Association of the human lymphocyte-DR2 antigen with Japanese ulcerative colitis.

The frequency deviation of human lymphocyte-DR antigens as well as human lymphocyte A, B, and C antigens was assessed in 40 Japanese patients with ulcerative colitis and compared with 51 ethnically matched healthy Japanese. The antigen that was of significantly higher frequency in patients with ulcerative colitis was HLA-DR2. This antigen was found in 70% of the patients vs. 31% of controls [chi 2 = 13.4, p less than 0.001, corrected p less than 0.01, relative risk = 5.1). In addition, an increased frequency of HLA-B5-DR2, which is the most common haplotype in Japanese populations, was found in 55% of the patients with ulcerative colitis compared with 22% of the controls (chi 2 = 10.84, p less than 0.001).