Heparin-induced thrombocytopenia as a cause of prolonged low platelet count in a patient with thrombotic thrombocytopenic purpura treated with plasmapheresis

Thrombotic thrombocytopenic purpura (TTP) is a rare disorder belonging to thrombotic microangiopathies (TMA) and is caused by functional deficiency of metalloproteinase ADAMTS-13. Plasma exchange (PE) remains the treatment of choice in this disease. Here were describe the case of patient who apparently recovered from TTP following multiple sessions of PE, but remained thrombocytopenic. Careful analysis revealed the development of heparin-induced thrombocytopenia (HIT) that precluded platelet count (PLT) normalization. Full normalization of PLT followed discontinuation of PE and low-molecular weight heparin.