Identification of the Risk HLA-A Alleles and Autoantigen in Han Chinese Vitiligo Patients and the Association of CD8+T Cell Reactivity with Disease Characteristics.

BACKGROUND Multiple studies have implicated a role for CD8+T cell-mediated immune response to autoantigens in vitiligo. However, the antigen-specific T lymphocyte reactivity against the peptide epitopes is diverse among different world populations. This study aimed to identify the risk HLA-A allele in vitiligo and study CD8+ T cell reactivity to 5 autoantigenic peptides in Han Chinese populations, and to analyze the association of CD8+ T cell reactivity with disease characteristics. MATERIAL AND METHODS The risk HLA-A allele was analyzed by case-control study. Enzyme linked immunospot (ELISPOT) assay was used to compare T cell reactivity to the 5 autoantigenic peptides between vitiligo patients and healthy controls, then we analyzed the association of CD8+ T cell reactivity to 2 positive peptides with disease activity and area of skin lesions. RESULTS The results indicated that the most frequent allele in the Han Chinese vitiligo patients was the HLA-A*02: 01 allele with a significantly higher frequency compared to controls (20.20% versus 13.79%, P=6.64×10-5). The most frequently encountered epitopes were 2 gp100 modified peptides, IMDQVPFSV and YLEPGPVTV, whereas a weak T cell reactivity against tyrosinase and Melan-A/MART-1 were evaluated. Moreover, we demonstrated that T cell reactivity against the 2 positive peptides was significantly associated with disease characteristics including disease activity and area of skin lesions. CONCLUSIONS Our findings showed that the HLA-A*02: 01 allele was the major risk HLA-A allele, and 2 gp100 modified peptides were identified as autoantigens and were found to be closely related to disease characteristics which might play a critical role in Han Chinese vitiligo patients.