[Study on the relationship of CTLA-4 -318, +49 polymorphisms with autoimmune hepatitis and primary biliary cirrhosis in a Chinese population].

OBJECTIVE

To investigate the association between Chinese patients with autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and the polymorphisms of cytotoxic T lymphocyte -associated antigen-4 (CTLA-4) gene promoter (-318) and exon 1 (+49).

METHODS

The CTLA-4 promoter (-318 T/C) and exon 1 (+49A/G) polymorphisms were genotyped via restriction fragment length polymorphism methods in 62 Chinese AIH patients, 77 Chinese PBC patients and 160 healthy controls.

RESULTS

There was no difference in the distribution of CTLA-4 promoter -318 T/C polymorphisms between AIH patients and controls, but the C allele frequency was significantly increased in patients with AIH, compared to controls (P=0.02, OR=2.43). The distribution of CTLA-4 gene exon 1 49 A/G genotypes exhibited significant difference between PBC patients and controls (P=0.006), and the frequency of G allele showed a significant increase in PBC group as compared with controls (P=0.0046, OR=1.8). Although the genotype distribution of the CTLA-4 exon 1-promoter gene displayed no significant difference between AIH and PBC patients and controls, the occurrence of GG-CC was increased in the patients of the two groups (AIH: 32.3%, PBC: 37.7%; control: 22.5%).

CONCLUSION

The above findings suggest that the polymorphisms of CTLA-4 gene probably confer susceptibility to AIH and PBC in the Chinese population.