A subset of Sjoegren's syndrome associates with the TCRBV13S2 locus but not the TCRBV2S1 locus

HGPSS associates with the TCRBV6S7 locus within the TCR beta -chain gene complex. However, V beta 6.7 T cells, encoded by this locus, have never been implicated in the salivary gland destruction that characterizes primary Sjoegren's syndrome. Both V beta 13 and V beta 2 T cells have been implicated in glandular destruction. We therefore analyzed the association of HGPSS with both TCRBV2S1, the only TCRBV2 locus, and the TCRBV13S2 locus (the TCRBV13 family member which lies closest to TCRBV6S7). Our results show that the prevalence of TCRBV13S2*2 homozygotes is significantly increased in HGPSS and that there is a high degree of linkage disequilibrium between this locus and TCRBV6S7 not previously described across the TCR beta -chain gene complex. However, HGPSS does not associate with the TCRBV2S1 locus. These results suggest that it is the V beta 13.2 T cell which may be responsible for the autoimmune destruction that characterizes HGPSS and that the previous association of this condition with the TCRBV6S7 locus is primary due to the linkage disequilibrium that exists between it and TCRBV13S2.