Background Rheumatoid arthritis (RA) is a multifactorial disease with a significant genetic component. The HLA locus accounts for about 1/3 of the total genetic effect, it is reasonable to investigate other areas of the genome for further susceptibility loci. There are convincing evidences for role T-cells in the pathogenesis of RA. T-cell receptor (TCR) genes are logical disease gene candidates. T-cells recognise specific antigens through the receptor (TCR) displayed on the cell surface. The TCR on most mature lymphocytes is composed from alpha and beta chains, although, a small proportion of cells use gamma/delta heterodimer.
Previously, we performed a linkage study in 19 multiplex RA families. The maximum LOD score at the polymorphism TCRD gene (coding T-cell receptor delta chain) was +1.65. To better understand the significance of these data the present study was performed.
Objectives To investigate if the polymorphism TCRD gene are associated with RA.
Methods The highly polymorphic dinucleotide repeat TCRD (14 q11.2) was analysed in 32 patients with RA and 40 Russian controls. All subjects were typed by polymerase chain reaction method.
Results No significant differences in TCRD allele frequencies were found in the group of Russian controls and Russian RA patients. Significant differences in TCRD allele frequencies (P = 0,03) were observed between the group of Russian controls and Caucasoid population (Jordan SA, 1991).
Conclusion These results argue against the hypothesis that TCRD polymorphism itself play a important role in the susceptibility to RA.
The study was supported by Russian Foundation Basic Research grant N 99–04–48643.