Flashcards in Haematology 3 Deck (18):
ANAEMIAS OF DECREASED RED CELL PRODUCTION
Can be PRIMARY- hypoplastic/aplastic.
SECONDARY- nutritional deficiency
- inflammatory disease
- chronic renal failure
NUTRITIONAL DEFICIENCY ANAEMIA
eg. protein deficiency- starvation.
-Mineral deficiencies- iron, copper, cobalt.
-Vitamin deficiency- B12, folate.
The above SELDOM cause anaemia in domestic species, APART FROM IRON.
IRON DEFICIENCY ANAEMIA
Seen in veterinary medicine.
Iron is an essential component of haem.
-> iron deficiency interferes with Hb production.
HYPOCHROMIC MICROCYTES are produced.
CAUSES- Decreased iron intake (eg. fast growing large breed puppies, suckling piglets)
- Chronic blood loss (eg. GI ulceration/neoplasia, inflammatory GI disease, parasites, clotting disorders)
Small cells (microcytes) with large areas of central pallor due to decreased Hb concentration and thus decreased staining abilities (hypochromic)
ANAEMIA OF INFLAMMATION
A mild to moderate NON REGENERATIVE anaemia.
may be due to a longstanding process- infectious, malignant or other.
FUNCTIONAL iron deficiency (to inhibit bacteria etc)
Some cytokines may inhibit erythropoeitin production, or bone marrow progenitor cells directly.
ANAEMIA SECONDARY TO RENAL DISEASE
Functional marrow failure is caused by decreased EPO levels (non functioning kidneys cannot produce EPO)
There are other potential factors- anaemia of inflammation.
-Uraemic toxins affect red blood cells and bone marrow.
NORMOCYTIC NORMOCHROMIC ANAEMIA- Cells are of normal size and normal colour; they contain normal levels of HB, there are just fewer of them due to decreased production.
PRIMARY HYPOPLASTIC/APLASTIC ANAEMIAS
Caused by primary marrow dysfunction- CELLULARITY OF BONE MARROW IS DECREASED.
May involve multiple cell lines (erythrocyte, granulocytes, platelets)- APLASTIC.
Or, may only affect red cell line- PURE RED CELL APLASIA.
PURE RED CELL APLASIA
Only red cell line is affected.
-EPO replacement therapy
CLASSIC APLASTIC ANAEMIA
Affects several cell lines.
PANCYTOPAENIA develops- reduction/absence of ALL cell lines.
Reduction or absence of all cell lines.
Development is usually gradual, starting with cells with shorter lifespans.
(granulocytes first, platelets, then erythrocytes.
SELECTIVE DEPRESSION of one or two lineages may occur.
eg. Bracken poisoning in cattle.
Ehrlichia, parvovirus, FeLV
Bleeding calf syndrome (newly recognised)
An abnormally increased red cell mass:
-Increased red cells
Like the opposite of anaemia!
Can be absolute or relative.
ABSOLUTE polycythaemias can be PRIMARY or SECONDARY.
PRIMARY ABSOLUTE POLYCYTHAEMIA
NOT controlled by EPO.
aka. POLYCYTHAEMIA VERA.
Uncontrolled expansion of red cell mass.
Chronic myeloproliferative disorder.
Rare in animals.
SECONDARY ABSOLUTE POLYCYTHAEMIA
IS controlled by EPO.
Excess EPO production is seen; this can be APPROPRIATE or INAPPROPRIATE.
MOST COMMON FORM OF POLYCYTHAEMIA.
Increased RBCs/PCV/HB concentration seen due to DECREASED PLASMA VOLUME.
eg. due to dehydration.
or seen due to SPLENIC CONTRACTION in exciteable/stressed animals (dogs and horses only).
This form is TRANSIENT.
EXCESS EPO PRODUCTION
Seen in secondary absolute polycythaemia.
APPROPRIATE EXCESS EPO PRODUCTION
Hypoxia is fundamental stimulus to EPO production and thus erythropoeisis.
Causes of chronic hypoxia include- CV disease
- Chronic respiratory disease.
INAPPROPRIATE EXCESS EPO PRODUCTION
Seen in kidney neoplasms or non-neoplastic disorders (eg. cysts), and in other, NON RENAL neoplasms.