Related Subjects:
|Alpha Thalassaemia
|Anaemia of Chronic Disease
|Aplastic anaemia(AML)
Erythropoietin given s/c can cause aplastic anaemia. For 75% of acquired AA the cause is unknown. Autoimmune causes may respond to immunosuppression.
About
- Causes pancytopenia with bone marrow aplasia
- Two peaks ages 15-25 and elderly
- Potentially fatal with low Hb, WCC, plt
Aetiology
- Aplastic anaemia is the main syndrome of bone marrow failure
- Can be Idiopathic - usually, an immune-mediated process involving cytotoxic T cells
- Resulting in a pancytopenia and a hypocellular bone marrow.
Clinical
- Low Hb Anaemia - tiredness, pallor, fatigue
- Reduced WCC - infections, cough, chest, urine infections
- Reduced platelets - bleeding mucous membranes and skin, petechiae, risk of spontaneous bleeds
- Normal lymph nodes, liver and spleen
Causes
- Idiopathic 40% - immune mediated
- Drugs/Toxins - Benzene, cytotoxics, chloramphenicol, carbimazole, NSAID's, Gold, Erythropoietin given s/c
- Inherited/Congenital - Fanconi's anaemia
- Radiation exposure, Pregnancy
- Myelodysplastic syndrome
- Infections e.g. HIV, TB, Parvovirus B19, EBV
- Paroxysmal nocturnal haemoglobinuria
- Immune - SLE, Graft versus host disease
- Bone marrow destruction - leukaemia, lymphoma, secondary malignancy, myelofibrosis
Investigations
- Blood film: Pancytopenia - low Hb, Low WCC e.g. severe neutropenia, low plt
- Bone marrow trephine: Hypocellular bone marrow or acellular marrow
- Reticulocyte count is low
- Cytogenetics as needed
Poor prognosis
- Mortality > 50% if following persist > 3 weeks
- Platelets < 20 x 109/L
- Neutrophils < 0.5 x 109/L
- Reticulocyte < 40 x 109/L
Severity
- Neutrophils < 0.2 x 109/L
- Platelets < 20 x 109/L
- Reticulocytes < 20x109/L
- Bone marrow cellularity < 25% of normal or haemopoietic cells < 30% normal
Management
- Supportive (Red cells and Leucocyte depleted platelets to avoid alloimmunisation)
- Idiopathic cause: usually treated with immunosuppression. Steroids, Ciclosporin A, Anti thymocyte globulin. Androgens
- Allogenic bone marrow transplant from HLA matched sibling or donor
- Eliminate or treat cause. Prevention and treatment of infection
- Stem cell transplantation: Allogeneic transplants have a success rate of up to 80%
- Immunosuppressive therapy
- EPO and GCSF - not useful