Fibrosing interstitial lung disease in primary Sjogren syndrome

Interstitial lung disease (ILD) represents the main pulmonary involvement in primary Sjogren syndrome (pSS). A proportion of patients with pSS develop a progressive fibrosing form of ILD, but no data are available about the prevalence of these patterns in pSS patients. Aim of this monocentric, cross-sectional study was to investigate the prevalence of fibrosing patterns in pSS patients with ILD.

All consecutive patients fulfilling classification criteria for pSS with a new or previous diagnosis of ILD were enrolled in the study. Diagnosis of ILD was always performed by mean of HRCT and specific patterns were identified according to current classification criteria and divided in two groups according to the detection of a fibrotic pattern.

Thirty-four pSS-ILD patients were enrolled in the study (males/females 3/31, median age 69.5 years, median pSS duration 47.5 months). Fibrotic pattern was detected in 52.9% of patients, namely: UIP (13 patients, 38.2%), fibrotic NSIP (4, 11.8%), fibrotic OP (1 2.9%) and group 2 (16 pts, 47.1%) including NSIP (6, 17.6%), OP (4, 11.8%), LIP (2, 5.9%) and unclassifiable (4, 11.8%). These patients were younger and with a shorter pSS duration at ILD diagnosis, in particular ILD diagnosis was prior or concurrent to pSS in 83.3% of cases compared to 62.5% in the group of nonfibrotic pattern (P<0.05).

Our data suggest a high prevalence of this pulmonary clinical phenotype in pSS-ILD patients. Since the course of progressive fibrosing pneumonia generally results in respiratory failure, this result could be worthy of further studies.