To determine which HLA antigens are associated with rheumatoid arthritis in Korean, we studied the HLA class II genotypes in 40 patients with rheumatoid arthritis and 35 normal healthy persons by the two step polymerase chain reaction. At first we designed 20 pairs of group specific primers followed by the alleles which have the same nucleotide sequences in the exon 2 region. We performed amplification reaction with these 20 pairs of primers for 32 cycles. Reaction products were electrophoresed and only specifically amplified products were reamplified for 15 cycles with total 76 pairs of allele specific primers. We typed the HLA class II genotypes with specific band patterns of each allele. The genotypes in patients were compared with those of normals. HLA-DR4 gave the highest relative risk for rheumatoid arthritis (RR=4), which was statistically significant (P<0.01). The frequency of HLA-DR4 was 75.0% in patient group and 42.9% in normal control group. Relative risk was also associated with HLA-DQw4 of DQB1 gene (RR=3.82), which was statistically significant (P<0.05). The frequency of HLA-DQw4 was 38.9% in patient group and 14.3% in normal control group. HLA-DRI and DQw3 were not associated with rheumatoid arthritis (P>0.05). Among HLA-DR4 subtypes, the frequency of Dwl4(0404) in patient group was relatively higher (19.2%) than that in normal control group(7.7%). The relative risk was high (2.85), although it was not statistically significant (P>0.05). From this study, HLA-DR4 was found to be highly associated while DRI was not associated with rheumatoid arthritis patients in Koreans.
Alleles ; Arthritis, Rheumatoid* ; Base Sequence ; Exons ; Genotype* ; HLA Antigens ; HLA-DR4 Antigen ; Humans ; Polymerase Chain Reaction