[Thrombotic microangiopathies].

The thrombotic microangiopathic diseases, which include acquired and congenital TTP and HUS, are most frequently acute disease entities. Untreated, these diseases are associated with a lethal course in many cases. Deficiency of the von Willebrand cleaving enzyme, ADAMTS13, is a decisive pathophysiological defect in most cases of thrombotic microangiopathic diseases. Early recognition and a secure distinction from other conditions that resemble TMA diseases is essential in order to institute adequate treatment and to obtain a favourable outcome in terms of both survival and development of serious sequelae.