Interferon gamma-1b (IFN) may improve lung function in patients with idiopathic pulmonary fibrosis (IPF). Previous trials have combined IFN with low dose corticosteroids (CS), however the efficacy of CS in IPF is unproven. We review our experience with IPF patients treated with IFN.
We identified IFN-treated patients from an IPF referral center. Subjects were included if they met ATS/ERS criteria for a diagnosis of IPF and had spirometry performed prior to and six months after initiation of IFN. Patients treated with IFN alone were compared to those treated with IFN + CS. The primary endpoint for our study was change in spirometry (FVC and DLCO) 6 months after initiation of IFN. Secondary endpoints were: a) change in FVC and DLCO 12 months after beginning IFN, and b) development of a new need for supplemental oxygen therapy.
28 patients were included; 10 treated with IFN alone and 18 treated with IFN + CS. The two groups were similar with regard to age, gender, need for supplemental oxygen, and previous treatment with cytotoxic agents. Baseline and 6 month spirometry values are shown:
IFN AloneIFN + CSp ValueMean pre-treatment2.65L2.62LNS FVC (mean % pred)(65% pred)(63% pred)Mean pre-treatment11.0 mL/mmHg/min10.8 mL/mmHg/minNS DLCO (mean % pred)(43% pred)(43% pred)Change FVC at 6−0.11L−0.18L (−6.9%)NS mo (% from baseline)(−4.2%)Change DLCO at 6−0.4mL/mmHg/min−0.9mL/mmHg/minNS mo (% from baseline)(−3.6%)(−8.3%)New need for supplemental O22 (20%)5 (27.8%)NS
Changes in FVC and DLCO between the two groups at 12 months were also not statistically different.CONCLUSIONS: Changes in pulmonary function 6 and 12 months after the initiation of IFN were similar independent of co-treatment with CS. The addition of CS to IFN did not alter the need for supplemental O2 therapy. Our results suggest that CS do not appear to have any additive effect to IFN in the management of IPF.
Based upon our data, the paucity of literature supporting the effectiveness of CS in IPF, and the known side effects of long-term CS use, we suggest that there is little utility to the practice of routinely adding CS to IFN in the treatment of patients with IPF. Prospective studies to evaluate these findings should be performed.
D.L. Helman, None.