Severity of lymphocytic bronchiolitis predicts long-term outcome after lung transplantation.
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.
Glanville
Allan R
AR
The Lung Transplant Unit, St. Vincent's Hospital, Darlinghurst, New South Wales, Australia. aglanville@stvincents.com.au
Aboyoun
Christina L
CL
Havryk
Adrian
A
Plit
Marshall
M
Rainer
Steven
S
Malouf
Monique A
MA
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