Association of tumour necrosis factor-alpha G/A -238 and G/A -308 single nucleotide polymorphisms with juvenile idiopathic arthritis

Functional impact of allelic variations/haplotypes of TNF-α on reproductive tract infections in Indian women

The aim of the present study is to investigate the functional role of TNF-α single-nucleotide polymorphisms/haplotypes in an association with reproductive tract infections (RTIs) in symptomatic and asymptomatic women. A total of 850 consecutive subjects consisting of 400 cases and 450 healthy controls, were screened for RTIs, along with their risk factors and associated symptoms. The propensity score matching was performed to reduce the confounding bias arise owing to covariates and to balance the data between two groups. A total of 211 pairs (1:1) have been created. Genotyping of rs1800629 (-308) and rs361525 (-238) SNPs of TNF-α was done by PCR–RFLP followed by sequencing. The functional implication of TNF-α SNPs in an association with RTIs was also checked by using ELISA. The frequency of -238A allele and -308A allele was found to be twofold (P < 0.0001) and threefold (P < 0.0001) higher in the presence of RTIs. AA haplotype emerged as a major player in an association with RTIs and elevated TNF-α expression. The present study revealed the functional role of rs1800629 (-308) and rs361525 (-238) of TNF-α in an association with RTIs. This information may be used to establish biomarkers for an inflammatory response during the persistence of RTIs.

Interleukin-23 receptor gene polymorphisms in Iranian patients with juvenile systemic lupus erythematosus

INTRODUCTION AND OBJECTIVES

Considering the possible roles of interleukin-23 receptor (IL-23R) gene in the pathogenesis of juvenile systemic lupus erythematosus (JSLE), the objective of this study was to elucidate whether polymorphisms of the IL23R are associated with susceptibility to JSLE in an Iranian population.

MATERIALS AND METHODS

A case-control study on 62 patients with JSLE and 78 healthy controls was performed to investigate the associations of four single nucleotide polymorphisms (SNPs) in IL-23R gene, namely, rs7517847, rs10489629, rs11209026, and rs1343151, with susceptibility to JSLE, using real-time polymerase chain reaction Taqman genotyping technique.

RESULTS

Analysis of allele and genotype frequency of four selected SNPs revealed statistically significant positive association between homozygous variant of rs7517847 (TT) (P, 0.02) and T allele at the same position (P, 0.01) with JSLE vulnerability. There was no significant association between other evaluated SNPs and JSLE susceptibility.

CONCLUSION

These findings suggest that particular IL-23R gene variants could affect individual susceptibility to JSLE.

Association between interleukin-1, interleukin-6, and tumor necrosis factor-alpha polymorphisms and juvenile idiopathic arthritis: a meta-analysis

INTRODUCTION

In juvenile idiopathic arthritis (JIA), interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha (TNF-α) are associated with development and progression of JIA. We investigated whether IL-1, IL-6, and TNF-α polymorphisms were associated with susceptibility to JIA.

EVIDENCE ACQUISITION

A meta-analysis was conducted on the associations between IL-1α-899 C/T, IL-1β-511 C/T, IL-6-174 G/C, and TNF-α-308 G/A and -238 G/A polymorphisms, and JIA (PubMed and Embase).

EVIDENCE SYNTHESIS

A total of 27 studies involving 4678 JIA patients and 7634 controls were considered in the meta-analysis. There was no association between the IL-1α-899 C/T, IL-1β-511 C/T, IL-6-174 G/C, and TNF-α-308 G/A and -238 G/A polymorphisms, and JIA in allele contrast or any other genetic models. In subgroup analysis based on subtype, except for the dominant model of TNF-α-238 G/A, systemic JIA was not significantly associated with IL-6 and TNF-α polymorphisms. In Caucasians, the dominant and additive models of IL-1β-511 C/T were significantly associated with JIA (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.09-2.00, P=0.01; OR 1.46, 95% CI 1.05-2.03, P=0.02, respectively).

CONCLUSIONS

This meta-analysis showed no association between IL-1, IL-6, and TNF-α polymorphisms, and JIA, but the TT genotype of IL-1β -511 C/T was associated with higher prevalence of JIA in Caucasians.

The association between TNF-α 238A/G and 308A/G polymorphisms and juvenile idiopathic arthritis: An updated PRISMA-compliant meta-analysis

OBJECTIVE

A previous meta-analysis concluded that TNF-α 238A/G and TNF-α 308A/G polymorphisms were not associated with the risk of juvenile idiopathic arthritis (JIA) in the overall population or Caucasian subjects. With the publication of a fair number of studies on the association between TNF-α polymorphisms and JIA in recent years, we conducted this updated meta-analysis to make a more accurate evaluation of such relationship.

METHODS

We adopted PubMed, EMBASE, ISI Web of Science and CNKI to identify observational studies that addressed the association between TNF-α polymorphisms and risk for JIA. The allelic effect of variant A for the risk of JIA was expressed as odds ratio (OR) along with the associated 95% confidence interval (95% CI). Meta-analyses were performed by pooling ORs and 95%CI from included studies using RevMan 5.3 software. The stratified-analysis based on ethnicity was performed to confirm the ethnicity-dependent effect on the relationship.

RESULTS

A total of 15 case-control studies including 2845 patients in JIA groups and 4771 patients in control groups were included in our study. The findings indicated a statistically significant association between the A allele of the TNF-alpha 238A/G polymorphism and the decreased JIA risk in Caucasians (P = .0002). The study in Iranian showed similar results (P = .0002) whereas the studies in other ethnicities failed to replicate this finding: Han (P = .29), Mexican (P = .64) and Turkish population (P = .32). TNF-α 308A/G was not statistically associated with JIA in overall subjects or Caucasians.

CONCLUSION

Our study confirmed the protective role of the A allele in TNF-α 238A/G but not TNF-α 308A/G against the occurrence of JIA in the Caucasian population. To exactly validate the correlation between TNF-α polymorphisms and JIA in other ethnic backgrounds, additional studies are required.

TNF-α -308G/A gene polymorphism in bullous pemphigoid and alopecia areata

BACKGROUND

TNF-α -308G/A polymorphism has been investigated in few studies for an association with susceptibility to bullous pemphigoid (BP) and alopecia areata (AA). Yet, these findings had so far not been independently replicated, and no data on a possible association of TNFα -308G/A polymorphism with these diseases in Iranian population were available.

OBJECTIVES

In the present study, a possible effect of TNF-α -308G/A variation on susceptibility to BP or AA disease was evaluated.

METHODS

Genomic DNA was extracted from the blood of the patients with BP and AA as well as control subjects which genotyped for the TNF-α -308 G/A polymorphism. TNF-α gene expression levels were analyzed by real-time RT-PCR.

RESULTS

No association was observed between the TNF-α -308 G/A variation and susceptibility to BP or AA diseases in our Iranian cohort. In contrast to AA patients, expression of TNF-α gene was significantly higher in BP patients compared to control group. TNF-α gene was found to be similarly expressed in mutant and wild-type genotypes.

CONCLUSIONS

TNF-α -308G/A polymorphism is not associated with the risk to develop of BP and AA in our Iranian cohort. Furthermore, this polymorphism is contributed to altering the levels of gene expression in BP disease.