The role of Pirfenidone in the treatment of interstitial pneumonia with autoimmune features

Abstract Rationale: No study indicated whether pirfenidone is appropriate for treatment of Interstitial pneumonia with autoimmune features (IPAF) patients. Objective: To evaluate the efficacy and safety of pirfenidone in the treatment of IPAF.Methods: The clinical data of 184 patients who met the diagnostic criteria of IPAF was selected. Those patients were assigned to pirfenidone treatment group (n=81) and control group (n=103). The baseline data and diagnostic characteristics of patients were retrospectively collected. Pulmonary function and prednisone dose were analyzed by mix-effect model.Results: 1. Baseline data: Forced vital capacity (FVC%, P< 0.001) and diffusion capacity of the lung for carbon monoxide (DLCO%, P= 0.003) of predicted values in the pirfenidone group were lower than those in the control group. 2. Diagnostic characteristics: There was no significant difference of diagnostic characteristics between two groups. 3. Therapeutic evaluation: The volume of FVC in pirfenidone group was increased by 0.0390 L/year, while that was decreased by 0.0769 L/year in the control group (P=0.038). 4. Subgroup analysis: Pirfenidone with dosage > 600 mg/day (P = 0.010) and medication course of treatment longer than 12 months (P = 0.007) showed superior therapeutic effects. 5. Dose of prednisone: During the period of 12-40 months, prednisone dose was reduced by 6.27 mg per day in pirfenidone group, compared with control group. 6. Side effects: A total of 17 patients (19.32%) experienced side effects after taking pirfenidone.Conclusion: Pirfenidone (600-1800 mg/day) can improve FVC of pulmonary function and help to reduce prednisone dose in IPAF patients. It contains controllable side effects.