The A-G polymorphism in exon 1 of the CTLA-4 gene is not associated with systemic lupus erythematosus

Objectives-Factors contributing to the development of systemic lupus erythe matosus (SLE) remain largely unknown although are likely to include both en vironmental and genetic components. Studies on murine lupus have indicated a role for an antibody that blocks binding of cytotoxic T lymphocyte associ ated-4 (CTLA-4) to B7 on antigen presenting cells in the treatment of disea se, suggesting that CTLA-4 may play an important part in the disease proces s. This study, therefore, investigated the frequency of a previously descri bed A-G polymorphism in exon 1 of the CTLA-4 gene, the G allele of which ha s shown to be associated with both Graves' disease and type I diabetes, to determine whether this polymorphism was playing a part in the development o f SLE. Methods-One hundred and twenty six SLE patients and 363 control subjects we re genotyped for the A-G polymorphism in exon 1 of the CTLA-4 gene. Target DNA was amplified using the polymerase chain reaction and the resulting pro duct was digested using the BbvI restriction enzyme. Results-No differences in allele or genotype frequencies were observed betw een patients with SLE and control subjects. Conclusion-These data suggest that the A-G polymorphism in exon 1 of the CT LA-4 gene does not play a part in the genetic susceptibility to the develop ment of SLE.