Abstract
Background: INSIP is a rare interstitial lung disease and diagnosis by definition, demands a multidisciplinary team (MDT) discussion. It has been suggested that iNSIP might be associated with an autoimmune background that later reveals itself as an autoimmune disease.
Aims: Using the MDT approach, we aimed at establishing a retrospective, multinational cohort of a larger number of iNSIP patients to characterize the clinical properties at baseline and development of CTD.
A pilot study was done to test the feasibility of the above. We report here the incidence of CTD during the follow-up.
Methods: Investigators from three expert centers (Denmark, Estonia and Norway) met and discussed 31 cases of biopsy-proven iNSIP at an international MDT. Cases were previously diagnosed at a national level between 2004 and 2014. Based on all available data, the diagnosis of iNSIP was re-evaluated and a consensus diagnosis was made. Cases incompatible with iNSIP were excluded. Relevant data were registered comprising any development of CTD.
Results: Twenty-three patients were included. Ten (43.5%) had extrapulmonary symptoms. Serology was positive in 6 patients (26.1%) of whom, 4 had extrapulmonary symptoms.
The mean follow-up time was 57 months. None of the patients developed any CTD that fulfilled the classical rheumatologic criteria during the observation period. Four patients (17.4%) fulfilled the criteria for interstitial pneumonia with autoimmune features (IPAF).
Conclusion: In this iNSIP cohort no patients developed CTD during the follow-up making the term “idiopathic” more confident and not supportive of the thesis of autoimmune pathogenesis.
- Copyright ©the authors 2016
