PEPTIDE TRANSPORTER GENES (TAP) POLYMORPHISMS AND GENETIC SUSCEPTIBILITY TO RHEUMATOID-ARTHRITIS

The association of rheumatoid arthritis (RA) with HLA-DRB1 alleles ind icates that at least one RA susceptibility gene is linked to the HLA c lass II region. Transporter associated with protein processing (TAP) g enes, which lie upstream of the HLA-structural genes, may also contrib ute to disease susceptibility. We investigated polymorphisms of the pe ptide transporter genes, TAP 1 and TAP 2, by PCR-ASO hybridization tec hniques in 82 RA patients and 66 control individuals. Although there w as a suggestion of linkage between some TAP polymorphisms and RA, thes e seem to be dependent on HLA-DRB104, since these positive associatio ns disappeared when HLA-DRB104 positive RA patients and controls were compared. Furthermore, no particular TAP allele or haplotype was asso ciated with any clinical or immunological subgroup of RA. We conclude that the TAP genes do not have a major influence on susceptibility to RA in the European Caucasian population.