Significance of HLA in the development of Graves' orbitopathy.

Graves' disease (GD), similarly to most autoimmune disease, is triggered by environmental factors in genetically predisposed individuals. Particular HLA alleles increase or decrease GD risk. No such correlation was demonstrated for Graves' orbitopathy (GO) in Caucasian population. HLA-A, -B, -C, -DQB1 and -DRB1 genotyping was performed using a high-resolution method in a total number of 2378 persons including 70 patients with GO, 91 patients with non-GO GD and 2217 healthy controls to compare allele frequencies between GO, non-GO and controls. Significant associations between GO and HLA profile were demonstrated, with HLA-A*01:01, -A*32:01, -B*37:01, -B*39:01, -B*42:01, -C*08:02, C*03:02, DRB1*03:01, DRB1*14:01 and DQB1*02:01 being genetic markers of increased risk of GO, and HLA-C*04:01, -C*03:04, -C*07:02 and -DRB1*15:02 being protective alleles. Moreover, correlations between HLA alleles and increased or decreased risk of non-GO GD, but with no impact on risk of GO development, were revealed. Identification of these groups of GO-related and GO-protective alleles, as well as the alleles strongly related to non-GO GD, constitutes an important step in a development of personalized medicine, with individual risk assessment and patient-tailored treatment.