Pulmonary Fibrosis Treated with Inhaled Interferon-gamma (IFN-γ)

Parenteral IFN-γ was unsuccessful as a treatment for pulmonary fibrosis. Inhaled IFN-γ targeted to the lungs may be more effective. Our patient, a 56-year-old male with biopsy proven usual interstitial pneumonia (UIP) and declining pulmonary function tests (PFTs) was initially diagnosed with idiopathic pulmonary fibrosis (IPF). He enrolled in a 2-year research protocol and was treated with inhaled IFN-γ (100 μg, Actimmune, Horizon Pharma, Deerfield, IL) 3 times per week. After completion of the protocol, he was able to secure the drug and continued therapy for a total of 7 years. He felt better, returning to work. His only complaint was transient cough during inhalation. PFTs improved (e.g., DLCO, 58% at baseline, 81% at 2 years, 69% currently). Clinical monitoring showed preserved exercise tolerance and stable CT scans. He was ultimately diagnosed (year 5) with scleroderma-like connective tissue disease after he developed sclerodactyly and a positive antinuclear antibody. Inhaled IFN-γ was well tolerated for 7 years and may stabilize fibrotic lung disease.