Interleukin-10 promoter polymorphisms in Southern Chinese patients with systemic lupus erythematosus

OBJECTIVE: To study the genetic association of interleukin-10 (IL-10) promoter polymorphisms in Southern Chinese patients with systemic lupus erythematosus (SLE), and to investigate possible associations with clinical manifestations of the disease. METHODS: DNA was extracted from 88 Chinese patients with SLE and 83 ethnically matched controls. The IL-10 promoter region between positions -533 and -1120 was amplified by polymerase chain reaction, and polymorphisms were detected by restriction-enzyme cleavage. RESULTS: No significant difference in the allele or haplotype frequencies between SLE patients and controls could be demonstrated. The *A and *C alleles at the -597 position were linked to the *T and *C alleles at the -824 position, respectively. However, when clinical features were examined, the *A allele at the -597 position and the *T allele at the -824 position were significantly associated with lupus nephritis, by chi-square analysis (P < 0.001, odds ratio 4.19, 95% confidence interval 2.02-8.71). Similarly, the haplotype -1087*A/-824*T/-597*A was also associated with renal involvement (P < 0.001, odds ratio 3.62, 95% confidence interval 1.80-7.31). CONCLUSION: IL-10 promoter polymorphisms are not strong determinants of susceptibility to the development of SLE, per se, in Southern Chinese individuals. However, IL-10 genotypes are strongly associated with certain clinical manifestations of SLE and may have a role in predicting disease prognosis.