Correlation between some Th1 and Th2 cytokine receptor gene polymorphisms and systemic lupus erythematosus in Chinese patients

Background: Genetic factors seem to play a significant role in the susceptibility to systemic lupus erythematosus (SLE). Some researchers have described amino acid polymorphisms within the interleukin-4 receptor (IL-4R) [isoleucine50valine (Ile50Val), arginine576glutamine (Arg576Gln), etc.], the IL-10R (G241A and G520A), and the interferon-γ receptor (IFN-γR) [valine14methionine (Val14Met) and glutamine64arginine (Gln64Arg)]: Methods: The Ile50Val genotypes were examined by the reverse transcription-polymerase chain reaction-single-strand conformation polymorphism (RT-PCR-SSCP) method and DNA sequencing. The RT-PCR-restriction fragment length polymorphism (RT-PCR-RFLP) method was used to detect the Arg576Gln, G241A, G520A, Val14Met, and Gln64Arg genotypes. Results: There were significant differences in the genotype frequencies of Ile50/Ile50, G520/G520, and G520/A520 between the SLE group and healthy control group. There was a positive correlation between the IL-4R Ile50/Ile50 genotype and the susceptibility to SLE (P=0.022). This was also found for the IL-10R G520/G520 (P=0.004) and G520/A520 (P=0.055) genotypes. The risk of SLE susceptibility was increased in individuals with the genotype combinations Ile50/Ile50 and Gln576/Arg576 (P=0.056) and G241/G241 and G520/G520 (P=0.004). The IFN-γR2 Arg64/Arg64 genotype decreased the risk of SLE (P=0.047). A decreased risk of development of SLE was detected in individuals with the genotype combination IFN-γR2 Arg64/Arg64 and IFN-γR1 Val14/Val14 (P=0.004). Conclusions: The IL-4R Ile50/Ile50 and IL-10R2 G520/G520 and G520/A520 genotypes were shown to determine the susceptibility to SLE in a Chinese population, as were the combinations Ile50/Ile50 and Gln576/Arg576, and G241/G241 and G520/G520.