A detailed meta-analysis shows no association between TNF-α -308G/A polymorphism and different forms of glaucoma

Association of TNF-α gene alterations (c.-238G>A, c.-308G>A, c.-857C>T, c.-863C>A) with primary glaucoma in north Indian cohort

BACKGROUND

Tumor Necrosis Factor-alpha (TNF-α) a pleuripotent pro-inflammatory cytokine, is involved in retinal ganglion cells apoptosis in glaucoma. Thus present study aimed to analyze the association of TNF-α promoter region alterations (c.-238G>A (rs361525), c.-308G>A (rs1800629), c.-857C>T (rs1799724) and c.-863C>A (rs1800630)) with glaucoma in north Indian cohort.

METHODS

Present hospital based case control study involved 286 glaucoma patients (Primary Open Angle Glaucoma [POAG], Primary Angle Closure Glaucoma [PACG], Primary Congenital Glaucoma [PCG]) and 300 controls. TNF-α gene alteration (c.-238G>A (also referred as c.-418G>A; NM_000594.3)), c.-308G>A (c.-488G>A; NM_000594.3), c.-857C>T (c.-1037C>T; NM_000594.3) and c.-863C>A (c.-1043C>A; NM_000594.3) harboring regions were PCR amplified and sequenced by Sanger sequencing. Allele frequency and genotype distribution in glaucoma cases and controls were compared using chi-square test and genetic association tested using different genetic models.

RESULTS

Statistically significant genotype and allelic association was observed between glaucoma cases and controls for c.-308G>A and c.-863C>A alterations (p = 0.001, p = 0.001; p = 0.001, p = 0.001 respectively). AA genotype of c.-308G>A conferred ~7 fold increased risk towards glaucoma (OR = 6.82, 95% CI = 2.82-16.53, p = 0.001). c.-863C>A alteration under dominant, recessive and co-dominant genetic models conferred ~2 fold increased risk for glaucoma. However, no association for c.-238G>A and c.-857C>T variants with glaucoma was observed. Further, three haplotypes (GGCA, GACC and GACA) (OR = 0.48, 95% CI = 0.35-0.67, p = 0.001; OR = 0.58, 95% CI = 0.36-0.91, p = 0.019 and OR = 0.16, 95% CI = 0.05-0.51, p = 0.002, respectively) conferred protective role towards glaucoma.

CONCLUSIONS

Present study is the first to indicate significant association of c.-308G>A and c.-863C>A alterations with glaucoma in cases from north Indian cohort. Also it is the first study from India to analyze the association and interaction of four promoter region alterations (c.-238G>A, c.-308G>A, c.-857C>T and c.-863C>A) in TNF-α resulting in three protective haplotypes.

Genes of tumor necrosis factors and their receptors and the primary open angle glaucoma in the population of Central Russia

AIM

To examine the association of genetic polymorphisms (-308)G/A TNFα, (+250)A/G Ltα, (+36)A/G TNFR1, (+1663)A/G TNFR2 with the development of primary open angle glaucoma (POAG) among people in Central Russia.

METHODS

The study sample included 443 individuals, of which 252 patients with POAG and 191 individuals in the control group. Genotyping of (-308)G/A TNFα, (+250)A/G Ltα, (+36)A/G TNFR1, (+1663)A/G TNFR2 was performed using polymerase chain reaction. The distribution of alleles and genotypes of the studied DNA markers in the groups was examined by 2×2 contingency tables and χ² with the Yates's correction for continuity and odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

Allele (-308)G TNFα (Р=0.01, OR=1.78, 95%CI 1.12-2.85) was identified as a risk factor for POAG. Homozygotes (-308) AA TNFα are at a lowest risk for development of the disease (Р=0.01, OR=0.0005). The following combination of genetic variants of cytokines were associated with a reduced risk of POAG: (+1663)A TNFR2 and (+250)G Ltα (OR=0.34).

CONCLUSION

Genetic polymorphisms (-308)G/A TNFα, (+250)A/G Ltα, (+1663)A/G TNFR2 associated with the development of POAG in the population of Central Russia.

Risk of open angle glaucoma due to tumor necrosis factor alpha gene polymorphisms

INTRODUCTION

Axonal degeneration and retinal ganglion cell apoptosis in glaucoma is associated with tumor necrosis factor alpha (TNF-α), which is an important pro-inflammatory cytokine. The aim of this study was to determine the association between the risk of open angle glaucoma (OAG) in the Egyptian population and tumor necrosis factor alpha (TNF-α) gene polymorphisms.

METHODS

Sixty OAG patients and 26 healthy unrelated controls were used to analyze TNF-α polymorphism G-308A using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP).

RESULTS

the GG genotype was found at a higher frequency in the controls than in the patients, and the AA and GA genotypes were associated strongly with OAG.

CONCLUSION

In this study, we found that the TNF-α polymorphism G-308A was associated significantly with OAG in the Egyptian population. However, there is a need for population-based studies with large numbers of subjects. Also, long-term follow up is required to verify the association between TNF-α polymorphism G-308A and glaucoma susceptibility.

TNF-α Gene Polymorphisms and Primary Open Angle Glaucoma in Romanian Population / Polimorfisme ale genei TNF-α în populația română cu glaucom primar cu unghi deschis

Primary open-angle glaucoma (POAG) represents the most common form of a heterogeneous group of glaucomatous optic neuropathies which are a worldwide cause of irreversible blindness. Immune dysregulation and the genetic background are considered important risk factors. The influence on susceptibility to POAG of single nucleotide polymorphisms (SNPs) of tumor necrosis factor-α (TNF-α) was intensively studied, mostly on Asian population. We investigated the possible association of two TNF-α SNPs (-308G/A and -857C/T) with susceptibility to POAG and its clinical characteristics. A case-control association study of aforementioned TNF-α SNPs was performed on 197 POAG patients (divided into two subgroups: high-tension and normal-tension glaucoma - HTG/ NTG) versus 208 ethnically matched controls. This is the first study performed on Romanian population. No significant differences were found in terms of allelic frequencies, genotype distribution of the studied SNPs, or their haplotypes between POAG and healthy control groups. In the subgroup analysis, TT genotype of TNF-α -857T-allele was found to be associated with higher values of central corneal thickness (CCT) in NTG subgroup (p-value 0.032). In order to confirm the association between -857C/T SNP of TNF-α and CCT in NTG subgroup of POAG patients, additional studies on different populations should be performed.

A nested case control study of plasma ICAM-1, E-selectin and TNF receptor 2 levels, and incident primary open-angle glaucoma

PURPOSE

To evaluate prediagnostic markers of endothelial dysfunction and inflammatory processes in primary open-angle glaucoma (POAG).

METHODS

Blood samples were collected from 1989 to 1990 in the nurses' health study (women) and from 1993 to 1995 in the health professionals follow-up study (men), and medical-record confirmed incident poag cases were identified (women: 229 cases and 455 controls; men: 116 cases and 228 controls). Controls were matched on cohort, age, race, ethnicity, cancer status, and date of blood collection. Plasma concentrations of ICAM-1, E-selectin, and soluble TNF receptor 2 (sTNF-R2), a marker related to TNF-α, were measured with ELISA assays. Cohort-specific multivariable conditional logistic regression model results were meta-analyzed.

RESULTS

We observed no associations with ICAM-1 or E-selectin. for sTNF-R2, the mean (SD) plasma levels (pg/ml) in cases and controls were 2888 (997) and 2993 (913), respectively, in women; and 2622 (664) and 2569 (688), respectively, in men. pooled multivariable results showed no relation between sTNF-R2 levels and POAG. however, compared with the lowest tertile of sTNF-R2, the highest tertile showed a significant decreased risk of POAG in women (multivariable odds ratio [OR] = 0.58, 95% confidence interval [CI] = 0.360.93; P(trend) = 0.03) but not in men (P(trend) = 0.21; P for heterogeneity by sex = 0.03). also, among women, the inverse association with sTNF-R2 was stronger with normal-tension glaucoma (ntg; maximum intraocular pressure 21 mm Hg at diagnosis): highest versus lowest tertile comparison OR = 0.29 (95% CI = 0.12-0.71; Ptrend = 0.007).

CONCLUSIONS

In women, but not in men, higher sTNF-R2 levels at 6 to 8 years before diagnosis were inversely associated with POAG, but more strongly for NTG.

Analysis ofCOCHandTNFAVariants in East Indian Primary Open-Angle Glaucoma Patients

Glaucoma represents a heterogeneous group of optic neuropathies with a complex genetic basis. It is the second-largest cause of blindness in the world that reduces vision without warning and often without symptoms. Among 3 major subtypes of glaucoma, primary open-angle glaucoma (POAG) is the most common form. The focus of this study is to understand the molecular basis of the disease among Indian patients with respect to two genes, Cochlin (COCH) and tumor necrosis factor alpha (TNFA), selected based on reports of possible association with POAG. The genes were screened in patients and controls by PCR and direct sequencing. Although two novel changes (–450 C/T and –79 G/G) were identified in the 5′upstream region of COCH, no causal variant could be identified in either gene. –450 C/T was detected in 3 patients and 2 controls and –79 G/C in a single patient. Further, we did not observe significant association with the promoter SNPs of TNFA that had been previously reported to be associated with POAG pathogenesis. Thus, our study suggests lack of association of both COCH and TNFA with POAG pathogenesis.