Non-regenerative anaemias Flashcards
(17 cards)
Mild to moderate non-regenerative anaemias
Re-test in 3-5 days to rule out pre-regnerative
Usually secondary to other diseases
Moderate to marked non-regenerative anaemias
Usually due to primary bone marrow disease
Primary bone marrow disorders
Moderate to severe anaemias
Other cells lines (white cells, platelets) may or may not be also affected
Serum/marrow iron also tends to be increased in these disorders
Aplastic anaemia (aplastic pancytopaenia)
Pure red cell aplasia
Leukaemia or other neoplasia
Myelofibrosis
Myelodysplastic syndrome
FeLV
Aplastic anaemia (pancytopaenia)
Damage to the haematopoietic stem cells in the marrow.
The damaged cells are replaced with fat.
Sometimes this damage can be reversed, but the prognosis is generally poor.
Damage can be caused by:
· Infections (parvovirus, FeLV, Ehrlichia canis)
· Drugs (oestrogen [including endogenous – e.g. Sertoli cell tumour], phenylbutazone, TMPS)
· Immune mediated mechanisms (idiopathic)
Leucopenia and thrombocytopenia precede the anaemia due to shorter life span of cells.
Pure red cell aplasia (PRCA)
This is also called intramedullary IMHA, and is caused by selective damage to erythroid precursor stem cells in marrow.
Other cell lines are not affected.
On bone marrow cytology we may see a complete lack of any erythroid cells (erythroid hypoplasia) or maturational arrest in erythroid cell line (develop up to a certain point then stop).
Usually PRCA has an immune mediated aetiology, and it tends to affect dogs, and respond favourably to immunosuppression, although the response can be slow.
In cats, PRCA can occur secondary to FeLV.
Leukaemia
Neoplastic transformation of precursor cells arising in the bone marrow
Any of the cell lines can undergo neoplastic transformation, but most often lymphoid or granulocytic lineages
Clonal proliferation of neoplastic cells results in crowding of the bone marrow
Competition for nutrients leads to reduced normal haematopoeisis
Anaemia, thrombocytopaenia, neutropaenia
Often see atypical neoplastic cells in the circulation
Bone marrow neoplasia
Leukaemia
Dogs with stage V lymphoma
Histiocytic sarcoma
Metastasis of other tumours (mammary carcinomas, MCTs)
Myelofibrosis
Normal haemotopoetic tissue is replaced with fibrous tissue
Reduced erythropoisis and marked non-regenerative anaemia, usually normal white cell and platelet numbers
Often secondary to other cause e.g. PK deficiency or IMHA
Diagnosed on bone marrow core biopsy histopath
Non-regenerative anaemia secondary to other causes
Tend to be mild-moderate
Anaemia of inflammatory or neoplastic disease (AID)
Anaemia od CKD
Anaemia of endocrine disease
Nutritional deficiencies- e.g. iron
Anaemia of inflammatory or neoplastic disease (anaemia of chronic disease)
Most common
Systemic inflammation leads to reduced bone marrow red cell production
- Increased hepcidin production - decreased iron absorption, low serum iron
- Shortened red cell survival due to oxidative damage
- blunted release and response to EPO
Often have inflammatory leukogram, and increased SAA/CRP
Inflammation has to be long standing (weeks) due to long life span of RBCs
Anaemia of chronic kindey disease
Reduced renal mass, fewer peritubular interstitial cells to secrete EPO
May also be reduced RBC life span due to uraemia, and possible chronic GI haemorrhage secondary to uraemia
Should see increased serum urea and creatinine
Anaemia of endocrine disease
Thyroid hormone, cortisol, androgens etc. enhance EPO action
Endocrinopathies associated with decreased levels of any of these (hypothyroidism, hypoadrenocorticism etc) can cause anaemia
Can present with dehydration (haemoconcentration) so masking anaemia
Nutritional deficiencies causing non-regenerative anaemias
Iron, copper, vitamine B12, folate
Iron deficiency anaemia
Iron deficiency can occur following chronic (GI) haemorrhage because red cells contain large quantities of iron.
Dietary iron deficiency is uncommon except in young animals (especially piglets), especially if they have large parasite burdens (e.g. fleas on kittens).
Iron deficiency anaemia is associated with a microcytic, hypochromic anaemia.
Diagnosis of iron deficiency anaemia
· Microcytic, hypochromic anaemia
· Reduced bone marrow iron stores
· Low serum iron concentration
· Normal or high serum total iron binding capacity (TIBC)
Approach to non-regenerative anaemias
Rule out pre-regenerative (recheck in 3-5d)
If severe - bone marrow cytology and core biopsy
If mild to moderate
- check haematology, biochemistry, FeLV/FIV
+/- serum iron/TIBC
+/- vitamin 12/folate
- imaging (for neoplasia)
- bone marrow cytology and core biopsy
How to differentiate iron deficiency from anaemia of inflammatory/neoplastic disease
AID associated with low serum iron, but ALSO with low TIBC (total iron-binding capacity)
