Long-term Outlook for Thrombotic Thrombocytopenic Purpura

Acquired thrombotic thrombocytopenic purpura (TTP) is an autoimmune disease characterized by microvascular thrombosis associated with autoantibodies against ADAMTS13, an antithrombotic protease. Although great progress has been made in the treatment of TTP and up to 80% of patients survive the acute episode, the frequency of long-term sequelae is uncertain.

To assess morbidity and mortality after recovery from an initial attack of acquired, severe TTP, investigators examined the records of 57 patients enrolled in the Oklahoma TTP-HUS (Hemolytic Uremic Syndrome) Registry. All patients had ADAMTS13 levels <10% during the acute episode.

The findings were as follows:

• At diagnosis, body-mass index and prevalence of systemic lupus erythematosus were higher than in the U.S. reference population (P<0.001).

• During remission, levels of ADAMTS13 activity on one or more occasions were consistently normal in 49% of patients, between 10% and 49% in 24%, and <10% in 27%.

• Between one and four relapses occurred in 37% of patients.

• During a median follow-up of 7 years, new-onset hypertension was recorded in 17 of 43 patients (40% vs. 23% expected; P=0.013).

• Major depression was noted in 7 of 37 patients (19% vs. 6% expected; P=0.005).

• Death occurred in 19% of patients (P<0.05); only one death was associated with TTP relapse.