Aplastic anaemia and bone marrow failure

Aplastic anaemia (AA) is the main syndrome of bone marrow failure. The term implies failure of production of all three cell lineages with replacement of normal haemopoietic marrow by fat cells. The condition may be inherited or acquired. There is overlap with other causes of bone marrow failure such as hypoplastic myelodysplastic syndrome (MDS). Haemopoietic stem cells are reduced in number and proliferative potential. Emergence of abnormal cell clones is common, including paroxysmal nocturnal haemoglobinuria, MDS and acute myeloid leukaemia. Diagnosis is made by examination of peripheral blood and bone marrow. The blood shows pancytopenia. Remaining cells appear normal morphologically, as do cells in the fatty bone marrow aspirate. A bone marrow trephine is necessary to assess cellularity. Management depends on the correct identification of the type of marrow failure. Support with red cell and platelet transfusions, and prevention and control of infection is needed in most cases. Acquired AA may be managed by immunosuppression (IS) or haemopoetic stem cell transplant from a suitable donor. Inherited syndromes of AA do not respond to IS.