A possible association of HLA-DR beta 1*04 subtypes and rheumatoid arthritis of peptide binding region amino acids.

: HLA-DR beta 1*04 subtypes associated with rheumatoid arthritis (RA) were studied by polymerase chain reaction with sequence specific primers and the 86th amino acid of the DR beta 1 chain was analysed in RA patients vs healthy controls. The frequency of HLA-DR beta 1*0401 and 0404/0407 alleles was significantly increased in RA patients vs the controls, HLA-DR beta 1*0401 and 0404 being the dominant variants in RA. In most RA patients hydrophilic glycine proved to be the 86th amino acid of the peptide binding region thus it could have an effect on the development of RA.