title: Thrombotic thrombocytopenic purpura is associated with a high relapse rate after plasma exchange: a single-centre experience.
abstract: 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.
  
  
  CONCLUSIONS
  Our results indicate the need for better treatments to reduce the high early relapse rate and significant mortality associated with current therapy.
authors.affiliation: Department of Nephrology, the Royal Melbourne Hospital, Melbourne, Victoria, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Frawley
authors.forename: A P
authors.initials: AP
authors.lastname: Ng
authors.forename: K
authors.initials: K
authors.lastname: Nicholls
authors.forename: S
authors.initials: S
authors.lastname: Cohney
authors.forename: C
authors.initials: C
authors.lastname: Hogan
authors.forename: A
authors.initials: A
authors.lastname: Grigg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010951:Plasma Exchange / Q000009:adverse effects*; D011697:Purpura, Thrombotic Thrombocytopenic / Q000150:complications / Q000401:mortality / Q000628:therapy*; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome