Short-term outcome of immunosuppressive therapy in idiopathic pulmonary fibrosis

Purpose: The purpose of this study was to evaluate the short-term efficacy of prednisolone and/or cyclophosphamide in patients with idiopathic pulmonary fibrosis and to analyse the determinants of treatment response. Methods: Twenty-one patients were included. Baseline evaluation of the patients included clinical history, pulmonary function tests, BAL findings, HRCT findings, and thoracoscopic lung biopsy. They were received oral prednisolone 1mg/kg) or cyclophosphamide(100mg/day) with or without low dose prednisolone. Follow up evaluation was performed after 6 months of therapy. If patients met any two of three criteria, they were considered to be responders: (1) improvement of dyspnea (2)10% or more improvement in any one of FVC, TLC or 20% improvement in DLco (3) decreased disease extent in HRCT findings. Results: One of 21patients died due to acute exacerbation of IPF. Eight of 20 patients were classified as responders and 12 as nonresponders. Responders showed 32.1% improvement in FVC, 17.9% in TLC and 7.6%in DLco. Nonresponders showed deterioration in all parameters. Histologic diagnosis was all NSIP in responder group, 1 NSIP and 11 UIP in nonresponder group. The significant differences were also found in the duration of symptom(3.75 month Vs 20.5 month, p=0.006) and lymphocyte percentage in cellular profiles of BAL fluid(23.7% Vs 7.3%, p-0.001) Conclusions: Our results suggest that patients with short duration of symptom, rich lymphocyte in BAL fluid and preferable histologic diagnosis (NSIP) are more likely to respond to immunosuppressive therapy.