title: Severity of lymphocytic bronchiolitis predicts long-term outcome after lung transplantation.
abstract: BACKGROUND
  Severe and recurrent acute vascular rejection of the pulmonary allograft is an accepted major risk factor for obliterative bronchiolitis.
  
  
  OBJECTIVE
  We assessed the role of lymphocytic bronchiolitis as a risk factor for bronchiolitis obliterans syndrome (BOS) and death after lung transplantation.
  
  
  METHODS
  Retrospective analysis of 341 90-day survivors of lung transplant performed in 1995-2005 who underwent 1,770 transbronchial lung biopsy procedures.
  
  
  RESULTS
  Transbronchial biopsies showed grade B0 (normal) (n = 501), B1 (minimal) (n = 762), B2 (mild) (n = 176), B3 (moderate) (n = 70), B4 (severe) (n = 4) lymphocytic bronchiolitis, and Bx (no bronchiolar tissue) (n = 75). A total of 182 transbronchial biopsies were ungraded (8 inadequate, 142 cytomegalovirus, 32 other diagnoses). Lung transplant recipients were grouped by highest B grade before diagnosis of BOS: B0 (n = 12), B1 (n = 166), B2 (n = 89), and B3-B4 (n = 51). Twenty-three were unclassifiable. Cumulative incidence of BOS and death were dependent on highest B grade (Kaplan-Meier, P < 0.001, log-rank). Multivariable Cox proportional hazards analysis showed significant risks for BOS were highest B grade (relative risk [RR], 1.62; 95% confidence interval [CI], 1.31-2.00) (P < 0.001), longer ischemic time (RR, 1.00; CI, 1.00-1.00) (P < 0.05), and recent year of transplant (RR, 0.93; CI, 0.87-1.00) (P < 0.05), whereas risks for death were BOS as a time-dependent covariable (RR, 19.10; CI, 11.07-32.96) (P < 0.001) and highest B grade (RR, 1.36; CI, 1.07-1.72) (P < 0.05). Acute vascular rejection was not a significant risk factor in either model.
  
  
  CONCLUSIONS
  Severity of lymphocytic bronchiolitis is associated with increased risk of BOS and death after lung transplantation independent of acute vascular rejection.
authors.affiliation: The Lung Transplant Unit, St. Vincent's Hospital, Darlinghurst, New South Wales, Australia. aglanville@stvincents.com.au
authors.forename: Allan R
authors.initials: AR
authors.lastname: Glanville
authors.forename: Christina L
authors.initials: CL
authors.lastname: Aboyoun
authors.forename: Adrian
authors.initials: A
authors.lastname: Havryk
authors.forename: Marshall
authors.initials: M
authors.lastname: Plit
authors.forename: Steven
authors.initials: S
authors.lastname: Rainer
authors.forename: Monique A
authors.initials: MA
authors.lastname: Malouf
mesh_terms: D000328:Adult; D001706:Biopsy / Q000379:methods; D001989:Bronchiolitis Obliterans / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000150:complications / Q000453:epidemiology / Q000473:pathology; D006801:Humans; D015994:Incidence; D016040:Lung Transplantation; D008214:Lymphocytes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011379:Prognosis; D012131:Respiratory Insufficiency / Q000601:surgery; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D015996:Survival Rate / Q000639:trends; D013997:Time Factors