Abnormlaities of the erythrom 2 Flashcards Preview

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Flashcards in Abnormlaities of the erythrom 2 Deck (36):
1

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

2

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 ?

3

What is the most common form of haemolyss? Dxx?

> IMHA
- 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

4

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

5

What causes intravascular haemolysis? How is this seen?

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

6

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

7

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)

8

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

9

Dx of mycoplasma haemofelis?

- PCR excellent
- blood smear not reliable

10

Tx babesia?

- Imidocarb

11

Which animals develop Heinz bodies more readily?

Cats
- low number unremarkable in cats

12

What are heinz bodies and how do they appear?

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

13

Causes of Heinz body formation?

- onions
- paracetamol
- Vit K
- propylene glycol

14

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

15

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

16

What are acanthocytes?

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

17

Pre-keratocytes and Keratocytes?

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

18

Spherocytes

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

19

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

20

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

21

Causes of non-regenerative anaemia? FINISH

- chronic disease
- renal
- endocrine
- FeLV

22

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)

23

Is endocrine anaemia a common problem?

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

24

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

25

Causes of aplastic anaemia

- FeLV, estrogen tox, phenylbutazone, chemotherapy, unknown

26

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

27

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

28

What is myelopthisis?

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

29

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

30

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

31

Why is melena particularly bad?

- LOSS of iron (cf. haemothorax etc. where RBC will be recycled)

32

Main 6 questions to ask wrt anaemia?

- mild mod severe?
- regenerative/non?
- macro/microcytic?
- hypo/normochromic?
- specific morphology changes?
- does the sample give you the answer?

33

What is polycythaemia?

= erythrocytosis
- ^ HCT, RBC count and Hbg
> may be spurious or relative
- dehydration (volume contraction) most common
- RBC redistribution (splenic contraction) esp in horses

34

Causes and subgroups of absolute erythrocytosis?

> 1* (polycythemia vera) neoplasia [ in humans all cell lines, in animals RBC only]
- myeloproliferative disorder of erythroid stem cells
- EPO level normal/decreased
- PO2 normal
> 2* (appropriate or innaropriate
- chronic hypoxia
- EPO secreting tumours
- EPO level raised

35

Hyperthyroid cats have ^ RBC - is this pathological?

- technically pathological but normal for the physiological state they are in (higher metabolic rates = higher oxygen demand)

36

What should be submitted alongside EDTA sample? How should this be stored??

Fresh blood smear
- store blood in fridge until analysis (slows changes)
- store smears at room temperature (NOT IN FRIDGE)