Interstitial pneumonia with autoimmune features – An observational study in a tertiary care institute from South India

Abstract

Background: Often, patients with idiopathic interstitial pneumonia (IIP) have certain specific clinical features to suggest an autoimmune disease but do not justify the current rheumatologic classification systems to fit into a diagnosis of connective tissue disease (CTD)-associated IIP. There is a great paucity of clinical, serological, and radiological data of these patients from India. Aim: The aim was to study the clinicoradiological and autoantibody profile in patients with interstitial pneumonia with autoimmune features (IPAF). Methodology: It was a prospective, observational study conducted in a tertiary care center between December 2015 and December 2016. A total of 30 patients who satisfied the criteria for IPAF according to the American Thoracic Society/European Respiratory Society research were included in the study. Results: All 30 patients satisfied IPAF criteria, but they did not meet the immunological criteria for CTD. Majority of them were female (86.67%) and nonsmokers. The mean age was 52.5 ± 14.5 years. The most common clinical symptom was inflammatory arthritis in 20 (66.67%) patients, followed by Raynaud's phenomenon in 5 (16%) patients. Nonspecific interstitial pneumonia was the most common radiological pattern seen in 20 (66.67%) patients, while antinuclear antibody (1:320) was the most common autoantibody positive in 18 (60.0%) patients, followed by rheumatoid arthritis factor in 15 (50%) patients. Conclusions: High female predominance along with distinct imaging, histologic and serological characteristic features are seen in patients with IPAF as compared to those with IIP. Further studies in patients with IPAF are needed to understand the natural history and its management.

Keywords

• autoantibody profile
• autoimmune features
• connective tissue disease
• interstitial pneumonia
• nonspecific interstitial pneumonia