International multidisciplinary team discussions on the diagnosis of idiopathic non-specific interstitial pneumonia and the development of connective tissue disease.

BACKGROUND

Idiopathic Non-Specific Interstitial Pneumonia (iNSIP) is a rare interstitial lung disease, diagnosed, by definition, on the basis of a multidisciplinary team discussion (MDD). Association with an autoimmune background has been suggested in iNSIP.

AIMS

To test the feasibility of conducting a multinational MDD to review the diagnosis in iNSIP cases and to estimate the emergence of connective tissue disease (CTD) during follow-up.

METHODS

Investigators from three expert centers (Denmark, Estonia and Norway) met and discussed cases of biopsy-proven iNSIP at an international MDD. The cases were previously diagnosed at a national level between 2004 and 2014. Based on clinical, radiographic and pathological 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

In total, 31 cases were discussed and 23 patients were included with a diagnosis of iNSIP. The mean follow-up time was 57 months. None of the patients developed CTD according to the rheumatologic criteria during the follow up period. Four patients (17.4%) met the criteria for interstitial pneumonia with autoimmune features.

CONCLUSION

We found that an international MDD was a feasible and valuable tool in the retrospective diagnostic evaluation of iNSIP. Diagnosis was changed in a statistically significant number of patients by our international MDD team. None of the patients developed CTD during follow-up.