Molecular techniques have identified the OspA163–175–binding molecules as the rheumatoid arthritis (RA) alleles (DRB1*0401, *0404, *0405, *0101, *0102) [21,22] and the DRB5*0101 allele linked to DRB1*1501 (the former DR2 allele) [22]. Here, HLA-DRB1 is linked to rheumatoid arthritis.