Tumor necrosis factor alpha (TNF-alpha) polymorphisms in Chinese patients with Graves' disease

Polymorphisms within the Tumor Necrosis Factor-Alpha Gene Is Associated with Preeclampsia in Taiwanese Han Populations

Preeclampsia (PE) occurs in women pregnant for more than 20 weeks with de novo hypertension and proteinuria, and is a devastating disease in maternal–fetal medicine. Cytokine tumor necrosis factor (TNF)-α may play a key role in the pathogenesis of PE. We conducted this study to investigate the regulatory regions of the TNF genes, by investigating two promoter polymorphisms, TNFA-308G/A (rs1800629) and -238G/A (rs361525), known to influence TNF expression, and their relationship to PE. An observational, monocentric, case–control study was conducted. We retrospectively collected 74 cases of severe PE and 119 pregnant women without PE as control. Polymerase chain reaction (PCR) was carried out for allele analysis. Higher A allele in women with PE was found in rs1800629 but not rs361525. In this study, we first found that polymorphism at the position -308, but not -238, in the promoter region of the TNF-α gene can contribute to severe PE in Taiwanese Han populations. The results of our study are totally different to previous Iranian studies, but have some similarity to a previous UK study. Further studies are required to confirm the roles of rs1800629 and rs361525 in PE with circulating TNF-α in PE.

Gene polymorphisms of pro-inflammatory cytokines may affect the risk of Graves' disease: a meta-analysis

PURPOSE

Gene polymorphisms of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1) and interleukin-6 (IL-6) may influence the risk of Graves' disease, but the results of so far published studies remain inconclusive. Therefore, the authors conducted this meta-analysis to assess relationships between TNF-α/IL-1/IL-6 polymorphisms and the risk of Graves' disease by pooling the findings of all relevant studies.

METHODS

A comprehensive literature searching of Pubmed, Embase, Web of Science and CNKI was conducted by the authors, and twenty-eight studies were found to be eligible for pooled analyses.

RESULTS

The pooled meta-analyses results showed that genotypic frequencies of TNF-α rs1800629, IL-1A rs1800587, IL-6 rs1800795 and IL-6 rs1800796 polymorphisms among patients with Graves' disease and control subjects differed significantly. Moreover, we found that genotypic frequencies of TNF-α rs1800629 and IL-6 rs1800795 polymorphisms among patients with Graves' disease and control subjects in Caucasians differed significantly, and genotypic frequencies of IL-1A rs1800587, IL-1B rs16944, IL-6 rs1800795 and IL-6 rs1800796 polymorphisms among patients with Graves' disease and control subjects in Asians also differed significantly. Nevertheless, we did not detect such genotypic frequencies differences for TNF-α rs361525 and IL-1B rs1143627 polymorphisms.

CONCLUSIONS

This meta-analysis suggests that TNF-α rs1800629, IL-1A rs1800587, IL-6 rs1800795 and IL-6 rs1800796 polymorphisms may influence the risk of Graves' disease in overall population. Moreover, TNF-α rs1800629 and IL-6 rs1800795 polymorphisms may influence the risk of Graves' disease in Caucasians, while IL-1A rs1800587, IL-1B rs16944, IL-6 rs1800795 and IL-6 rs1800796 polymorphisms may influence the risk of Graves' disease in Asians.

Differential profiling of lacrimal cytokines in patients suffering from thyroid-associated orbitopathy

The aim was to investigate the levels of cytokines and soluble IL-6R in the tears of patients with thyroid-associated orbitopathy (TAO) disease. Schirmer’s test was adopted to collect tears from TAO patients (N = 20, 17 women, mean age (±SD): 46.0 years (±13.4)) and healthy subjects (N = 18, 10 women, 45.4 years (±18.7)). Lacrimal cytokines and soluble IL-6R (sIL-6R) were measured using a 10-plex panel (Meso Scale Discovery Company) and Invitrogen Human sIL-6R Elisa kit, respectively. Tear levels of IL-10, IL-12p70, IL-13, IL-6 and TNF-α appeared significantly higher in TAO patients than in healthy subjects. Interestingly, IL-10, IL-12p70 and IL-8 levels increased in tears whatever the form of TAO whereas IL-13, IL-6 and TNF-α levels were significantly elevated in inflammatory TAO patients, meaning with a clinical score activity (CAS) ≥ 3, compared to controls. Furthermore, only 3 cytokines were strongly positively correlated with CAS (IL-13 Spearman coeff. r: 0.703, p = 0.0005; IL-6 r: 0.553, p = 0.011; IL-8 r: 0.618, p = 0.004, respectively). Finally, tobacco use disturbed the levels of several cytokines, especially in patient suffering of TAO. The differential profile of lacrimal cytokines could be useful for the diagnosis of TAO patients. Nevertheless, the tobacco use of these patients should be taken into account in the interpretation of the cytokine levels.

Association of TNF-α promoter polymorphism and Graves' disease: an updated systematic review and meta-analysis

Graves' disease (GD) is a common autoimmune disorder with a genetic predisposition. Owing to the biological effect of tumor necrosis factor-α (TNF-α) on the thyroid gland and its gene location, TNF-α should be able to influence an individual's susceptibility to GD. In the present study, we conduct a meta-analysis of rs1800629 and rs361525 in TNF-α gene from all eligible case-control studies to assess the associations amongst reported TNF-α gene with GD. A total of ten case-control studies involving 2790 GD patients and 3472 healthy controls were included. The results showed that a significant association was characterized between the rs1800629 polymorphism and GD in the homozygous model (AA compared with GG: odds ratio (OR) = 1.97, 95% confidence interval (CI) = 1.27-3.06, P=0.002) and recessive model (AA compared with GA + GG: OR = 1.62, 95% CI = 1.04-2.50, P=0.03). GD susceptibility was significantly detected in European population in all genetic models after ethnicity stratification. In sharp contrast, no significant association could be detected in Asian population. Next, we conducted a meta-analysis for another promoter SNP rs361525. However, SNP rs361525 did not show a significant association with GD in any genetic model before and after ethnicity stratification. Together, our data support that only the promoter single-nucleotide polymorphism (SNP) rs1800629 within the TNF-α gene is associated with increased risk for developing GD, especially in European population. Future large-scale studies are required to validate the associations between TNF-α gene and GD.

Polymorphisms in inflammation-related genes and the risk of primary varicose veins in ethnic Russians

Inflammation was shown to be activated in varicose veins, although its role in the development of vein wall transformation remains inconclusive. We aimed to investigate the influence of 13 inflammation-related single nucleotide polymorphisms (SNPs) TNF rs1800629 and rs3093661, IL1A rs1800587, IL1RN rs4251961, IL6 rs1800795 and rs1800796, IFNG rs2430561, IL10 rs1800896, TGFB1 rs1800469, HIF1A rs11549465, NFKB1 rs28362491, and rs4648068 on the risk of primary varicose veins (PVVs) in ethnic Russians. We genotyped 709 patients with PVVs and 278 individuals without a history of chronic venous disease and performed a single SNP and a haplotype analysis. Several associations with P < 0.05 were revealed in our study. Variant allele HIF1A rs11549465 T, TNF rs3093661 A, and NFKB1 rs28362491 ATTG deletion showed the reverse association with PVV risk, and allele IL6 rs1800795 C was associated with the increased risk of the studied pathology. Haplotype analysis revealed associations of TNF haplotypes rs3093661 A-rs1800629 G and IL6 rs1800795 C-rs1800796 G with the decreased and the increased risk of PVVs, correspondingly. However, all the observed associations failed to reach statistical significance after the correction for multiple testing, which was set at a level of 10^-3 due to many tests performed. Our study therefore provides evidence that investigated polymorphisms do not play a major role in susceptibility to PVVs.

Tumor Necrosis Factor Alpha Gene Polymorphism and Association With Its Serum Level in Iranian Population with Rheumatoid Arthritis

Objectives

This study aims to determine whether promoter -238 G/A polymorphism in tumor necrosis factor-alpha (TNF-α) gene is associated with susceptibility to rheumatoid arthritis (RA) in Iranian population and serum level of TNF-a.

Patients and methods

This case-controlled study was performed on two groups including 90 RA patients (20 males, 70 females; mean age 50.3 years; range 26 to 65 years) and 90 healthy controls (21 males, 69 females; mean age 48.6 years; range 27 to 63 years). We determined the frequency of -238 G/A TNF-a gene polymorphism by polymerase chain reaction restriction fragment length polymorphism. We measured the serum level of TNF-a using enzyme-linked immunosorbent assay method. Also, we determined the association of serum TNF-a level with the polymorphism in RA patients.

Results

There was no significant difference in terms of sex and age in the two groups. In the RA group, the genotype frequency of -238 G/A polymorphism was GG (76.6%), GA (17.8%), and AA (5.6%). In the control group, the genotype frequency of -238 G/A polymorphism was GG (83.5%), GA (8.8%), and AA (7.7%). Statistical analysis showed no significant difference in the genotype frequency of this polymorphism between two groups (p=0.07). The serum level of TNF-a were 5.21±1.69 Pg/mL (range 0 to 11.6) in the control group and 62.4±27.1 Pg/mL (range 0 to 117.22) in the RA group (p<0.0001). There was no significant difference in terms of serum TNF-a level and different genotypes in the RA group (p=0.5).

Conclusion

Our findings demonstrate that the TNF-a -238 G/A gene polymorphism may not represent a significant risk factor for RA in Iranian population and there is no association between the polymorphism and serum TNF-a level in RA patients.

The Tumor Necrosis Factor-α-308 and -238 Polymorphisms and Risk of Hepatocellular Carcinoma for Asian Populations: A Meta-Analysis

BACKGROUND

Tumor necrosis factor-α (TNF-α) has been suggested to play a very important role in the development and progression of hepatocellular carcinoma (HCC). Many studies have identified the associations of TNF-α-308 and -238 polymorphisms with HCC risk, but the results remain controversial.

AIM

We conducted this meta-analysis to evaluate the associations between TNF-α-308 and -238 polymorphisms and HCC susceptibility.

METHODS

PubMed, Embase, and China National Knowledge Infrastructure electronic databases were searched for all articles on associations between TNF-α-308 and -238 polymorphisms and HCC risk in Asians through September 30, 2013. Odds ratios (ORs) and their 95% CIs were calculated to assess the strength of this association.

RESULTS

A total of 17 case-control studies were identified in our meta-analysis. For the TNF-α-308 G/A polymorphism, 14 studies containing 3154 cases and 3767 controls were included. Overall, the frequency of the A allele was higher in patients with HCC than in the healthy controls (10.2% vs 7.5%), and the A allele and allele carrier were significantly associated with increased risk of HCC in a random effects model (A vs G: OR = 1.57; 95% CI, 1.22-2.01; P = 0.0004; AA + AG vs GG: OR = 1.62; 95% CI, 1.18-2.22; P = 0.003). For the TNF-α-238 polymorphism, 10 research articles were identified. No association was found between the TNF-α-238 G/A polymorphism and risk of HCC in any genetic models (P > 0.05). The sensitivity analysis further strengthened the overall correlations.

CONCLUSIONS

Our meta-analysis proved that the TNF-α-308 G/A polymorphism is associated with increased susceptibility to HCC. However, the TNF-α-238 G/A polymorphism is not significantly associated with risk of HCC in Asian populations. Further studies with large sample sizes are needed to confirm these associations among other populations.

TNF-α promoter single nucleotide polymorphisms and haplotypes associate with susceptibility of immune thrombocytopenia in Chinese adults

OBJECTIVE

Tumor necrosis factor-alpha (TNF-α) participates as a candidate susceptibility factor for immune thrombocytopenia (ITP). This study attempted to investigate the association between five single nucleotide polymorphisms (SNPs) spanning the TNF-α promoter and the susceptibility of primary ITP in Chinese Han adults.

METHODS

In 215 adult primary ITP patients and 206 healthy controls, SNPs were detected by PCR-RFLP and PCR-SSP. The χ(2) test or fisher's exact test was used to compare frequencies of genotypes and alleles between patients and controls. Haplotypes were analyzed with the SHEsis online program. TNF-α, IFN-γ and Galectin-9 mRNA of 35 newly diagnosed adult ITP patients and 35 healthy controls were detected by qRT-PCR.

RESULTS

The haplotype GGC (-238G/-308G/-857C) of TNF-α promoter was significantly associated with a decreased susceptibility of primary ITP, especially in males. The relative levels of mRNA expression of TNF-α, IFN-γ and Gal-9 in adult active primary ITP patients was significantly up-regulated compared with patients in remission and controls.

CONCLUSIONS

This study represented the first report that the haplotype GGC of TNF-α was differentially associated with the susceptibility of primary ITP in Chinese Han adults. The up-regulation of TNF-α, IFN-γ and Galectin-9 was significantly correlated with active primary ITP in adult patients.

Polymorphisms in the TNFA and IL6 genes represent risk factors for autoimmune thyroid disease

BACKGROUND

Autoimmune thyroid disease (AITD) comprises diseases including Hashimoto's thyroiditis and Graves' disease, both characterized by reactivity to autoantigens causing, respectively, inflammatory destruction and autoimmune stimulation of the thyroid-stimulating hormone receptor. AITD is the most common thyroid disease and the leading form of autoimmune disease in women. Cytokines are key regulators of the immune and inflammatory responses; therefore, genetic variants at cytokine-encoding genes are potential risk factors for AITD.

METHODS

Polymorphisms in the IL6-174 G/C (rs1800795), TNFA-308 G/A (rs1800629), IL1B-511 C/T (rs16944), and IFNGR1-56 T/C (rs2234711) genes were assessed in a case-control study comprising 420 Hashimoto's thyroiditis patients, 111 Graves' disease patients and 735 unrelated controls from Portugal. Genetic variants were discriminated by real-time PCR using TaqMan SNP genotyping assays.

RESULTS

A significant association was found between the allele A in TNFA-308 G/A and Hashimoto's thyroiditis, both in the dominant (OR = 1.82, CI = 1.37-2.43, p-value = 4.4×10(-5)) and log-additive (OR = 1.64, CI = 1.28-2.10, p-value = 8.2×10(-5)) models. The allele C in IL6-174 G/C is also associated with Hashimoto's thyroiditis, however, only retained significance after multiple testing correction in the log-additive model (OR = 1.28, CI = 1.06-1.54, p-value = 8.9×10(-3)). The group with Graves' disease also registered a higher frequency of the allele A in TNFA-308 G/A compared with controls both in the dominant (OR = 1.85, CI = 1.19-2.87, p-value = 7.0×10(-3)) and log-additive (OR = 1.69, CI = 1.17-2.44, p-value = 6.6×10(-3)) models. The risk for Hashimoto's thyroiditis and Graves' disease increases with the number of risk alleles (OR for two risk alleles is, respectively, 2.27 and 2.59).

CONCLUSIONS

This study reports significant associations of genetic variants in TNFA and IL6 with the risk for AITD, highlighting the relevance of polymorphisms in inflammation-related genes in the etiopathogenesis of AITD.

Tumour necrosis factor gene polymorphism and disease prevalence

Tumour necrosis factor (TNF), an important proinflammatory cytokine, plays a role in the regulation of cell differentiation, proliferation and death, as well as in inflammation, innate and adaptive immune responses, and also implicated in a wide variety of human diseases. The presence of DNA sequence variations in regulatory region might interfere with transcription of TNF gene, influencing the circulating level of TNF and thus increases the susceptibility to human diseases (infectious, cancer, autoimmune, neurodegenerative and other diseases). In this review, we have comprehensively analysed various published case-control studies of different types of human diseases, in which TNF gene polymorphism played a role, and computationally predicted several single nucleotide polymorphisms (SNPs) lie in transcription factor-binding sites (TFBS) of transcription factors (TFs). It has been observed that TNF enhancer polymorphism is implicated in several diseases, and TNF rs1800629 and rs361525 SNPs are the most important in human disease susceptibility as these might influence the transcription of TNF gene. Thirty-two SNPs lies in TFBS of 20 TFs have been detected in the TNF upstream region. It has been found that TNF enhancer polymorphism influences the serum level of TNF in different human diseases and thus affects the susceptibility to diseases. The presence of DNA sequence variation in TNF gene causes the modification of transcriptional regulation and thus responsible for association of susceptibility/resistance with human diseases.