Polymorphisms of the CTLA-4 exon 1 and promoter gene in systemic lupus erythematosus

The objective of this study was to determine whether the polymorphisms of t he CTLA-4 exon 1 (+49) and promoter (-318) are associated with susceptibili ty to systemic lupus erythematosus (SLE) and its clinical features. Polymer ase chain reaction of genomic DNA-restriction fragment length polymorphism was used to determine genotypes of the CTLA-4 exon 1 (+49) and promoter (-3 18) in 80 SLE patients and 86 healthy control subjects. The genotype distri bution of the CTLA-4 exon 1 (+49) differed between SLE patients and control s (chi (2) = 6.74, 2 degrees of freedom (d.f.), P = 0.03). The CTLA-4 AG ge notype occurred more frequently in patients with SLE (46.3% vs 33.7% contro ls). On the other hand, the CTLA-4 AA genotype as well as the CTLA-4 GG gen otype was less frequent among SLE patients than among control subjects (13% vs 9.3% and 52.5% Vs 57.0%, respectively). The genotype distribution of th e CTLA-4 promoter (-318) differed between SLE patients and control subjects (CT, TT, CC; genotypes 27.5%, 0%, 72.5% vs 16.3%, 4.7%, 79.1% controls res pectively, chi (2) = 6.36, 2 d.f., P = 0.04). However, Fischer's exact or c hi (2) P-values for each genotypes of the CTLA-4 exon 1 (+49) and promoter (-318) between SLE and control group were > 0.05. Clinically, in the lupus patients there was no significant difference according to the CTLA-4 polymo rphisms. In conclusion, no correlation was found between CTLA-4 exon 1 (+49) and pro moter (-318) polymorphisms and SLE in our study.