Thrombotic thrombocytopenic purpura: a review of the literature in the light of our experience with plasma exchange.

1 . The disease is now better understood from a pathophysiological point of view even though its rarity (annual incidence of 11.3 cases per 1,000,000 population) 2 and the lack of specificity of the signs, symptoms and laboratory findings make its management difficult. The symptoms, as stated, are non-specific: fever, renal dysfunction (to the point of acute renal failure in some cases), fluctuating neurological disorders (mild headache, onset of behavioural anomalies, transient sensory and motor deficits, coma), possible ischaemic gastrointestinal complications (abdominal pain) and retinal detachment. More than 35% of patients do not have neurological symptoms at onset; fever and renal dysfunction are present in only a small minority of cases. The diagnosis can, therefore, be made in the presence of a microangiopathic haemolytic anaemia (with schistocytes in a peripheral blood smear), thrombocytopenia (from platelet consumption) and increased levels of lactate dehydrogenase (LDH) not due to other identifiable causes