Thrombotic thrombocytopenic purpura is associated with a high relapse rate after plasma exchange: a single-centre experience.

BACKGROUND: Thrombotic thrombocytopenic purpura (TTP) is a rare condition characterized by microangiopathic haemolytic anaemia, thrombocytopenia, renal and/or neurological dysfunction secondary to microvascular or macrovascular thrombosis. Despite advances in treatment, TTP remains a serious condition with significant morbidity and mortality.

METHODS: We undertook an audit of patients with TTP over 14 years to assess remission, relapse, survival and factors predictive of outcome using current therapy based on plasma exchange with fresh-frozen plasma.

RESULTS: Forty patients were identified between January 1992 and December 2005. Thirty-one (82%) achieved complete response (CR) to therapy using plasma exchange with fresh-frozen plasma (median 11 exchanges) and steroids. Twelve (37%) relapsed a median of 14 days following cessation of therapy, with multiple relapses occurring in two patients. TTP-related death occurred in four patients during their initial presentation and in two during subsequent relapse. Four patients were only partially responsive to first-line therapy. The absence of neurological features at presentation was the only factor predicting a sustained CR to first-line therapy (P = 0.027, log-rank analysis). The mean duration of inpatient treatment was 18 days (range 4-38 days) with 30% of patients requiring intensive care admission. Thirty-four per cent of patients acquired central venous line infection, with a median of two episodes of line sepsis per patient.

CONCLUSION: Our results indicate the need for better treatments to reduce the high early relapse rate and significant mortality associated with current therapy.