Steroid treatment based on the findings of transbronchial biopsy in idiopathic interstitial pneumonia

This study was performed to find the rationale for administering steroids to patients with idiopathic interstitial pneumonia (IIP), which was unlikely to be usual interstitial pneumonia (UIP) but was not surgically biopsied. Among IIP patients in the file of the departments, nine patients who met the following criteria were selected for this study (“non-UIP” group): 1) transbronchial lung biopsy showed dense mononuclear cell infiltration in thickened alveolar septa; 2) chest radiograph and computed tomography showed irregular linear, reticular or ground-glass opacities with alveolar consolidation without honeycombing in the lung base; and 3) spirometry was performed before and after steroid therapy. Ten patients with pathologically confirmed nonspecific interstitial pneumonia (“NSIP” group) were also selected for the comparison. Baseline values and percentage increase of vital capacity (VC) after steroid therapy were plotted. Steroids improved VC in both groups of patients. After 1 yr of steroid therapy, percentage increase of VC in “non-UIP” was 28.8±7.7%, which was not significantly different from that in NSIP (30.0±11.7%). One “non-UIP” patient and one NSIP patient died after 6.4 and 4.3 yrs of follow-up, respectively. Patients with idiopathic interstitial pneumonia presenting cellular interstitial pneumonia in transbronchial lung biopsy, in addition to radiographic findings not typical for usual interstitial pneumonia, could expect a beneficial effect of steroids without undergoing surgical biopsy.