Comparison of single nucleotide polymorphisms in the human interleukin-10 gene promoter between rheumatoid arthritis patients and normal subjects in Malaysia

Abstract

In this study, three single nucleotide polymorphisms (SNPs) located within the promoter of the human interleukin (IL)-10 gene [rs1800896 (position: ?1087G > A), rs1800871 (position: ?824C > T) and rs1800872 (position: ?597C > A)] were investigated in 84 rheumatoid arthritis (RA) patients and 95 age- and sex-matched healthy subjects using polymerase chain reaction-restriction fragment length polymorphism method. Production of IL-10 by peripheral blood lymphocytes from the RA patients and healthy subjects cultured in the presence of Concanavalin A (Con A) was determined by using enzyme-linked immunosorbent assay. The results show that the distribution of the IL-10 genotypes did not differ significantly between RA patients and healthy subjects (P > 0.05). However, a significant difference was observed in allele frequencies of ?824CT, ?824TT, ?597CA, and ?597AA between the RA patients and healthy volunteers (P = 0.04). The ?1087A/?824T/?597A (ATA) haplotype, which comprises all mutant alleles, was associated with lower IL-10 production when compared with the other haplotypes. In contrast, the RA patients who did not display the ATA haplotype produced significantly higher levels of IL-10 when compared with those carrying either one (P = 0.012) or two (P = 0.005) ATA haplotypes. Our findings suggest that there is an association between SNPs in the promoter of the human IL-10 gene and susceptibility to RA.