First two patients with ulcerative colitis who developed classical thrombotic thrombocytopenic purpura successfully treated with medical therapy and plasma exchange.

The association of ulcerative colitis (UC) and thrombotic thrombocytopenic purpura (TTP) is rare. Only one prior patient with these two syndromes has been reported in the literature. In that case, splenectomy and proctectomy were performed to control the symptoms of TTP. We present two patients with UC who developed TTP and were successfully treated with multiple plasma exchanges (PEXs) in conjunction with medical therapy without the necessity for surgical intervention. Acquired TTP may be another extraintestinal autoimmune feature of UC. TTP in association with UC may be refractory to high-dose steroids and PEX, possibly requiring vincristine and splenectomy, as in the one previously reported case, to achieve remission.