Lack of association of interieukin-6 and interleukin-8 gene polymorphisms in Chinese patients with systemic lupus erythematosus

The purpose of this study was to determine whether interleukin (IL)-6 and IL-8 gene polymorphisms were markers of susceptibility to or severity of systemic lupus erythematosus (SLE) in Chinese patients. The study included 150 Chinese patients with SLE. A total of 130 unrelated healthy individuals living in central Taiwan served as control subjects. Polymorphisms of the IL-6 and IL-8 gene were typed from genomic DNA. The genotypes, allelic frequencies, and carriage rates were compared between SLE patients and control subjects. The relationship between allelic frequencies and clinical manifestations of 135 SLE patients was evaluated. There were no statistically significant differences in IL-6 and IL-8 gene polymorphisms between the SLE and control groups (chi-squared test, P = 0.53, x(2) = 1.27 and P = 0.44, x(2) = 1.62, respectively). In addition, there was no significant association between the two groups in allelic frequency of IL-6 and IL-8 (P = 0.89 and P = 0.26, respectively). We also did not detect any association between the IL-6 and IL-8 genotype and clinical or laboratory profiles in SLE patients. The results suggest that the IL-6 and IL-8 gene polymorphisms are not related to SLE.