Tumor necrosis factor alpha -308 gene locus promoter polymorphism: an analysis of association with health and disease

Exploring the Potential Consortium of Migraine and Periodontitis

Objectives

Various researches have shown periodontitis to share common pathophysiological pathways with systemic diseases such as diabetes, cardiovascular diseases, and osteoporosis and recently neurological disorders. This article provides a narrative review summarizing the various linking mechanisms and the nature of association between two multifactorial diseases-periodontitis and migraine.

Materials and Methods

A literature search was performed for articles related to periodontitis and migraine up till the year 2023 which yielded totally 14 articles. There were only three randomized controlled clinical trials; therefore, we were unable to conduct a systematic review and focused on a narrative review. The keywords searched were "migraine", "periodontitis" and "biomarkers" in PubMed/Medline, Web of Science, and Embase databases. Any article related to the association of periodontitis and migraine and the dental management of subjects with headache disorders were included and studies with migraine and other dental diseases were excluded.

Results

It is found that the occurrence of periodontitis and migraine are associated with each other. There is reasonable evidence to believe that periodontitis and migraine are linked by direct and indirect mechanisms which can eventually lead to chronic inflammatory conditions like periodontitis worsening neurovascular conditions such as migraine. However, upon detailed analysis it was found that the strength of association is weak owing to the presences of various common confounding and risk factors.

Conclusions

The association between periodontitis and migraine cannot be denied, however, not all the criteria are fulfilled while examining the nature of association and future long-term studies are required to prove the same. Clinical Relevance. Various studies have reported poor periodontal health in patients with migraine. The risk of exacerbation of migraine also increases in subject undergoing dental therapy if the triggering factors are manipulated. Hence, knowing the precise pathophysiologic mechanisms linking both the diseases would be favorable in planning treatment protocols for subjects with migraine.

Cervical cancer risk in association with TNF-alpha gene polymorphisms in Bangladeshi women

BACKGROUND

Tumor necrosis factor-alpha (TNF-α) is among the vital pro-inflammatory cytokines that potentially exerts a significant influence on the immune response, hence potentially regulating the advancement of cervical lesions.

OBJECTIVE

Our study objective was to examine the relationship between two single nucleotide polymorphisms (SNPs) (rs1799724 and rs1800629) of TNF-α and the risk of cervical cancer in women from Bangladesh.

METHODS

We recruited 133 patients with cervical cancer and 126 healthy individuals for this study. Genotyping was performed using real-time PCR SNP genotyping assay. Multivariate logistic regression analysis was used to determine the odds ratio (OR) along with 95% confidence intervals (CI) and p-values.

RESULTS

For rs1799724 (C > T) polymorphism, TT mutant homozygous genotype carried 3.26 times increased risk of developing cervical cancer (OR = 3.26, 95% CI = 1.15-9.28, p = 0.027). Polymorphism of rs1800629 (G > A) was also related to an elevated risk of cervical cancer. Individuals with the AG heterozygous genotype (OR = 2.85, 95% CI = 1.20-6.74, p = 0.017) and AA mutant homozygous genotype (OR = 4.55, 95% CI = 1.24-16.60, p = 0.022) also had a higher likelihood of having cervical cancer. Moreover, we found that injectable contraceptives increase the risk of cervical cancer. Individuals who smoked and/or had first-degree relatives with cancer were more likely to carry the risk allele, which increases the likelihood of developing cervical cancer.

CONCLUSION

TNF-α polymorphisms in rs1799724 and rs1800629 increase the susceptibility of developing cervical cancer in women from Bangladesh.

Relationship of TNFα-238 G/A (rs 361525) genotypes with TNFα gene expression in liver and pancreas disorders in sample of beta thalassemia major adult Iraqi patients

BACKGROUND

Tumor necrosis factor-α (TNFα) is a crucial physiologic regulator of immune responses, and several disorders have been associated with its dysregulation.

OBJECTIVE

This study aimed to understand TNFα gene expression in adult patients with liver and pancreas disorders and examine the impact of TNFα-238 genotypes on this population.

METHODS

At the Ibn Al-Baladi Hospital in Baghdad, blood samples were collected from forty patients who were diagnosed with beta thalassemia together with pancreatic disease, forty patients who were diagnosed with thalassemia together with liver disorder, and forty patients who were diagnosed with thalassemia without pancreas or liver disorder. For the purpose of establishing a control group, forty samples were collected from persons who were of the same age and gender and seemed to be in good health. All of these individuals were deemed to be older than 18 years old. Through the utilization of real-time polymerase chain reaction (PCR), the level of TNF-α gene expression was investigated and assessed. The T-ARMS-PCR method was performed for detection and genotyping of TNFα-238 in thalassemia patients and healthy control samples.

RESULTS

The result showed that TNF α gene expression assessment showed that group B (thalassemia patients with liver disorder) had higher folding than other groups while the lowest gene expression was in group D (as control group). Furthermore, the relationship between TNFα gene expressions folding with TNFα-238 genotypes in beta thalassemia major patients, discovered a considerable increase at GA genotype patients in TNFα gene expression level, followed by AA genotype compared to the GG genotype. Furthermore, the results of the current study showed an association between the presence of the mutant (A) allele whether heterozygous (GA) and homozygous (AA) with the TNF-α gene expression in thalassemia patients with liver and pancreatic disorders.

CONCLUSION

Based on the results, it can be concluded that there is a relationship between the presence of the mutant (A) allele, whether heterozygous (GA) or homozygous (AA) of TNF-α 238, and TNF-α gene expression in liver and pancreatic diseases as well as in patients with thalassemia.

Tumor necrosis factor alpha gene polymorphism affects the pattern of idiopathic nephrotic syndrome in Kuwaiti Arab children

OBJECTIVES

TNF-α is a pro-inflammatory cytokine that has been implicated in many inflammatory diseases, but its association with idiopathic nephrotic syndrome (INS) is poorly understood. This study looked for an association of TNF-α gene polymorphisms with INS, as well as its effect on steroid responsiveness among Kuwaiti Arab children.

METHODS

Genotypes of the TNF-a gene polymorphisms were analyzed using polymerase chain reaction-restriction fragment length polymorphism in 151 INS Kuwaiti Arab patients and 64 age and sex-matched controls. Clinical data of all subjects were reviewed.

RESULTS

The heterozygous AG genotype was detected in 8.6% of INS patients compared 23.4% of the controls (p < 0.01). Comparing steroid responsiveness, AA genotype was significantly more common in steroid-sensitive nephrotic syndrome (SSNS) cases than steroid-resistant nephrotic syndrome (SRNS) patients (p = 0.001). However, AG genotype was significantly more common in SRNS patients compared to the SSNS cases (p = 0.001). No difference was found between these two subgroups in the GG genotype frequency.

CONCLUSION

AG genotype of TNF-a gene polymorphisms may be considered a suitable marker for INS disease among Kuwaiti children. Both AA and AG genotypes may be useful in predicting steroid responsiveness among these cases of Arab ethnicity. The findings might open the era for the use of genetic markers in the early treatment of NS.

One year of experience with combined pharmacokinetic/pharmacogenetic monitoring of anti-TNF alpha agents: a retrospective study

Anti-tumor necrosis factor alpha (anti-TNFα) inhibitors are used extensively for the management of moderate to severe inflammatory bowel disease (IBD) in both adult and pediatric patients. Unfortunately, not all patients show an optimal response to induction therapy, while others lose their response over time for reasons yet poorly understood. We report on a pharmacokinetic/pharmacogenetic approach to monitor the therapy with anti-TNFα in a real-world cohort of seventy-nine pediatric patients affected by IBD that was analyzed retrospectively. We evaluated plasma concentrations of infliximab, adalimumab, and related anti-drug antibodies (ADAs), and single nucleotide polymorphisms (SNPs) in genes involved in immune processes and inflammation on the anti-TNFα response. We found a significant association between the SNP in TNFα promoter (-308G>A) and clinical remission without steroids in patients on infliximab therapy. Additionally, a potential connection between HLA-DQA1*05 genetic variant carriers and a higher risk of anti-TNFα immunogenicity emerged.

Salivary biomarkers: novel noninvasive tools to diagnose chronic inflammation

Several chronic disorders including type 2 diabetes (T2D), obesity, heart disease and cancer are preceded by a state of chronic low-grade inflammation. Biomarkers for the early assessment of chronic disorders encompass acute phase proteins (APP), cytokines and chemokines, pro-inflammatory enzymes, lipids and oxidative stress mediators. These substances enter saliva through the blood flow and, in some cases, there is a close relation between their salivary and serum concentration. Saliva can be easily collected and stored with non-invasive and cost-saving procedures, and it is emerging the concept to use it for the detection of inflammatory biomarkers. To this purpose, the present review aims to discuss the advantages and challenges of using standard and cutting-edge techniques to discover salivary biomarkers which may be used in diagnosis/therapy of several chronic diseases with inflammatory consequences with the pursuit to possibly replace conventional paths with detectable soluble mediators in saliva. Specifically, the review describes the procedures used for saliva collection, the standard approaches for the measurement of salivary biomarkers and the novel methodological strategies such as biosensors to improve the quality of care for chronically affected patients.

Enlightening the association between TNF-α -308 G > A and migraine: a meta-analysis with meta-regression and trial sequential analysis

BACKGROUND

Migraine is a complex neurological disorder that is characterized by a "lower threshold of neuronal hyperexcitability" with distinctive periodicity and complex vascular dysfunction. Genetic factors have impacted incredibly on the susceptibility of migraine and one such example is the TNF-α 308G > A.

AIM

Therefore, we aim to provide a glimpse of the association of the TNF-α 308G > A risk on the susceptibility of migraine.

METHOD

The pooled odds ratio with the associated 95% of confidence interval were calculated using different genetic models. Heterogeneity was accessed by using Cochran's Q Test and I² statistics and Begg's and Egger's tests were used for finding the publication bias, tests were two-sided, and a p-value of < 0.05 was considered statistically significant. The Trial Sequential Analysis with Meta-regression Analysis were also utilized to find out the sample size requirement for meta-analysis to avoid type I error and source of heterogeneity respectively.

RESULT

A total of 13 studies with cases: 7193 and controls: 23,091 were included and after using different genetic models, no overall association with migraine and its clinical subtype migraine with aura was observed (Allele model "OR: 1.28, 95% C.I. [0.96-1.69] and OR: 0.99,95% C.I. [0.69-1.42]) respectively. Interestingly, after sub-grouping using the "ethnicity criteria" in the migraine group, it was observed that the allelic genetic model and the dominant model were found to be significantly associated with the Asian ethnic group (OR: 1.79, 95% C.I. [1.13-2.84], and OR: 1.85, 95% C.I. [1.0927; 3.1580].

CONCLUSION

In conclusion, the present meta-analysis has provided evidence that 308G > A increases the risk of migraine only in the Asian population.

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.

Does TNF-α 308 G/A (rs1800629) gene polymorphism associate with liver and pancreas disorders in Iraqi adults with beta thalassemia major?

BACKGROUND

TNF-α has been considered as the key regulator of inflammatory responses and is known to be participated in the pathogenesis of several diseases.

OBJECTIVE

The aim of this study was to explore the relationship of (rs1800629) gene polymorphism associated to liver and pancreas disorders in sample of β-thalassemia major adult Iraqi Patients.

MATERIAL AND METHOD

Blood samples were obtained from 40 patients suffered from beta thalassemia with pancreas disorder, along with 40 patient suffered from thalassemia with liver disorder, and 40 patient suffered from thalassemia without pancreas or liver, from Ibn Al-Baladi Hospital, Baghdad, and 40 samples from age and gender-matched apparently healthy individuals as control group, all subjects with age more than 18 years. TNF-308G/A (rs1800629) gene polymorphisms were assessed by Tetra- ARMS-PCR.

RESULTS

The result of showed that heterogeneous GA and homogeneous AA genotypes were higher, while GG wild genotype was lower in beta thalassemia major patients with liver and pancreas disorders compared to control group.

CONCLUSION

It can be concluded that the prevalence of TNF-α 308 G/A SNP plus (A) allele could be associated with risk of liver and pancreas disorders in sample of beta thalassemia major adult.

The Effect of TNF-alpha rs1800629 Polymorphism on White Matter Structures and Memory Function in Patients With Schizophrenia: A Pilot Study

OBJECTIVE

This study investigated the effect of TNF-α rs1800629 polymorphism on white matter integrity and memory function in patients with schizophrenia.

METHODS

Fifty-five participants with schizophrenia were enrolled in this study. They were genotyped for TNF-α rs1800629 polymorphism and underwent diffusion tensor imaging. Memory function was assessed using the Rey-Kim memory test. Participants with schizophrenia were grouped into GG homozygotes and A-allele carriers.

RESULTS

Compared to GG homozygotes, A-allele carriers had significantly lower scores for immediate and delayed recall and recognition of verbal memory and showed significantly lower fractional anisotropy in extensive brain regions. Lower total scores in immediate and delayed recall of verbal memory, immediate recall of visual memory, and figure copy of visual memory were significantly correlated with decreased mean fractional anisotropy in the white matter tracts of the corresponding brain regions.

CONCLUSION

Our findings suggest that the A-allele, which is associated with higher levels of TNF-α expression, correlates with lower connectivity of the fronto-temporal white matter compared to that in GG homozygotes. Impaired fronto-temporal connectivity may be associated with genetic vulnerability to schizophrenia, leading to verbal and visual memory deficits in patients with schizophrenia.

Host Factors in the Natural History of Chronic Hepatitis B: Role of Genetic Determinants

BACKGROUND

The host immune system plays an important role in hepatitis B virus (HBV) infection manifestation. Genetic polymorphisms of several inflammatory cytokines, including TNF-α and IL-10, have been associated with chronic hepatitis B (CHB) progression, although with contradicting results. CHB progression can be categorized into four phases, immune tolerance (IT), immune clearance (IC), low/no replicative (LR), and e-negative hepatitis (ENH), with HBeAg seroconversion as an important milestone. Here, we determined the association of TNF-α (rs1800629) and IL-10 (rs1800896 and rs1800872) SNPs in the context of CHB natural history progression, particularly to HBeAg seroconversion, in Indonesian CHB patients.

METHODS

A total of 287 subjects were recruited and categorized into distinct CHB phases based on HBeAg, viral load, and ALT levels. TNF-α and IL-10 SNPs were determined using PCR-RFLP and confirmed with direct sequencing. The association between SNP genotypes with CHB dynamics was determined using logistic regression presented as odds ratio (OR) with 95% CI.

RESULTS

No significant association was found between IL-10 -592A/C polymorphism and progression of IT and IC to LR, IT and IC to ENH, and LR to ENH phases in all the gene models. IL-10 rs1800896 and TNF-α rs1800629 could not be analyzed using logistic regression. Subjects' age (≥40 years old) was significantly associated with IT and IC to LR (OR: 2.191, 95% CI 1.067-4.578, P = 0.034), IT and IC to ENH (OR: 7.460, 95% CI 3.316-18.310, P < 0.001), and LR to ENH (OR: 5.252, 95% CI 2.010-14.858, P = 0.001). Male gender was associated with LR to ENH (OR: 4.077, 95% CI 1.605-11.023, P = 0.004).

CONCLUSIONS

Age and male gender were associated with CHB phase progression instead of the TNF-α and IL-10 polymorphisms. It would be beneficial to study not only the effect of host determinants but also the viral factor to understand the mechanisms of CHB phase progression.

Association of TNF-α rs1800629 with Adult Acute B-Cell Lymphoblastic Leukemia

TNF−α influences lymphomagenesis by upregulating proinflammatory and antiapoptotic pathways. In this study, we evaluated the frequency of TNF−α rs1800629 (−308 G>A) polymorphism in newly diagnosed adult patients with acute lymphoblastic leukemia (ALL) and its correlation with age at diagnosis, gender and subtype of ALL. In this case control study, a total of 330 individuals were recruited, including 165 newly diagnosed adult patients with ALL, from the Radiation and Isotope Center in Khartoum (RICK) and 165 healthy normal controls. TNF−α rs1800629 polymorphism was tested through allele-specific polymerase chain reaction (PCR) assay. The frequency of the rs1800629 GA genotype was high (70.9% vs. 60%, OR = 1.84) in the patient group as compared to healthy controls, whereas GG and AA genotypes did not exhibit any statistically significant difference between controls and patients. Based on subtype, GG and GA rs1800629 genotypes showed increased risk of B-ALL (OR 0.46 and 2.12, respectively), whereas rs1800629 GG, GA and AA genotypes did not show any disease association with T-ALL (p > 0.05). Age at diagnosis and gender did not exhibit any association of rs1800629 with ALL in the patient group. In conclusion, rs1800629 is associated with high risk of adult B-ALL, with an insignificant effect of age at diagnosis and gender.

Effect of Humanin G (HNG) on inflammation in age-related macular degeneration (AMD)

Inflammation plays a crucial role in the etiology and pathogenesis of AMD (Age-related Macular Degeneration). Humanin G (HNG) is a Mitochondrial Derived Peptide (MDP) that is cytoprotective in AMD and can protect against mitochondrial and cellular stress induced by damaged AMD mitochondria. The goal of this study was to test our hypothesis that inflammation-associated marker protein levels are increased in AMD and treatment with HNG leads to reduction in their protein levels. Humanin protein levels were measured in the plasma of AMD patients and normal subjects using ELISA assay. Humanin G was added to AMD and normal (control) cybrids which had identical nuclei from mitochondria-deficient ARPE-19 cells but differed in mitochondrial DNA (mtDNA) content derived from clinically characterized AMD patients and normal (control) subjects. Cell lysates were extracted from untreated and HNG-treated AMD and normal cybrids, and the Luminex XMAP multiplex assay was used to measure the levels of inflammatory proteins. AMD plasma showed reduced Humanin protein levels, but higher protein levels of inflammation markers compared to control plasma samples. In AMD RPE cybrid cells, Humanin G reduced the CD62E/ E-Selectin, CD62P/ P-Selectin, ICAM-1, TNF-α, MIP-1α, IFN–γ, IL-1β, IL-13, and IL-17A protein levels, thereby suggesting that Humanin G may rescue from mtDNA-mediated inflammation in AMD cybrids. In conclusion, we present novel findings that: A) show reduced Humanin protein levels in AMD plasma vs. normal plasma; B) suggest the role of inflammatory markers in AMD pathogenesis, and C) highlight the positive effects of Humanin G in reducing inflammation in AMD.

Association of tumor necrosis factor alpha ‐308 single nucleotide polymorphism with SARS CoV‐2 infection in an Iraqi Kurdish population

Uncovering risk factors playing roles in the severity of Coronavirus disease 2019 (Covid‐19) are important for understanding pathoimmunology of the disease caused by severe acute respiratory syndrome Coronavirus 2 (SARS CoV‐2). Genetic variations in innate immune genes have been found to be associated with Covid‐19 infections. A single‐nucleotide polymorphism (SNP) in a promoter region of tumor necrosis factor alpha (TNF‐α) gene, TNF‐α −308G>A, increases expression of TNF‐α protein against infectious diseases leading to immune dysregulations and organ damage. This study aims to discover associations between TNF‐α −308G>A SNP and Covid‐19 infection. Polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) was used for genotyping a general Kurdish population and Covid‐19 patients. The homozygous mutant (AA) genotype was found to be rare in the current studied population. Interestingly, the heterozygous (GA) genotype was significantly (p value = 0.0342) higher in the Covid‐19 patients than the general population. This suggests that TNF‐α −308G>A SNP might be associated with Covid‐19 infections. Further studies with larger sample sizes focusing on different ethnic populations are recommended.

IL-10 (-819C/T), TNFA (-30G/A) and ENOS (-786T/C) Polymorphisms Modulating the Outcome Related to Mental Disorders in Crack Addicted Users

Background

Cocaine/crack use affects immune system molecules and development of mental disorders has been identified.

Objective

To investigate the relationship of polymorphisms in the TNFA (-308G/A), IL-10 (-819C/T) and ENOS (-786T/C) genes with mental disorders in cocaine and crack users.

Methods

A case-control study was carried out, which included 107 cocaine and crack users and 115 controls who never used healthy cocaine and crack. The SNPs in the TNFA (-308G/A), IL-10 (-819C/T) and ENOS (-786T/C) genes were genotyped by real time PCR.

Results

As for the individuals included in this study, the average age of 31.4 years (± 8.59). We identified that the G/A genotype to TNFA (-308) (OR = 0.24; p = 0.03) and the A allele (OR = 0.30; p = 0.03) were associated with reduced risk for dysthymic disorder. The T allele of the IL-10 (-819) polymorphism was associated with decreased risk of developing panic disorder (OR = 0.44; p = 0.01), while the C allele was correlated with an increased risk for alcohol dependence (OR = 1.97; p = 0.04), alcohol abuse (OR = 1.81; p = 0.04) and psychotic syndrome (OR = 2.23; p = 0.01). C/C genotype was correlated with increased chances of developing current psychotic syndrome (OR = 4.23; p = 0.01).

Conclusion

Our results suggest that genetic polymorphisms promote susceptibility or promote protection for clinical phenotypes of psychiatric comorbidities in cocaine and crack users and be considered as good prognostic markers.

Immunological findings in patients with migraine and other primary headaches: a narrative review

Experimental findings suggest an involvement of neuroinflammatory mechanisms in the pathophysiology of migraine. Specifically, preclinical models of migraine have emphasized the role of neuroinflammation following the activation of the trigeminal pathway at several peripheral and central sites including dural vessels, the trigeminal ganglion, and the trigeminal nucleus caudalis. The evidence of an induction of inflammatory events in migraine pathophysiological mechanisms has prompted researchers to investigate the human leukocyte antigen (HLA) phenotypes as well as cytokine genetic polymorphisms in order to verify their potential relationship with migraine risk and severity. Furthermore, the role of neuroinflammation in migraine seems to be supported by evidence of an increase in pro-inflammatory cytokines, both ictally and interictally, together with the prevalence of Th1 lymphocytes and a reduction in regulatory lymphocyte subsets in peripheral blood of migraineurs. Cytokine profiles of cluster headache (CH) patients and those of tension-type headache patients further suggest an immunological dysregulation in the pathophysiology of these primary headaches, although evidence is weaker than for migraine. The present review summarizes available findings to date from genetic and biomarker studies that have explored the role of inflammation in primary headaches.

Association of Promoter Methylation and Expression of Inflammatory Genes IL-6 and TNF-α with the Risk of Coronary Artery Disease in Diabetic and Obese Subjects among Asian Indians

The inflammatory cytokines such as interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) are considered as the most important contributors to the endothelial dysfunction in subjects with type 2 diabetes mellitus (T2DM) and obesity. The hypomethylation of CpG sites in the promoter region of the IL-6 and TNF-α have shown to be associated with the increased expression of IL-6 and TNF-α. However, there are no studies on the methylation and expression of IL-6 and TNF-α with the risk of coronary artery disease (CAD) in subjects with T2DM and obesity in Asian Indians. Hence, the present study was aimed to investigate whether the IL-6, TNF-α promoter methylation and expression in blood leukocyte DNA is associated with the risk of CAD in diabetic and obese subjects in Asian Indians. For this study, we recruited 574 subjects which includes, 207 angiographically confirmed CAD patients, 100 T2DM patients, 82 obese subjects and 185 healthy controls. The methylation status of IL-6 and TNF-α gene loci was determined by methylation specific PCR (MPCR) and gene expression was determined by qPCR. We found significant hypomethylation of IL-6 in CAD and T2DM subjects (OR 1.98 95% CI: 1.32-2.97, p = 0.001, OR: 2.23 95% CI:1.34-3.76, p = 0.001, respectively). Further, a significant increase in the expression of IL-6 in CAD and T2DM subjects (fold change: 26.39 & 14.7, p = 0.0001) compared to the control subjects was observed. A significant increase in the hypomethylation of TNF-α in CAD, T2DM and obese subjects was observed as compared to the control (OR: 2.04 95% CI: 1.36-3.05, p = 0.0005, OR: 1.81 95% CI 1.10-2.96, p = 0.01, and OR: 2.1 95% CI 1.24-3.57, p = 0.007, respectively).We also found an increased expression of TNF-α in CAD, T2DM and obese subjects as compared to controls. In addition, presence of low folate, and hyperhomocysteinemia was observed in the present study, may be the contributing factors for the hypomethylation of IL-6 and TNF-α and oxidative stress. In conclusion, increased expression of IL-6 and TNF-α due to hypomethylation in T2DM and obese individuals may contribute to CAD risk in these subjects. The presence of hyperhomocysteinemia and increased oxidative risk may enhance the CAD risk further.

Impact of TNF-α profile in recurrent pregnancy loss pathogenesis: A patient based study from Assam

BACKGROUND

Lacunae exist in understanding the underlying etiology in majority of recurrent pregnancy loss (RPL) cases. Given the significance of regulated immune-modulation in pregnancy, and the central role of pro-inflammatory TNF-α plays in it; this study targeted to appraise the significance of TNF-α profile in RPL pathogenesis in an ethnically distinct population from Assam, India.

METHODS

Term delivery, medically terminated pregnancy (MTP) and RPL cases (based on ASRM criteria) were enrolled with no anatomical and chromosomal abnormalities or pathological infections; and blood and/or placenta/product of conceptus (POC) tissue samples were collected with informed consent. Serum level and tissue level TNF-α expression profile were screened using specific molecular tools, and was correlated with TNF-α -308 G/A genotype; for its association with RPL predisposition.

RESULTS

A significant gestation specific increase in serum TNF-α levels was observed in MTP cases (19.932 ± 4.407 pg/mL) compared to term delivery subjects (p = 0.001), while a comparable levels were observed with RPL cases (22.709 ± 5.833 pg/mL) (p = 0.646). A site specific (POC) increased expression was observed in RPL compared to MTP cases at both at transcript (6.37 ± 3.714 folds) and protein levels. The TNF-α -308 variant genotype was associated with increased predisposition to RPL (OR = 1.721) compared to MTP as well as significantly increased serum TNF-α levels (p = 0.017); especially in subjects with a homozygous TNF-α -308 A/A genotype.

CONCLUSION

Our data emphasizes on the importance of site specific TNF-α expression levels in RPL pathogenesis in the studied population, and underlines its importance in screening, clinical stratification, and therapeutics by molecular targeting using TNF-α inhibitors.

Interleukin-10 and tumour necrosis factor alpha promoter region polymorphisms and susceptibility to urogenital schistosomiasis in young Zimbabwean children living in Schistosoma haematobium endemic regions

Background

Host genetic factors can influence susceptibility, morbidity and mortality from schistosomiasis. The study explored the association between single nucleotide polymorphisms (SNPs) in interleukin-10 (IL-10) and tumour necrosis factor alpha (TNF-α) promoter regions and susceptibility to Schistosoma haematobium infection.

Methods

Urine specimens were collected from 361 primary school children aged 5–15 years from schistosomiasis endemic areas of Manicaland and Mashonaland central provinces. Schistosoma haematobium was diagnosed using the urine filtration method. Only 272 participants provided adequate blood for genotyping. Genotyping was performed using the amplification refractory mutation system-polymerase chain reaction. The association between IL-10 and TNF-α SNPs and S. haematobium infection was analysed using the chi-square test.

Results

Schistosoma haematobium infection was confirmed in 26.8% of the participants. No significant difference in S. haematobium prevalence between men (51.6% of those infected) and women (48.4%) (χ² = 0.008, df = 1, p = 0.928) was observed. The total IL-10 -1082 G, IL-10 -819 C and TNF-α -308G allele distribution between S. haematobium infected and uninfected participants was 50.7% and 51.5% (χ² = 0.025, df = 1, p = 0.87), 54.3% and 60.6% (χ² = 1.187, df = 1, p = 0.187) and 82.1% and 80.9% (χ² = 0.099, df = 1, p = 0.753), respectively, and the differences were not significant.

Conclusion

Interleukin-10 -1082 G/A, IL-10 -819 C/T and TNF-α -308 G/A SNPs were not significantly associated with susceptibility to S. haematobium infection. The prevalence of schistosomiasis is still in the moderate range and is similar in boys and girls.

The synergistic role of TNFA - 308G/A and IL10 - 1082A/G polymorphisms in ankylosing spondylitis

OBJECTIVE

Genetic polymorphisms of the cytokine genes could alter their protein expression, thus creating a genetic basis of dysregulated cytokine production and function, which render them as excellent candidates predisposing to autoimmune diseases. We investigated single nucleotide polymorphisms (SNPs) at TNFA - 308G/A and IL10 - 1082A/G locus to identify their involvement, separately or in combination, in determining susceptibility to ankylosing spondylitis (AS), as well as their functional connections with relevant serum cytokines and associations with disease characteristics.

METHODS

Eighty-one AS patients and 215 healthy controls were genotyped by polymerase chain reaction-based method; 76 patients and sex-matched controls were also subjected to analysis of serum TNF-α and IL-10 levels by enzyme-linked immunosorbent assay.

RESULTS

We identified the homozygous genotype GG of the TNFA-308 significantly more common in patients than controls; whereas the - 308 minor A-allele predicts a threefold decreased risk against developing AS and shows associations with milder radiographic spinal impairments and functional limitations. This protective effect was multiplied by fivefold in synergistic interaction with the homozygous - 1082AA genotype of the IL10 which acts as a modifying factor, since IL10 - 1082A/G SNPs by itself did not have a significant impact on AS genetic susceptibility. In comparison with controls, AS patients had significantly elevated mean serum TNF-α levels and decreased mean IL-10 concentrations not restricted to any particular genotype.

CONCLUSION

TNFA - 308 A-allele is essential for reducing susceptibility to AS, with a considerable synergistic protective effect of the combined TNF-α - 308 (GA/AA)/IL-10 - 1082AA genotypes. In addition, the presence of this variant allele is associated with more benign clinical phenotype of the disease. No conclusive statements on the functional relevance of both gene variants on cytokines production should be made.

The Association of Renal Function and Plasma Metals Modified by EGFR and TNF-α Gene Polymorphisms in Metal Industrial Workers and General Population

Exposure to metals may be associated with renal function impairment, but the effect modified by genetic polymorphisms was not considered in most studies. Epidermal growth factor receptor (EGFR) and tumor necrotic factor-α (TNF-α) play important roles in renal hemodynamics, and they have been reported to be associated with some renal diseases. The aim of our research is to explore whether genetic variations in EGFR and TNF-α have influence on renal function under exposure to various metals. This cross-sectional study consisted of 376 metal industrial workers, 396 participants of Taiwan Biobank, and 231 volunteers of health examinations. We identified 23 single nucleotide polymorphisms (SNPs) on the EGFR gene and 6 SNPs on the TNF-α gene, and we also measured their plasma concentration of cobalt, copper, zinc, selenium, arsenic, and lead. Multiple regression analysis was applied to investigate the association between various SNPs, metals, and renal function. Our results revealed some protective and susceptible genotypes under occupational or environmental exposure to metals. The individuals carrying EGFR rs2280653 GG might have declined renal function under excessive exposure to selenium, and those with EGFR rs3823585 CC, rs12671550 CC, and rs4947986 GG genotypes might be susceptible to lead nephrotoxicity. We suggest the high-risk population to prevent renal diseases.

Analysis of the Potential Genetic Links between Psoriasis and Cardiovascular Risk Factors

Cardiovascular risk factors are one of the most common comorbidities in psoriasis. A higher prevalence of hypertension, insulin resistance and type 2 diabetes, dyslipidemia, obesity, metabolic syndrome, depression, as well as cardiovascular disease was confirmed in psoriatic patients in comparison to the general population. Data suggest that psoriasis and systemic inflammatory disorders may originate from the pleiotropic interactions with many genetic pathways. In this review, the authors present the current state of knowledge on the potential genetic links between psoriasis and cardiovascular risk factors. The understanding of the processes linking psoriasis with cardiovascular risk factors can lead to improvement of psoriasis management in the future.

Host polymorphisms and COVID-19 infection

Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus, severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). There is growing evidence that host genetics play an important role in COVID-19 severity. Based on current knowledge about the human protein machinery for SARS-CoV-2 entry, the host innate immune response, and virus-host interactions, the potential effects of human genetic polymorphisms, which may contribute to clinical differences in SARS-CoV-2 pathogenesis, may help to determine the individual risk for COVID-19 infection and outcome.

Synergistic effect of genetic polymorphisms in TLR6 and TLR10 genes on the risk of pulmonary tuberculosis in a Moldavian population

Polymorphisms in genes that control immune function and regulation may influence susceptibility to pulmonary tuberculosis (TB). In this study, 14 polymorphisms in 12 key genes involved in the immune response (VDR, MR1, TLR1, TLR2, TLR10, SLC11A1, IL1B, IL10, IFNG, TNF, IRAK1, and FOXP3) were tested for their association with pulmonary TB in 271 patients with TB and 251 community-matched controls from the Republic of Moldova. In addition, gene-gene interactions involved in TB susceptibility were analyzed for a total of 43 genetic loci. Single nucleotide polymorphism (SNP) analysis revealed a nominal association between TNF rs1800629 and pulmonary TB (Fisher exact test P = 0.01843). In the pairwise interaction analysis, the combination of the genotypes TLR6 rs5743810 GA and TLR10 rs11096957 GT was significantly associated with an increased genetic risk of pulmonary TB (OR = 2.48, 95% CI = 1.62-3.85; Fisher exact test P value = 1.5 × 10^-5, significant after Bonferroni correction). In conclusion, the TLR6 rs5743810 and TLR10 rs11096957 two-locus interaction confers a significantly higher risk for pulmonary TB; due to its high frequency in the population, this SNP combination may serve as a novel biomarker for predicting TB susceptibility.

Human Genetic Variation Influences Enteric Fever Progression

In the 21st century, enteric fever is still causing a significant number of mortalities, especially in high-risk regions of the world. Genetic studies involving the genome and transcriptome have revealed a broad set of candidate genetic polymorphisms associated with susceptibility to and the severity of enteric fever. This review attempted to explain and discuss the past and the most recent findings on human genetic variants affecting the progression of Salmonella typhoidal species infection, particularly toll-like receptor (TLR) 4, TLR5, interleukin (IL-) 4, natural resistance-associated macrophage protein 1 (NRAMP1), VAC14, PARK2/PACRG, cystic fibrosis transmembrane conductance regulator (CFTR), major-histocompatibility-complex (MHC) class II and class III. These polymorphisms on disease susceptibility or progression in patients could be related to multiple mechanisms in eliminating both intracellular and extracellular Salmonella typhoidal species. Here, we also highlighted the limitations in the studies reported, which led to inconclusive results in association studies. Nevertheless, the knowledge obtained through this review may shed some light on the development of risk prediction tools, novel therapies as well as strategies towards developing a personalised typhoid vaccine.

A TNF Block Genotype may Influence CMV Retinitis in HIV Patients without Affecting Systemic Viral Replication

BACKGROUND

A conserved TNF block haplotype marked by the minor alleles of rs1800629 (TNFA-308*A) and rs9281523 [BAT1(intron 10)*C] has been linked with several immunopathological conditions and with rapid progression of HIV disease. Reported associations with cytomegalovirus (CMV) retinitis in HIV patients before or during early antiretroviral therapy (ART) may therefore reflect greater replication of CMV in advanced HIV disease or an immunopathological response to CMV in the retina.

OBJECTIVE

As all Indonesian HIV patients display high levels of CMV replication, we evaluated whether TNF block genotypes alter markers of their burden of CMV and/or associate with retinitis.

METHODS

We assessed 79 consecutive HIV patients beginning ART, 25 HIV patients with a history of CMV-retinitis and 63 healthy adults. HIV RNA, CD4 T-cell counts, CMV-reactive antibody and CMV DNA were measured and alleles of TNFA-308, BAT1(intron 10) and TNFA-1031 (rs1799964) were determined.

RESULTS

TNFA-308 and BAT1(intron 10) were in complete linkage disequilibrium. Patients carrying minor alleles at both loci had higher levels of CMV-reactive antibody after one month on ART (p=0.01), but not at other time points spanning 1 year on ART. 50% of patients had detectable CMV DNA before ART, irrespective of TNF block genotypes. However, the TNFA-308*A/- BAT1(intron 10)*C haplotype was more common in CMV-retinitis patients than other patients or healthy controls (p<0.01).

CONCLUSION

The TNFA-308*A/BAT1(intron 10)*C haplotype appears to affect CMV-induced pathology rather than CMV replication.

Polymorphisms in the IL-6 and TNF-α gene are associated with an increased risk of abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) is a complex disease of the aging population that is associated with inflammation and the cellular immune response. To investigate the influence of interleukin (IL)-6 and tumor necrosis factor (TNF)-α single nucleotide polymorphisms (SNPs) on the risk of AAA formation and progression, the frequency of AAA and its associated risk factors were determined.

METHOD

Four SNPs in the IL-6 (-174G/C, rs1800795; -572G/C, rs1800796) and TNF-α (-238G/A, rs361525; -308G/A, rs1800629) genes were studied by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in patients with AAA and healthy volunteers. The mRNA expression and plasma IL-6 and TNF-α levels were also determined.

RESULTS

A mutation detected in at least one allele of the IL-6 -174G/C SNP was associated with a 2-fold increased risk of AAA occurrence (OR: 2.08; 95% CI: 1.15-3.76; p = 0.014, in the dominant model). An increased risk of AAA incidence among heterozygous carriers of the TNF-α - 308G/A genotype was observed (OR: 2.06; 95% CI: 1.17-3.62; p = 0.011, in the overdominant model). The wild-type genotypes of the IL-6 -174G/C and the TNF-α -308G/A SNPs coexisted more frequently in healthy subjects than in AAA patients and was associated with decreased risk of AAA (p < 0.001). Moreover, elevated levels of IL-6 and TNF-α were associated with an increased risk of hypertension (p < 0.001 and p = 0.022, respectively).

CONCLUSIONS

The IL-6 -174G/C and the TNF-α -238G/A gene polymorphisms are associated with an increased risk of abdominal aortic aneurysm development.

Association of polymorphism -308G/A in tumor necrosis factor-alpha gene (TNF-α) and TNF-α serum levels in patients with relapsing-remitting multiple sclerosis

TNF-α is an important cytokine of the inflammatory response involved in the pathogenesis of relapsing-remitting multiple sclerosis (RRMS). The aim of this study is to explore the association between the promoter polymorphism -308G/A in the TNF-α gene (rs1800629) with genetic susceptibility to RRMS.Methods: A group of 183 RRMS patients and 169 age and gender-matched healthy controls were enrolled in the study. Genotyping of the polymorphism was performed by PCR-restriction fragment length polymorphism and quantification of TNF-α serum levels was conducted by ELISA.Results: The genotype distribution in female patients showed a significantly elevated frequency of heterozygotes (AG) (23.5% vs. 12.8%, OR = 2.072, p = 0.029) in comparison with the healthy women. Substantially higher TNF-α serum levels were observed in females compared to males, in both patients and healthy controls (p < 0.05). According to the genotype, TNF-α levels in the RRMS group were calculated in the following order: for GA/AA genotypes (5.67pg/ml vs. 3.48pg/ml, p = 0.0031) and for GG genotypes (4.58pg/ml vs. 3.52pg/ml, p = 0.00043). Moreover, the carriers of at least one A-allele of -308G/A TNF-α polymorphism (GA+AA) are significantly associated with two fold increased risk for RRMS development (OR = 1.950; p = 0.042) in women in contrast to men as well as associated with early onset of the disease (OR = 2.400; p = 0.021).Conclusion: Our study showed that the level of TNF-α in the serum of patients with RRMS showed a significant association with the -308G/A TNF-α polymorphism and gender dependency.

Association of TNF-α G-308 a Promoter Polymorphism with the Course and Outcome of COVID-19 Patients

Background: Tumor necrosis factor-ɑ (TNF-ɑ) is one of the most important cytokines that manage the host defense mechanism, which may play a role in the pathogenesis of COVID-19 patients. The work aims to study the association of TNF-ɑ G-308 A gene polymorphism with the course and outcome of COVID-19 patients in Mansoura University Hospital.Methods: 900 patients with COVID-19 infection and 184 controls were tested for TNF-ɑ G-308 A promoter polymorphism. Different genotypes of TNF-ɑ G-308 A were compared as regards the severity and prognosis of the disease.Results: No statistically significant difference was found between patients and controls as regards the demographic data. The AA genotype of TNF-ɑ showed a higher incidence of the disease in comparison to the other genotypes. As regards the demographic and laboratory characters, no statistically significant difference was found between the different genotypes except for age, lymphopenia, CRP, and serum ferritin levels. In 336(80.0%) cases of the AA genotype, the disease was severe in comparison to 90(41.7%) cases in the GA genotype and no cases in the GG genotype with P = .001.Conclusion: People who carry the A allele of TNF-ɑ polymorphism are more prone to COVID-19 infection. The AA genotype of TNF-ɑ is associated with a more aggressive pattern of the disease. In those patients, the use of anti - TNF therapy may be promising.

Effect of TNF-α -308G/A (rs1800629) Promoter Polymorphism on the Serum Level of TNF-α Among Iraqi Patients with Generalized Vitiligo

Background

Vitiligo is a chronic acquired pigmentary disorder of the skin; it results from immunological distruction of functioning melanocytes. The cytokine TNF-α plays a central role in the initiation of melanocyte apoptosis in vitiligo. Single nucleotide polymorphism (SNP) in the promoter region of the gene coding for serum TNF-α may affect its production.

Objective

The aim of this study is to assess serum TNF-α as a risk factor for generalized vitiligo among Iraqi patients and to rule out that polymorphism at the -308 position affects serum TNF-α.

Materials and Methods

This case-control study was conducted at Sulaymaniyah Dermatology Teaching Center (SDTC), Iraq. Serum concentration of TNF-α was measured using enzyme linked immunosorbent assay (ELISA) technique in 80 patients with generalized vitiligo and 40 clinically healthy controls. The amplification refractory mutation system polymerase chain reaction (ARMS-PCR) technique was used for detection of TNF-308G/A gene polymorphism. TNF-α level correlated with TNF-308G/A gene polymorphism. Serum concentration and TNF -308G/A gene polymorphism have been analyzed in correlation with demographic features and clinical characteristics of patients with generalized vitiligo.

Results

Statistically significant elevation of serum TNF-α seen in patients compared to a control group (p-value 0.01). Significantly higher TNF-α level (p-value 0.01) found among patients with active generalized vitiligo. Elevated serum levels of TNF-α were significantly associated with both TNFA1 (TNF-308G) allele (p-value 0.04) and TNFA2 (TNF-308A) allele (p-value 0.03). TNF-α -308GA polymorphism was not affected by demographic features and clinical characteristics of patients with generalized vitiligo.

Conclusion

TNF-α in the serum is a risk factor for generalized vitiligo among Iraqi patients. Patients with active vitiligo have a higher serum TNF-α level. No difference was found between serum level of TNF-α with TNF-α polymorphism at position -308 (TNF -308). This involves substituting G allele for the A allele.

Association of single nucleotide polymorphisms in TNF-α (-308G/A and -238G/A) to dengue: Case-control and meta-analysis study

Dengue is an acute viral disease whose clinical condition is related to the interaction of factors related to the Dengue virus (DENV), environment and the host, with the immunity of the human host contributing a substantial role in the pathogenesis of DENV infection. Studies have demonstrated that single nucleotide polymorphisms (SNPs) in the promoter regions of cytokine genes such as tumor necrosis factor (TNF-α) affect transcription and/or expression; and therefore, may influence the pathogenesis of infectious diseases, such as dengue. Consequently, the objective of this study was to assess through a case-control study whether there was an association between the presence of SNPs -308G/A and -238G/A in the TNF-α gene and 158 patients with dengue and 123 controls. No association was found between the SNPs and the dengue cases in the study population. We then performed a meta-analysis, retrieving data from case-control studies in the literature for the same polymorphisms. For SNP-308G/A, the GG genotype was associated with dengue fever (DF) risk (OR = 1.24, 1.00-1.53; p = 0.05; I² = 0%), while the GA genotype (OR = 0.75, 0.60-0.93; p = 0.01; I² = 0%) and allele A (OR = 0.75, 0.60-0.93; p = 0.01; I² = 0%) were associated with protection. The genotype GG population in the Asian continent (OR = 1.81 [1.06, 3.09], p = 0.03, I² = 0%) and American (OR = 1.29 [1.00, 1.65], p = 0.05, I² = 0%) was also associated with protection in the comparison between the cases versus the control group. In each comparison, the dominant model AA + GA (p < 0.00001) conferred protection. For SNP-238G/A the GA genotype was associated with risk for dengue hemorrhagic fever (DHF; OR = 2.17, 1.28-3.67; p = 0.004; I² = 0%)), and the dominant AA + GA model (p < 0.00001) was associated with protection in each comparison. In summary, our results did not associate SNPs in the TNF-α gene to dengue in the Brazilian northeast population. However, combined literature data suggested the effect of the GG and GA genotypes of the SNP-308G/A on risk and protection, respectively, in Asian and American populations.

The prevalence of HPA-1a alloimmunization and the potential risk of FNAIT depend on both the DRB3*01:01 allele and associated DR-DQ haplotypes

Alloimmunization against human platelet antigen (HPA)-1a during pregnancy can cause foetal/neonatal alloimmune thrombocytopenia (FNAIT) and severe bleeding in the foetus or newborn and likely depends on several factors. HPA-1a alloimmunization is associated with DRB3*01:01, which is associated with several DR-DQ haplotypes. However, it is not known to what extent these haplotypes contribute to the prevalence of HPA-1a alloimmunization. HPA-1a-alloimmunized women, identified in a prospective study, and random donors were typed for selected DRB3, DRB4, DRB1, DQA1 and DQB1 alleles to determine allele and DR-DQ haplotype frequencies. DRB3*01:01 was carried by 94% HPA-1a-immunized women compared to 27% in the general population. In the first population, the DR3-DQ2 haplotype was overrepresented (P < .003). The prevalence of HPA-1a alloimmunization was estimated to be about twice as frequent with DR3-DQ2 compared to DR13-DQ6, together accounting for about 90% of DRB3*01:01-positive individuals. Further, we examined DQB1*02 and DRB4*01:01 alleles for their reported association with HPA-1a alloimmunization, in the context of DR-DQ haplotypes. Since ~ 80% of DQB1*02 alleles are linked to the DR3-DQ2 haplotype, the association might be coincidental. However, the DQB1*02:02-associated DR7-DQ2 haplotype was also overrepresented in alloimmunized women, suggesting a role for this allele or haplotype in HPA-1a alloimmunization. As DRB4*01:01 is predominantly associated with the DR7-DQ2 haplotype in HPA-1a-alloimmunized individuals, the reported association with FNAIT may be coincidental. Typing for DR-DQ haplotypes revealed important genetic associations with HPA-1a alloimmunization not evident from typing individual alleles, and the presence of different DRB3-associated DR-DQ haplotypes showed different prevalence of HPA-1a alloimmunization.

Nutritional genomics, inflammation and obesity

The Human Genome Project has significantly broadened our understanding of the molecular aspects regulating the homeostasis and the pathophysiology of different clinical conditions. Consequently, the field of nutrition has been strongly influenced by such improvements in knowledge - especially for determining how nutrients act at the molecular level in different conditions, such as obesity, type 2 diabetes, cardiovascular disease, and cancer. In this manner, characterizing how the genome influences the diet and vice-versa provides insights about the molecular mechanisms involved in chronic inflammation-related diseases. Therefore, the present review aims to discuss the potential application of Nutritional Genomics to modulate obesity-related inflammatory responses. Arch Endocrinol Metab. 2020;64(3):205-22.

Association of TNF-α-308G/A and IL-18 Polymorphisms with risk of HPV infection among sexually active women in Burkina Faso

Human papillomavirus (HPV) infection is the most common sexually transmitted infection worldwide. Persistence infection can lead to the development of cervical cancer potentially due to some genetic factors such as polymorphisms in regulatory and coding regions of cytokine genes. The purpose of this study was to determine whether there is a relationship between TNF-308 G/A or IL18 polymorphisms and high-risk HPV infection among sexually active women from Burkina Faso. Ninety-one HPV infected and two hundred and nine HPV negative women (the latter used as healthy controls) were screened. TNFA-308 G/A and IL18-607 C/A polymorphisms were detected using the TaqMan allelic discrimination. HPV 52 (21.19%), HPV 39 (11.86%) and HPV 33 (11.02%) were the most common HPV genotypes. The TNFA-308A and IL18-607 C alleles were predominant in all women in the study. None of the TNFA and IL18 alleles were associated with HPV infection. The results suggest that there is no relationship between TNF-308 G/A or IL18-607C/A polymorphisms and HPV infection among women in the study.

Association between polymorphic markers human leucocyte antigen-G and tumour necrosis factor alpha and susceptibility to recurrent miscarriages among Bulgarian women

OBJECTIVE

To analyze the role of 14 base pair (bp) insertion (ins)/deletion (del) and tumour necrosis factor alpha (TNF-α) G/A polymorphisms as risk factors for spontaneous miscarriage in patients with two or more unsuccessful pregnancies and a group of control women with at least two normal live births.

MATERIALS AND METHODS

To investigate the role of these mutations, 50 patients with two or more idiopathic recurrent miscarriages and 50 normal fertile women were tested for the presence of human leucocyte antigen-G (HLA-G) 14 bp ins/del and TNF-α -308 G/A variants. The frequencies of the studied polymorphisms were compared between the two groups.

RESULTS

Individuals with a history of miscarriages had a significantly higher prevalence of 14 bp insertion alleles compared with control patients (p=0.04). There was also a two times higher relative risk for miscarriage among carriers of this variant. No statistical difference in allele frequencies of the TNF-α -308 G/A polymorphism was established between controls and study patients (p=0.78).

CONCLUSION

The 14 bp ins HLA-G variant could be associated with a higher risk for unsuccessful pregnancy according to the results from the study. There is no association between the studied TNF-α -308 GA polymorphism and rate of spontaneous abortions.

Association Analysis of Tumor Necrosis Factor Alpha Promoter Polymorphisms and Vitiligo Susceptibility in South Indian Tamils

Tumor necrosis factor alpha (TNF-α) has been associated with the pathogenesis of several autoimmune diseases. Also, various studies in different ethnics showed an association between TNF-α gene polymorphisms and susceptibility to vitiligo. The paucity of genetic data led us to undertake this study to evaluate the association of five TNF-α SNPs (rs1799964, rs1800630, rs1799724, rs1800629, and rs361525) with the development of vitiligo in South Indian Tamils. A total of 264 vitiligo patients and 264 healthy controls were recruited and TNF-α genotyping was performed using amplification-refractory mutation system polymerase chain reaction and TaqMan allele discrimination assay. Circulatory TNF-α levels were measured by enzyme-linked immunosorbent assay. We observed that a single polymorphic allele A in the promoter region -308 (rs1800629) conferred significant risk to develop vitiligo (p = 0.0002, OR = 1.70, 95% CI = 1.28-2.25), whereas the other polymorphisms failed to contribute to disease risk (p > 0.05). From the constructed haplotypes, TCCAG was found to be a significant risk factor for vitiligo (p < 0.05). Also, a strong linkage disequilibrium was observed between the following SNPs: (1) rs1799964 and rs1800629 (2) rs1800630 and rs1799724 (D' = 0.90). Analysis of the influence of genotype on phenotypes revealed that the A allele of rs361525 was a risk factor for vitiligo in females (p = 0.04, OR = 0.45, 95% CI = 0.21-0.95), whilst the rs1800629 allele conferred protection against early disease onset (p < 0.05). A statistically significant difference in plasma TNF-α levels was found between cases and controls (p < 0.05). The TNF-α -308A allele and TCCAG haplotype were identified as genetic risk factors for vitiligo susceptibility in South Indian Tamils.

The role of Tumor necrosis factor alpha −308 G>A promoter polymorphism in pediatric community acquired pneumonia

Background

Tumor necrosis factor alpha (TNF-α) −308 G>A promoter polymorphism might be associated with excessive production of the proinflammatory cytokine TNF-α, modulating host response to pulmonary infections. Our objective was to evaluate the association of TNF-α gene −308 G>A polymorphism with susceptibility to, and severity of, community-acquired pneumonia (CAP).

Results

This was a cross-sectional study including 45 Egyptian children hospitalized for CAP in addition to 45 healthy children who served as a control group. Pneumonia severity was assessed on admission by the World Health Organization (WHO) guidelines; Pediatric Respiratory Severity Score (PRESS) score; Predisposition, Infection, Response and Organ failure (PIROm) score; and Respiratory Index of Severity in Children (RISC) score. Genotyping of TNF-α polymorphism was performed to all individuals by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Patients were monitored till hospital discharge. Frequency of AG genotype was lower among patients compared with control [odds ratio (OR) and 95% confidence interval (CI) = 0.13 (0.03–0.63); p = 0.012]. Prevalence of genotypes AA+AG was lower among patients compared with controls [OR and 95% CI = 0.34 (0.12–0.99); p = 0,048]. The “A” allele prevalence was higher among controls, but no significant association was found with CAP [OR and 95% CI = 0.58 (0.25–1.35); p = 0.21]. When PRESS score was used to classify patients into “severe pneumonia” and “non-severe pneumonia,” no significant association of any of the alleles or genotypes with CAP severity was found.

Conclusion

TNF-α −308 G>A polymorphism confers protection from pediatric CAP but is not associated with indicators of CAP severity. Larger studies are needed to confirm these findings in pediatric patients from different ethnicities.

The Association of Serum TNF-α Levels and Blood Multi-Elements Modified by TNF-α Gene Polymorphisms in Metal Industrial Workers

Health of the metal industrial workers should be a noteworthy issue due to the hazard of chronic exposure to metals or toxic elements. The interactions among multiple elements are sophisticated and may differ from person to person. Tumor necrosis factor-α (TNF-α) gene polymorphisms were supposed to be involved with the interactions because TNF-α plays an important role in inflammation, a mechanism by which toxic elements cause threats to human health. This research aimed to analyze the influence of TNF-α gene polymorphisms and multi-elements on serum TNF-α level. Blood multi-elements concentrations (lead, cadmium, arsenic, selenium, cobalt, copper, and zinc), serum TNF-α level, and TNF-α single nucleotide polymorphisms (SNPs), including −238G > A (rs361525), −308G > A (rs1800629), −857C > T (rs1799724), −863C > A (rs1800630), and −1031T > C (rs1799964), were measured in 462 metal industrial workers. We applied mixed-effect models to analyze the interactions among multi-elements and TNF-α SNPs. Blood concentration of all elements were positively associated with serum TNF-α level, and the effects may be modified by TNF-α gene polymorphisms. Our study revealed that TNF-α −308A/A and −1031C/C may be susceptible genotypes, and thus we suggest that those workers should take preventive measures against metal toxicity.

The effect of tumor necrosis factor alpha (-308G/a) and interferon gamma (+874T/a) polymorphisms on susceptibility to coronary heart disease

Background: Coronary heart disease (CHD) is a chronic inflammatory disease, which is still regarded as a major cause of morbidity and mortality worldwide. Several studies have suggested that polymorphisms in cytokine genes are associated with the pathogenesis of CHD. The genotype distribution of Tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) genes polymorphisms have been shown to be different in various ethnic populations. This study was aimed to investigate the association of TNF-α-308 G/A and IFN-γ + 874T/A polymorphisms with risk of CHD in an Iranian population. Methods: A total of 187 unrelated subjects comprised 96 CHD patients and 91 healthy controls were enrolled in this cross-sectional study. The TNF-α-308 G/A and IFN-γ + 874T/A polymorphisms were genotyped using amplification refractory mutation system-PCR (ARMS-PCR). The chi-square and logistic regression tests were used to calculate the odds ratios (ORs) as a measure of differences in genotype frequencies. Results: A significant differences in the allelic and genotypic distribution of TNF-α-308 G/A and IFN-γ + 874T/A polymorphisms was found between CHD patients and healthy controls (P = 0.017, P = 0.011, P = 0.006 and P = 0.002, respectively). Logistic regression analyses were also revealed statistically significant risk for CHD with respect to TNF-α-308 A and IFN-γ + 874 T carriers either in crude or after adjustment for potential confounders (P = 0.003 and P = 0.006, respectively). Conclusion: This study provides strong evidence supporting the association of TNF-α-308G/A and IFN-γ + 874T/A polymorphisms with the increased risk of CHD. Therefore, these two cytokine polymorphisms may play a role in predisposition to coronary heart disease.

Risk Factors of Ventilator-Associated Pneumonia in Critically III Patients

Ventilator-associated pneumonia (VAP), a hospital acquired pneumonia that occurs more than 48 h after mechanical ventilation, is a common complication of mechanical ventilation with a high mortality rate. VAP can cause patients to have difficulty weaning off the ventilator and to stay in the hospital longer, which results in a huge financial burden to patients and a huge demand for medical resources. Several strategies, such as drugs including chlorhexidine, β-lactam antibiotics and probiotics, have been used to prevent VAP in clinic. The incidence and the mortality rate of VAP have been decreased with the development of preventative strategies in the past decades, but VAP remains one of the most common causes of nosocomial infections and death in the intensive care unit. Current challenges in the management of VAP involved the lack of a gold standard for diagnosis, the absence of effective preventative strategies, and the rise in antibiotic resistance. Therefore, in order to reduce the incidence of VAP and improve the outcome of patients with mechanical ventilation, it is necessary to clarify the risk factors of VAP for clinical prevention and control of VAP. This paper reviews the international risk factors of VAP occurrence reported in recent years, including patient characteristics, increased mechanical ventilation time and prolonged length of hospital stay, disorders of consciousness, burns, comorbidities, prior antibiotic therapy, invasive operations, gene polymorphisms, and mentions the corresponding preventive measures. Each factor is not only an independent risk factor of VAP, but also has an influence on each other. A better understanding of risk factors for VAP is helpful for predicting the occurrence of VAP, improving the prevention and control of VAP, and reducing the morbidity and mortality rates of patients with VAP.

TNF-α G-308A genetic variants, serum CRP-hs concentration and DNA damage in obese women

Obesity is associated with inflammation, which can disturb genome stability. Tumor necrosis factor (TNF-α) polymorphism was found to affect TNF-α protein production and inflammation. Therefore, the present study illustrates the relationship between TNF-α polymorphism, the degree of inflammation assessed by serum high sensitivity C-reactive protein concentration (CRP-hs) and basal DNA damage in patients with obesity (BMI 30–34.9 kg/m²) and control subjects with proper body mass (BMI < 25 kg/m²). A total of 115 participants (75 obese premenopausal women; and 40 age-, and gender-matched controls) were included. Biochemical parameters (serum concentrations of total-cholesterol, HDL-cholesterol, LDL- cholesterol, triglycerides, glucose, apolipoprotein AI, CRP-hs) and endogenous DNA damage (determined by comet assay) were measured. TNF-α G-308A polymorphism (rs1800629) was analyzed by PCR-RFLP (PCR-restriction fragments length polymorphism). An effect of TNF-α genotype on serum CRP-hs concentration was noted (p = 0.031). In general, carriers of the rare A allele of the TNF-α G-308A polymorphism had significantly lower endogenous DNA damage and serum CRP-hs concentrations than GG homozygotes, however, the protective effect of the A allele was especially visible in non-obese women. Serum CRP-hs concentrations and levels of DNA damage (% DNA in tail) were significantly higher in obese than in controls (p = 0.001 and p < 0.0001, respectively). The adjusted multiple linear regression analyses revealed a significant, independent impact of obesity on DNA damage (p = 0.00000) and no effect of other covariates i.e. age, TNF-α genotype and serum CRP-hs concentration. Our study showed that obesity has a significant impact on the levels of endogenous DNA damage. Obesity abolished the protective effect of A allele of the TNF-α G-308A polymorphism on DNA damage and on inflammation development observed in non-obese A allele carriers.

Multidisciplinary Roles of LRRFIP1/GCF2 in Human Biological Systems and Diseases

Leucine Rich Repeat of Flightless-1 Interacting Protein 1/GC-binding factor 2 (LRRFIP1/GCF2) cDNA was cloned for a transcriptional repressor GCF2, which bound sequence-specifically to a GC-rich element of epidermal growth factor receptor (EGFR) gene and repressed its promotor. LRRFIP1/GCF2 was also cloned as a double stranded RNA (dsRNA)-binding protein to trans-activation responsive region (TAR) RNA of Human Immunodeficiency Virus-1 (HIV-1), termed as TAR RNA interacting protein (TRIP), and as a binding protein to the Leucine Rich Repeat (LRR) of Flightless-1(Fli-1), termed as Flightless-1 LRR associated protein 1 (FLAP1) and LRR domain of Flightless-1 interacting Protein 1 (LRRFIP1). Subsequent functional studies have revealed that LRRFIP1/GCF2 played multiple roles in the regulation of diverse biological systems and processes, such as in immune response to microorganisms and auto-immunity, remodeling of cytoskeletal system, signal transduction pathways, and transcriptional regulations of genes. Dysregulations of LRRFIP1/GCF2 have been implicated in the causes of several experimental and clinico-pathological states and the responses to them, such as autoimmune diseases, excitotoxicity after stroke, thrombosis formation, inflammation and obesity, the wound healing process, and in cancers. LRRFIP1/GCF2 is a bioregulator in multidisciplinary systems of the human body and its dysregulation can cause diverse human diseases.

TNF-α gene polymorphisms: association with age-related macular degeneration in Russian population

AIM

To study polymorphisms in promotor regions of tumor necrosis factor (TNF)-α TNF-863A/C (rs1800630), TNF-308A/G (rs1800629), and TNF-238A/G (rs361525) in patients with age-related macular degeneration (AMD) and associations of complex TNF-α genotypes with AMD.

METHODS

One hundred and two patients (82 women, 20 men; mean age 64.2±1.2y) with AMD and 100 healthy age- and sex-matched controls (82 women, 18 men; 60±1.4y) were included in the study. All subjects were Caucasian, all subjects and their parents were inhabitants of Russia. Genomic DNA was obtained from EDTA-preserved blood using the standard phenol-chloroform method. Polymorphisms were detected by polymerase chain reaction followed by the restriction fragment length polymorphism method. The following TNF-α genotypes were studied: TNF-α-238 AA, GA, GG, TNF-α-308 AA, GA, GG, TNF-α-863 AA, CA, CC.

RESULTS

Differences in TNF-α-863 and TNF-α-238 genotypes frequencies in patients with AMD and healthy controls were not found. The distribution of TNF-α-308 AA and TNF-α-308 GA genotypes was significantly different between the studied group and the controls [odds ratios (OR) =0.22, P=0.0287 and OR=2.91, P=0.0063, respectively]. TNF-863CC/TNF-308GA and TNF-308GA/TNF-238GG genotypes were associated with the increased risk of AMD (OR=2.48, P=0.0332 and OR=2.51, P=0.0187, respectively). Five genotypes combinations appeared to be protective.

CONCLUSION

In the present study, single nucleotide polymorphisms and complex polymorphisms of one of the key inflammatory cytokines TNF-α, and a number of significant associations of these polymorphisms with AMD in Russian population have been shown. Complex analysis of genotypes could be important in AMD risk factors detection and studying pathogenesis.

Single Nucleotide Polymorphisms and Post-operative Complications Following Major Gastrointestinal Surgery: a Systematic Review and Meta-analysis

BACKGROUND

The human genome is an under-researched area of pre-operative risk stratification. Studies of genetic polymorphisms and their associations with acute post-operative complications in gastrointestinal surgery have reported statistically significant results, but have varied in methodology, genetic variations studied, and conclusions reached. To provide clarity, we conducted a systematic review and meta-analysis of single nucleotide polymorphisms and their association with post-operative complications after major gastrointestinal surgery.

METHODS

We performed a literature search using Ovid MEDLINE and Web of Science databases. Studies were included if they investigated genetic polymorphisms and their associations with post-operative complications after major gastrointestinal surgery. We extracted clinical and genetic data from each paper and assessed for quality against the STrengthening the REporting of Genetic Association Studies (STREGA) guidelines. Odds ratios were presented, with 95% confidence intervals, to assess strengths of association. We conducted a meta-analysis on TNF-α-308, which had been assessed in three papers.

RESULTS

Our search returned 68 papers, of which 5 were included after screening and full-text review. Twenty-two different single nucleotide polymorphisms (SNPs) were investigated in these studies. We found that all papers were genetic association studies, and had selected SNPs related to inflammation. The outcome investigated was most commonly post-operative infection, but also anastomotic leak and other non-infectious complications. Statistically significant associations were found for TNF-α-308, IL-10-819, PTGS2-765 and IFN-γ-874. There was significant variability in study quality and methodology. We conducted a meta-analysis on associations between the TNF-α-308 polymorphism and post-operative infection and report an OR of 1.18 (CI 0.27-5.21).

CONCLUSIONS

We found biologically plausible associations between SNPs involved in inflammation and post-operative infection, but the available data were too limited and of insufficient quality to reach definitive conclusions. Further work is needed, including genome-wide association studies (GWAS).

Pharmacogenetics of treatments for inflammatory bowel disease

INTRODUCTION

Inflammatory bowel disease is a chronic inflammation of the gut whose pathogenesis is still unclear. Although no curative therapy is currently available, a number of drugs are used in induction and maintenance therapy; however, for most of these drugs, a high inter-individual variability in response is observed. Among the factors of this variability, genetics plays an important role. Areas covered: This review summarizes the results of pharmacogenetic studies, considering the most important drugs used and in particular aminosalycilates, glucocorticoids, thiopurines, monoclonal antibodies and thalidomide. Most studies used a candidate gene approach, even if significant breakthroughs have been obtained recently from applying genome-wide studies. When available, also investigations considering epigenetics and pharmacogenetic dosing guidelines have been included. Expert opinion: Only for thiopurines, genetic markers identified as predictors of efficacy or adverse events have allowed the development of dosing guidelines. For the other drugs, encouraging results are available and great expectations rely on the study of epigenetics and integration with pharmacokinetic information, especially useful for biologics. However, to improve therapy of IBD patients with these drugs, for implementation in the clinics of pharmacogenetics, informatic clinical decision support systems and training about pharmacogenetics of health providers are needed.