22nd July 2024

Aplastic anaemia

This is a disorder whereby the bone marrow ceases to produce stem cells, leading to pancytopenia. It can present with symptoms related to reduction in any of the cell lineages, for example anaemia, infection or bleeding.

An FBC shows evidence of cytopenia (at least 2 cytopenias needed for diagnosis: Hb <100 g/L, platelet <50 10⁹/L, neutrophils <1.5 10⁹/L). Reticulocytes are low as the bone marrow is hypo-productive. Bone marrow biopsy confirms the diagnosis with a hypocellular marrow but no abnormal cell populations or fibrosis (suggestive of leukaemia and myelofibrosis respectively).

Acquired aplastic anaemia is commonly idiopathic, but causes include drugs (chloramphenicol, NSAIDs – indomethacin, gold), viral illness, PNH and SLE.

Treatment varies depending on the severity. Asymptomatic patients may only need observation or supportive transfusions. Severe disease (reticulocytes <50 x10⁹/L, platelets <20 x 10⁹/L and neutrophils <0.5 x10⁹/L) can be cured with a stem cell transplant, however this is reserved for those under the age of 40 who are medically fit, as otherwise prognosis is poor. For those who are likely not able to tolerate stem cell transplantation or those with more moderate disease, treatment with triple therapy (eltrombopag, horse antithymocyte globulin and cyclosporine) is another option. Supportive care is considered for frailer patients (performance status >2).