Serum rheumatoid factors were measured by routine methods in 2, 095 serum samples. In all subjects, 4.7% and 4.2% were positive by RAHA test and RA test respectively. The percent positivity tended to increase with age by RA test, but not significant difference was noted by RAHA test. HLA antigens were determined in 15 healthy individuals, who were positive in rheumatoid factors. HLA-B51 antigen prevalence was increased in healthy seropositive individuals compared with control, but Bw52, Cw7 and DR2 antigens were decreased in them. On the other hand, the prevalence of HLA-DR4 and DRw53 antigens were higher in healthy seropositive individuals. But the prevalence was not statistically significant.
