Objective: To investigate the possible association of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) promoter -1722 polymorphism with systemic lupus erythematosus (SLE) in the population in southern China.
Methods: A total of 103 SLE patients (13 males and 90 females with an average age of 33.63+/-12.58 years) diagnosed according to the SLE diagnostic criteria of the American College of Rheumatology revised in 1982 and 110 healthy ethnically matched controls (21 males and 89 females with an average age of 27.49+/-8.60 years), all from southern China, were enrolled in the study. DNA was extracted from EDTA-treated blood samples according to the standard isolation procedure. The restriction fragment length polymorphism-polymerase chain reaction was used to analyze CTLA-4 promoter-1722 polymorphism in SLE patients and healthy controls.
Results: Compared with the controls, the SLE patients had higher frequencies of TC genotype (42% vs 58%, P<0.05) and lower frequency of CC genotype (25% vs 15%, P<0.05). There were no significant differences in the frequencies of TT genotype, alleles and phenotypes between SLE patients and controls; however, significant differences in the frequencies of TT genotype and alleles of CTLA-4 promoter -1722 were found among different races (P<0.05).
Conclusion: CTLA-4 promoter -1722 polymorphism appears to be associated with SLE susceptibility in southern Chinese population.