Abnormlaities of the erythrom 2 Flashcards Preview

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Flashcards in Abnormlaities of the erythrom 2 Deck (36)
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How can you test for meleana?

- meat free diet (red meat) for 5d before test or will be positive
- not always visable blood
- "feacal occult blood" very sensitive but NOT specific


Causes of increased losses?

> haemorrhage (external)
- meleana
- UT
- Epistaxis
- Post-trauma/surgery
> haemorrhage (internal)
- bleeding tumour
- trauma
- into tissue (bleeding diathesis)
- surgery
> haemolysis
- ^ internal RBC destruction
- intra v extravascualr
- normal erythrocytes or abnormal/damaged ?


What is the most common form of haemolyss? Dxx?

- anti-redcell Ab (IgG, IgM, IgA)
- red cells opsonised -> lysis (IgM) or phagocytosis
- may agglutinate
- Coombs test + (for anti RBC Ab)
- may be severe/rapid, usually strongly regenerative


What is seen microscopically with IMHA? Ddx?

> agglutination
- flaky blood macroscopicallly
- grape like bunches of RBC
- in saline agglutination test (screening)
- one drop saline one EDTA anticoagulated blood mix on slide
- look for flecking before starts to dry (will still occour if AGGLUTINATION, will get rid of ROULEUX artefact)
> Ddx = Rouleaux artefact
- stack of coins
- high protein stuck on RBC
- gritty, lumpy macroscopically
- but not pathological


What causes intravascular haemolysis? How is this seen?

> complement mediated
- ghost cells (barey visable, membrane still present, Hbg gone)


What causes extravascular haemolysis?

- macrophages in liver/spleen
- takes bites out of lipid bilayer -> spherical cell (spherocytes) as membrane reforms
- smaller, and very dark (no central pallor)
- normal volume though diameter will appear less


What else may be found with IMHA? Dxxx

- ^ bilirubin (esp with extravascular breakdown)
- neutrophilia, monocytosis (marrow upregulation)
- patelets may also be affected (Evans syndrome IMHA+ platelets)


What parasites may cause haemolysis?

> mycoplasma haemofelis and M. haemominutum (formerly haemobartonella)
- epicellular
- large and small forms
- ^ fragility and hameolysis
- cyclical 3-8 weeks
- not in UK
> Babesia (dogs, USA, mediterranean)
- tick borne dz
- pyriform bodies INSDIE RBC
- haemolytic
> Cytauxzoon felis (US)
- intracellular
- prominant splenic RBC removal


Dx of mycoplasma haemofelis?

- PCR excellent
- blood smear not reliable


Tx babesia?

- Imidocarb


Which animals develop Heinz bodies more readily?

- low number unremarkable in cats


What are heinz bodies and how do they appear?

- denatured/oxidised Hbg
- Little 'nose' on cell, same colour of RBC


Causes of Heinz body formation?

- onions
- paracetamol
- Vit K
- propylene glycol


What are eccentrocytes?

- Hbg uneven distribution within the cell -> eccentric distribution
- oxidative damage to membrane (cf. Heinz - Hbg)
- seen most commonly in dogs, seen horses with red maple toxicosis


What are schistocytes and keratocytes?

- Shear injury products d/t microangiopathic dmage (tumours w/ narrow vessels eg. angiosarcoma) or organ inflammatory beds (severe hepatitis, DIC) d/t fibrin stranding cutting them in half
- Clue to underlying disease vs cause
> schistocytes
- RBC fragments 2* to shear injury
- assoc with fibrin deposition in vessels and DIC


What are acanthocytes?

- surface prjections (spicules)
- variable length, unevenly spacd
- narrow base and blunted
> seen with splenic dz


Pre-keratocytes and Keratocytes?

- red cells with apposed and sealed membrane
- helmet shaped cells
- associated with shearing (intravascular trauma eg. vasculitis, DIC) alongside shistocytes



- extravascular destruction by macrophages taking a bite out -> membrane reforms as a sphere
- darker and smaller, perfectly round
- no central pallor


Give egs of inherited hemolytic dz

> Pyruvate kinase deficiency [Basenjis and Beagles]
- Energy production deficiency
- initially may be very regnerative
- may go on to develop myelofibrosis and acute crisis (death @ 1yr)
- chronic, severe haeolysis
> PFK deficiency [English springers]
- RBC sensitive to alkaline ph : low grade haemolysis with severe episodes superimposed
> feline porphyria


MOst common non-regenerative anemia?

> anaemia of inflammatory/chronic disease
- normocytic, normochromic
- usually mild and lowly progressive
- Fe sequestration (bugs want iron)
- inflam mediators -> shortened erythrocyte survival


Causes of non-regenerative anaemia? FINISH

- chronic disease
- renal
- endocrine
- FeLV


How does renal anaemia occour? Tx?

- EPO production v
- normocytic, normochromic, mild - mod
- impacts quality of life
> Tx: EPO injections (though human so can => immune response)
> aim to ^ PCV (though not to normal)


Is endocrine anaemia a common problem?

- hypothyroid and hypoadrenocorticism
- normocytic, normochromic, mild
- thyroid hormone and cortisol facultative effect on RBC production


How common is FeLV anaemia? How are they linked? What type of anaemia is seen?

- FeLV subgroup C
- 70% anaemic cats!
- selective depression of erythropoeisus
- dyspalstic production
- myeloproliferative dz 'crowding out'
> usually non-specific erythroid hypoplasia
- may be normocytic/chromic but may be macrocytic


Causes of aplastic anaemia

- FeLV, estrogen tox, phenylbutazone, chemotherapy, unknown


What is missing with apastic anaemia? What remains? What is needed to dx this?

- ALL precursors (complete non-regenerative marrow)
- fat, plasma cells and mast cells left
- need core biopsy otherwise cant tell if youve just got a rubbish sample


What is myelodysplasia? What is seen in the marrow?

- type of non-regenerative anaemia (pre-leakaemia)
- adequate cellularity in marrow but abnormal maturation/proliferation of cells (ineffective haemopoiesis)
- in the marrow: erythrocyte macrocytosis, binucleates, maturation defects, giant neutrophils, hypersegmented neuts, macroplatelets
- may progress to leukaemia


What is myelopthisis?

- neoplasia crowding out the bone marrow and altering environment
- usually haematopoetic neoplasia (esp lymphoid)


What is myelofibrosis? Dxx?

- response to injury of fibrous elements of marrow -> dry taps
- may be reactive following prolonged regenerative attempts
- Need core biopsy: reticulin stains up the fibrous elements
- osteosclerosis: cortical bone ^
+- marked extramedullary haematopoiesis


Which dz are exeptions to the non-regenerative type thing..

> iron deficiency anaemia may -> non-regenerative in the long term
> immune mediated attack of RBC precursors no the mature cells -> non-regenerative