HLA-DRB1 Alleles and Rheumatoid Arthritis-related Pulmonary Fibrosis

Abstract

To the Editor: Pulmonary fibrosis is a well recognized extraarticular manifestation of rheumatoid arthritis (RA)1. Several studies have shown an association between the HLA-DRB1 gene and extraarticular manifestations of RA2,3. We analyzed the effect of the HLA-DRB1 gene and cytokine gene polymorphisms on the association of pulmonary fibrosis in Japanese patients with RA. We examined 131 adult patients with RA, who fulfilled the American Rheumatism Association 1987 revised criteria for RA4. Clinical characteristics were (mean ± SD) age at study 62.4 ± 13.0 years and disease duration 11.2 ± 4.7 years. Pulmonary fibrosis was diagnosed by chest radiograph and chest high-resolution computed tomography (HRCT). Patients with dry cough or exertional dyspnea or suspicious findings for interstitial changes in chest radiography were further investigated with HRCT at suspended end-inspiratory effort without intravenous contrast material. The abnormalities used to screen for pulmonary fibrosis were ground-glass attenuation and honeycombing defined as areas of cystic spaces with thickened walls. Patients with RA with other autoimmune … Address correspondence to Dr. K. Migita, Clinical Research Center, NHO Nagasaki Medical Center, Kubara 2-1001-1, Omura 856-8652, Japan; E-mail: migita{at}nmc.hosp.go.jp