Usual interstitial pneumonia preceding rheumatoid arthritis: Clinical, imaging, and histopathologic features

Purpose: To determine which clinical, radiologic, or histopathologic characteristics might predict which patients with idiopathic pulmonary fibrosis/usual interstitial pneumonia (IPF/UIP) go on to develop rheumatoid arthritis (UIP/pre-RA). Methods: We reviewed the records of 74 patients (IPF/UIP, 63; UIP/pre-RA, 11) with UIP-pattern identified in surgical lung biopsy specimens. For the study, chest CT and histopathology slides were re-reviewed by two expert pulmonary radiologists and pathologists respectively. Results: The median follow up period was 4.2 years. In patients with UIP/pre-RA, mean duration from UIP diagnosis to RA development was 0.9 years. There were no significant differences in clinical features or CT findings between two groups. UIP/pre-RA group was more likely to have higher pO 2 (p=0.009), rheumatoid factor, anti-cyclic citrullinated peptide antibody (p Conclusions: Clinical and radiologic features of UIP/pre-RA were similar to those seen in IPF/UIP. The fibrobrastic foci score and germinal centers score were the best discriminative between IPF/UIP and UIP/pre-RA patients. In patients with IPF/UIP and a low fibrobrastic foci score and high germinal center score on biopsy, there is a risk of development of RA in the future.