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 erythematosus (SLE) remain largely unknown although are likely to include both environmental and genetic components. Studies on murine lupus have indicated a role for an antibody that blocks binding of cytotoxic T lymphocyte associated-4 (CTLA-4) to B7 on antigen presenting cells in the treatment of disease, suggesting that CTLA-4 may play an important part in the disease process. This study, therefore, investigated the frequency of a previously described A-G polymorphism in exon 1 of the CTLA-4 gene, the G allele of which has shown to be associated with both Graves' disease and type I diabetes, to determine whether this polymorphism was playing a part in the development of SLE. METHODS One hundred and twenty six SLE patients and 363 control subjects were 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 product was digested using the BbvI restriction enzyme. RESULTS No differences in allele or genotype frequencies were observed between patients with SLE and control subjects. CONCLUSION These data suggest that the A-G polymorphism in exon 1 of the CTLA-4 gene does not play a part in the genetic susceptibility to the development of SLE.