HLA-DRB1 and rheumatoid arthritis: All of the "classical" RA-associated HLA-DRB1*01, HLA-DRB1*04 and HLA-DRB1*10 alleles showed statistically significant ORs, with HLA-DRB1*04 the most prominent (Table 3), underscoring the significance of the HLA-DRB1 SE previously reported in the African population [34-38].