Interleukin-6 gene -174 promoter polymorphism is associated with endothelial dysfunction in patients with rheumatoid arthritis

CER361
2009 Vol.27, N°6
PI 0964, PF 0970
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PMID: 20149313 [PubMed]

Received: 27/04/2009
Accepted : 26/06/2009
In Press: 02/04/2010
Published: 02/03/2010

Abstract

OBJECTIVES:
To determine whether the interleukin (IL)6 -174 gene polymorphism may influence the development of subclinical atherosclerosis manifested by the presence of endothelial dysfunction in RA patients.PATIENTS AND
METHODS:
311 patients (228 [73.3%] women; 243 [78.1%] rheumatoid factor positive) who fulfilled the 1987 ACR classification criteria for RA seen at the Rheumatology outpatient clinic of Hospital Xeral-Calde, Lugo between March 1996 and December 2006 and 226 matched controls were included in this study. Between March and December 2007, a subgroup of 98 patients randomly selected was assessed for the presence of endothelial dysfunction. Patients and controls were genotyped for a single biallelic (G/C) nucleotide polymorphism (rs1800795) in the promoter region at the position -174 of the IL6 gene using a TaqMan 5´ allele discrimination assay.
RESULTS:
No significant differences in the IL6 -174 allele or genotype frequency between RA patients and controls were found. However, RA patients homozygous for the IL6 -174 GG genotype had more severe endothelial dysfunction (flow-mediated endothelium-dependent vasodilatation-FMD%: 4.2±6.6) than those carrying the IL6 -174 GC (FMD%: 6.3±8.1) or IL6 -174 CC (FMD%: 6.0±3.3) genotypes. In this regard, significant differences were observed when FMD% values in RA patients carrying the IL6 -174 GG genotype were compared with that observed in those carrying the IL6 -174 GC and the IL6 -174 CC genotypes (FMD%: 6.3±4.6) (p=0.02).
CONCLUSIONS:
Our results support a role of IL6 -174 gene polymorphism in the development of subclinical atherosclerosis in patients with RA.