title: Improved survival with plasma exchange in patients with thrombotic thrombocytopenic purpura-hemolytic uremic syndrome.
abstract: OBJECTIVE
  Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are uncommon disorders that are generally fatal if left untreated. Plasma exchange therapy is associated with high response rates and improved short-term survival, but most previous studies have been limited by small numbers of patients or short duration of follow-up.
  
  
  METHODS
  We performed a retrospective cohort analysis in 126 consecutive patients with thrombotic thrombocytopenic purpura/hemolytic uremic syndrome, most of whom were treated principally with plasma exchange at the Sacramento Medical Foundation Blood (Center and the University of California Davis Medical Center between 1978 and 1998. We measured the effect of therapeutic plasma exchange on 30-day mortality, response rate, and overall survival, and determined which factors were associated with 30-day mortality and relapse.
  
  
  RESULTS
  The overall 30-day mortality was 10% of the 122 patients who received plasma exchange as their principal treatment (a median of 9 exchanges and a mean cumulative infused volume of 43 +/- 77 L fresh frozen plasma); 56% were complete responders and 21% were partial responders. The relapse rate was 13%. The estimated 2-year survival was about 60%; among patients without serious underlying comorbid conditions, the estimated 2-year survival was about 80%. Each unit increase in clinical severity score (on a 0 to 8 scale) was associated with a 2.2-fold (95% confidence interval [CI]: 1.3 to 3.9) increase in the odds of 30-day mortality. Patients who were febrile at presentation were substantially less likely to suffer a relapse (odds ratio = 0.2; 95% CI: 0.03 to 0.9).
  
  
  CONCLUSIONS
  Plasma exchange therapy produced high response and survival rates in this large cohort of patients with thrombotic thrombocytopenic purpura/hemolytic uremic syndrome. The Clinical Severity Score may be useful in predicting 30-day mortality, whereas fever at onset was associated with a lesser risk of relapse. Prospective studies should stratify patients according to these prognostic factors.
authors.affiliation: Division of Hematology-Oncology, University of California Davis School of Medicine, UC Davis Cancer Center, Sacramento 95817, USA.
authors.forename: P N
authors.initials: PN
authors.lastname: Lara
authors.forename: T L
authors.initials: TL
authors.lastname: Coe
authors.forename: H
authors.initials: H
authors.lastname: Zhou
authors.forename: L
authors.initials: L
authors.lastname: Fernando
authors.forename: P V
authors.initials: PV
authors.lastname: Holland
authors.forename: T
authors.initials: T
authors.lastname: Wun
mesh_terms: D000328:Adult; D000368:Aged; D003404:Creatinine / Q000097:blood; D005260:Female; D006417:Hematuria / Q000209:etiology; D006454:Hemoglobins; D006463:Hemolytic-Uremic Syndrome / Q000150:complications / Q000401:mortality* / Q000628:therapy*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000209:etiology; D010951:Plasma Exchange; D010976:Platelet Count; D011379:Prognosis; D011507:Proteinuria / Q000209:etiology; D011697:Purpura, Thrombotic Thrombocytopenic / Q000150:complications / Q000401:mortality* / Q000628:therapy*; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D006454:Hemoglobins; D003404:Creatinine