Abstract
Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an important inhibitor of T-lymphocyte response. Polymorphisms in the CTLA-4 gene have been reported to be associated with numerous autoimmune diseases. The aim of this study was to determine whether polymorphisms of CTLA-4 exon 1 (+49) genes are associated with susceptibility and clinicolaboratory findings of primary biliary cirrhosis (PBC) in the J apanease population. Blood samples were obtained from 45 patients (6 men and 39 women, aged 23-56 years) with PBC and 73 healthy controls (48 men and 25 women, aged 22-72 years). CTLA-4 exon 1 (+49) polymorphism was defined using a polymerase chain reaction-restriction fragment length polymorphism with Bst71I restriction enzyme. The genotype frequencies of A/A, A/G, and G/G in 45 patients with PBC were 11% (5 patients), 44% (20 patients), and 44% (20 patients), respectively. There was no significant difference between frequencies in PBC patients and healthy controls. PBC patients with G/G genotype had significantly higher serum levels of AL T, GGT, and IgM than those in patients with A/A or A/G genotype. In conclusion, CTLA-4 gene polymorphisms are not associated with susceptibility of PBC in Japan; however, G/G genotype may be associated with liver damage.
