Patients with interstitial lung disease (ILD) that is associated with connective tissue diseases (CTDs) or with autoimmune features (interstitial pneumonia with autoimmune features; IPAF) are eligible for immunosuppressive treatment and generally have better outcomes compared with patients with idiopathic interstitial pneumonias (IIPs). A study in Clinical Immunology now identifies a small subset of patients with IIP who have anti-IFI16 autoantibodies, and considers the potential implications for prognosis and treatment. Anti-IFI16 autoantibodies, which have been previously reported in patients with various CTDs, recognize IFI16, a component of the antiviral cellular response that triggers production of type I interferon.

Sasai et al. retrospectively analysed sera from 295 patients with IIP who did not meet criteria for any CTD. Six patients were positive for anti-IFI16 autoantibodies at the time of IID diagnosis, of whom two were classified as having IPAF. Only two of these six patients received immunosuppressive or antifibrotic treatment. As these six patients consistently exhibited the lowest overall survival and acute exacerbation-free survival rates of the cohort, the authors highlight the need to investigate whether patients with IIP and anti-IFI16 autoantibodies could be classified as having IPAF and potentially benefit from immunosuppressive treatment.