The remarkable diversity of thrombotic thrombocytopenic purpura: a perspective.

Understanding the autoimmune etiology of acquired thrombotic thrombocytopenic purpura (TTP) has provided precision for the diagnosis and a rationale for immunosuppressive treatment. These advances have also allowed recognition of the remarkable clinical diversities of patients' initial presentations and their long-term outcomes. These diversities are illustrated by the stories of patients from the Oklahoma TTP Registry. The initial presentation of TTP may be the discovery of unexpected severe thrombocytopenia in a patient with minimal or no symptoms. The patient may remain asymptomatic throughout treatment or may die suddenly before treatment can be started. ADAMTS13 activity may be reported as normal in a patient with characteristic clinical features of TTP, or the unexpected report of ADAMTS13 deficiency in a patient with another established disorder may lead to the discovery of TTP. ADAMTS13 activity during clinical remission is unpredictable. ADAMTS13 activity may recover and remain normal, it may remain severely deficient for many years, or it may become normal only many years after recovery. Our treatment of initial episodes and management of patients after recovery and during remission continue to change. The addition of rituximab to the treatment of acute episodes and preemptive rituximab for patients with severe ADAMTS13 deficiency during remission are reported to prevent relapse. Because TTP is uncommon, there are few data to guide these changes. Therefore our patients' stories are profoundly influential. Their stories are the foundation of our experience, and our experience is the guide for our decisions.