Interstitial Pneumonia with Autoimmune Features (IPAF): a single center prospective experience

Introduction: The term Interstitial Pneumonia with Autoimmune Features (IPAF) has been proposed to classify patients with Interstitial Lung Disease (ILD) associated with autoimmune signs not classifiable for a specific Connective Tissue Disease (CTD). Currently, no prospective IPAF cohort are reported. Aims and Objectives: To describe a prospective cohort of IPAF patients. Methods: The study was conducted according to the declaration of Helsinki. A total of 170 consecutive ILD patients with at least one IPAF criteria were considered in the last year (Fischer A, Eur Respir J 2015; 46 (4): 976-987). From these, 58 patients were able to satisfy classification criteria for CTDs, while 33 patients were classified as IPAF. Results: IPAF patients (69.7% females) referred a history of smoke in 51.5% of cases and reported a restrictive pattern in Pulmonary Function Tests in 66.7% of cases. A clinical domain was present in 72.7% of patients, whereas serological and morphological domains respectively in 72.7% and 87.9% of cases. The most frequent item from each domain were arthritis (42.4%), Antinuclear Antibodies (ANA) (30.3%) and Nonspecific Interstitial Pneumonia (75.8%) as HRCT pattern. No cases of ulcers, telangiectasia and mechanic’s hand were reported. Only ANA, Rheumatoid Factor, anti-SSA, anti DsDNA and Anti Citrullinated Protein Antibodies were found as serological domain. Conclusions: This study suggests that most of IPAF patients have a clinically relevant ILD without serological and clinical items highly specific for CTDs. When these items were present, patients were generally able to satisfy specific CTD criteria. Probably, some of IPAF patients can have an early form of CTDs.