophilic granules
3. myelocyte - secondary granules to distiguish neutrophil, eosinophil, basophil
4. metamyelocyte - loss of ability to undergo cell division
5. band neutrophil - young circulating neutrophil
6. segmented neutrophil - progressively developed band
What is orderly production versus disorderly production of granulocytes?
orderly = more mature circulating granulocytes that immature
disorderly = more immature circulating granulocytes than mature
What is the normal time from myeloblast to segmented neutrophil? What is the time during an inflammatory response?
normal = 7 days
inflammatory response = 2-3 days
What is the normal circulation time for neutrophils (release from bone marrow to migration into tissue)?
6-10 hours, so blood neutrophils normally renewed 2-3 times per day
What is a left shift (when referring to neutrophils)?
increased concentration of immature (band) neutrophils in the blood
What are the 3 classes of lymphoproliferative disorders?
lymphosarcoma/sarcoma (solid tissue)
lymphoproliferative leukemia (bone marrow/blood)
myeloma (disorder from B cell -> plasma cell differentiation)
What are the 5 classes of myeloproliferative disorders?
1. erythroid ---> erythemic myelosis
2. granulocytic-monocytic ---> granulocytic-monocytic leukemia
3. megakaryocytic ---> megakaryocytic leukemia
4. osteoblastic/fibroblastic ---> osteosclerosis and myelofibrosis
5. poorly differentiated ---> poorly differentiated leukemis, reticuloendotheliosis
Describe the appearance and cause of neutrophil toxic change.
cytoplasmic basophilia, Dohle bodies and cytoplasmic vacuolization, common in cats, caused by premature neutrophil release during inflammatory response, but neutrophils still have normal function
Too many hypersegmented neutrophils in the blood is likely caused by?
the steroid effect, causing abnormal neutrophil retention in circulation
What does neutrophil degeneration look like? What is it often caused by?
see cytoplasmic vacuolization, nuclear swelling, usually an artifact on a blood film made from aged blood (longer than 12 hours after collection)
What is the common cause of lymphocyte vacuolization?
Swainsonine (Locoweed) toxicity
Your patient is a 2 year old neutered mixed breed dog, his leukogram shows a large concentration of immature band neutrophils, but you have ruled out inflammatory diseases and the animal is otherwise healthy. What condition could this animal have?
Pelger Huet anomaly, genetic disorder.
What is the Pelger Huet anomaly?
have immature band or myelocyte nucleus but mature chromatin pattern, a genetic disorder but individual is otherwise healthy
What is the Birman Cat Neurophil Granulation anomaly? What other disorder is it often confused with?
eosinophilic fine granules, but normal cell function and animal is healthy, can be confused with Mucopolysaccharidosis which is a toxic granulation (granules usually more coarse with mucopolysaccharidosis)
Your patient is a 6 month old female kitten, presents with dwarfism, degenerative joint disease, facial dysmorphia, hepatomegaly, corneal clouding, enlarged tongue, heart valve thickening, and increased glycosaminoglycans in her urine. Her leukogram shows metachromatic granules in leukocytes, the lymphocytes have dark purple granules and vacuoles. What is the most likely condition that this animal has? What is the prognosis?
Mucopolysaccharidosis, a lysosomal storage disorder, the animal may live several years.
What are the characteristics of mucopolysaccharidosis?
a lysosomal storage disorder with dark granules in leukocytes, and lymphocytes have granules and vacuoles; clinical signs include dwarfism, degenerative joint disease, facial dysmorphia, enlarged tongue, hepatomegaly, corneal clouding, heart valve thickening, and increased glycosaminoglycans in the urine
Your patient is a 3 year old spayed Persion, has bleeding tendencies due to an abnormal platelet function, see large fused pink lysosomes in the neutrophils. What is your most likely diagnosis?
Chediak Higashi syndrome
Describe the Chediak Higashi syndrome.
large, fused, pink lysosomes in neutrophils, cats have tendency to bleed, common in Persians, cat usually remains healthy
What is the significance of inherited lymphocyte cytoplasmic vacuolization?
results in progressive neurological disease, is fatal
3 main causes of neutrophilia?
inflammation, stress, excitement
Which species commonly shows neutropenia with inflammation? In which species does neutropenia indicate emergency?
neutropenia common cow because they have very low marrow reserve, but the dog has high marrow reserve and neutropenia indicates emergency
What neutrophil response is seen to cellulitis (due to bite wound, etc.)?
there will be a balance between consumption and production of neutrophils and the leukogram will show normal neutrophil levels
What neutrophil response is seen to acute peritonitis?
major neutrophil consumption so see neutropenia with prominant left shift
What neutrophil response is seen to a closed caviuse of ty inflammatory lesion (ex: pyometra)?
high neutrophilia
What are the characteristics of an excitement response leukogram? Which species most commonly shows an excitement leukogram?
epinephrine release causes shift of WBCs from margination pool to circulation, so approximate doubling of WBCs, this response is most frequent in cats, see in large animal that had blood drawn after over-exercise
What are the characteristics of a stress leukogram?
- most consistent finding: lymphopenia (steroids induce lymphocyte apoptosis)
- 2nd most consistent finding: doubled neutrophils with hypersegmentation
What are the 2 major causes of lymphocytosis?
excitement and lymphocytic leukemia
What is the typical lymphocyte concentration in a dog with lymphocytic leukemia? What about it cats?
Dogs -> 12000 lymphocytes per uL
Cats -> 20000 lymphocytes per uL
Lymphocytosis does NOT usually accompany inflammation, what is the exception?
In chronic canine Ehrlichiosis, see high proportion of large granular lymphocytes (30000-40000 in dogs)
What is the appearance of the leukogram of a patient with BLV (bovine leukemia virus)?
see bovine persistent lymphocytosis with concentration of 7500 cells/uL, usually normal cell morphology, often progresses to lymphocytic leukemia or lymphosarcoma
What are the 5 major causes of neutropenia?
1. acute inflammation
2. acute viral infection
3. acute marrow injury
4. chronic marrow injury
5. immune mediated destruction
What are the characteristics of a CBC from the Canine Parvovirus or Feline Panleukopenia patient?
neutropenia mainly due to stem cell injury, but also due to neutrophil consumption at GI injury, marrow repopulation occurs before thrombocytopenia and anemia develop
What are the 2 most common chemical/drug toxicities that cause neutopenia accompanied by thrombocytopenia and nonregenerative anemia?
Estrogen or Phenylbutazone toxicity
What are the 3 major causes of irreversible stem cell injury that results in neutropenia, nonregenerative anemia, and thrombocytopenia?
1. FIV
2. Idiopathic hypoproliferative disorder
3. Myelodysplasia
Which species never displays polychromatophilic RBCs? Why?
Horses, because they do not release immature cells into circulation. The only evidence of RBC regeneration in the horse may be macrocytosis.
Define anisocytosis.
variable RBC size
What is the most common cause of microcytic RBCs?
iron deficiency anemia
Dogs with a portocaval shunt display what RBC morphology?
microcytosis
Which 2 dogs breed normally display microcytosis?
Akita and Sheba Inu
What is the appearance of a torocyte?
"punched out"
Macrocytic RBCs are usually accompanied by polychromasia, what disease often displays macrocytosis with NO polychromasia?
The anemic cat with myelodysplasia due to FeLV
Hereditary stomatocytosis is prevalent in what dog breeds? What is the appearance of the RBC?
Prevalent in Poodles, Alaskan Malamutes, and Schnauzers, stomatocytes are uniconcave with mouth-like clear area near center, accompanied by macrocytosis and sometimes presence of Howell-Jolly bodies (round dark blue inclusions, nuclear remnants in RBCs), also see hypersegmented neutrophils. The Alaskan malamute also has chondrodysplasia but the Poodle/Schnauzer are usually asymptomatic.
Define poikilocytes.
abnormal shaped RBCs
What 2 conditions display schistocytes and keratocytes? Why?
DIC and Iron deficiency. Iron deficient RBC develops blister/vacuole due to oxidative injury, lesion enlarges and breaks becoming the schistocyte.
What causes acanthocytes to form?
change in lipid in the cell membrane causes the spurred/spiculated appearance. See in cats with hepatic lipidosis and dogs with hemangiosarcoma.
What characteristic shape do red blood cells take with rattlesnake envenomation?
echinocytes, then spherocytes
What conditions display spherocytosis?
IMHA, bee sting, late stage rattlesnake envenomation, zinc toxicosis, Heinz body anemia
What is the hallmark characteristic of RBCs in IMHA?
spherocytosis
What are the appearance and causes of eccentrocytes?
shifting of Hg to one side with loss of central pallor, see with Heinz bodies in dogs and onion toxicity.
What is the appearance/cause of a leptocyte?
leptocytes have too much membrane for their contents, often form in vitro due to contact to EDTA
What is the "target shaped" RBC called?
codocyte, it is not significant, seen in dogs with high cholesterol
Which species displays Heinz bodies in the normal healthy blood cells?
cats, 1-2% RBCs in the healthy cat contain Heinz bodies, because they have more sulfhydryl groups in the Hg than other species
What is the cause of basophilic stippling? What does it indicate?
pyrimidine 5' nucleotidase usually catabolizes ribosome but the enzyme is reduced in ruminants so see persistent aggregation as basophilic granules (basophilic stippling). Also see in lead toxicosis.
Lead toxicosis leads to what appearance of RBCs?
basophilic stippling due to reduced pyrimidine 5' nucleotidase which is needed to break down the ribosomes
What is a Howell-Jolly body and when are they seen?
A round dark blue RBC inclusion, variable sized nuclear remnants. See with regenerative anemia or splenectomy.
What are siderotic granules and when do you see them?
iron granules in mitochondria/ribosomes, due to impaired heme synthesis, see with chloramphenicol therapy, myelodysplasia, or ineffective erythropoiesis
See periodic weakness in a dog, think?
hemangiosarcoma (abdominal bleeding) acanthocytes
Thrombocytopenia with platelet count at what level results in bleeding?
25,000 platelets per uL or less
What is the most common cause of iron deficiency anemia?
chronic blood loss
Which breeds are predisposed to IMHA?
cocker spaniel, poodle, collie
IMHA in the horse is often associated with what 3 conditions?
1. treatment with penicillin/antibiotic
2. Clostridial infection
3. Neoplasia
IMHA in the cat is often associated with what 3 conditions?
1. Haemobartonella felis (Mycoplasma felis)
2. FeLV
3. Myeloproliferative/Lymphoproliferative disorders
What are the lab findings in a patient with IMHA?
decreased PCV, RBC count and Hg, hemoglobinuria, hyperbilirubinemia, and bilirubinuria. often thrombocytopenia with secondary DIC. leukogram almost alway inflammatory with increased band neutrophils.
What is the prognosis for a patient with IMHA?
20-50% mortality, death often due to thromboembolism
What is the form of IMHA in neonates due to maternal antibodies against neonates blood group antigen?
Neonatal Isoerythrolysis, most common in the horse
What are the 3 types of organic material (plants) that cause Heinz body anemia?
onion/garlic (decrease glutathione which increases oxidation of Hg), cabbage/kale/rape, wilted red maple leaves.
What are the 7 major drugs/chemicals can cause Heinz body anemia?
acetaminophen, propylene glycol, zinc, Cu, selenium deficiency, methylene blue, crude oil
What is the concentration of phosphate in the blood if the patient is suffering from severe hypophosphatemia? What are the 3 conditions that predispose to hypophosphatemia?
concentration less than 1 mg/dL, post-parturient hemoglobinuria, diabetes in cats (due to phosphorus loss with PU), and enteral alimentation in cats (unknown cause)
Signs of pruvate kinase deficiency.
regenerative anemia, 1/2 of RBCs may be reticulocytes, death by myelofibrosis or hepatic failure by 3-5 years of age, see osteosclerosis but NOT in the cat so cats will live longer with this condition
Signs of phosphofructokinase deficiency.
lack of lactate prod and accum of glycogen in muscle, see exercise induced anemia/muscle cramps, life expectancy is normal