HLA, CTLA-4 and TNF-beta Gene Polymorphisms and Disease Susceptibility in Korean Children with Graves' Disease / 대한내분비학회지

ABSTRACT

BACKGROUND: Graves' disease(GD) is an organ-specific autoimmune disorder that is inherited as a complex trait. At present three loci, namely the human leukocyte antigen(HLA), the cytotoxic T lymphocyte antigen-4(CTLA-4) and a thyroid stimulating hormone receptor(TSHR) are the only well-known genetic determinants for GD. To understand the mechanisms underlying the development of GD, we investigated the relationship of HLA alleles, polymorphisms of CTLA-4 gene and the tumor necrosis factor(TNF)-beta gene, with the disease susceptibility. METHODS: Fifty-two Korean children with GD(45 girls and 7 boys), and 119 healthy children, were investigated in this study. The HLA alleles were determined by a standard lymphocyte microtoxicity technique, ARMS-PCR(Amplification Refractory Mutation System-Polymerase Chain Reaction), PCR-SSP(Sequence Specific Primer) and PCR-SSOP(Sequence Specific Oliogonucleotide Probe) method. The CTLA-4 gene polymorphism was analyzed by PCR-SSCP(Single Strand Conformation Polymorphism), and the TNF-beta gene polymorphism by PCR-RFLP(Restriction Fragment Length Polymorphism). RESULTS: (1) The frequencies of HLA-A2, B46, DRB1*08 and DPB1*0202 were significantly increased, and those of HLA-A24, DQA1*01 and DQB1*05 were significantly decreased, in the GD patients compared to the control subjects. (2) A significant difference in the distributions of the AA, AG, and GG genotypes of the CTLA-4 exon 1 were observed between the GD patients and the control subjects, and a significant increase in the frequency of the G (alanine) allele was seen in the GD patients compared with the control subjects(84.6% vs 63.4%; RR=3.2; p or =45% compared with GD patients having TSHRAb <45%(37.5% vs 3.6%; RR=14.8; p<0.01). CONCLUSION: These data suggest that HLA-A2, B46, Cw*0102, DRB1*08 and DPB1*0202 are markers for disease susceptibility, and that HLA-A24, DQA1*01 and DQB1*05 are markers for disease protection, in Korean children with GD. This study showed that the CTLA-4 gene polymorphism was an additional marker of susceptibility in the GD patients, and was associated with exophthalmos, and that the TNF-beta gene polymorphism was associated with the TSHRAb activity.