Effects of a Single Nucleotide Polymorphism on the Expression of Human Tumor Necrosis Factor-alpha

Effects of tumor necrosis factor (TNF) gene polymorphisms on the association between smoking and lung function among workers in swine operations

Workers in swine operations may be at increased risk of developing respiratory problems. These respiratory conditions are more prevalent among workers who are smokers. Tumor necrosis factor (TNF) genes play an important role in human immune responses to various respiratory hazards. This study aimed to investigate whether polymorphisms in TNF genes might alter the effects of smoking on lung function among workers in swine operations. Three hundred and seventy-four full-time workers from large swine operations and 411 non-farming rural dwellers in Saskatchewan were included in this study. Information on demographic and lifestyle characteristics, pulmonary function, and blood samples were obtained. Multiple linear regression analyses were used in the statistical analysis. Three promoter polymorphisms (rs1799724, rs361525, and rs1800629) in the TNF gene were investigated. Only the interaction term between smoking status and rs1799724 was significant in the multiple regression models. Among workers with the rs1799724 polymorphism (TT+TC), current smokers exhibited significantly lower lung function than nonsmokers. These associations were not observed among workers with the wild-type (CC). These findings were not observed among non-farming rural dwellers. Data demonstrated the possible involvement of TNF gene in (1) development of adverse respiratory conditions among workers who are smokers, (2) importance of smoking cessation among workers, especially those with polymorphisms in the TNF gene, and (3) potential implications in treatment, screening, and prevention.

TNFα -857 C/T and TNFR2 +587 T/G polymorphisms are associated with cystic fibrosis in Iranian patients

Identification of modifier genes influencing phenotype of cystic fibrosis (CF) patients has become a challenge in CF pathophysiology, prognostic estimations and development of new therapeutic strategies. The aim of this study was to explore the association between four genetic polymorphisms of three modifier genes with CF, by comparing their alleles, genotypes and haplotype frequencies in patients and controls. In this favor, two regulatory polymorphic loci in TNFα promoter (-857C/T, rs1799724 and -238A/G, rs361525) and two functional polymorphic loci in TNFR1 (+36A/G, rs767455) and TNFR2 (+587T/G, rs1061622) were genotyped in 70 patients and 79 controls, using PCR-RFLP. Clinical pulmonary data were also recorded from all studied patients. Results indicated that an association was observed between both T allele and CT/TT genotypes of TNFα (P = 0.0005, OR = 7.06, 95% CI = 3.71-13.45) with CF under dominant model of inheritance. GG genotype of TNFR2 +587 (P = 0.0005, OR = 4.92, 95%CI = 2.34-10.34) was significantly associated with CF using recessive model. Consistently, more severe pulmonary disorder was found for patients carrying either T dominant allele of TNFα -857 or GG genotype of TNFR2 +587 polymorphic sites. Despite an association of A-T and G-T haplotypes with CF, no significant association was found between these haplotypes and clinical parameters of CF. Overall, TNFα -857 T allele and GG genotype of TNFR2 +587 were more frequent in CF patients compared to healthy controls and hence, they showed an association with CF and severe pulmonary phenotype in Iranian patients.

Polymorphisms of the TNF-α gene interact with plasma fatty acids on inflammatory biomarker profile: a population-based, cross-sectional study in São Paulo, Brazil

The aim of the present study was to investigate the relationship of four TNF-α SNP with inflammatory biomarkers and plasma fatty acids (FA), and the interaction among them in a population-based, cross-sectional study in São Paulo, Brazil. A total of 281 subjects, aged >19 and <60 years, participated in a cross-sectional, population-based study performed in Brazil. The following SNP spanning the TNF-α gene were genotyped: -238G/A (rs361525), -308G/A (rs1800629), -857C/T (rs1799724) and -1031T/C (rs1799964). In all, eleven plasma inflammatory biomarkers and plasma FA profile were determined. To analyse the interaction between TNF-α SNP and plasma FA, a cluster analysis was performed to stratify individuals based on eleven inflammatory biomarkers into two groups used as outcome: inflammatory (INF) and non-inflammatory clusters. The -238A allele carriers had higher TNF-α (P=0·033), IL-6 (P=0·013), IL-1β (P=0·037), IL-12 (0·048) and IL-10 (P=0·010) than the GG genotype. The -308A allele carriers also had lower levels of plasma palmitoleic acid (P=0·009), oleic acid (P=0·039), total MUFA (P=0·014), stearoyl-CoA desaturase (SCD) activity index-16 (P=0·007), SCD-18 (P=0·020) and higher levels of PUFA (P=0·046) and DHA (P=0·044). Significant interactions modifying the risk of belonging to the INF cluster were observed with inflammatory cluster as outcome between -857C/T and plasma α-linolenic acid (P=0·026), and also between -308G/A and plasma stearic acid (P=0·044) and total SFA (P=0·040). Our study contributes to knowledge on TNF-α SNP and their association with inflammatory biomarker levels, plasma FA and the interaction among them, of particular interest for the Brazilian population.

Tumor Necrosis Factor-α T-857C (rs1799724) Polymorphism and Risk of Cancers: A Meta-Analysis

Objectives. To investigate the potential association of tumor necrosis factor-α T-857C polymorphism with susceptibility to the five common malignant tumors. Materials and Methods. A comprehensive search of PubMed/Medline, Embase, and Web of Science databases was performed up to November 2015. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to assess the strength of the association. Subgroup analysis, heterogeneity analyses, and publication bias were also texted in the meta-analysis. Results. A total of twenty-two publications involving 5215 cases and 6755 controls were recruited. Overall, the meta-analysis revealed an increased risk between the TNF-α T-857C polymorphism and gastric cancer susceptibility in T versus C model, heterozygote genetic model, and dominant genetic model. An increased risk between the TNF-α T-857C polymorphism and hepatocellular cancer susceptibility in homozygote genetic model and recessive genetic model was also found. No significant association was found between the TNF-α T-857C polymorphism and colorectal cancer, cervical cancer, and prostate cancer. Conclusions. Our meta-analyses suggest that TNF-α T-857C polymorphism may be associated with increased risk of gastric cancer and hepatocellular cancer development. Therefore, the TNF-α T-857C polymorphism could be considered as one possible risk factor of gastric cancer and hepatocellular cancer according to our study.

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.

Polymorphisms in tumor necrosis factor-alpha (-863C>A, -857C>T and +488G>A) are associated with idiopathic recurrent pregnancy loss in Korean women

Polymorphisms in TNF-a have been reported as genetic risk factors for recurrent spontaneous abortion and TNF-α may be immunologically important. We therefore examined the contribution of several TNF-a mutations to this phenomenon. The study participants consisted of 388 patients with idiopathic recurrent pregnancy loss (RPL), which was diagnosed on the basis of at least two consecutive spontaneous abortions; control subjects were 224 healthy women with a history of successful pregnancies. Polymerase chain reaction-restriction fragment length polymorphism analysis was performed to determine the TNF-α -863C>A, -857C>T, and +488G>A genotypes. The TNF-α -863C>A variants correlated with increased risk of RPL (CA+AA; adjusted odds ratio [AOR], 2.142; 95% confidence interval [CI], 1.493-3.074). These data did not differ in a stratified analysis according to number of consecutive spontaneous abortions. In haplotype analysis, there were similar trends of data for combination analysis, but in patients with 3+ pregnancy losses, a stratified analysis revealed that this correlation did not increase directly with the number of pregnancy losses. The TNF-α -863C>A variant is a possible genetic risk factor for idiopathic RPL in Korean women.

Polymorphisms in the inflammatory pathway genes TLR2, TLR4, TLR9, LY96, NFKBIA, NFKB1, TNFA, TNFRSF1A, IL6R, IL10, IL23R, PTPN22, and PPARG are associated with susceptibility of inflammatory bowel disease in a Danish cohort

BACKGROUND

The inflammatory bowel diseases (IBD), Crohn's disease (CD) and ulcerative colitis (UC), result from the combined effects of susceptibility genes and environmental factors. Polymorphisms in genes regulating inflammation may explain part of the genetic heritage.

METHODS

Using a candidate gene approach, 39 mainly functional single nucleotide polymorphisms (SNPs) in 26 genes regulating inflammation were assessed in a clinical homogeneous group of severely diseased patients consisting of 624 patients with CD, 411 patients with UC and 795 controls. The results were analysed using logistic regression.

RESULTS

Sixteen polymorphisms in 13 genes involved in regulation of inflammation were associated with risk of CD and/or UC (p ≤ 0.05). The polymorphisms TLR2 (rs1816702), NFKB1 (rs28362491), TNFRSF1A (rs4149570), IL6R (rs4537545), IL23R (rs11209026) and PTPN22 (rs2476601) were associated with risk of CD and the polymorphisms TLR2 (rs1816702), TLR4 (rs1554973 and rs12377632), TLR9 (rs352139), LY96 (rs11465996), NFKBIA (rs696), TNFA (rs1800629), TNFRSF1A (rs4149570), IL10 (rs3024505), IL23R (rs11209026), PTPN22 (rs2476601) and PPARG (rs1801282) were associated with risk of UC. When including all patients (IBD) the polymorphisms TLR2 (rs4696480 and rs1816702), TLR4 (rs1554973 and rs12377632), TLR9 (rs187084), TNFRSF1A (rs4149570), IL6R (rs4537545), IL10 (rs3024505), IL23R (rs11209026) and PTPN22 (rs2476601) were associated with risk. After Bonferroni correction for multiple testing, both the homozygous and the heterozygous variant genotypes of IL23R G>A(rs11209026) (OR(CD,adj): 0.38, 95% CI: 0.21-0.67, p = 0.03; OR(IBD,adj) 0.43, 95% CI: 0.28-0.67, p = 0.007) and PTPN22 1858 G>A(rs2476601) (OR(CD,unadj) 0.54, 95% CI: 0.41-0.72, p = 7*10-4; OR(IBD,unadj): 0.61, 95% CI: 0.48-0.77, p = 0.001) were associated with reduced risk of CD.

CONCLUSION

The biological effects of the studied polymorphisms suggest that genetically determined high inflammatory response was associated with increased risk of CD. The many SNPs found in TLRs suggest that the host microbial composition or environmental factors in the gut are involved in risk of IBD in genetically susceptible individuals.

Associations between functional polymorphisms in the NFκB signaling pathway and response to anti-TNF treatment in Danish patients with inflammatory bowel disease

Antitumor necrosis factor-α (TNF-α) is used for treatment of severe cases of inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). However, one-third of the patients do not respond to the treatment. Genetic markers may predict individual response to anti-TNF therapy. Using a candidate gene approach, 39 mainly functional single nucleotide polymorphisms (SNPs) in 26 genes regulating inflammation were assessed in 738 prior anti-TNF-naive Danish patients with IBD. The results were analyzed using logistic regression (crude and adjusted for age, gender and smoking status). Nineteen functional polymorphisms that alter the NFκB-mediated inflammatory response (TLR2 (rs3804099, rs11938228, rs1816702, rs4696480), TLR4 (rs5030728, rs1554973), TLR9 (rs187084, rs352139), LY96 (MD-2) (rs11465996), CD14 (rs2569190), MAP3K14 (NIK) (rs7222094)), TNF-α signaling (TNFA (TNF-α) (rs361525), TNFRSF1A (TNFR1) (rs4149570), TNFAIP3(A20) (rs6927172)) and other cytokines regulated by NFκB (IL1B (rs4848306), IL1RN (rs4251961), IL6 (rs10499563), IL17A (rs2275913), IFNG (rs2430561)) were associated with response to anti-TNF therapy among patients with CD, UC or both CD and UC (P ⩽ 0.05). In conclusion, the results suggest that polymorphisms in genes involved in activating NFκB through the Toll-like receptor (TLR) pathways, genes regulating TNF-α signaling and cytokines regulated by NFκB are important predictors for the response to anti-TNF therapy among patients with IBD. Genetically strong TNF-mediated inflammatory response was associated with beneficial response. In addition, the cytokines IL-1β, IL-6 and IFN-γ may be potential targets for treating patients with IBD who do not respond to anti-TNF therapy. These findings should be examined in independent cohorts before these results are applied in a clinical setting.

Innate immunity pathways and breast cancer Risk in African American and European-American women in the Women's Circle of Health Study (WCHS)

African American (AA) women are more likely than European American (EA) women to be diagnosed with early, aggressive breast cancer. Possible differences in innate immune pathways (e.g., inflammatory responses) have received little attention as potential mechanisms underlying this disparity. We evaluated distributions of selected genetic variants in innate immune pathways in AA and EA women, and examined their associations with breast cancer risk within the Women's Circle of Health Study (WCHS). In stage I of the study (864 AA and 650 EA women) we found that genotype frequencies for 35 of 42 tested SNPs (18 candidate genes) differed between AAs and EAs (corroborated by ancestry informative markers). Among premenopausal AA women, comparing variant allele carriers to non-carriers, reduced breast cancer risk was associated with CXCL5-rs425535 (OR=0.61, P=0.02), while among EA women, there were associations with TNFA-rs1799724 (OR =2.31, P =0.002) and CRP-rs1205 (OR=0.54, P=0.01). For postmenopausal women, IL1B-rs1143627 (OR=1.80, P=0.02) and IL1B-rs16944 (OR=1.85, P =0.02) were associated with risk among EA women, with significant associations for TNFA-rs1799724 limited to estrogen receptor (ER) positive cancers (OR=2.0, P =0.001). However, none of the SNPs retained significance after Bonferroni adjustment for multiple testing at the level of P0.0012 (0.05/42) except for TNFA-rs1799724 in ER positive cancers. In a stage II validation (1,365 AA and 1,307 EA women), we extended evaluations for four SNPs (CCL2-rs4586, CRP-rs1205, CXCL5-rs425535, and IL1RN-rs4251961), which yielded similar results. In summary, distributions of variants in genes involved in innate immune pathways were found to differ between AA and EA populations, and showed differential associations with breast cancer according to menopausal or ER status. These results suggest that immune adaptations suited to ancestral environments may differentially influence breast cancer risk among EA and AA women.

Association between tumor necrosis factor-alpha 857C/T polymorphism and gastric cancer: a meta-analysis

Tumor necrosis factor-alpha (TNF-α) is an inflammatory cytokine which may play an important role on the immune response may control the progression of gastric cancer. Previous studies on the association between TNF-α 857C/T polymorphism and gastric cancer risk reported conflicting results. We performed a meta-analysis to comprehensively assess the association between TNF-α 857C/T polymorphism and gastric cancer risk. Literature search was performed for all publications on the association between TNF-α 857C/T polymorphism and gastric cancer risk through March 6, 2013. The pooled odds ratios (ORs) with their 95% confidence interval (95%CIs) were calculated to assess the association between TNF-α 857C/T polymorphism and gastric cancer risk. Nine individual case-control studies with a total of 5,054 subjects (1,835 cases and 3,219 controls) were finally included into the meta-analysis. Meta-analysis of total nine studies showed that TNF-α 857C/T polymorphism was significantly associated with increased risk of gastric cancer under four genetic models (for T vs. C: OR = 1.19, 95%CI 1.07-1.33, P = 0.002; for TT vs. CC: OR = 1.44, 95%CI 1.03-2.02, P = 0.032; for CT vs. CC: OR = 1.19, 95%CI 1.05-1.36, P = 0.008; and for TT/CT vs. CC: OR = 1.21, 95%CI 1.07-1.38, P = 0.003). Subgroup analysis by ethnicity further showed that there was a significant association between TNF-α 857C/T polymorphism and increased risk of gastric cancer in Asians but not in Caucasians. The meta-analysis suggests that TNF-α 857C/T polymorphism is significantly associated with increased risk of gastric cancer, especially in Asians.

Single nucleotide polymorphisms in the tumor necrosis factor-alpha gene promoter region alter the risk of psoriasis vulgaris and psoriatic arthritis: a meta-analysis

BACKGROUND

It has been confirmed that tumor necrosis factor-alpha (TNFα), a macrophage-derived pro-inflammatory cytokine, plays an important role in the pathogenesis of psoriasis vulgaris and psoriatic arthritis (PsV&PsA). In contrast, the reported association of TNFα gene promoter region single nucleotide polymorphisms (SNPs) and PsV&PsA has remained controversial. Accordingly, we performed a meta-analysis to provide new evidence that SNPs in the TNFα gene promoter region alter not only the risk of psoriasis vulgaris (PsV) or psoriatic arthritis (PsA) but also of PsV&PsA.

METHODS

Interrelated literature dated to October 2012 was acquired from the PubMed, ScienceDirect, and SpringerLink databases. The number of the genotypes and/or alleles for the TNFα promoter in the PsV and PsA and control subjects was obtained. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to calculate the risk of PsV and/or PsA with TNFα promoter SNPs.

RESULTS

A total of 26 papers of 2159 for PsV (2129 normal controls) and 2360 for PsA (2997 normal controls) were included in our meta-analysis. The results showed that the variant genotype and allele of TNFα -308A/G was protective in pooled groups of patients with PsV&PsA (OR = 0.682, 0.750; 95% CI, 0.596-0.779, 0.653-0.861). However, the variant genotypes and alleles of TNFα -238A/G and -857T/C had an increased risk of PsV&PsA (OR = 2.493, 2.228, 1.536, 1.486, 95% CI, 1.777-3.498, 1.628-3.049, 1.336-1.767, 1.309-1.685). Moreover, the meta-analysis revealed a significant association between TNFα -238A/G and -857T/C polymorphism and PsA susceptibility (OR = 2.242, 2.052, 1.419, 1.465; 95% CI, 1.710-2.941, 1.614-2.610, 1.214-1.658, 1.277-1.681). In contrast, the variant genotypes and alleles of TNFα -308A/G proved to be protective against PsV (OR = 0.574, 0.650, 95% CI, 0.478-0.690, 0.556-0.759), whereas TNFα -238A/G was found to have a risk association (OR = 2.636, 2.223, 95% CI, 1.523-4.561, 1.317-3.751).

CONCLUSIONS

SNPs in the TNFα gene promoter region alter the risk of PsV and/or PsA.

TNF-α -857 and -1031 polymorphisms predict good therapeutic response to TNF-α blockers in Chinese Han patients with ankylosing spondylitis

AIM

To evaluate whether polymorphisms at -857, -1031, -308 and -238 positions of the TNF-α gene influence response to TNF-α-blocker therapy in Chinese Han patients with ankylosing spondylitis.

PATIENTS & METHODS

A total of 106 patients with ankylosing spondylitis were recruited and genotyped for -857, -1031, -308 and -238 TNF-α gene polymorphisms. In total, 32 received infliximab and 74 received a recombinant human TNF-α receptor II-IgG Fc fusion protein (rhTNFR-Fc). At the end of 12 weeks, patients were assessed using the Assessment of SpondyloArthritis International Society (ASAS) 20, 40, 50 and 70 criteria.

RESULTS

Polymorphisms at -308 and -238 did not affect therapeutic response. The -857 C/C genotype (p = 0.0021) responded better to therapy. The -1031 T/T genotype (p = 0.0004) showed better outcome.

CONCLUSION

In Chinese Han ankylosing spondylitis patients, polymorphisms at the -308 and -238 positions of the TNF-α gene are unable to predict TNF-α-blocker response; however, -857 C/C and -1031 T/T genotypes have the ability to predict good response.

Interaction between early maternal smoking and variants in TNF and GSTP1 in childhood wheezing

BACKGROUND

Children exposed to tobacco smoke early in life have a higher risk of wheeze. Individual susceptibility may depend on genetic factors.

OBJECTIVE

We studied whether variations in single nucleotide polymorphisms (SNPs) in the TNF, glutathione S transferase P1 (GSTP1) and beta2-adrenoreceptor (ADRB2) genes modify the effect of early maternal smoking on the development of childhood asthma, wheeze and allergic sensitization.

METHODS

In the Swedish prospective birth cohort BAMSE (Children, Allergy, Milieu, Stockholm, Epidemiological Survey) (n=4089), data collection included questionnaires to measure tobacco smoke exposure and clinical outcomes up to age 4 and medical examinations with blood sampling for specific IgE measurements and genotyping. We defined early maternal smoking as daily smoking by the mother during pregnancy and/or postnatally. We investigated five TNF, six GSTP1 and three ADRB2 SNPs in 982 selected wheezers and non-wheezers.

RESULTS

An interaction with early maternal smoking was found for three TNF SNPs (-857C/T, Intron 1, Intron 3) with respect to early wheeze (up to 2 years of age). For example, the odds ratio (OR) for developing early wheeze related to early maternal smoking was 2.4 [95% confidence interval (CI) 1.6-3.7] in children with a wild-type CC homozygote genotype of the TNF-857 SNP, while no tobacco-related risk was seen in children carrying the rare T allele. A clear dose response was observed in children with the CC genotype, with an OR of 1.3 (95% CI 1.1-1.5) per each additional pack per week smoked by the mother during pregnancy. A suggestive interaction with early maternal smoking was also seen for three GSTP1 SNPs (Intron 5, Intron 6 and Ile105Val) with respect to transient wheeze, but not for ADRB2 and wheeze phenotypes. No effect modifications were observed for allergic sensitization.

CONCLUSION

Our results suggest that the risk of early childhood wheeze associated with early maternal smoking may be modified by TNF and GSTP1 polymorphisms.

Genetic variants in inflammation-related genes are associated with radiation-induced toxicity following treatment for non-small cell lung cancer

Treatment of non-small cell lung cancer (NSCLC) with radiotherapy or chemoradiotherapy is often accompanied by the development of esophagitis and pneumonitis. Identifying patients who might be at increased risk for normal tissue toxicity would help in determination of the optimal radiation dose to avoid these events. We profiled 59 single nucleotide polymorphisms (SNPs) from 37 inflammation-related genes in 173 NSCLC patients with stage IIIA/IIIB (dry) disease who were treated with definitive radiation or chemoradiation. For esophagitis risk, nine SNPs were associated with a 1.5- to 4-fold increase in risk, including three PTGS2 (COX2) variants: rs20417 (HR:1.93, 95% CI:1.10-3.39), rs5275 (HR:1.58, 95% CI:1.09-2.27), and rs689470 (HR:3.38, 95% CI:1.09-10.49). Significantly increased risk of pneumonitis was observed for patients with genetic variation in the proinflammatory genes IL1A, IL8, TNF, TNFRSF1B, and MIF. In contrast, NOS3:rs1799983 displayed a protective effect with a 45% reduction in pneumonitis risk (HR:0.55, 95% CI:0.31-0.96). Pneumonitis risk was also modulated by polymorphisms in anti-inflammatory genes, including genetic variation in IL13. rs20541 and rs180925 each resulted in increased risk (HR:2.95, 95% CI:1.14-7.63 and HR:3.23, 95% CI:1.03-10.18, respectively). The cumulative effect of these SNPs on risk was dose-dependent, as evidenced by a significantly increased risk of either toxicity with an increasing number of risk genotypes (P<0.001). These results suggest that genetic variations among inflammation pathway genes may modulate the development of radiation-induced toxicity and, ultimately, help in identifying patients who are at an increased likelihood for such events.

Tumor necrosis factor-alpha polymorphisms and expression in Guillain-Barré syndrome

Tumor necrosis factor-alpha (TNF-alpha) polymorphisms with increased expression is associated with many autoimmune and inflammatory diseases. Possible role of TNF-alpha polymorphism in the pathogenesis of Guillain-Barré syndrome (GBS) largely remains unknown. We investigated polymorphisms in the promoter region of TNF-alpha gene and its expression in GBS patients and healthy controls. TNF-alpha (-308 G>A, -857 C>T, and -863 C>A) polymorphisms in 140 GBS patients and 206 healthy controls were studied using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele specific-PCR. TNF-alpha level in serum by ELISA was determined in 60 patients and an equal number of controls. Prevalence of TNF-alpha -308 G > A polymorphic A allele was associated with increased risk of GBS (p < 0.001; OR = 2.58, 95% CI = 1.61-4.14). Heterozygous genotype (G/A) had an association with acute motor axonal neuropathy (p < 0.001; OR = 4.23, 95% CI = 2.00-8.95) and variant genotype A/A with both axonal subtypes, acute motor axonal neuropathy (p = 0.015, OR = 7.00, 95% CI = 1.46-33.57) and acute motor sensory axonal neuropathy (p = 0.017; OR = 7.73, 95% CI = 1.44-41.37). Variant genotype T/T of TNF-alpha -857 C>T polymorphism was also significantly associated with acute motor axonal neuropathy (p = 0.034; OR = 3.93, 95% CI = 1.11-13.91). Patients with A and T alleles had higher TNF-alpha level in serum. TNF-alpha -308 G > A and -857 C>T (only T/T) polymorphisms with increased TNF-alpha level may predict susceptibility to axonal subtypes of GBS.

Inflammatory genetic markers of prostate cancer risk

Prostate cancer is the most common cancer in Western society males, with incidence rates predicted to rise with global aging. Etiology of prostate cancer is however poorly understood, while current diagnostic tools can be invasive (digital rectal exam or biopsy) and/or lack specificity for the disease (prostate-specific antigen (PSA) testing). Substantial histological, epidemiological and molecular genetic evidence indicates that inflammation is important in prostate cancer pathogenesis. In this review, we summarize the current status of inflammatory genetic markers influencing susceptibility to prostate cancer. The focus will be on inflammatory cytokines regulating T-helper cell and chemokine homeostasis, together with the Toll-like receptors as key players in the host innate immune system. Although association studies indicating a genetic basis for prostate cancer are presently limited mainly due to lack of replication, larger and more ethnically and clinically defined study populations may help elucidate the true contribution of inflammatory gene variants to prostate cancer risk.

Polymorphisms of tumor necrosis factor-α promoter region for susceptibility to HLA-B27-positive ankylosing spondylitis in Korean population

This study designed to assess the relationship between tumor necrosis factor (TNF)-α promoter polymorphisms and disease susceptibility to human leukocyte antigen (HLA)-B27-positive ankylosing spondylitis (AS). One hundred and nineteen HLA-B27(+) AS patients, 95 HLA-B27(+) healthy controls, and 135 random healthy controls were enrolled in this study. Six single nucleotide polymorphisms (SNPs) of the TNF-α promoter at positions -1031T/C, -863C/A, -857C/T, -646G/A, -308G/A, and -238G/A were analyzed. Differences between groups were evaluated using the chi-square test or Fisher's exact test. Haplotypes from each SNP were constructed, and differences in haplotypic frequencies between groups were evaluated. There were significant differences in the allelic and genotypic frequencies of 1031T/C, -863C/A, and -857C/T TNF-α promoters polymorphisms between HLA-B27(+) AS patients and random controls, but not between patients with AS and HLA-B27(+) healthy individuals. TNF-α polymorphisms did not influence the extra-spinal clinical features in patients with AS. The haplotypic sequence -1031T/-863C/-857C/-308G increased the risk of susceptibility to AS compared to random controls (P (corr) < 0.001, OR = 2.756, 95% CI = 1.894-4.010), whereas the sequence -1031C/-863A/-857C/-308G appeared to be associated with decreased susceptibility to AS compared to random controls (P (corr) = 0.006, OR = 0.396, 95% CI = 0.231-0.679). This study indicates that TNF-α promoter polymorphism between controls and AS patients with HLA-B27(+) genetic background is not associated with susceptibility to AS. However, TNF-α polymorphism, irrespective of HLA-B27, increases risk of susceptibility to AS in general population.

Involvement of functional polymorphisms in the TNFA gene in the pathogenesis of autoimmune thyroid diseases and production of anti-thyrotropin receptor antibody

The severity of Hashimoto's disease (HD) and intractability of Graves' disease (GD) varies among patients. Severity of HD is associated with the functional +874A/T polymorphism for interferon-gamma, an inflammatory cytokine. To clarify the association between functional polymorphisms in two other inflammatory cytokine genes [tumour necrosis factor (TNF)-alpha and interleukin (IL)-2] and the severity of autoimmune thyroid disease (AITD), we examined the TNF-alpha-1031T/C, TNF-alpha-857C/T and IL-2 -330T/G polymorphisms in genomic DNA samples. We genotyped 41 patients with intractable GD, 34 patients with GD in remission, 41 patients with severe HD, 36 patients with mild HD and 70 healthy controls. The frequency of carriers of TNF-alpha-1031C (CT + CC), which correlates with higher TNF-alpha production, was significantly higher in HD and GD patients than in controls, but was not associated with the severity of HD. In GD patients, the levels of anti-thyrotropin receptor antibody (TRAb) at onset of the disease was higher in patients with the TNF-alpha-857T (CT + TT) genotype, which correlates with higher TNF-alpha production, than in those with the -857CC genotype. We found no differences in the IL-2 -330T/G polymorphism among groups of AITD patients. In conclusion, the functional -1031T/C polymorphism of the TNFA gene is associated with the development of AITD and the functional -857C/T polymorphism is associated with the levels of TRAb in active GD patients.

Tumor necrosis factor alpha −308 polymorphism is associated with rheumatoid arthritis in Han population of Eastern China

The aim of this study was to investigate the association of single nucleotide polymorphisms (SNPs) in tumor necrosis factor alpha (TNFalpha) promoter with rheumatoid arthritis (RA) in Chinese Han population. Six SNPs at positions -238, -244, -308, -376, -857, -863 within TNFalpha promoter were genotyped in 367 unrelated RA patients and 271 healthy controls, using direct DNA sequencing method. Allelic, genotypic, and haplotypic associations of these SNPs with RA were examined. The frequencies of TNFalpha -308A allele and the haplotype GACC (in order of -238, -308, -857, -863) were significantly lower in RA patients when compared with healthy controls (P = 0.0046, P = 0.0045, respectively) but TNFalpha -308 polymorphism was not related to the clinical manifestations of RA patients. These results implied that TNFalpha gene itself or a gene in linkage disequilibrium with it might be associated with RA in Han population of Eastern China.

Association of HLA genes with ankylosing spondylitis in Han population of eastern China

Ankylosing spondylitis (AS) is a chronic inflammatory disorder with a multifactorial genetic basis. HLA-B27 was reported with the greatest susceptibility to AS but did not act alone. The aim of this study was to search for other gene(s) associated with AS independently of HLA-B27 using 13 microsatellite markers spanning 1.5 Mb from locus TAP1 to HLA-Cw and a single-nucleotide polymorphism marker within NFkappaBIL1 gene promoter. Genotyping for microsatellites was performed in 175 AS patients of eastern Chinese and 219 ethnically matched healthy controls using polymerase chain reaction with fluorescence-labelled primers, whereas the SNP marker was genotyped by direct DNA sequencing. Allele as well as haplotype frequencies were compared between cases and controls, and a linkage disequilibrium analysis was performed to estimate the LD relationship between the candidate regions. The frequencies of alleles D6S2811*128, STR_MICA*A5.1 and D6S2672*109, as well as haplotypes D6S2811*128-D6S2927*213-D6S2810*340, D6S2927* 221-D6S2810*350-MICA*A5.1, and D6S2810*350-MICA*A5.1-D6S2800* 136 were significantly increased in B27-positive AS patients when compared with B27-positive controls. The results indicated that there may be other gene(s) within the HLA region, especially around locus HLA-B or HLA-Cw, with susceptibility to AS independently of HLA-B27.

TNF polymorphisms in psoriasis: Association of psoriatic arthritis with the promoter polymorphismTNF*-857 independent of thePSORS1 risk allele

OBJECTIVE

Single-nucleotide polymorphisms (SNPs) of the tumor necrosis factor gene TNF at positions -238 and -308 have been associated with psoriasis vulgaris and psoriatic arthritis (PsA). The strong linkage disequilibrium (LD) at chromosome region 6p21, a region known to harbor risk factors for psoriasis susceptibility (PSORS1) other than just SNPs of the TNF gene, renders the interpretation of these findings difficult. The aim of this study was to analyze several SNPs of the TNF gene and its neighboring LTA gene for independent and dependent carriage of the PSORS1 risk allele.

METHODS

SNPs in the promoter of the TNF (-238G/A, -308G/A, -857C/T, and -1031T/C), LTA (+252A/G), TNLFRSF1A (+36A/G), and TNLFRSF1B (+676T/G) genes were genotyped in 375 psoriasis patients, 375 PsA patients, and 376 controls. The Trp- Trp-Cys-Cys haplotype of the CCHCR1 gene (CCHCR1*WWCC) was used as an estimate of the risk allele PSORS1.

RESULTS

Whereas we were able to confirm the previously described strong association of allele TNF*-238A with psoriasis, our study revealed that this association was completely dependent on carriage of the PSORS1 risk allele. For PsA, but not psoriasis vulgaris without joint involvement, a strong association with the allele TNF*-857T (odds ratio 1.956 [95% confidence interval 1.334-2.881]; corrected P = 0.0025) was also detected in patients negative for the PSORS1 risk allele.

CONCLUSION

Our results indicate that there are genetic differences between psoriasis vulgaris patients with and without joint manifestations. While the previously reported association between TNF*-238A and psoriasis seems to primarily reflect LD with PSORS1, TNF*-857T may represent a risk factor for PsA that is independent of the PSORS1 allele.