PURPOSE: Presence of pulmonary fibrosis detected on computed tomography may correlate with prognosis in patients with hypersensitivity pneumonitis. Purpose of this study was to establish the prognostic significance of pulmonary fibrosis detected by computed tomography in patients with hypersensitivity pneumonitis.
METHODS: We identified 69 consecutive patients with hypersensitivity pneumonitis diagnosed between January 1997 and December 2002 at Mayo Clinic, Rochester, MN. Patients were stratified into the fibrotic and non-fibrotic groups based on the computed tomographic findings. Fibrosis was defined by the presence of irregular linear opacities, traction bronchiectasis, or honeycombing.
RESULTS: Of 69 patients, 26 were classified as fibrotic and 43 as non-fibrotic. Patients in the fibrotic group were older, had longer symptom duration, were more likely to have crackles on auscultation, more likely to be exposed to avian antigen, and had greater restrictive lung impairment (p<0.05 for all comparisons). There were 11 deaths in the fibrotic and 1 death in the non-fibrotic group (p<0.0001). In the regression analysis, the computed tomography evidence of fibrosis, more severe pulmonary function abnormalities, and the presence of crackles on auscultation were predictive of survival (p<0.05 for all). The presence as well as the extent of fibrosis was associated with increased mortality. The age-adjusted hazard ratio for mortality in patients with fibrosis was 4.6 (95% confidence intervals 2.0-20.1; p<0.0001).
CONCLUSION: Computed tomographic findings of parenchymal fibrosis are associated with reduced survival in patients with hypersensitivity pneumonitis.
CLINICAL IMPLICATIONS: The results of our study provide insight into the prognosis of hypersensitivity pneumonitis and help in identifying those patients who may require intensified measures to avoid antigen exposure.
DISCLOSURE: Viktor Hanak, No Financial Disclosure Information; No Product/Research Disclosure Information