SEARCH

SEARCH BY CITATION

Keywords:

  • autoimmune hepatitis;
  • CTLA4;
  • genetic susceptibility;
  • SNPs

Aim:  Autoimmune hepatitis (AIH) is an organ-specific autoimmune disease characterized by chronic inflammation of the liver. Although the HLA DR4 allele is associated with type 1 AIH in Japanese, the exact genetic etiology of AIH remains undefined. The cytotoxic T-lymphocyte antigen 4 (CTLA4) is an inhibitory receptor expressed by T-cells that acts largely as a negative regulator of T-cell responses, and polymorphisms of CTLA4 have been reported to be associated with susceptibility to various autoimmune diseases. Therefore, we sought to clarify whether CTLA4 single-nucleotide polymorphisms are associated with disease susceptibility in Japanese patients with type 1 AIH.

Methods:  We genotyped 76 patients with AIH and 100 ethically matched controls for allelic determinants using TaqMan genotyping assays at four polymorphism sites: −1722 and −318 in the promoter; +49 in exon 1 and +6230 in the 3′ untranslated region.

Results:  We observed no difference in the distribution of the alleles, genotypes, or haplotypes between patients and controls. Compared with −1722 C/C patients, −1722 T/T patients were younger (56 vs. 63 years; P = 0.01) and had significantly lower serum levels of aspartate aminotransferase (313 vs. 763 IU/L; P = 0.031) and bilirubin (1.1 vs. 8.6 mg/dL; P = 0.027). Analysis of allelic frequencies revealed no significant difference between patients with and without the HLA DR4 allele.

Conclusion:  These data suggest that the CTLA4 polymorphism is not associated with susceptibility to type 1 AIH in the Japanese population.