Cytokine (IL-6) and chemokine (IL-8) gene polymorphisms among rheumatoid arthritis patients in Taiwan

CER3350
2008 Vol.26, N°4
PI 0632, PF 0637
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PMID: 18799095 [PubMed]

Abstract

OBJECTIVES:
The involvement of cytokines and chemokines in the pathogenesis of rheumatoid arthritis (RA) is well studied; however, the genetic bases behind this is not well understood. The aim of this study was to examine whether -572 G/C polymorphism in the IL-6 gene and 2767 A/G polymorphism in the 3`-untranslated region (UTR) of the IL-8 gene are associated with rheumatoid arthritis (RA).
METHODS:
We enrolled 199 RA patients and 130 normal controls. Polymerase chain reaction was used to identify the IL-6 -572G/C and IL-8 3`-UTR 2767A/G polymorphisms. The relationships between clinical manifestations of RA and the polymorphisms of each gene were investigated by comparing the genotypes among RA patients with different clinical variables.
RESULTS:
We found no significant difference in the genotypic and allelic frequencies of the single nucleotide polymorphisms of IL-6 and IL-8 genes between RA patients and controls. Clinical characteristics such as age at onset, rheumatoid factor positivity, joint erosion and extra-articular manifestations were compared among patients with different genotypes of the IL-6 and IL-8 genes. We found that patients with IL-8 3`-UTR 2767AA genotype had a significantly younger age of onset of RA than patients without that genotype.
CONCLUSIONS:
The IL-6 -572 G/C and IL-8 3`-UTR 2767A/G polymorphisms are not associated with the risk of developing rheumatoid arthritis. However, the finding that patients with IL-8 3`-UTR 2767AA developed RA at a younger age suggests that this genotype may influence the etiopathology of RA in patients in Taiwan. Therefore, further single nucleotide polymorphism studies of this 3`UTR region may give more novel findings and understanding of the genetic basis of rheumatoid arthritis.