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 theCTLA-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.

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 theCTLA-4 gene does not play a part in the genetic susceptibility to the development of SLE.