Diffuse panbronchiolitis and rheumatoid arthritis: a possible correlation with HLA-B54.

We analyzed the HLA antigens in two patients with rheumatoid arthritis accompanied by diffuse panbronchiolitis in whom HLA typing could be done and found the presence of B54 and DR4 alleles. We previously reported that the frequency of HLA-B54 is significantly increased in patients with diffuse panbronchiolitis. This allele demonstrates a linkage disequilibrium with DR4 (or DR4.1) in Japanese individuals. The association of rheumatoid arthritis with HLA-DR4 is well established in various ethnic groups including Japanese people. Since both diseases show the same pattern of HLA correlation, more Japanese patients with these two diseases are likely to be encountered.