POSITIVE AND NEGATIVE ASSOCIATION OF HLA-DR GENOTYPES WITH JAPANESE RHEUMATOID-ARTHRITIS

Objective. To clarify the relationship between the HLA-DR genotype and susceptibility to rheumatoid arthritis (RA) in Japanese patients. Met hods. HLA-DR typing and DRB1 genotyping were carried out by PCR and P CR-SSCP (single stranded DNA conformation polymorphism), respectively. Results. In RA, the prevalence of HLA-DR4 was significantly higher (5 7.3%, p < 0.05). In particular DRB10405 was predominantly higher (46. 9%, p < 0.05) and DRB10401 was also increased although not significan tly. HLA-DR8, especially DRB10802, was significantly lower (1.0%, p < 0.01). RA patients homozygous for DRB10405 showed slightly higher va lues for the erythrocyte sedimentation rate, gamma-globulin, and IgG, as well as positivity for rheumatoid factor and high titers for the Wa alar-Rose test, and a decrease in the albumin/globulin ratio, albumin, and hemoglobin in comparison to patients without RA susceptibility ge nes, although the difference for each of these parameters was not sign ificant. Conclusion. DRB10405 and DRB1*0802, which are both rare alle les in Caucasians, are positively and negatively correlated respective ly, with the pathogenesis of RA in Japan.