title: Prognostic value of bronchiolitis obliterans syndrome stage 0-p in single-lung transplant recipients.
abstract: BACKGROUND
  Early diagnosis of bronchiolitis obliterans syndrome (BOS) is critical in understanding pathogenesis and devising therapeutic trials. Although potential-BOS stage (BOS 0-p), encompassing early changes in FEV(1) and forced expiratory flow, midexpiratory phase (FEF(25-75%)), has been proposed, there is a paucity of data validating its utility in single-lung transplantation.
  
  
  OBJECTIVE
  The aim of this study was to define the predictive ability of BOS 0-p in single-lung transplantation.
  
  
  METHODS
  We retrospectively analyzed spirometric data for 197 single-lung recipients. Sensitivity, specificity, and positive predictive value of BOS 0-p were examined over time using Kaplan-Meier methodology.
  
  
  RESULTS
  BOS 0-p FEV(1) was associated with higher sensitivity, specificity, and positive predictive value than the FEF(25-75%) criterion over different time periods investigated. The probability of testing positive for BOS 0-p FEV(1) in patients with BOS (sensitivity) was 71% at 2 years before the onset of BOS. The probability of being free from development of BOS 0-p FEV(1) in patients free of BOS at follow-up (specificity) was 93% within the last year. Of patients who met the BOS 0-p FEV(1) criterion, 81% developed BOS or died within 3 years. The specificity and positive predictive value curves for the BOS 0-p FEV(1) were significantly different between patients with underlying restrictive versus obstructive physiology (p = 0.05 and 0.01, respectively).
  
  
  CONCLUSIONS
  The FEV(1) criterion for BOS 0-p provides useful predictive information regarding the risk of development of BOS or death in single-lung recipients. The predictive value of this criterion is higher in patients with underlying restriction and is superior to the FEF(25-75%) criterion.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Biostatistics, University of Michigan School of Public Health, Ann Arbor, 48109-0360, USA. vlama@umich.edu
authors.forename: Vibha N
authors.initials: VN
authors.lastname: Lama
authors.forename: Susan
authors.initials: S
authors.lastname: Murray
authors.forename: Jeanette A
authors.initials: JA
authors.lastname: Mumford
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Flaherty
authors.forename: Andrew
authors.initials: A
authors.lastname: Chang
authors.forename: Galen B
authors.initials: GB
authors.lastname: Toews
authors.forename: Marc
authors.initials: M
authors.lastname: Peters-Golden
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Martinez
mesh_terms: D001989:Bronchiolitis Obliterans / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D005541:Forced Expiratory Volume; D006801:Humans; D016040:Lung Transplantation / Q000009:adverse effects; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013147:Spirometry; D013577:Syndrome