Is there a future for TNF promoter polymorphisms?

Metabolomics analysis in saliva from periodontally healthy, gingivitis and periodontitis patients

OBJECTIVE

The aim of this study was to investigate metabolomics markers in the saliva of patients with periodontal health, gingivitis and periodontitis.

BACKGROUND

The use of metabolomics for diagnosing and monitoring periodontitis is promising. Although several metabolites have been reported to be altered by inflammation, few studies have examined metabolomics in saliva collected from patients with different periodontal phenotypes.

METHODS

Saliva samples collected from a total of 63 patients were analysed by nuclear magnetic resonance (NMR) followed by ELISA for interleukin (IL)-1β. The patient sample, well-characterised clinically, included periodontal health (n = 8), gingivitis (n = 19) and periodontitis (n = 36) cases, all non-smokers and not diabetic.

RESULTS

Periodontal diagnosis (healthy/gingivitis/periodontitis) was not associated with any salivary metabolites in this exploratory study. Periodontal staging showed nominal associations with acetoin (p = .030) and citrulline (p = .047). Among other investigated variables, the use of systemic antibiotics in the previous 3 months was associated with higher values of the amino acids taurine, glycine and ornithine (p = .002, p = .05 and p = .005, respectively, at linear regression adjusted for age, gender, ethnicity, body mass index and staging).

CONCLUSION

While periodontal staging was marginally associated with some salivary metabolites, other factors such as systemic antibiotic use may have a much more profound effect on the microbial metabolites in saliva. Metabolomics in periodontal disease is still an underresearched area that requires further observational studies on large cohorts of patients, aiming to obtain data to be used for clinical translation.

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.

Polymorphisms in Lymphotoxin-Alpha as the "Missing Link" in Prognosticating Favourable Response to Omega-3 Supplementation for Dry Eye Disease: A Narrative Review

Elements of inflammation are found in almost all chronic ocular surface disease, such as dry eye disease. The chronicity of such inflammatory disease speaks to the dysregulation of innate and adaptive immunity. There has been a rising interest in omega-3 fatty acids to attenuate inflammation. While many cell-based (in vitro) studies verify the anti-inflammatory effects of omega-3, different human trials report discordant outcomes after supplementation. This may be due to underlying inter-individual differences in inflammatory cytokine metabolism (such as tumor necrosis factor alpha (TNF-α)), in which genetic differences might play a role, such as polymorphisms in the lymphotoxin alpha (LT-α) gene. Inherent TNF-α production affects omega-3 response and is also associated with LT-α genotype. Therefore, LT-α genotype might predict omega-3 response. Using the NIH dbSNP, we analyzed the relative frequency of LT-α polymorphisms among various ethnicities, each weighted by the genotype's probability of positive response. While the probability of response for unknown LT-α genotypes are 50%, there is greater distinction in response rates between various genotypes. Hence, there is value in genetic testing to prognosticate an individual's response to omega-3.

Polymorphisms of TNF-alpha (− 308), IL-1beta (+ 3954) and IL1-Ra (VNTR) are associated to severe stage of endometriosis in Mexican women: a case control study

Background

Endometriosis is an estrogen-dependent and chronic inflammatory disease affecting up to 10% of women. It is the result of a combined interaction of genetic, epigenetic, environmental, lifestyle, reproductive and local inflammatory factors. In this study, we investigated whether single nucleotide polymorphisms (SNPs) mapping to TNF-alpha (TNF, rs1800629) and IL-1beta (IL1B, rs1143634) and variable number tandem repeat polymorphism mapping to IL1-Ra (IL1RN intron 2, rs2234663) genetic loci are associated with risk for endometriosis in a Mexican mestizo population.

Methods

This study included 183 women with confirmed endometriosis (ENDO) diagnosed after surgical laparoscopy and 186 women with satisfied parity and without endometriosis as controls (CTR). PCR/RFLP technique was used for genotyping SNPs (rs1800629 and rs1143634); PCR for genotyping rs2234663.

Results

We found no statistical differences in age between groups nor among stages of endometriosis and the CTR group. We observed no difference in genotype and allele frequencies, nor carriage rate between groups in none of the three studied polymorphisms. The prevalence of TNF*2-allele heterozygotes (p = 0.025; OR 3.8), TNF*2-allele (p = 0.029; OR 3.4), IL1B*2-allele heterozygotes (p = 0.044; OR 2.69) and its carriage rate (p = 0.041; OR 2.64) in endometriosis stage IV was higher than the CTR group. Surprisingly, the carriage rate of IL1RN*2-allele (ENDO: p = 0.0004; OR 0.4; stage I: p = 0.002, OR 0.38; stage II: p = 0.002, OR 0.35; stage III: p = 0.003, OR 0.33), as well as the IL1RN*2-allele frequencies (ENDO: p = 0.0008, OR 0.55; I: p = 0.037, OR 0.60; II: p = 0.002, OR 0.41; III: p = 0.003, OR 0.38) were lower than the CTR group. Women with endometriosis stage IV (severe) had frequencies more alike to the CTR group in the IL1RN*2 allele frequency (31.2% vs. 27.2%) and carriage rate (37.5% vs. 41.9%).

Conclusion

Although these polymorphisms are not associated with the risk of endometriosis, Mexican mestizo women with severe stage of endometriosis have higher frequencies of TNF*2-, IL1B*2- and IL1RN*2-alleles, which may explain a possible correlation with disease severity rather than predisposition or risk.

Potential Value of TNF-α (-376 G/A) Polymorphism and Cystatin C (CysC) in the Diagnosis of Sepsis Associated Acute Kidney Injury (S-AK I) and Prediction of Mortality in Critically Ill patients

Sepsis Associated Kidney Injury represents a major health concern as it is frequently associated with increased risk of mortality and morbidity. We aimed to evaluate the potential value of TNF-α (-376 G/A) and cystatin C in the diagnosis of S-AKI and prediction of mortality in critically ill patients. This study included 200 critically ill patients and 200 healthy controls. Patients were categorized into 116 with acute septic shock and 84 with sepsis, from which 142 (71%) developed S-AKI. Genotyping of TNF-α (-376 G/A) was performed by RT-PCR and serum CysC was assessed by Enzyme Linked Immunosorbent Assay. Our results showed a highly significant difference in the genotype frequencies of TNF-α (-376 G/A) SNP between S-AKI and non-AKI patients (p < 0.001). Additionally, sCysC levels were significantly higher in the S-AKI group (p = 0.011). The combination of both sCysC and TNF-α (-376 G/A) together had a better diagnostic ability for S-AKI than sCysC alone (AUC = 0.610, 0.838, respectively). Both GA and AA genotypes were independent predictors of S-AKI (p= < 0.001, p = 0.002 respectively). Additionally, sCysC was significantly associated with the risk of S-AKI development (Odds Ratio = 1.111). Both genotypes and sCysC were significant predictors of non-survival (p < 0.001), suggesting their potential role in the diagnosis of S-AKI and prediction of mortality.

SNPs in genes encoding for IL-10, TNF-α, and NFκB p105/p50 are associated with clinical prognostic factors for patients with Hodgkin lymphoma

Classical Hodgkin lymphoma (cHL) is a B-cell-derived malignant neoplasia that has a unique histological distribution, in which the scarce malignant Hodgkin and Reed-Sternberg cells are surrounded by nonmalignant inflammatory cells. The interactions between the malignant and inflammatory cells are mediated by aberrantly produced cytokines, which play an important role in tumor immunopathogenesis. Single nucleotide polymorphisms (SNPs) in genes encoding cytokines and their regulatory proteins may influence the peripheral levels of these molecules and affect disease’s pathobiology. In this study, we evaluate SNPs in the promoter regions of the genes encoding for two key cytokines in Hodgkin lymphoma: IL-10 (SNP/pIL10–592, rs1800872; and SNP/pIL10–1082, rs1800896) and TNF-α (SNP/pTNF -238, rs361525; and SNP/pTNF -862, rs1800630), as well as an SNP in the intronic region of the NFκB1 gene (SNP/iNFKB1, rs1585215), an important regulator of cytokine gene expression. We then look to their possible association with clinical and laboratory features in cHL patients. Seventy-three patients with cHL are genotyped by qPCR-high resolution melting. The SNPs’ genotypes are analyzed individually for each SNP, and when more than two allelic combinations are identified, the genotypes are also divided into two groups according to proposed biological relevance. By univariate analysis, patients harboring SNP/pTNF -238 AG genotype more frequently have EBV-associated cHL compared to homozygous GG, whereas the presence of mediastinal disease (bulky and nonbulky) is more common in the pIL10–592 AC/CC group compared to the AA homozygous group. Patients with SNP/iNFKB1 AA genotype more frequently have stage IV and extranodal disease at diagnosis. These results indicate that some SNPs’ genotypes for IL-10 and TNF-α genes are associated with prognostic parameters in cHL. For the first time, the SNP/iNFKB1 is described in association with clinical features of the disease.

TNF-α/HMGB1 inflammation signalling pathway regulates pyroptosis during liver failure and acute kidney injury

OBJECTIVE

Acute kidney injury (AKI) is a common complication of acute liver failure (ALF). Pyroptosis is a necrosis type related to inflammation. This study aimed to investigate the role of TNF-α/HMGB1 pathway in pyroptosis during ALF and AKI.

METHODS

An ALF and AKI mouse model was generated using LPS/D-Gal, and a TNF-α inhibitor, CC-5013, was used to treat the mice. THP-1 cells were induced to differentiate into M1 macrophages, then challenged with either CC-5013 or an HMGB1 inhibitor, glycyrrhizin. pLVX-mCMVZsGreen-PGK-Puros plasmids containing TNF-α wild-type (WT), mutation A94T of TNF-α and mutation P84L of TNF-α were transfected into M1 macrophages.

RESULTS

Treatment with CC-5013 decreased the activation of TNF-α/HMGB1 pathway and pyroptosis in the treated mice and cells compared with the control mice and cells. CC-5013 also ameliorated liver and kidney pathological changes and improved liver and renal functions in treated mice, and the number of M1 macrophages in the liver and kidney tissues also decreased. The activation of TNF-α/HMGB1 pathway and pyroptosis increased in the M1 macrophage group compared with the normal group. Similarly, the activation of TNF-α/HMGB1 pathway and pyroptosis in the LPS + WT group also increased. By contrast, the activation of the TNF-α/HMGB1 pathway and pyroptosis decreased in the LPS + A94T and LPS + P84L groups. Moreover, glycyrrhizin inhibited pyroptosis.

CONCLUSION

The TNF-α/HMGB1 inflammation signalling pathway plays an important role in pyroptosis during ALF and AKI.

DNA hypermethylation does not negatively impact the transcription of the TNF-α gene in an acute T-cell leukemia

Aims: To better understand the roles of DNA methylation and histone acetylation in the transcription of the TNF-α gene (TNFA) in leukemic T cells. Materials & methods: Methylation levels of cytosine-guanosine dinucleotides (CPGs) were assessed by mass spectrometry. The influence of epigenetic modifiers on DNA methylation and TNFA transcription was also determined. Results: CPG at the 5' promoter region, first exon and first intron of TNFA were hypermethylated in leukemic T cells and not impacted by epigenetic drugs. Activation of the class III histone deacetylases but not inhibitors of DNA methylation or histone deacetylases repressed TNFA transcription. Conclusion: These results lend insights into the impact of epigenetic mechanisms on the TNFA transcription in leukemic T cells.

Frequency of Interleukins IL1ß/IL18 and Inflammasome NLRP1/NLRP3 Polymorphisms in Sickle Cell Anemia Patients and their Association with Severity Score

BACKGROUND

Interleukins IL1ß/IL18 and Inflammasome NLRP1/NLRP3 polymorphisms can change the course of multiple human diseases, both inflammatory as infectious. SNPs these proteins were associated with the constructive activation of the Inflammasome and excessive production of IL-1β induce a serious autoinflammatory disease, as sickle cell anemia (SCA). The present study aims to association of interleukins IL1ß/IL18 and inflammasome NLRP1/NLRP3 polymorphisms in SCA patients in Amazon region and their association with severity score.

METHODS

The study was developed at Fundação Hospitalar de Hematologia e Hemoterapia do Amazonas (HEMOAM) with 21 patients diagnosed SCA (HbSS) and 50 Healthy Donor´s. Genetic polymorphisms (SNPs) in interleukins IL1ß/IL18 and inflammasome NLRP1/NLRP3 were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and real time PCR. Simple and multiple logistic regression were performed to investigate association between the polymorphisms and the SCA and severe score.

RESULTS

The genotypes C/C (IL18 -137G/C) and C/A (NLRP3, rs35829419) appear to be risk factors for SCA disease (IL18: G/G vs C/C OR=103.500 [95% CI: 8.32-1287.79, p<0.00001]; IL18: G/G vs G/C OR=7.360 [95% CI: 0.85-63.48, p=0.040]; IL18: G/G vs CC+CG OR=14.481 [95% CI: 1.79-117.32, p=0.002; NLRP3: C/C vs C/A: OR=10.967 [95% CI: 2.41-49.89, p=0.0004]). In addition, only allelic C (IL18 -137G/C) and A (NLRP3) appear to be risk factors for SCA disease (IL18: G vs C OR=6.366 [95% CI: 2.73-14.86, p<0.00001]; NLRP3: C vs A OR=8.383 [95% CI: 2.03-34.62, p=0.005]. No associations were observed between genotypes and alleles with the severity score.

CONCLUSION

Evidence of association between the IL18 (rs16944) and NLRP3 (rs35829419) polymorphisms with sickle cell anemia were described. Our results suggest that individuals with genotypes evaluated are associated SCA disease even though it does not influence the severe score.

TNF-α promoter polymorphisms (G-238A and G-308A) are associated with susceptibility to Systemic Lupus Erythematosus (SLE) and P. falciparum malaria: a study in malaria endemic area

Tumor necrosis factor-α (TNF-α) is a proinflammatory cytokine associated with autoimmune and infectious diseases. Importance of TNF-α in P. falciparum malaria and systemic lupus erythematosus (SLE) have been demonstrated. However, association of functional promoter variants with SLE and malaria is lacking in malaria endemic population. A total of 204 female SLE patients and 224 age and sex matched healthy controls were enrolled in the study. Three hundred fourteen P. falciparum infected patients with different clinical phenotypes were included. TNF-α polymorphisms (G-238A & G-308A) were genotyped by PCR-RFLP. Plasma levels of TNF-α was quantified by ELISA. Heterozygous mutants and minor alleles of TNF-α (G-238A and G-308A) polymorphisms were significantly higher in SLE patients compared to healthy controls and associated with development of lupus nephritis. In addition, both promoter variants were associated with severe P. falciparum malaria. SLE patients demonstrated higher levels of plasma TNF-α compared to healthy controls. TNF-α (G-238A and G-308A) variants were associated with higher plasma TNF-α. In conclusion, TNF-α (G-238A & G-308A) variants are associated with higher plasma TNF-α levels in SLE patients residing in malaria endemic areas and could be a contributing factor in the development of SLE and susceptibility to severe P. falciparum malaria.

Association between tumor necrosis factor polymorphisms and rheumatoid arthritis as well as systemic lupus erythematosus: a meta-analysis

Tumor necrosis factor-alpha (TNF-α) plays an important role in autoimmune diseases. Previous studies have investigated the association of TNF-α-238G/A (rs361525) and -308G/A (rs1800629) polymorphisms with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). However, no agreed conclusion had been made. Therefore, this meta-analysis was conducted to assess the associations of TNF-α-238G/A and -308G/A polymorphisms with RA and SLE risk. A systematic search was conducted in commonly used databases. Meta-analysis was performed by STATA12.0. A total of 43 studies were included. In the overall population, the TNF-α-238A allele was observed to be a protective factor for RA (A vs G: OR=0.75, 95%CI=0.57–0.99, P=0.040) and the TNF-α-308A allele was found to be a risk factor for SLE (A vs G: OR=1.78, 95%CI=1.45–2.19, P<0.001). However, no evidence of association was found between TNF-α-238 G/A polymorphism and SLE nor between -308G/A and RA. In the subgroup analysis, TNF-α-308A allele played a pathogenic role for RA in Latin Americans (A vs G: OR=1.46, 95%CI=1.15–1.84, P=0.002) and for SLE in Latin Americans (A vs G: OR=2.12, 95%CI=1.32–3.41, P=0.002) and Europeans (A vs G: OR=2.03, 95%CI=1.56–2.63, P<0.001), while it played a protective role for RA in Asians (A vs G: OR=0.54, 95%CI=0.32–0.90, P=0.017). No significant association was found between TNF-α-308G/A and SLE susceptibility in Africans and Asians. This meta-analysis demonstrated that TNF-α-238A was associated with decreased risk of RA rather than SLE, while -308G/A polymorphism was associated with SLE rather than RA. Stratification analysis indicated that different ethnicities would have different risk alleles.

Lack of association of -863C/A (rs1800630) polymorphism of tumor necrosis factor-a gene with rheumatoid arthritis

INTRODUCTION

Multifunctional pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) has been implicated in a variety of inflammatory diseases including rheumatoid arthritis (RA). TNF-α polymorphisms are mostly located in its promoter region and play a significant role in disease susceptibility and severity. We therefore sought to investigate TNFA -863C/A (rs1800630) polymorphism association with RA activity in our Pakistani study group.

MATERIAL AND METHODS

A total of 268 human subjects were enrolled. Among them, 134 were RA patients and 134 were controls. In this study the physical parameters of RA patients were collected, and the disease activity was measured by DAS28. The genotypes were determined following the allele-specific PCR along with the pre-requisite internal amplification controls. Subsequently, data were analyzed statistically for any significant association including χ²/Fisher's exact test using GraphPad prism 6 software.

RESULTS

We found that the TNF-α -863 C/A (rs1800630) variant was not differentially segregated between cases and controls in either genotype frequency, with χ² of 2.771 and a p-value of 0.2502, or allele frequency, with χ² of 2.741 and a p-value of 0.0978, with an odds ratio (95% CI) of 0.7490 (0.5317-1.055).

CONCLUSIONS

The lack of positive association of TNF-α -863(rs1800630) polymorphism in our study group implies that TNF-α -863 polymorphism is not a susceptible marker to RA and cannot serve as a genetic factor for screening RA patients in Pakistan. There might be other factors that may influence disease susceptibility. However, further investigations on additional larger and multi-regional population samples are required to determine the consequences of genetic variations for disease prognosis.

Association between tumor necrosis factor-α-308G/A gene polymorphism and susceptibility to pre-eclampsia: An updated meta-analysis

AIMS

Although two meta-analysis have reported no association between the tumor necrosis factor-α (TNF-α)-308G/A polymorphism and susceptibility to pre-eclampsia (PE), recent studies showed the association was still controversial. Thus, we conduct an updated meta-analysis to elucidate this association.

METHODS

Studies related to TNF-α-308G/A and PE risk were retrieved from PubMed, the Web of Science, Embase, Cochrane Library, CNKI, Wanfang, CBM, VIP Database. The odds ratios (OR) and 95% confidence intervals (CIs) were calculated to estimate the association between the TNF-α-308G/A polymorphism and susceptibility to PE under the models of allelic contrast (A vs. G), recessive (AA vs. AG+GG), dominant (AA+AG vs. GG), and co-dominant (AA vs. GG).

RESULTS

22 studies (including 2459 cases and 4246 controls) were included in the meta-analysis. The overall analysis indicated that the significant association between TNF-α-308G/A polymorphism and susceptibility to pre-eclampsia existed in allele model (A vs. G: OR = 1.37, 95%CI: 1.06-1.77), but not in dominant model, recessive model, and co-dominant model. In subgroup analysis by ethnicity, pre-pregnancy BMI and pregnancy parity, the results showed the significant association between TNF-α-308G/A polymorphism and the risk of PE was obvious in Caucasian (A vs. G: OR = 1.36, 95%CI: 1.13-1.64; AA vs. GG: OR = 1.71, 95%CI: 1.03-2.86; AA+AG vs. GG: OR = 1.32, 95%CI: 1.03-1.71), Iranian (A vs. G: OR = 4.28, 95%CI: 2.01-9.11), and primipara (A vs. G: OR = 1.49, 95%CI: 1.15-1.92; AA vs. GG: OR = 2.15, 95%CI: 1.10-4.21).

CONCLUSION

Current evidence demonstrates that carriers of TNF-α (308A) allele would increase the susceptibility to PE, especially among Caucasian, Iranian and primipara.

Role of Complex Epigenetic Switching in Tumor Necrosis Factor-α Upregulation in the Prefrontal Cortex of Suicide Subjects

OBJECTIVE

Proinflammatory cytokines have recently received considerable attention for their role in suicidal behavior; however, how the expression of cytokine genes is regulated is not clearly known. The authors examined underlying mechanisms of critical cytokine gene tumor necrosis factor-alpha (TNF-α) dysregulation in the brains of individuals who died by suicide.

METHOD

TNF-α expression was examined in the dorsolateral prefrontal cortex of the postmortem brains of persons with and without major depressive disorder who died by suicide and of persons with major depressive disorder who died of causes other than suicide. The role of putative microRNAs targeting TNF-α and RNA-binding protein Hu antigen R (HuR) was tested with in vitro and in vivo approaches and by examining expression of transactivation response RNA binding protein (TRBP). Genetic influence on TNF-α expression was determined by expression quantitative trait loci analysis and by genotyping three single-nucleotide polymorphisms in the promoter region of the TNF-α gene. Promoter methylation of TNF-α was determined by using methylated DNA immunoprecipitation assay. Expression of miR-19a-3p and TNF-α was also determined in the peripheral blood mononuclear cells of 12 healthy control subjects and 12 currently depressed patients with severe suicidal ideation.

RESULTS

TNF-α expression was significantly higher in the dorsolateral prefrontal cortex of individuals who died by suicide, regardless of psychiatric diagnosis. Its expression level was also increased in individuals with major depressive disorder who died by causes other than suicide. On the other hand, expression of miR-19a-3p was upregulated specifically in individuals who died by suicide. In a preliminary observation, similar upregulation of TNF-α and miR-19a-3p was observed in the peripheral blood mononuclear cells of depressed patients with suicidal ideation. Despite its ability to directly target TNF-α in vitro, miR-19a-3p showed no interaction with TNF-α in the dorsolateral prefrontal cortex. HuR potentially stabilized TNF-α transcript, presumably by sequestering its 3' untranslated region from miR-19a-3p-mediated inhibition. Furthermore, decreased TRBP expression supported abnormality in the interaction between miR-19a-3p and TNF-α. Additionally, TNF-α transcriptional upregulation was associated with promoter hypomethylation, whereas no genetic influence on altered TNF-α or miR-19a-3p expression was observed in individuals who died by suicide.

CONCLUSIONS

The data in this study provide mechanistic insights into the dysregulation of the TNF-α gene in the brains of individuals who died by suicide, which could potentially be involved in suicidal behavior.

Host genetics and dengue fever

Dengue is a major worldwide problem in tropical and subtropical areas; it is caused by four different viral serotypes, and it can manifest as asymptomatic, mild, or severe. Many factors interact to determine the severity of the disease, including the genetic profile of the infected patient. However, the mechanisms that lead to severe disease and eventually death have not been determined, and a great challenge is the early identification of patients who are more likely to progress to a worse health condition. Studies performed in regions with cyclic outbreaks such as Cuba, Brazil, and Colombia have demonstrated that African ancestry confers protection against severe dengue. Highlighting the host genetics as an important factor in infectious diseases, a large number of association studies between genetic polymorphisms and dengue outcomes have been published in the last two decades. The most widely used approach involves case-control studies with candidate genes, such as the HLA locus and genes for receptors, cytokines, and other immune mediators. Additionally, a Genome-Wide Association Study (GWAS) identified SNPs associated with African ethnicity that had not previously been identified in case-control studies. Despite the increasing number of publications in America, Africa, and Asia, the results are quite controversial, and a meta-analysis is needed to assess the consensus among the studies. SNPs in the MICB, TNF, CD209, FcγRIIA, TPSAB1, CLEC5A, IL10 and PLCE1 genes are associated with the risk or protection of severe dengue, and the findings have been replicated in different populations. A thorough understanding of the viral, human genetic, and immunological mechanisms of dengue and how they interact is essential for effectively preventing dengue, but also managing and treating patients.

Influence of a TNF-α Polymorphism on the Severity of Schistosomiasis Periportal Fibrosis in the Northeast of Brazil

AIMS

The proinflammatory cytokine tumor necrosis factor-alpha (TNF-α) is an essential component in the host immune response to infection, and it has been reported to be an important mediator in severe periportal fibrosis (PPF). We hypothesized that the (-G308A) polymorphism of the TNF-α gene is associated with the severity of PPF and that these polymorphisms influence TNF-α expression.

METHODS

In this cross-sectional study, we genotyped these polymorphisms within the TNF-α gene in 256 Brazilian subjects infected with Schistosoma mansoni, with different patterns of PPF.

RESULTS

The genotype (-308) AA was associated with a significant increase in the risk to advanced PPF (OR = 4.60; p = 0.009). In addition, median levels of TNF-α were higher in patients with moderate to advanced PPF, compared with mild fibrosis (20 and 17.3 pg/mL, respectively; p = 0.040). There was no association between average serum levels of TNF-α and (-G308A) TNF-α polymorphism.

CONCLUSIONS

Our results suggest the (-308) AA genotype may be a risk factor for severity in advanced PPF, in this Brazilian population, and could potentially be used to predict the severity of advanced PPF in schistosomiasis.

Tumor necrosis factor alpha polymorphisms are associated with Parkinson's disease age at onset

The role of neuroinflammation in Parkinson's disease (PD) has been demonstrated through several different approaches. It was suggested an inflammation-derived oxidative stress and cytokine-dependent toxicity role in the nigrostriatal pathway degeneration and hasten progression of disease. Tumor necrosis factor alpha (TNFA) gene promoter polymorphisms might alter the expression of this cytokine contributing to the pro- and anti-inflammatory polarization. An increased TNFA expression might lead to inflammatory profile predominance. The aim of study was to determine if TNFA haplotypes are associated with PD age at onset. Five polymorphisms in TNFA gene were investigated in 226 patients with idiopathic PD in relation to age at onset. Haplotype grouping was based on allele expression. Logistic binary regression analysis showed that the genetic background leading to higher TNF-α expression confers a higher risk to develop PD earlier. Gender and ancestry did not differ between groups. High TNFA expression may contribute for faster dopaminergic neuron degeneration. In this context, a higher genetic pro-inflammatory profile confers a higher risk to develop PD earlier.

Tumor necrosis factor-alpha -863C/A polymorphism is associated with Guillain-Barré syndrome in Bangladesh

Guillain-Barré syndrome (GBS) is a post-infectious autoimmune polyneuropathy regulated by pro- and anti-inflammatory cytokines; TNFA polymorphisms may exert immune pathogenic roles in GBS. We assessed TNFA promoter region polymorphisms (-238G/A, -308G/A, -857C/T, -863C/A) in Bangladeshi patients with GBS (n=300) and healthy controls (n=300) by PCR-RFLP and ASO-PCR. TNFA -863CA was significantly associated with GBS disease susceptibility (P=0.0154) and disease severity (P=0.0492). TNFA -238A allele was more frequent among anti-ganglioside (GM1) antibody-positive patients (P=0.0092) and -863AA associated with AMAN subtype of GBS (P=0.0398). TNFA -863C/A may contribute to GBS severity and pathogenesis in Bangladeshi patients.

No Association between TNF-α -308G/A Polymorphism and Idiopathic Recurrent Miscarriage: A Systematic Review with Meta-Analysis and Trial Sequential Analysis

Background

Conflicting results were reported on the association between the TNF-α -308G/A polymorphism and idiopathic recurrent miscarriage (IRM). Though three meta-analyses have been conducted on this topic, the conclusions were contradictory, and the results may be unreliable as certain crucial conditions were neglected.

Method

A complete search was conducted in PubMed, Cochrane Library, and Embase, other sources like Google Scholar, ClinicalTrial.gov and reference lists of relevant articles were also retrieved. All candidate articles were accessed and screened using specific inclusion and exclusion criteria. Statistical analyses were performed on data extracted from eligible studies using the STATA 12.0 software and the TSA 0.9 beta software.

Results

Eventually, 12 case-control studies from 11 publications (with 1,807 cases and 2,012 controls) were included in this meta-analysis, and no evidence of any significant association was found in the overall analyses between the TNF-α -308G/A polymorphism and IRM risk. However, significant association was shown in Asian population (four studies from three publications) in the dominant model (AA + GA vs. GG), the allelic model (A vs. G), and the heterozygote model (GA vs. GG).

Conclusions

TNF-α -308G/A polymorphism is not associated with IRM risk. Though significant association was found in Asian population, the result needs further confirmation from more studies.

Lack of tumor necrosis factor alpha gene polymorphism -857c/t (rs1799724) association in Pakistani rheumatoid arthritis patients

BACKGROUND

Rheumatoid arthritis (RA) is a common systemic autoimmune disease, influenced greatly by the pro-inflammatory cytokine tumor necrosis factor- alpha (TNF-α). Single nucleotide polymorphisms (SNPs) in regulatory regions of the TNF-α gene play a significant role in disease development and pathogenesis. The aim of this study was to investigate the association of TNF-α -857C/T (rs1799724) SNP with RA activity or severity in our Pakistani study group.

METHODS

The study included 134 (116 women, 18 men) patients with RA and 134 ethnically matched healthy controls (108 women, 26 men). Each patient's disease activity was measured by Disease Activity Score of 28 joints. The genotypes were determined in all included individuals following allele-specific polymerase chain reaction along with the prerequisite internal amplification controls. Statistical analysis including chi-square/Fischer exact test and one-way analysis of variance; nonparametric Kruskal-Wallis test was employed using Graphpad Prism 6 software for association study.

RESULTS

The prevalence of TNF-α -857C/T (rs1799724) polymorphism was not differentially distributed between RA patients and controls in either allele frequency, with odds ratio (95% CI) of 0.9661 (0.6714-1.390) and P-value of 0.8527, or genotype frequency with χ² of 0.5015 and P-value of 0.7782. Moreover, no correlation was found when genotype frequency distribution was analyzed with disease severity (P = 0.6321 and Kruskal-Wallis statistics of 1.098).

CONCLUSION

The study demonstrated -857C/T (rs1799724) polymorphism may not have influenced RA susceptibility in our study group. However, investigations of genetic variability influence on disease outcome in large prospective cohorts are required, so the complicated interconnection of genetic and environmental elements can be emulated for better understanding.

Promoter polymorphism at the tumour necrosis factor/lymphotoxin-alpha locus is associated with type of diabetes but not with susceptibility to sight-threatening diabetic retinopathy

AIM

To investigate, in a large cohort of 2494 individuals with diabetes mellitus, whether functional single nucleotide polymorphisms in the promoter region of tumour necrosis factor (TNF) and lymphotoxin-alpha (LTA) genes are associated with type of diabetes or presence of diabetic retinopathy.

METHODS

A total of 334 type 1 diabetes and 999 type 2 diabetes participants with sight-threatening diabetic retinopathy, and 260 type 1 diabetes and 901 type 2 diabetes participants with no diabetic retinopathy or minimal non-proliferative diabetic retinopathy, were genotyped for two single nucleotide polymorphisms (rs1800629 and rs361525).

RESULTS

The A allele of rs1800629 was associated with type 1 diabetes (p < 0.001; odds ratio = 0.62). After adjustment for age, sex, diabetes duration, HbA1c, hypertension and nephropathy, no significant association was found between rs1800629 or rs361525 and sight-threatening diabetic retinopathy.

CONCLUSION

An association between the A allele of rs1800629 and type of diabetes was found. No association was found between two promoter variants of TNF and LTA, and diabetic retinopathy in a large cohort of Caucasian patients with type 1 diabetes and type 2 diabetes.

The -308 bp TNF gene polymorphism influences tumor necrosis factor expression in leprosy patients in Bahia State, Brazil

Leprosy or Hansen's disease is a debilitating chronic granulomatous disease caused by Mycobacterium leprae, with high incidence and prevalence in Brazil. The -308 bp G/A single nucleotide polymorphism (SNP rs1800629) in the tumor necrosis factor (TNF) gene promoter is a proposed risk factor for leprosy. In Brazil, Northern India, Egypt and Nepal, the common G allele was associated with leprosy. In Eastern India, Thailand and Malawi the minor A allele was the risk factor. Allele A was previously associated with high TNF. We genotyped rs1800629 in 326 leprosy cases from Bahia State, Brazil, including 72 paucibacillary (PB) and 47 multibacillary (MB) without reactions, and 69 reversal reaction (RR) and 78 erythema nodosum leprosum (ENL) with reactions. Logistic regression was used to compare patient groups with 331 healthy controls. Relative TNF mRNA was determined in peripheral blood leukocytes by QRTPCR, and serum TNF levels measured by ELISA. We found that TNF mRNA expression was higher (P=0.03) in leprosy patients compared to endemic controls, but did not differ significantly between clinical subgroups. Carriage of the minor A allele was associated (P=0.003) with low TNF mRNA across leprosy patients. Nevertheless, we found no evidence for either allele at this SNP as a risk factor for leprosy per se (OR=1.12, 95% CI 0.79-1.60, P=0.52), PB (OR=0.99, 95% CI 0.54-1.81, P=0.97), MB (OR=0.86, 95% CI 0.40-1.83, P=0.70), RR (OR=1.37, 95% CI 0.79-2.38, P=0.27) or ENL (OR=0.76, 95% CI 0.40-1.45, P=0.42) when compared to endemic controls. Further studies are required to determine whether the influence of the minor A allele on TNF mRNA levels determines response to treatment, particularly in the context of ENL reaction treatment with anti-TNF therapies and RR reactions where treatment with prednisolone is known to reduce TNF levels. Our findings contribute to understanding TNF as an important determinant of leprosy immunopathology in Brazil.

Preliminary evaluation of exome sequencing to identify genetic markers of susceptibility to tuberculosis disease

Background

Recent studies have shown that certain human genetic polymorphisms could be associated with susceptibility to tuberculosis (TB) infection and disease. Advances in next generation sequencing include the ability to rapidly sequence the entire human exome. These new technologies can be exploited to identify new associations of human genetic polymorphisms and TB infection and disease. In this preliminary study we compared two different strategies for sequencing of the human exome in a small sample set consisting of three individuals with a history of TB disease and two individuals with latent TB infection.

Findings

Sequencing of the entire exome of the five participants using Agilent SureSelect kit resulted in the identification of 1611 single nucleotide polymorphisms (SNPs) that were only present in the individuals with a history of active TB but not in the latent TB cases. Alternatively, sequencing of 4000 target genes available in the TruSight kit resulted in identification of 182 SNPs only present in the active TB cases and not in the latent TB participants. The overlap of the two kits was 112 SNPs.

Conclusions

Even though this pilot study was restricted to a small number of participants, we demonstrated the feasibility of using exome sequencing technologies to mine potential genetic associations of susceptibility to TB disease and presented a number of potential targets that can be further explore in larger research trials.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1740-5) contains supplementary material, which is available to authorized users.

TNF-α -308 G/A as a risk marker of cervical cancer progression in the Polish population

BACKGROUND AND OBJECTIVE

There are inconclusive data on the tumor necrosis factor-α (TNF-α) -308 G/A (rs1800629) polymorphism as a risk factor for cervical carcinogenesis.

METHODS

Using high-resolution melting curve analysis, we investigated the prevalence of the TNF-α -308 G/A transition (rs1800629) in patients with cervical cancer (n = 362) and control subjects (n = 399).

RESULTS

The p trend value calculated for the TNF-α -308 G/A transition was statistically significant (p trend = 0.026) for all patients. Logistic regression analysis with adjustment for age demonstrated that the A/A versus G/G genotype was significantly associated with cervical tumors. The adjusted odds ratio (OR) was 1.599 (95 % confidence interval [CI] 1.017-2.513; p = 0.042). Stratification of patients on the basis of the tumor stage revealed no contribution of the TNF-α -308 G/A transition to cervical cancer in stages I and II. However, we found a significant trend for the p value, as well as the contribution of TNF-α -308 G/A to cervical cancer, in stages III and IV. The p trend value was 0.003 in this group of patients. Moreover, logistic regression analysis with adjustment for age demonstrated that the adjusted OR for A/A versus G/G was 2.014 (95 % CI 1.122-3.613; p = 0.019) and the adjusted OR for A/A or A/G versus G/G was 1.583 (95 % CI 1.025-2.444; p = 0.038) for cervical cancer in stages III and IV.

CONCLUSION

Our results indicate that the TNF-α -308 G/A transition is a risk factor for cervical cancer, particularly in stages III and IV.

Influence of Polymorphism (-G308A) TNF-α on the Periportal Fibrosis Regression of Schistosomiasis After Specific Treatment

AIMS

Tumor necrosis factor alpha (TNF-α) is a proinflammatory cytokine and important mediator of severity for periportal fibrosis (PPF). We hypothesized that the (-G380A) polymorphism in the TNF-α gene is associated with regression of PPF after treatment for schistosomiasis mansoni.

METHODS

This is a retrospective cohort study, involving 124 Brazilian patients infected with Schistosoma mansoni, who were followed for 2 years after treatment to estimate the likelihood of PPF regression. Sociodemographic and clinical factors were also identified, with emphasis on specific treatment.

RESULTS

No statistical difference was observed between sociodemographic and clinical factors among the exposed groups. Genotypes (-308) GA/AA were positively associated with the degree of PFF regression (relative risk [RR] = 0.52; ρ = 0.025), as well as in the image pattern of PPF (RR = 0.56; ρ = 0.048), when compared with the genotype (-308) GG. There was no statistical difference in TNF-α serum levels between the exposed groups.

CONCLUSIONS

These results suggest that the (-G308A) polymorphism of the TNF-α gene may be one of the factors that prevents the regression of the degree and pattern of PPF in the Brazilian population, and thus it may potentially be a predictive factor of PPF intensity in schistosomiasis.

Systematic Review by Multivariate Meta-analyses on the Possible Role of Tumor Necrosis Factor-α Gene Polymorphisms in Association with Ischemic Stroke

A number of studies have investigated the association between tumor necrosis factor (TNF)-α gene polymorphisms and ischemic stroke susceptibility. However, results of different individual studies are often inconsistent. To provide a more robust evaluation of the association between polymorphisms of the TNF-α gene and ischemic stroke risk, we performed a systematic review with multivariate meta-analyses. PubMed, Embase, CNKI, and WanFang databases were searched up to December 20, 2014. Two reviewers independently extracted information and assessed quality of included studies after all the eligible studies were identified. Afterward, multivariate meta-analyses were performed using Stata 13. The estimation of polymorphisms and disease risk was presented by odds ratios (ORs) and corresponding 95 % confidence intervals (CIs). Forty-nine eligible case-control studies from 25 articles that explored the association between 10 TNF-α polymorphisms and ischemic stroke were indentified from aforementioned databases. The results of multivariate meta-analysis showed a significant association between -238G/A polymorphism (4760 patients and 4389 controls) and ischemic stroke risk in heterozygotes compared with wild genotype (AG vs. GG: OR 1.44, 95 % CI 1.11-1.87; AA vs. GG: OR 1.98, 95 % CI 0.73-5.40). No significant association of -308G/A, -857C/T, and -1031T/C polymorphisms was observed. The results of stratification analyses of -238G/A polymorphism showed that the AG genotype only increased the risk of ischemic stroke in Asians compared to GG genotype. No additional significant association was observed in this study. In conclusion, the present systematic review and meta-analysis support a prominent role of the TNF-α -238G/A polymorphism in the risk of ischemic stroke in Asian adults only, but do not support the role of -308G/A, -857C/T, -1031T/C, -244G/A, -367G/A, -646G/A, -806C/T, -863C/A, and +448G/A in the risk of ischemic stroke. The current evidence warrants further studies with high quality and large sample size to confirm.

Tumour necrosis factor allele variants and their association with the occurrence and severity of malaria in African children: a longitudinal study

Background

Tumour necrosis factor (TNF) is central to the immune response to Plasmodium infection. Its plasma concentration is influenced by allele variants in the promoter region of TNF. The study’s objectives were to assess TNF allele variants (TNF₋₁₀₃₁, TNF₋₃₀₈): (1) modulation of malaria rates in young Tanzanian children; (2) modulation of the severity of malaria as indicated by haemoglobin concentrations at the time of presentation with febrile episodes; and (3) the association between Plasmodium infection and haemoglobin concentration in symptomless parasite carriers.

Methods

Data from a placebo-controlled trial in which 612 Tanzanian children aged 6–60 months with height-for-age z-score in the range −3 SD to 1.5 SD was utilised. Those with Plasmodium infection at baseline were treated with artemether-lumefantrine. An episode of malaria was predefined as current Plasmodium infection with an inflammatory response (axillary temperature ≥37.5°C or whole blood C-reactive protein concentration ≥8 mg/L) in children reported sick. Linkage disequilibrium (LD) pattern assessment as well as haplotype analysis was conducted using HAPLOVIEW. Cox regression models used in the primary analysis accounted for multiple episodes per child.

Results

Genotyping of 94.9% (581/612) children for TNF₋₁₀₃₁ (TNF₋₁₀₃₁T>C); allele frequency was 0.39. Corresponding values for rs1800629 (TNF₋₃₀₈G>A) were 95.4% (584/612) and 0.17. Compared to the wild type genotype (TT), malaria rates were increased in the TNF₋₁₀₃₁CC genotype (hazard ratio, HR [95% CI]: 1.41 [1.01‒1.97] and 1.31 [0.97‒1.76] for crude analysis and adjusting for pre-specified baseline factors, respectively) but decreased in those with the TNF₋₃₀₈AA genotype (corresponding HR: 0.13 [0.02‒0.63] and 0.16 [0.04‒0.67]). These associations were weaker when analysing first episodes of malaria (P value −0.59 and 0.38, respectively). No evidence that allele variants of TNF₋₁₀₃₁ and TNF₋₃₀₈ affected haemoglobin concentration at first episode of malaria, or that they modified the association between Plasmodium infection and haemoglobin concentrations at baseline was observed.

Conclusion

In this cohort of Tanzanian children, the TNF₋₁₀₃₁CC genotype was associated with increased rates of malarial episodes, whereas the TNF₋₃₀₈AA genotype was associated with decreased rates.

IL-18, TNF, and IFN-γ alleles and genotypes are associated with susceptibility to chronic hepatitis B infection and severity of liver injury

This study evaluated the association of polymorphisms in the IL-18 (-607C/A and -137C/G), IFNγ (+874 A/T), and TNF (-238 A/G and -308 A/G) genes with susceptibility to HBV infection and severity of liver injury. A total of 259 chronic HBV-infected patients followed at the University Hospital, Faculty of Medicine of Ribeirão Preto, São Paulo, Brazil, and 202 healthy individuals were studied. Four Single Nucleotide Polymorphisms (SNPs) were amplified by Polymerase Chain Reaction (PCR). Liver biopsy was performed in 212 HBV-infected patients and classified according to severity of liver fibrosis (scores 0-4) and necroinflammatory activity (HAI scores 0-18). TNF-308*A allele (P < 0.001; OR = 2.16) and TNF -308 AA genotype (P = 0.026; OR = 5.43) were associated with susceptibility to HBV infection. An association was found between severe liver fibrosis when compared to mild fibrosis and the following polymorphisms: Alleles IL-18 -137*G (P = 0.004; OR = 3.45), TNF -308*A (P < 0.001; OR = 3.39), and IFNγ +874*T (P = 0.029; OR = 1.85) and IL-18 -137 GG genotype (P = 0.009; OR = 3.70). No significant association was found between IL-18 (-607 A/C) polymorphism and severity of liver fibrosis. Alleles IL-18 -137*G (P = 0.028; OR = 2.64) and TNF-308*A (P = 0.002; OR = 3.06) and IL-18 -137 GG genotype (P = 0.011; OR = 4.20) were associated with severe necroinflammatory activity (HAI>12) when compared to mild necroinflammatory activity (HAI 1-8). The results suggest that IL-18 -137C/G, TNF-308 G/A and IFNγ +874 A/T SNPs were associated to more severe liver injury in chronic HBV infection. TNF -308*A allele and TNF -308 AA genotype could play a role in the susceptibility to HBV infection.

Effects of chronic interpersonal stress exposure on depressive symptoms are moderated by genetic variation at IL6 and IL1β in youth

AIMS

Close to one third of patients with major depression show increases in pro-inflammatory cytokines, which are in turn associated with risk for inflammatory disease. Genetic variants that enhance immune reactivity may thus enhance inflammatory and depressive reactions to stress. The aim of the present study was to investigate a trio of functional SNPs in the promoter regions of IL6 (-174G>C, rs1800795), IL1β (-511C>T, rs16944), and TNF (-308G>A, rs1800629) as moderators of the relationship between chronic stress exposure and elevations in depressive symptoms.

METHODS

Participants were 444 Australian youth (mean age=20.12) whose exposure to chronic stress in the past 6months was assessed using the semi-structured UCLA Life Stress Interview, and who completed the Beck Depression Inventory II at ages 15 and 20. Between ages 22 and 25, all participants in the selected sample provided blood samples for genotyping.

RESULTS

In line with a hypothesized moderation effect, -174G allele carriers at IL6 had fewer depressive symptoms following interpersonal stress, relative to C/C homozygotes with equal interpersonal stress exposure. However, IL6 genotype did not moderate the effects of non-interpersonal stress exposure (i.e., financial, work and health-related difficulties) on depression. Also in line with hypotheses, the -511C allele in IL1β, previously associated with higher IL-1β expression, was associated with more severe depression following chronic interpersonal stress exposure, relative to T/T homozygotes. Again, the moderating effect was specific to interpersonal stressors and did not generalize to non-interpersonal stress. TNF was not a moderator of the effects of either interpersonal or non-interpersonal stress on later depression outcomes.

CONCLUSION

Findings were consistent with the hypothesis that pro-inflammatory genetic variation increases the risk of stress-induced depression. The present results provide evidence of a genetic mechanism contributing to individual differences in depressive symptomatology following interpersonal stress exposure.

Association of tumor necrosis factor (TNF) promoter polymorphisms with plasma TNF-α levels and susceptibility to diabetic nephropathy in North Indian population

AIM

The concept of diabetic nephropathy (DN) as a metabolic disease is now being replaced by chronic low-grade inflammatory disease. Tumor necrosis factor-alpha (TNF-α) is a proinflammatory cytokine which plays an important role in the pathogenesis and clinical outcome of DN. Therefore, this work was planned to evaluate the association of -863C/A (rs1800630) and -1031T/C (rs1799964) polymorphisms in TNF gene with plasma TNF-α levels and DN among subjects with type 2 diabetes (T2DM) in a population from North India.

METHODS

Age and sex matched 100 healthy controls (HC), 100 T2DM subjects without nephropathy (DM) and 100 subjects with DN were screened for above polymorphisms using the PCR-RFLP methods. Plasma TNF-α levels were measured by ELISA. Analysis of variance and logistic regression were used to associate individual polymorphisms with plasma TNF-α levels and DN.

RESULTS

The allelic frequencies of -863C/A were 0.86/0.14 in HC, 0.72/0.23 in DM and 0.84/0.16 in DN, and that of -1031T/C were 0.89/0.11 in HC, 0.95/0.05 in DM and 0.80/0.20 in DN. The carriers of -863A allele had significantly lower plasma TNF-α levels (p<0.05). The -863C/A (OR=0.439, 95% CI=0.244-0.789, p=0.006) and -1031T/C (OR=3.0, 95% CI=1.355-6.642, p=0.007) were strongly associated with risk of development of DN.

CONCLUSIONS

-863C/A was associated with low whereas -1031T/C with high TNF-α levels. The, results suggest that -863C/A polymorphism might be protective whereas -1031T/C may be associated with increased risk for DN in subjects with T2DM from North India.

Association of Tumor Necrosis Factor-alpha Polymorphisms and Risk of Coronary Artery Disease in Patients With Non-alcoholic Fatty Liver Disease

BACKGROUND

Cardiovascular events account for the main cause of death in patients with non-alcoholic fatty liver disease (NAFLD), and are largely influenced by genetic factors. Although multiple studies showed that tumor necrosis factor-alpha (TNF-α) polymorphisms are risk factors in the progression of NAFLD, few papers on the association of the polymorphisms and the developing coronary artery disease (CAD) in NAFLD patients have been reported.

OBJECTIVES

The present study was designed to evaluate the association of TNF-α polymorphisms at residues -238 and -308, with the risk of developing CAD in Chinese patients with NAFLD.

PATIENTS AND METHODS

The TNF-α polymorphisms at residues 238 and 308 were genotyped in B-type ultrasonography proven NAFLD patients with (n = 246), without (n = 247) CAD and healthy controls (n = 304), using polymerase chain reaction (PCR). Serum lipid profiles were determined using biochemical methods. Statistical analyses were performed using SPSS statistical software, version 20.0 for Mac.

RESULTS

We found a significant association between TNF-α-238 guanine to alanine (GA) polymorphism and carriers of variant allele A between NAFLD patients with and without CAD (P < 0.05). Carriers of the A allele of TNF-α-238 had higher serum triglycerides (TG) and low density lipoprotein (LDL) levels in NAFLD patients with CAD (P = 0.025 and 0.001, respectively) and a higher TG level in NAFLD patients without CAD (P = 0.017), than their non-carrier counterparts.

CONCLUSIONS

In the Chinese Han population that we studied, NAFLD patients who carry the TNF-α-238 GA polymorphism have an increased risk of developing CAD. Mechanisms underlying this potentially important association require further investigation.

TNF-alpha-308G>A polymorphism and the risk of familial CAD in a Pakistani population

A case-control and trio-families study was performed to establish a potential association between TNF-alpha gene promoter SNPs at -308 and -238, and occurrence of CAD in a Pakistani population. In the first phase, 150 patients and 150 controls were enrolled in the case-control association study. In the second phase, heritability of susceptible alleles was investigated from 88 trio-families with CAD affected offspring. Biochemical analysis of lipids and hs-CRP was carried out spectrophotometrically, while serum TNF-alpha concentrations were determined by enzyme-linked immunosorbent assay. Genotyping of the TNF-alpha SNPs were determined by PCR-RFLP method. Elevated serum TNF-alpha and hs-CRP were observed from CAD vs. controls (P<0.0001; for both). The evaluation of TNF-alpha-308G>A polymorphism in case-control study revealed that the said SNP was significantly associated with the increased risk of CAD. The findings demonstrated a significant link between the TNF-alpha variant allele A at -308 and CAD (P=0.0035), whereas the -238 SNP was not associated with the disease. Haplotype A-G of the TNF-alpha gene at -308G>A and -238G>A showed higher frequency in the patient group compared with controls (P<0.05). Moreover, data showed preferential transmission of the disease susceptible allele A at TNF-alpha-308 from parent to affected offspring in a trio-family study (P<0.0001). The current research leads to conclusion that the TNF-alpha-308G>A polymorphism is associated with CAD in the study population. Furthermore, for the first time, we showed that the TNF-alpha-308A allele was significantly associated with the familial CAD in our high risk population.

Association of single nucleotide polymorphism at position -308 of the tumor necrosis factor-alpha gene with ankylosing spondylitis and rheumatoid arthritis

In this study, we analyzed the putative association between the −308 G/A polymorphism in the promoter region of the tumor necrosis factor (TNF) α gene (rs1800629) and chronic inflammatory arthritis in the Bulgarian population. A case-control study was carried out on 58 patients with ankylosing spondylitis (AS), 108 rheumatoid arthritis (RA) patients and 177 healthy subjects. −308 G/A TNF-α genotypes of patients and controls were determined by restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR). No significant association between the rs1800629 polymorphism and RA risk in the study cohort was observed. However, there were significant differences in the genotype and allele frequencies of the −308 G/A TNF-α polymorphism between AS patients and the healthy subjects. In logistic regression analysis, the presence of the TNF-α −308A allele in the genotype (AA + AG vs. GG) was associated with a 3.298 times lower risk of developing AS. In addition, in AS, there were associations for age at disease onset (<29 years; odds ratio (OR) = 0.222), disease severity (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score > 4; OR = 0.152) and response to anti-TNF treatment (OR = 2.25) under a dominant model (AA + AG vs. GG). In conclusion, our results suggested that the promoter polymorphism −308 G/A in the TNF-α gene had no significant effect on RA development, but could play a role in AS development and in determining the age of disease onset, disease severity and therapeutic outcome of AS in the Bulgarian patients who participated in our study.

Tumor necrosis factor-α promoter -308/238 polymorphism association with less severe disease in ankylosing spondylitis is unrelated to serum TNF-α and does not predict TNF inhibitor response

OBJECTIVE

Despite the clinical efficacy of tumor necrosis factor inhibitors (TNFi), the manner in which TNF-α contributes to disease in patients with ankylosing spondylitis (AS) remains unresolved. We investigated the relationship between TNF-α gene promoter region polymorphism, serum TNF-α levels, and clinical phenotype.

METHODS

We did a cross-sectional and longitudinal cohort study in TNFi-naive patients with AS (n = 335). Clinical data and biological samples were collected during a research visit with genotyping for TNF-α -238 A/G and -308 A/G performed by Taqman RT-PCR and TNF levels determined by sandwich ELISA. Longitudinal TNF levels were monitored in unselected patients (n = 61).

RESULTS

TNF-α -308 GA/AA genotype was present in 14% and TNF-α -238 GA/AA genotype in 1% of patients. TNF-α -308 GA/AA genotype was associated with a reduced risk of uveitis and better spinal function, while TNF-α -238 GA/AA genotype was associated with later age of onset and lower erythrocyte sedimentation rate (ESR). Serum TNF-α level was lower in patients with AS (151 pg/ml) than in controls (263 pg/ml), because more patients with AS had undetectable serum TNF-α (66 vs 25%, p < 0.001). TNFi treatment did not influence serum TNF-α. There was no effect of TNF-α -308/-238 or HLA-B27 genotype on serum TNF-α or subsequent initiation of TNFi.

CONCLUSION

TNF-α -238 or -308 GA/AA genotypes in patients with AS are associated with signs of less severe disease. Serum TNF-α is, however, undetectable in two-thirds of patients with AS and is not influenced by TNF-α promoter genotype or TNFi therapy. These data suggest a more significant role for TNF-α at local sites of inflammation in AS than through systemic effects.

The importance of evolution in the development and course of rheumatoid arthritis

Rheumatoid arthritis (RA) is a complex autoimmune disease of recent evolutionary origin. Genetic drift determines diverse polymorphisms implicated in the susceptibility to RA including the major histocompatibility complex (MHC) class II genes in the so-called shared epitope. These genes originated after the divergence between Homo and Pan from their common ancestry Ardipithecus ramidus about 5 million years ago. Natural selection determined the particular changes in the legs (bipedal position), hands, neck, brain and eusociality in humans which influence the clinical presentation of RA. In this article, we hypothesized that the origin and course of RA may be explainable in the light of evolution.

The -308 G/A polymorphism in the tumor necrosis factor-α gene is not associated with development and progression of rheumatoid arthritis in Argentinean patients

AIM

A polymorphism in the tumor necrosis factor-alpha (TNF-α) promoter region has been associated with disease susceptibility and progression in rheumatoid arthritis (RA). The presence of an adenosine (TNF2 allele) instead of a guanine (TNF1 allele) at position -308 may be responsible for a general increase in the transcriptional activity of the TNF-α gene. Our aim was to evaluate the association of the TNF2 allele with the risk of disease development and/or progression of RA in an Argentine population cohort.

METHODS

Two hundred and twenty-three consecutive patients with RA according to the 1987 criteria of the American College of Rheumatology were included in the study. Clinical variables, Disease Activity Score 28, Health Assessment Questionnaire and Rheumatoid Arthritis Quality of Life were recorded. The radiographic erosions were determined by the method of Sharp/van der Heijde. A group of 111 healthy subjects matched by sex and age was used as a control. All samples were genotyped for the -308 G/A TNF-α polymorphism.

RESULTS

No significant differences were observed either in the frequency of the TNF2 allele or in the genotypic distributions of the -308 G/A TNF-α polymorphism (P > 0.05) between the control group and the RA patients. No association was found between the TNF2 allele and the variables related to the course and outcome of the disease (P > 0.05).

CONCLUSION

In this cohort of Argentinean patients with RA, the TNF2 allele was neither associated with susceptibility to the disease nor was it associated with the variables related to the course and outcome of the disease.

TNF-α promoter polymorphisms and risk of recurrence in patients with squamous cell carcinomas of the nonoropharynx

Functional polymorphisms of tumor necrosis factor-alpha (TNF-α) may play a critical role in the regulation of immune and inflammatory responses and could affect transcriptional levels of the TNF-α gene and thus contribute to carcinogenesis and outcomes of cancer patients. In a cohort study, we explored the associations between TNF-α polymorphisms and risk of recurrence of squamous cell carcinoma of the nonoropharynx (SCCNOP). We used log-rank test and multivariable Cox models to evaluate the associations between TNF-α polymorphisms and risk of recurrence. In overall comparisons, patients with the TNF-α -857 CC, TNF-α -863 CC and TNF-α -1031 TT genotypes had significantly worse disease-free survival (log-rank, p = 0.014, log-rank, p = .020, and log-rank, p = .002, respectively) and higher risk of disease recurrence than patients with the corresponding variant genotypes, respectively (hazard ratio [HR], 1.4, 95% CI, 1.1-1.9, HR, 1.4, 95% CI, 1.0-1.8 and HR, 1.6, 95% CI, 1.2-2.2, respectively). However, no significant association was detected for the TNF-α -308 polymorphism. Moreover, in further stratified analyses based on smoking status and treatment, we found that the associations of the TNF-α -857, TNF-α -863 and TNF-α -1031 polymorphisms with risk of recurrence were more pronounced in smokers and patients treated with chemoradiation. Our findings support a significant role of the TNF-α -857, TNF-α -863 and TNF-α -1031 polymorphisms in recurrence of SCCNOP, especially in smokers and patients treated with chemoradiation. Future prospective studies with larger sample size are needed to confirm these findings.

Tumor necrosis factor-alpha gene promoter region polymorphism and the risk of coronary heart disease

BACKGROUND

Tumor necrosis factor-alpha (TNF- α ) gene polymorphisms have been implicated in the manifestation of atherosclerosis. Controversy exists regarding the link between the cytokine's variant genotype and CHD among different ethnic groups. There have been fewer studies on the TNF- α gene -1031T>C and -863C>A polymorphisms in relation to CHD. Therefore, the current study was designed to investigate the association of the TNF- α gene -1031T>C and -863C>A polymorphisms with CHD in a Pakistani population.

METHODS

Patients with CHD (n = 310) and healthy individuals (n = 310) were enrolled in this study. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

A significant difference was observed in the -863C>A polymorphism between patients with CHD and control subjects (P < 0.0001). CHD risk was positively associated with the variant allele -863A (P < 0.0001) in the study subjects. There was no significant link between the -1031T>C polymorphism and CHD risk in the study population. Haplotypes A-T and A-C of the TNF-alpha gene loci at -863 and -1031 showed higher frequency in the patient group compared with controls (P < 0.05).

CONCLUSION

The TNF- α   -863C>A gene polymorphism was associated with the pathogenesis of CHD while the -1031T>C polymorphism did not show any link with the disease in a Pakistani population.

Association of cytokine and Toll-like receptor gene polymorphisms with severe malaria in three regions of Cameroon

P. falciparum malaria is one of the most widespread and deadliest infectious diseases in children under five years in endemic areas. The disease has been a strong force for evolutionary selection in the human genome, and uncovering the critical human genetic factors that confer resistance to the disease would provide clues to the molecular basis of protective immunity that would be invaluable for vaccine development. We investigated the effect of single nucleotide polymorphisms (SNPs) on malaria pathology in a case- control study of 1862 individuals from two major ethnic groups in three regions with intense perennial P. falciparum transmission in Cameroon. Twenty nine polymorphisms in cytokine and toll-like receptor (TLR) genes as well as the sickle cell trait (HbS) were assayed on the Sequenom iPLEX platform. Our results confirm the known protective effect of HbS against severe malaria and also reveal a protective effect of SNPs in interleukin-10 (IL10) cerebral malaria and hyperpyrexia. Furthermore, IL17RE rs708567 GA and hHbS rs334 AT individuals were associated with protection from uncomplicated malaria and anaemia respectively in this study. Meanwhile, individuals with the hHbS rs334 TT, IL10 rs3024500 AA, and IL17RD rs6780995 GA genotypes were more susceptible to severe malarial anaemia, cerebral malaria, and hyperpyrexia respectively. Taken together, our results suggest that polymorphisms in some immune response genes may have important implications for the susceptibility to severe malaria in Cameroonians. Moreover using uncomplicated malaria may allow us to identify novel pathways in the early development of the disease.

Anger induced by interferon-alpha is moderated by ratio of arachidonic acid to omega-3 fatty acids

OBJECTIVE

Anger worsens in some patients during interferon-alpha (IFN-α) therapy. Elevated anger has also been associated with lower long-chain omega-3 (LCn-3) fatty acid levels. We examined whether fatty acids could influence vulnerability to anger during IFN-α exposure.

METHODS

Plasma arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) levels were determined prior to IFN-α therapy by mass spectroscopy. Repeated-measure analyses examined the relationship between AA/EPA+DHA and the subsequent development of labile anger and irritability in 82 subjects who prospectively completed the Anger, Irritability, and Assault Questionnaire (AIAQ) during the first eight weeks of IFN-α therapy.

RESULTS

Prior to IFN-α therapy, AA/EPA+DHA did not correlate with either labile anger or irritability. Pre-treatment AA/EPA+DHA did correlate with the subsequent maximal increase in labile anger during IFN-α therapy (r=0.33; p=0.005). Over time, labile anger increased more in subjects with above median AA/EPA+DHA ratios (p<0.05). Of the 17 subjects ultimately requiring psychiatric intervention for anger, 14/17 had above-median AA/EPA+DHA ratios (p=0.009). There was also an interaction with the tumor necrosis factor-alpha (TNF-α) promoter polymorphism (A-308G), such that only those with both elevated AA/EPA+DHA and the A allele had increased labile anger (p=0.001). In an additional 18 subjects, we conversely observed that selective serotonin reuptake inhibitor treatment was associated with increased irritability during IFN-α therapy.

CONCLUSION

LCn-3 fatty acid status may influence anger development during exposure to elevated inflammatory cytokines, and may interact with genetic risk for increased brain TNF-α. LCn-3 supplements may be one strategy for minimizing this adverse side effect of IFN-α.

Genetic variants in TNF-α promoter are predictors of recurrence in patients with squamous cell carcinoma of oropharynx after definitive radiotherapy

The promoter variants of TNF-α, a major regulator of immune and inflammation responses, have been implicated in cancer development and prognosis. Thus, we investigated associations between four TNF-α promoter variants and risk of recurrence of squamous cell carcinoma of the oropharynx (SCCOP). We evaluated associations of four TNF-α polymorphisms with risk of recurrence in a cohort of 846 patients with SCCOP. Log-rank test and multivariable Cox models were used to evaluate associations. Compared with patients with variant genotypes of the TNF-α -308 and TNF-α -863 polymorphisms, patients with common homozygous genotypes had worse disease-free survival (log-rank p = 0.0002 and p < 0.0001, respectively) and increased risk of SCCOP recurrence (HR, 1.9, 95% CI, 1.3-2.8 and HR, 1.9, 95% CI, 1.3-2.7, respectively) after multivariable adjustment. Furthermore, among patients with HPV16-positive tumors, those with common homozygous genotypes of the TNF-α -308 and -863 polymorphisms had worse disease-free survival (log-rank p = 0.005 and p = 0.007, respectively) and higher recurrence risk than patients with variant genotypes of these polymorphisms (HR, 5.1, 95% CI, 1.4-18.4 and HR, 3.7, 95% CI, 1.5-9.1, respectively), while no such significant associations were found for TNF-α -857 or -1031 polymorphisms. Our findings suggest that TNF-α -308 and -863 polymorphisms may modulate the risk of SCCOP recurrence in patients with HPV16-positive tumors. However, larger studies are needed to validate these results.