Relapse of thrombotic thrombocytopenic purpura associated with decreased VWF cleaving activity.

Thrombotic thrombocytopenic purpura (TTP) is an uncommon syndrome characterized by reversible, systemic aggregation of platelets in the microcirculation and disseminated microvascular thrombosis. Surgery may precipitate TTP and has been associated with relapse in some patients. However, relapse of this life-threatening disorder is unpredictable.