Interleukin-1β, Interleukin1-Ra, Interleukin-10, and tumor necrosis factor-α polymorphisms in Tunisian patients with rheumatoid arthritis

Abstract

Objectives: The aim of this study was to investigate the role of IL-1β (-511C>T), TNFα (-308 G>A), IL-10 (-1082 G>A) and IL-1RN VNTR polymorphisms in the susceptibility to rheumatoid arthritis (RA) in Tunisians.

Patients and methods: Using PCR-based methods, 104 RA patients and 150 healthy controls were investigated. We compared allele and genotype frequencies in RA patients versus controls and analyzed their correlations with erosive form (EF).

Results: IL1-RN VNTR A1A3 genotype is associated with higher risk of RA (P=0.012, OR=4.31). Among the cases, males who carry this genotype were more exposed to RA (P=0.044, OR=8, 47). For IL1- β gene, a significantly higher frequency of the -511C/C genotype was observed in RA patients in comparison to controls (P=0.013, OR=2.45). This higher frequency was especially observed in women (P=0,003, OR=3.42). In contrast, IL10-1082G/G genotype was less common in patients (P=0.046, OR=0.46). According to EF, men carrying IL1-RN VNTR A1A3 (P=0.005 OR=5.28) and IL1-β-511C/C (P=0.015 OR=2.61) genotypes develop non EF of RA. Moreover, TNFα-308 A allele (P=0.024, OR=1.84) and A/A genotype (P=0.033, OR=3.1) were positively associated to EF of RA. However, G allele (P=0.024, OR=0.31) and GG genotype (P=0.31, OR=0.031) of the TNFα-308 were protectors.

Conclusion: Our results indicated that IL-1RN VNTR, IL-1β (-511C>T) and IL-10 (-1082 G>A) are associated with susceptibility to RA, and that IL-1RN VNTR, IL-1β (-511C>T) and TNFα (-308 G>A) are associated with severity of RA.

Keywords: Arthrite rhumatoïde; Gene polymorphism; IL-10; IL-1β; IL1-Ra; Polymorphisme du gène; Rheumatoid arthritis; Susceptibility; Susceptibilité; TNF-α.