Survival of patients with biopsy-proven usual interstitial pneumonia and nonspecific interstitial pneumonia.

This is the first Australian study to examine survival and clinical characteristics in biopsy-proven idiopathic interstitial pneumonia. A cohort of 70 patients from a single institution between January 1990 and December 1999 was reviewed. All patients were Caucasian, 23 (33%) female. Mean age+/-SD at diagnosis was 60+/-12 yrs for males and 54+/-14 yrs for females. A total 24% of patients had never smoked. The histopathological diagnoses were usual interstitial pneumonia (UIP) (n=59), nonspecific interstitial pneumonia (NSIP) (n=7), desquamative interstitial pneumonia (n=3) and acute interstitial pneumonia (n=11). Clinical and functional characteristics of the two main histological subgroups of UIP and NSIP showed significantly older patients in the UIP group and a significantly lower mean forced expiratory volume in one second (FEV1) in the NSIP group. Median survival for UIP was 78 months compared with 178 months for NSIP. No survival difference between treated and untreated patients with UIP was found. Multivariate analysis revealed smoking alone to be predictive of poorer survival. This study demonstrates the best median survival for usual interstitial pneumonia of available series and confirms a survival difference between usual interstitial pneumonia and nonspecific interstitial pneumonia. Furthermore, the reported results may have implications for treatment timing using conventional protocols currently recommended.