Clinical features and treatment response in 18 cases with idiopathic nonspecific interstitial pneumonia

Abstract

Background: Nonspecific interstitial pneumonia (NSIP) has been reported recently to have shown much better response to medical treatment and better prognosis compared with idiopathic UIP. However, clinical characteristics of idiopathic NSIP discriminating it from UIP have not been clearly defined. Method: Among 120 patients with biopsy-proven diffuse interstitial lung diseases admitted to the Samsung Medical Center between July 1996 and March 2000, 18 patients with idiopathic NSIP were included in this study. Retrospective chart review and radiographic analysis were performed. Results: 1) At diagnosis, 17 patients were female and the average age was 55.2 ± 8.4 years (44~73 years). The average duration from development of respiratory symptom to surgical lung biopsy was 9.9 ± 17.1 months. Increase in bronchoalveolar lavage fluid lymphocytes (23.0±13.1%) was noted. On HRCT, ground glass and irregular linear opacity were observed, but honeycombing was absent in all patients. 2) Corticosteroids were initially given to 13 patients, but the medication was stopped in 3 patients due to severe side effects. Further medical therapy was not possible in 1 patient who experienced streroid-induced psychosis. Herpes zoster (n=3), tuberculosis (n=1), avascular necrosis of the hip (n=1), cataract (n=2) and diabetes mellitus (n=1) developed during prolonged corticosteroid administration. Of the 7 patients receiving oral cyclophosphamide therapy, hemorrhagic cystitis hindered one patient from continuing with the medication. 3) After medical treatment, 14 of 17 patients improved, and 3 patients remained stable (mean follow-up; 24.1 ± 11.2 months). FVC increased by 20.2 ± 11.2% of predicted value and the extent of ground glass opacity on HRCT decreased significantly (15.7±14.7%). 4) Of the 14 patients who had stopped medication, 5 showed recurrence of NSIP and 2 became aggravated during steroid tapering. All patients with recurrence showed deterioration within one year after completion of initial treatment. Conclusion: Since idiopathic NSIP has unique clinical profiles and shows good prognosis, diagnosis different from UIP, and aggressive medical treatment are needed.