Comparison between cryptogenic organizing pneumonia and connective tissue disease-related organizing pneumonia.

Abstract

Although the overall prognosis of CTD-related interstitial pneumonia is better than that of idiopathic interstitial pneumonia, the prognosis of CTD-related organizing pneumonia (CTD-OP) was suggested to be worse than that of cryptogenic organizing pneumonia (COP). The aim of this study was to compare the clinical features and outcome of the two conditions. A retrospective review of 100 patients diagnosed by lung biopsy as having organizing pneumonia patterns (CTD, 24; COP, 76) at three tertiary referral centres. Underlying CTDs were mostly RA, SS and PM/DM. The median follow-up period was 43.6 months. There were no differences in initial symptoms, lung function or bronchoalveolar lavage fluid findings except significantly more females (83.3 vs. 59.2%, P = 0.048) in the CTD-OP than in the COP group. Over 80% of the patients in both the groups improved. However, complete recovery rate was lower in CTD-OP (20.8%) than in COP (46.1%; P = 0.028) with a tendency towards higher recurrence rate in CTD-OP (40.0 vs 20.3%; P = 0.072). There was no significant difference in the frequency of rapid progression or overall survival between the two groups. The clinical features and prognosis of CTD-OP are similar to COP. However, lower complete recovery rate with a tendency towards higher recurrence rate in CTD-OP compared with COP suggest the need for closer follow-up in patients with CTD-OP.