Lecture 4 - Morphology of RBC Flashcards
what is the morphology of normal erythrocytes
- biconcave disc
- round cell with central pallor: most prominent in dogs
exception: camelids have oral erythrocytes - Anucleate; exception= birds, amphibians, reptiles
what are two RBC associations
rouleaux - look like fallen coin stacks, normal in cats and horses, usually reflects increased protein
agglutination - grape like clusters; concern for immune mediated diseases.
what is anisocytosis
variability in cell size
what poikilocytosis?
variability in cell shape
what are macrocytes?
large RBC
what are macrocytosis?
increased average RBC
what are microcytes
small RBC
what are microcytosis?
decreased average RBC size
what are all polychromatophils reticulocytes but not all reticulocytes polychromatophils?
polychromatophils are all young cells by definition, they have therefore they are all reticulocytes. however some reticulocytes are in the last stages of maturation and will no longer be polychromatic to the naked eye - ie/ can’t see the blue colour but machine can pick it up
what is the difference between aggregate and punctate reticulocytes?
aggregate polychromatophils released in low numbers in healthy dogs 1% and cats 0.4%
punctate reticulocytes - more mature form with only fine reticulum granules. have a long maturation time in cats so up to 10% seen in health
basophilic stippling is seen in the regenerative response, what is it?
aggregation of residual RNA
most common in ruminants
can also indicate lead poisoning or dyserythropoiesis
howell jolly bodies are often seen in a regenerative response, what are they?
nuclear remnants
seen in low numbers in normal horses, cats.
increased numbers are seen with accelerated erythropoiesis, post splenectomy, hypercotisolaemia
can also indicate dyserthropoiesiss
nucleated RBC are often seen in a regenerative response, what are they?
nucleated red blood cells
increased numbers are seen with accelerated erythropoiesis = appropriate metarubricytosis.
increased numbers without region response = inappropriate metarubicytosis = spleen disease, bone marrow injury, lead poisoning, heat stroke
what morphological changes appear with IMHA?
agglutination
perfectly round RBC with no central pallor
heinz bodies are caused by oxidative damage, what are these?
- round structures protrude from membrane
denatured, precipitated haemoglobin
highlighted with NMB stain
cats are more susceptible –> paracetamol
eccentrocytes can be caused by oxidative damage, what are they?
oxidative injury to the erythrocyte membrane, haemoglobin becomes condensed on one side
often seen with heinz bodies
more frequent in dogs
what are some causes of oxidative damage?
toxins - garlic, onions (dogs, zinc (dogs) paracetamol (cats) brassica plants (ruminants) metabolic diseases - hyperthyroidism, diabetes mellitus, lymphoma
what are echinocytes?
spiked erythrocytes
REGULAR spaced spikes
often an artefact of slow drying blood sample on smear
pathologic causes: electrolyte depletion, strenuous exercise, uraemia, glomerulonephritis
what are codocytes? also known as target cells
increased cell membrane to haemoglobin ratio
seen in regenerative response, liver disease, lipid metabolism disorders
central pallor byt Hb in the middle, usually immature floppy membrane in regenerative response
what are acanthocytes?
IRREGULAR membrane projections
causes: splenic disease, liver disease, iron deficiency, intravascular damage (DIC - sheer injury)
what are schistocytes?
cell fragments
causes - intravascular damage due to DIC, haemangiosarcomas, vasculitis, endocarditis, iron deficiency (fragility of cell)
what are ovalocytes?
oval shaped RBC
associated with bone marrow disease, hepatic disease eg/ hepatic lipidosis, PSS
NORMAL In CAMELIDS
what are keratocytes and blister cells?
indicate microvascular antipathy/sheer injury. associated with DIC, iron deficiency, haemangiosarcoma, liver disease, marrow disease
keratocyte is when the blister has popped
