Background: Pirfenidone is an anti-fibrotic agent shown to slow the progression of idiopathic pulmonary fibrosis (IPF). However, its effectiveness in association with serological autoimmune features in IPF remains unclear.
Methods: We retrospectively reviewed the medical records of patients with IPF treated at a tertiary care hospital in South Korea. The autoantibody status was defined as positive if we detected autoantibodies meeting the serological domain criteria for interstitial pneumonia with autoimmune features or anti-neutrophil cytoplasmic antibodies.
Results: We included 142 patients with IPF treated with pirfenidone for over six months (93 were autoantibody-positive and 49 were autoantibody-negative). The mean age was 69.5 ± 7.3 years, and 77.5% of the patients were male. The adjusted mean changes over one year were - 34.4 and - 112.2 mL (p = 0.168) in forced vital capacity (FVC), and - 0.53 and - 0.72 mL/mmHg/min (p = 0.356) in the lungs diffusion capacity for carbon monoxide (DLCO) in the autoantibody-negative and autoantibody-positive groups, respectively.
Conclusions: Reductions in FVC and DLCO were similar in autoantibody-positive and autoantibody-negative patients with IPF treated with pirfenidone. Pirfenidone is effective in attenuating the progression of IPF, irrespective of the autoantibody status.
Keywords: Autoantibodies; Idiopathic pulmonary fibrosis; Pirfenidone.