Erythrocyte Flashcards
Pathogenesis of Extracellular Hemolytic Anemia
- Initiating event (immune, metabolic, traumatic, oxidative)
- Macrophages recognize and destroy RBCs
——> Anemia
- Macrophages degrade Hb to bilirubin
—–> Icterus
——–> Bilirubinuria
Pathogenesis of Hemolytic Icterus
- Macrophage destructin of RBCs results in unconjugated Bilirubin to enter plasma and bind to albumin
- Bu/Alb complex transported to liver
—> Hyperbilirubinemia (Bu) (if incomplete removal)
- Bu enters hepatocytes and is conjugated (Bc)
- Bc excreted in bile
- Bc may be regurgitated to plasma if formation > excretion
—> Hyperbilirubinemia (Bc)
- Bc passed through kidneys, excrete
—-> Biliruninuria
If your patient is icteric, what type of anemia will you suspect (intra- or extravascular)
Extravascular
The icterus is caused by macrophages destroying RBCs and then degrading Hb to bilirubin
Pathogenesis of intravascular hemolytic anemias
- Initiating event (immune, metabolic, oxidative)
- Marked damage to RBC membrane and lysis of RBCs in blood
—–> Anemia
- Hb in plasma
——> Hemoglobinemia
Pathogenesis of hemoglobinemia
Starts with intravascular hemolysis. Hb is present in plasma and unstable. 3 things can happen next
- Hb binds to haptoglobin (Hpt) —> Hb/Hpt complex removed
- Hb binds to hemoplexin (Hpx) —> Hb/Hpx complex removed
- Too much Hb released so….
—–> Hemoglobinemia
—–> Hemoglobinuria
Hemoglobinemia and hemoglobinuria are associated with what type of anemia (intra- or extravascular)
Intravascular - RBCs lyse and Hb accumulates in blood/passes through urine
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Antibodies (especially colostral Abs in horses) are a cause of what type of hemolysis
Extravascular
Mycoplasma and Anaplasma cause what type of anemia
Extravascular hemolytic anemia
Penicillin causes what kind of hemolysis
Intravascular (and then extravascular)
Heinz bodies are found in what type of hemolytic anemia
Intravascular (and then extravascular)
Your patient has tons of Eccentrocytes. What type of anemia do you suspect
Intravascular hemolytic anemia
(extravascular hemolytic anemia will follow)
Hypophosphatemia causes which kind of anemia
Extravascular
(PO4 needed for major metabolic pathways. Without PO4 —> reduced ATP –> membrane cant repair –> extravascular hemolysis)
A dairy cow recently gave birth and you now worry she is anemic. Based on this information, what may be causing this and why type of anemia is she suffering from?
She may be suffering from post-parturient hypophosphatemia, which would cause extravascular (??) hemolytic anemia
What is a common cause of hypophosphatemia in dogs and how will this effect the dog?
Hyperinsulinemia drives PO4 into cells (ie myocytes), resulting in hyphosphatemia and intravascular hemolysis
What does L-sorbose intoxication cause?
It cause hypophosphatemia
L-sorbose binds to PO4 and inhibits glycolysis —> Reduced ATP —> Reduced membrane repair
—> Intravascular hemolysis
Agglutinated RBCs will cause artefact to which indice
MCV –> agglutination results in increased MCV
What are Wintrobe’s formulas
- MCV
- MCH
- MCHC
Can you calculate the hematocrit?
Yes: MCV x [RBC] / 10
Which stain is best for reticulocytes
Methylene Blue
Whats reticulocyte percentage
# reticulocytes / 1000 RBCs
(counted)
Whats Corrected Reticulocyte Percentage (CRP)
It compensates for the degree of anemia
RP X (Hct/Average Hct for spp)
Tells you what reticulocyte percentage would be if animal were not anemic (as anemia = fewer RBCS = platelets will seem more plentiful)
Whats a disadvantage of corrected reticulocyte percentage
It assumes a normal hematocrit
–> this may not be normal for all animals. (ie greyhounds have higher PCV than other dog breeds)
What is reticulocyte concentration
It is used if reliable [RBC] is available
RP x [RBC}
What is appropriate rubricytosis
- Seen in regenerative anemias
- Regenerative blood cells following blood loss or hemolysis
What is inappropriate rubricytosis
Regeneration of RBCs without anemia or in non-regenerative anemia
Causes of inappropriate rubricytosis
- Marrow damage, inflammation, necrosis
- Lead poisoning in dogs
- Extramedullary hematopoiesis, splenic contraction (horses), splenectomy
RBC lifespan for cats, dogs, cows, horses
Cats: 70d
Dogs: 100d
Cows: 280d
Horses: 450d
Which species have a sinusoidal spleen? What’s the clinical significance?
Dogs, horses
- Pools of blood can be released quickly*
- More efficient removal of old, damaged RBCs (by macrophages outside spleen)*
What’s a morphological sign of regenerative anemia in cows?
Basophillic stripping (Ribosomal RNA that isnt degraded)