New strategies in diagnosis and treatment of thrombotic thrombocytopenic purpura: case report and review

The pentad of thrombocytopenia, haemolytic anaemia, mild renal dysfunction, neurological signs and fever, classically characterizes the syndrome of th rombotic thrombocytopenic purpura (TTP). TTP usually occurs in adults but a lso children have been described with this condition. The disorder may take a relapsing course, termed chronic relapsing TTP (CRTTP), which although v ery rare, may also begin in childhood. Deficiency of a recently identified enzyme, the von Willebrand factor (vWF)-cleaving protease, seems to play a major role in the development of TTP. We report on a 3-year-old boy with a dramatic but typical clinical course of CRTTP. At the time of diagnosis, ne urological deficits and multiple cerebral infarctions had already occurred. In plasma; vWF-cleaving protease was completely absent, both during acute TTP and in remission. There was no protease inhibitor detected. Regular inf usions of fresh frozen plasma were successfully given for replacement on a prophylactic basis. Conclusion Assay of von Willebrand factor-cleaving protease helps to diagno se a form of thrombotic thrombocytopenic purpura which may be managed by pr ophylactic treatment with fresh frozen plasma.