Treatment of patients with microangiopathic haemolytic anaemia with heparin

The response of three children and four adult women with microangiopathic haemolytic anaemia to treatment with heparin is described. The one child and three adults treated within 10 days of the onset of the illness recovered rapidly and completely from their anaemia, thrombocytopenia and uraemia. The two children and one adult treated between 18 and 31 days after the onset of the illness responded less well. The two children who were given small doses of heparin died from complications of the renal microangiopathy despite improvement in the haemolysis and thrombocytopenia. The adult woman made a slow and partial recovery; the haemolysis and thrombocytopenia improved, but renal function did not return to normal. The importance of recognizing and treating the low grade intravascular coagulation which may accompany microangiopathic haemolytic anaemia is stressed. It is suggested that the variable response to treatment with heparin of patients with microangiopathic haemolytic anaemia observed by ourselves and others may be due to relative roles of intravascular coagulation and primary vascular disease in the pathogenesis of the microangiopathy, and to the development of irreversible vascular damage if treatment is delayed.