Autoimmune haemolytic anaemia complicating Mycoplasma pneumoniae infection.

Although a positive direct Coombs' test is common in patients with Mycoplasma pneumoniae infection, manifest haemolysis is rare. A case is presented in which M. pneumoniae infection was followed by severe autoimmune haemolytic anaemia with intravascular haemolysis and haemoglobinuria. The presence of cold haemagglutinins suggests that these autoantibodies caused the haemolysis. Corticosteroid treatment corrected the haemolysis, which was of brief duration. Published data indicate that the mycoplasma agent is capable of altering the I-receptors of normal erythrocytes by haemadsorption and production of a soluble haemolysin.