Recently it has been reported that the intrathyroidal T cells in Graves' disease display restriction in V alpha T cell receptor (TcR) gene family usage, although this is not found with TcR V beta gene families in the same individuals.
These results indicate that in Japanese subjects at least two loci are involved in the susceptibility to Graves' disease and Hashimoto's thyroiditis, one related to HLA and another to TCR beta.
Using the complex phenotype TCR homozygote (hetero) DR3 as a reference (odds ratio = 1.00), we found that the risk for Graves' disease was restricted to TCR beta heterozygote/DR3+ individuals (odds ratio = 8.31; chi 2 = 11.82; P = 0.0009); in the absence of TCR beta heterozygosity, DR3 was not significantly associated with the disease.