The effect of pulmonary fibrosis on survival in patients with hypersensitivity pneumonitis.
OBJECTIVE
To determine the effect of pulmonary fibrosis on survival in an unselected group of patients with hypersensitivity pneumonitis.


METHODS
We identified 72 patients with hypersensitivity pneumonitis confirmed by surgical lung biopsy in the database of the Clinical Interstitial Lung Disease Program at the National Jewish Medical and Research Center. All biopsy specimens were scored according to the presence or absence of fibrosis. Comparisons were made between patients with (fibrotic group) and without (nonfibrotic group) pathologic fibrosis. Vital status was ascertained and Kaplan-Meier curves were plotted. Cox regression analysis was used to determine predictors of survival.


RESULTS
Forty-six patients were classified as fibrotic and 26 as nonfibrotic. Twenty-nine percent had exposure to a bird antigen, 33% had exposure to a microbial antigen, and 38% had unknown exposure. Patients with fibrosis were significantly older, showed greater restrictive lung physiology, and had greater all-cause and respiratory mortality. Median survival in fibrotic patients was 7.1 years, which was significantly less than survival in those without fibrosis. In an age-adjusted regression analysis, antigen class, symptom duration, and lung function had no effect on survival. Only the presence of pathologic fibrosis was predictive of increased mortality (hazard ratio = 6.01; 95% confidence interval: 1.68 to 21.45; P = 0.006).


CONCLUSIONS
Pulmonary fibrosis is associated with diminished survival in patients with hypersensitivity pneumonitis.
Vourlekis
Jason S
JS
Lung and Upper Aerodigestive Cancer Research Group, Division of Cancer Prevention, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA.
Schwarz
Marvin I
MI
Cherniack
Reuben M
RM
Curran-Everett
Douglas
D
Cool
Carlyne D
CD
Tuder
Rubin M
RM
King
Talmadge E
TE
Brown
Kevin K
KK
D000542:Alveolitis, Extrinsic Allergic / Q000401:mortality* / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011658:Pulmonary Fibrosis / Q000150:complications* / Q000453:epidemiology*; D018709:Statistics, Nonparametric; D015996:Survival Rate; D014481:United States / Q000453:epidemiology