An HLA study on 149 Japanese patients with Crohn's disease.

To search for possible immunogenetic roles in the pathogenesis of Crohn's disease, we examined the HLA-A, -B, -C, -DR and -DQ locus antigens in 149 Japanese patients with Crohn's disease. All patients were living on Kyushu island. We also examined the HLA of 136 healthy controls who resided in Kyushu. The results were compared with both controls throughout Japan and Kyushu controls. In Japanese patients with Crohn's disease, HLA-DR4, especially -DR4.1, and -DQ4 were more frequent than in the controls throughout Japan and in Kyushu. In light of these observations, an immunogenetic factor may have some role in the development of Crohn's disease. The susceptibility to Crohn's disease may relate to HLA-DR4, especially -DR4.1, and -DQ4, in Japanese patients.