A case of thrombotic thrombocytopenic purpura in late pregnancy

TO THE EDITOR: Thrombotic thrombocytopenic purpura (TTP) was first described by Eli Moschowitz about 90 years ago [1]. TTP is caused by a severe deficiency in the protein A disintegrin and metalloprotease with thrombospondin 1 motifs 13 (ADAMTS13), a metalloprotease that cleaves ultra-large von Willebrand factor (vWF) multimers [2]. Deficiency in this enzyme causes the accumulation of large vWF multimers, which increase platelet adhesiveness and impair fibrinolytic activity with subsequent thrombotic occlusion of the microvasculature. TTP is a rare and potentially life-threatening disorder. The incidence rate of suspected TTP-hemolytic uremic syndrome (TTP-HUS) in the general population is 11 cases per 1,000,000 people [3], compared to the estimated incidence of one in 25,000 deliveries [4]. The clinical features of TTP may resemble those of the more common pregnancy complications, such as preeclampsia or of hemolytic anemia, elevated liver enzymes, and low platelet count (HELLP) syndrome. However, the management of TTP is completely different from that of preeclampsia/HELLP. Here, we present the case of a young woman who developed TTP in late gestation.