Auto-immune haemolytic anaemia--a high-risk disorder for thromboembolism?

An audit of the effect of anticoagulant prophylaxis in acute exacerbations of severe autoimmune haemolysis was undertaken. All cases of this disorder presenting to one institution over a 16 year period were reviewed. There were 28 patients who had a total of thirty six exacerbations of haemolysis. Anticoagulant prophylaxis had been introduced from 1992 following three cases with fatal pulmonary emboli. Venous thromboembolism occurred in 5 of 15 exacerbations without prophylaxis but in only one of 21 in which prophylaxis was given. It is suggested that auto-immune haemolysis increases the risk of thromboembolism but further studies are required to quantify the risks and to define optimal prophylactic regimens.