Association of TNF-α and IL-10 polymorphisms with tuberculosis in Tunisian populations

Cytokine Th1/Th2 balance is known to play a key role in controlling Mycobacterium tuberculosis infection. Based upon the functional role of the TNF-α [-308 G(low)?→?A(high) (rs1800629)] and IL-10 [-1082 A(low)?→?G(high) (rs1800870), -819 T(low)?→?C(high) (rs1800871) and -592 A(low)?→?C(high) (rs1800872)] single nucleotide polymorphisms (SNPs) on production levels, we genotyped 76 patients with pulmonary tuberculosis (TB) (pTB), 55 patients with extrapulmonary TB (epTB) and 95 healthy blood donors by polymerase chain reaction fragment length polymorphism (PCR-RFLP). We observed that -308 A allele was associated with increased risk susceptibility to epTB (OR?=?1.96; 95% CI, 1.04-3.71; P?=?0.024). The -1082 AG genotype was significantly associated with increased risk development of epTB (odds ratio [OR]?=?3.69; 95% confidence intervals [CI], 1.73-7.92; P corrected for the number of genotypes [Pc]?=?0.0003). By contrast, -1082 AA genotype appeared to be associated with resistance to pTB (OR?=?0.38; 95% CI, 0.19-0.74; Pc?=?0.006) and epTB (OR?=?0.22; 95% CI, 0.1-0.48; Pc?=?0.00006). High-producer IL-10 GCC haplotype seemed to be associated with 2.11-fold (95% CI, 1.28-3.46; Pc?=?0.003) and 2.57-fold (95% CI, 1.5-4.4; Pc?=?0.0006) increased susceptibility to pTB and epTB, respectively. Combination of TNF-α/IL-10 high producer genotypes was associated with increased 3.13-fold (95% CI, 1.23-8.05; Pc?=?0.028) susceptibility to epTB. However, combined TNF-α/IL-10 low producer genotypes appeared to have protect effect to pTB (OR?=?0.44, 95% CI, 0.21-0.89; Pc?=?0.04) and epTB (OR?=?0.26, 95% CI, 0.1-0.62; Pc?=?0.0028). Collectively, our results showed that analysed SNPs in the TNF-α and IL-10 gene polymorphisms play key role in susceptibility to or protection against TB development in Tunisian populations.     

Assessment of IL-10, IL-1ß and TNF-α gene polymorphisms in patients with peri-implantitis and healthy controls

Molecular Biology Reports - Peri-implantitis (PI) is a multifactorial condition caused by the interactions of pathogens and the host immune response. Previous studies have demonstrated a...     

Influence of IL-6, IL-10, IFN-γ and TNF-α genetic variants on susceptibility to diabetic kidney disease in type 2 diabetes mellitus patients

Background: Data from previous studies on the role of inflammatory cytokines as biomarkers for diabetic kidney disease (DKD) are contradictory. The association of a particular inflammatory cytokine single nucleotide polymorphism (SNP) with susceptibility to DKD has not been consistently replicated. We aimed to investigate the utility of inflammatory cytokines as biomarkers for DKD in type 2 diabetes mellitus (T2DM) patients. Association of inflammatory cytokine gene SNPs with the development of DKD was also explored.

Subjects and Methods: One hundred and fifty-nine Kuwaiti subjects were recruited in this study, including 50 T2DM patients without DKD, 67 diabetic DKD patients and 42 healthy subjects. Plasma levels of interleukin-6 (IL-6), IL-10, interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) were measured by enzyme-linked immunosorbent assays. Nine SNPs, including 2 SNPs in IL-6, 3 SNPs in IL-10, 1 SNP in IFN-γ and 3 SNPs in TNF-α, were genotyped using TaqMan SNP genotyping assays.

Results: Diabetic DKD patients showed higher IL-6, IL-10, IFN-γ and TNF-α levels than those without DKD. Diabetic DKD patients had a significantly higher frequency of IL-10???1082?A allele than those without DKD (p?=?0.001). No significant association of IL-6???174/?597 haplotypes with DKD risk was detected (p?=?0.188). Distribution of IL-10???592/?819/?1082 haplotypes differ significantly between T2DM patients with/without DKD (p?=?0.014). Diabetic DKD patients had a significantly lower frequency of IL-10???592C/?819C/?1082G haplotype than those without DKD (p?=?0.002).

Conclusions: Although inflammatory cytokine genotypes and, more importantly, haplotypes may have the potential to identify those patients at risk of DKD, hence, improving DKD predisposition prediction, further investigations regarding their real clinical significance is warranted in a large cohort of patients.     

TNF-α gene expression is increased following zinc supplementation in type 2 diabetes mellitus

Chronic low-grade inflammation in type 2 diabetes mellitus (DM) can elicit changes in whole-body zinc metabolism. The interaction among the expression of inflammatory cytokines, zinc transporter and metallothionein (MT) genes in peripheral blood mononuclear cells in type 2 DM remains unclear. In a 12-week randomized controlled trial, the effects of zinc (40 mg/day) supplementation on the gene expression of cytokines, zinc transporters and MT in women with type 2 DM were examined. In the zinc-supplemented group, gene expression of tumour necrosis factor (TNF)-α tended to be upregulated by 27 ± 10 % at week 12 compared to baseline (P = 0.053). TNF-α fold change in the zinc-treated group was higher than in those without zinc supplementation (P < 0.05). No significant changes were observed in the expression or fold change of interleukin (IL)-1β or IL-6. Numerous bivariate relationships were observed between the fold changes of cytokines and zinc transporters, including ZnT7 with IL-1β (P < 0.01), IL-6 (P < 0.01) and TNF-α (P < 0.01). In multiple regression analysis, IL-1β expression was predicted by the expression of all zinc transporters and MT measured at baseline (r ² = 0.495, P < 0.05) and at week 12 (r ² = 0.532, P < 0.03). The current study presents preliminary evidence that zinc supplementation increases cytokine gene expression in type 2 DM. The relationships found among zinc transporters, MT and cytokines suggest close  interactions between zinc homeostasis and inflammation.     

Association of TNF-α and PTPN22 SNPs with the risk and clinical outcome of type 1 diabetes

Type 1 Diabetes mellitus (T1DM) begins with aberrant inflammatory process followed by auto-destruction in genetically susceptible individuals. Therefore, we hypothesized that gain-of-function allelic variants TNF-α-238A, -308A and PTPN22 1858T could be associated not only with T1DM development but also with the clinical outcome in patients of Bosnia and Herzegovina. A total of 402 subjects were enrolled in the association study. SNPs were determined by PCR-RFLP. Data was analyzed by GraphPad Prism and Sigma Stat 3.5 software. Genotypes frequencies at TNF-α-238 and -308 loci were not statistically different between patients and controls. In contrast, distribution of genotypes at the 1858 position of PTPN22 was significantly different, due to higher frequency of gain-of-function gene variants in patients than controls. Moreover, long term glucose regulation (based on HbA1c level) was significantly worse in patients with the risk TNF-α-308A allele than in patients with non-risk (G) allele. However, patients with the risk allele of both genes (TNF-α-308A and PTPN22 1858T) had the worst glycemic control, suggesting that those two work synergistically. In conclusion, in a cohort from Bosnia and Herzegovina TNF-α-308A allele is significantly associated with the worse long-term glucose control, but PTPN22 1858T allele is significantly associated with diabetes development.     

Association of IL-6 promoter and IFN-γ gene polymorphisms with acute rejection of liver transplantation

Liver transplantation is one of the most important therapies for end-stage liver diseases and is associated with major problems including infections and acute rejection. The outcome of transplantation can be determined by immune responses as a key role in response to the graft. Inflammatory and anti-inflammatory mediators especially cytokines influence the graft microenvironment. Th1 and Th2 immune responses in contrast to regulatory responses cause acute rejection or help graft survival. In this study, we evaluated the gene polymorphisms of IL-6 G-174C, TGF-β T + 869C, IL-4 C-590T, and IFN-γ T + 874A cytokines in liver transplant patients. ARMS-PCR method was used to characterize IL-6 G-174C, TGF-β T + 869C and IFN-γ T + 874A polymorphisms and PCR-RFLP using AvaII restriction enzyme was done for IL-4 C-590T characterization in 70 liver transplant patients. Acute rejection episodes were diagnosed according to standard criteria. The analysis of the results showed that IL-6-174 GG genotype ( P = 0.009, OR = 4.333, 95% CI = 1.043–18.000), IL-6-174G allele (P = 0.011, OR = 5.273, 95% CI = 1.454–19.127) was more frequent and IFN-γ +874 TT genotype was less frequent (P = 0.043, OR = 0.143, 95% CI = 0.0118–1.190) in acute rejection than in non-rejection patients. TGF-β T + 869C and IL-4 C-590T frequencies were not significantly different (P > 0.05). According to the results, it can be conclude that IL-6 G-174C and IFN-γ T + 874A gene polymorphisms have predictive values for acute rejection after liver transplantation. High producer genotype of IL-6 is a genetic risk factor and IFN-γ is a protective factor for acute rejection development.     

Association studies of CTLA-4, CD28, and ICOS gene polymorphisms with type 1 diabetes in the Japanese population

Co-stimulatory molecules of CD28, cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), and the newly identified inducible co-stimulator (ICOS) are expressed on cell surfaces and provide regulatory signals for T-cell activation. Their genes are candidate susceptibility genes for type 1 diabetes because they co-localize to Chromosome 2q33 with the IDDM12 locus. After determining the genomic structure and screening for polymorphisms of the ICOS gene, we performed association studies between newly identified polymorphisms of the ICOS gene, together with known polymorphisms of CD28 and CTLA-4 genes, and type 1 diabetes. The 49A/G dimorphism in exon 1 and the (AT)n in the 3' untranslated region of the CTLA-4 gene were significantly associated with type 1 diabetes. Evaluation of the CTLA-4 49A-3'(AT)n 86-bp haplotype frequency in patients and controls confirmed the results from the analysis of each polymorphic site. Dimorphism in intron 3 of the CD28 gene was associated with type 1 diabetes only in the early-onset group. In contrast, there was no association with the microsatellite polymorphisms in the ICOS gene or dimorphisms in the promotor region of CTLA-4. Of the three genes encoding co-stimulatory molecules, the CTLA-4 gene appears to confer risks for the development of type 1 diabetes.     

Effect of curcumin on glucose and lipid metabolism,FFAs and TNF-α in serum of type 2 diabetes mellitus rat models

ObjectiveTo investigate how curcumin affects the glucose and lipid metabolism in type 2 diabetes mellitus (DM) rat models, and to explore its effect on the free fatty acid (FFA) and tumor necrosis factor α (TNF-α) in serum.MethodsSuccessfully established type 2 DM rats were divided into three groups, i.e. the normal control group, model group and curcumin group, and received the medication for consecutive 8 weeks. Thereafter, we detected the level of fasting blood glucose (FBG), and the blood glucose at 30 min, 60 min and 120 min; besides, we also carried out the insulin tolerance tests to measure the levels of fasting serum insulin (FINS) and blood glucose at 40 min and 90 min; additionally, we also detected the levels of TC, TG, HDL-C, LDL-C, FFA and TNF-α in serum. The results were expected to discover the mechanism of curcumin in decreasing the blood glucose level in DM rats.ResultsCompared with the model group, AUCs of FBG, blood glucose at 30 min, 60 min and 120 min, and glucose were decreased in varying degrees in the curcumin group, and the differences had statistical significance (p < .05). After subcutaneous injection of insulin, we found that the blood glucose at 40 min and 90 min in the curcumin group was decreased, while AUC of glucose level was also decreased (p < .05 or .01). Eight weeks after medication, compared with the rats in the normal group, the levels of HDL-C, LDL-C, TC and TG in rats of the model group and the curcumin group were obviously increased (p < .05). In comparison with the model group, the level of LDL-C in rats of the curcumin group was also decreased significantly (p < .05). In comparison with the normal control group in the same period, we found that the content of FFAs and TNF-α in serum of rats of the model group were elevated significantly, and the differences had statistical significance (p < .05 or .01); the levels in the curcumin group were significantly decreased in comparison with the model group in the same period, and the difference had statistical significance (p < .05 or .01).ConclusionTreatment with curcumin can significantly improve the metabolic disorder of glucose and lipid, enhance the sensitivity to the insulin, and ameliorate the resistance to insulin of the type II DM rats. Meanwhile, this treatment method can also significantly decrease the level of FFA and TNF-α in serum of type II DM rats. Thus, we inferred that the mechanism of curcumin to improve the insulin resistance might be correlated with the decreases of FFA and TNF-α in serum.     

Adiponectin and peroxisome proliferator-activated receptor-γ gene polymorphisms and gene-gene interactions with type 2 diabetes

Aims

To investigate whether gene polymorphisms of both adiponectin and peroxisome proliferator-activated receptor gamma (PPARγ) influence type 2 diabetes mellitus (T2DM) respectively in the Han people of the Wenzhou region of China and whether the interaction of gene polymorphism between adiponectin and PPARγ influences T2DM in the same subjects.

Main methods

This study included 198 patients with T2DM and 255 healthy individuals. Polymerase chain reaction–restriction fragment length polymorphism analyses were used to detect single nucleotide polymorphisms (SNPs). Logistic regression and multifactor dimensionality reduction (MDR) methods were used to analyze gene–gene interactions.

Key findings

The frequency distribution of adiponectin SNP11377 was not different (p = 0.792), but the frequency of CC, CG and GG genotypes showed the difference between two groups (T2DM: 57.1%, 33.3%, and 9.6%; control: 53.7%, 41.6%, and 4.7%, respectively; p = 0.047). Adiponectin SNP45, SNP276 and PPAR γ SNPp12a were equally distributed between the two groups (p = 0.586, 0.119, 0.437, respectively), and there were no significant differences in genotype frequencies between the two groups (p = 0.751, 0.144, 0.479, respectively). Linkage disequilibrium existed between SNP11377 and SNP45 (p < 0.001) and SNP45 and SNP276 (p < 0.001). Haplotype analyses showed no significant differences between the T2DM and control groups. According to the logistic regression and MDR gene–gene interaction analyses, SNP11377GG and SNP276GT interactions increased the risk of T2DM (odds ratio = 6.984, p = 0.012).

Significance

Adiponectin SNP11377 and SNP276 gene–gene interactions are associated with the increased risk of T2DM in this population.     

Association of TNF-α polymorphisms (−857, −863 and −1031), TNF-α serum level and lipid profile with acne vulgaris

BackgroundAcne is an inflammatory condition principally affected by genetic and dietary factors. Investigation into functional polymorphisms of TNF-α gene and their association with acne vulgaris will be helpful in exploring genetic influence on skin immune mediated inflammatory events. In the present study, we analyzed association of TNF-α gene polymorphisms, its expression levels and lipid profiles in a large cohort of acne patients and controls.MethodsWe used PCR-RFLP to study association of TNF-α polymorphisms at −857C/T, −863C/A and −1031 T/C sites with acne vulgaris. Lipid profiles were measured using enzymatic end-point method. The serum levels of TNF-α and apolipoprotein a were measured using ELISA. NIH, LDlink was used to investigate patterns of linkage disequilibrium across south Asian reference genome (Punjabi from Lahore Pakistan).ResultsWe found that TNF-α −863 polymorphism is strongly associated with acne in overall population as well as in gender and severity based groups of acne patients. Polymorphisms at −863 and −1031 position were in linkage disequilibrium. Importantly, TNF-α serum level was significantly increased in acne patients with severe disease symptoms. Furthermore, levels of total cholesterol (TC) and triglycerides (TG) were significantly increased, whereas high density lipoprotein cholesterol (HDL-C) level was significantly decreased in acne patients. The levels of apolipoprotein a varied widely in studied populations and no significant difference was found in the analyzed groups.ConclusionIn conclusion, we found that TNF-α expression increases in acne patients affected by TNF-α polymorphisms, and that the lipid profile is specifically disrupted in acne patients.     

Association of MTHFR and PPARγ2 gene polymorphisms in relation to type 2 diabetes mellitus cases among north Indian population

Background

Type 2 diabetes mellitus is a multifactorial and polygenic disease, which is considered as a major life threatening problem all over the world. There has been a worldwide effort in the identification of susceptibility genes for type 2 diabetes mellitus and its complications. At present, adequate data is not available dealing with MTHFR (rs1801133) and PPARγ2 (rs1801282) gene polymorphisms and its association with type 2 diabetes mellitus cases among north Indian populations. Thus, we conceived the need for further studies to investigate MTHFR and PPARγ2 gene polymorphisms and their susceptibility to type 2 diabetes mellitus in north Indian population.

Materials and methods

In this study, a total 175 subjects including 87 type 2 diabetes mellitus cases and 88 controls were enrolled. MTHFR and PPARγ2 gene polymorphisms in the cases and controls were evaluated by polymerase chain reaction and restriction fragment length polymorphism (PCR–RFLP).

Results

The MTHFR gene CC, CT, TT genotype frequencies obtained were 40%, 43%, and 17% in type 2 diabetes mellitus cases and 56%, 29%, and 15% in healthy controls respectively. The OR for CC was 0.54 (95%CI 0.29–0.98, P = 0.041, χ2 = 4.18, power = 0.98), for CT 1.76 (95%CI 0.94–3.30, P = 0.07, χ2 = 3.2, power = 0.96), and for TT 1.2 (95%CI 0.53–2.70, P = 0.66, χ2 = 0.198, power = 0.76). The PPARγ2 gene GG CG, CC genotype frequencies obtained were 28%, 41%, and 31% in cases and 40%, 39%, and 21% in healthy controls respectively. OR for GG was 0.58 (95%CI 0.30–1.09, P = 0.08, χ2 = 2.9, power = 0.96), for CG 1.12 (95%CI 0.61–2.05, P = 0.71, χ2 = 0.137, power = 0.778), and for CC 1.63 (95%CI 0.82–3.23, P = 0.156, χ2 = 2.01, power = 0.92).

Conclusion

It might be recommended that MTHFR CC genotype seems to be a good marker for the early identification of population at risk of type 2 diabetes mellitus. While we have detected significant difference in allelic frequencies of PPARγ2 C (Proline) and G (Alanine), but at genotypic level significant difference was not detected in this case–control study. Further study with larger groups may be required to validate the study.     

Polymorphisms in the TNF-α and IL-10 gene promoters and risk of psoriasis and correlation with disease severity

Several cytokines were assumed to play an essential role in the induction and the pathogenesis of psoriasis. The aim of this work was to investigate the role of TNF-α-308 and IL-10-1082 polymorphisms and their serum levels in the pathogenesis of psoriasis and determine their relation to disease severity. 110 Psoriasis patients and 120 healthy volunteers were genotyped for TNF-α-308 and IL-10-1082 polymorphism by polymerase chain reaction. Serum level of TNF-α and IL-10 were measured by ELISA. Our study demonstrated an association of IL-10-1082 polymorphism and psoriasis and between TNF α-308 polymorphism and psoriasis disease and severity. Serum TNF α increased in patients, while serum IL-10 decreased in patients with significant correlation between serum TNF-α and psoriasis severity. These results indicated that TNF-α-308 and IL-10-1082 polymorphisms imparted significant risk towards the development of psoriasis.     

Association of HS6ST3 gene polymorphisms with obesity and triglycerides: gene × gender interaction

The heparan sulfate 6-O-sulfotransferase 3 (HS6ST3) gene is involved in heparan sulphate and heparin metabolism, and has been reported to be associated with diabetic retinopathy in type 2 diabetes. We hypothesized that HS6ST3 gene polymorphisms might play an important role in obesity and related phenotypes (such as triglycerides). We examined genetic associations of 117 single-nucleotide polymorphisms (SNPs) within the HS6ST3 gene with obesity and triglycerides using two Caucasian samples: the Marshfield sample (1442 obesity cases and 2122 controls), and the Health aging and body composition (Health ABC) sample (305 cases and 1336 controls). Logistic regression analysis of obesity as a binary trait and linear regression analysis of triglycerides as a continuous trait, adjusted for age and sex, were performed using PLINK. Single marker analysis showed that six SNPs in the Marshfield sample and one SNP in the Health ABC sample were associated with obesity (P?<?0.05). SNP rs535812 revealed a stronger association with obesity in meta-analysis of these two samples (P?=?0.0105). The T–A haplotype from rs878950 and rs9525149 revealed significant association with obesity in the Marshfield sample (P?=?0.012). Moreover, nine SNPs showed associations with triglycerides in the Marshfield sample (P?<?0.05) and the best signal was rs1927796 (P?=?0.00858). In addition, rs7331762 showed a strong gene × gender interaction (P?=?0.00956) for obesity while rs1927796 showed a strong gene × gender interaction (P?=?0.000625) for triglycerides in the Marshfield sample. These findings contribute new insights into the pathogenesis of obesity and triglycerides and demonstrate the importance of gender differences in the aetiology.     

Clinical differences between patients with MODY-3, MODY-2 and type 2 diabetes mellitus with I27L polymorphism in the HNF1α gene

ObjectiveThe aim of our study was to describe and evaluate the clinical and metabolic characteristics of patients with MODY-3, MODY-2 or type 2 diabetes who presented I27L polymorphism in the HNF1α gene.MethodsThe study included 31 previously diagnosed subjects under follow-up for MODY-3 (10 subjects from 5 families), MODY-2 (15 subjects from 9 families), or type 2 diabetes (6 subjects) with I27L polymorphism in the HNF1α gene. The demographic, clinical, metabolic, and genetic characteristics of all patients were analyzed.ResultsNo differences were observed in distribution according to sex, age of onset, or form of diagnosis. All patients with MODY-2 or MODY-3 had a family history of diabetes. In contrast, 33.3% of patients with type 2 diabetes mellitus and I27L polymorphism in the HNF1α gene had no family history of diabetes (p < 0.05). No differences were observed in body mass index, prevalence of hypertension, or microvascular or macrovascular complications. Drug therapy was required by 100% of MODY-3 patients, but not required by 100% of MODY-2 patients or 16.7% of patients with type 2 diabetes mellitus and I27L polymorphism in the HNF1α gene (p < 0.05).ConclusionsOccasional difficulties may be encountered when classifying patients with MODY-2, MODY-3 or type 2 diabetes of atypical characteristics, in this case patients who present I27L polymorphism in the HNF1α gene.     

Association between the −11377 C/G and −11391 G/A polymorphisms of adiponectin gene and adiponectin levels with susceptibility to type 1 and type 2 diabetes mellitus in population from the west of Iran,correlation with lipid profile

Adipose tissue, an endocrine organ, secretes bioactive factors including adiponectin. Adiponectin is a protein hormone that enhances insulin sensitivity through increased fatty acid oxidation and inhibition of hepatic glucose production. We assessed the association of the adiponectin promoter region polymorphisms −11391 G/A and −11377 C/G with susceptibility to type 1 (T1DM) and type 2 (T2DM) diabetes mellitus in the population of west Iran. Also, we investigated the effect of adiponectin level and lipid profile on T1DM and T2DM development. In this case-control study, we recruited 189 patients with diabetes (100 T2DM and 89 T1DM) and 161 sex and age-matched unrelated healthy controls. Adiponectin mutations were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and the protein level was measured by the enzyme-linked immunosorbent assay. Other biochemical parameters were determined by routine laboratory methods. The G allele of adiponectin gene at −11377 position (C/G) significantly increased the risk of T1DM. With respect to genotype models, codominant (2.97 times), dominant (3.6-fold), and over-codominant (2.9-fold) patients with T1DM who carried −11377 C > G single-nucleotide polymorphisms were significantly susceptible to the development of the disease. A significantly higher level of adiponectin in T1DM was oberved compared with the control group. In contrast, patients with T2DM had lower adiponectin levels compared with healthy controls. The genotype distributions of −11391 G/A polymorphisms were the same for patients with diabetes and control groups. The presence of G allele at −11377 C/G adiponectin gene significantly increased serum adiponectin level and may be a risk factor for T1DM susceptibility among the western Iranian population.     

Association of PARP-1, NF-κB,NF-κBIA and IL-6, IL-1β and TNF-α with Graves Disease and Graves Ophthalmopathy

Background

Graves Disease (GD) is an autoimmune disorder affected by an interaction of multiple genes such as Nuclear Factor-κB (NF-κB), Nuclear Factor-κB Inhibitor (NF-κBIA), Poly (ADP-ribose) polymerase-1 (PARP-1) and cytokines like Interleukin-1β (IL-1β), Interleukin-6 (IL-6) and Tumor Necrosis Factor-α (TNF-α) and mostly accompanied by an ocular disorder, Graves Ophthalmopathy (GO). We hypothesize that there is a relationship between GD, GO, polymorphisms of inflammatory related genes and their association with cytokines, which may play important roles in autoimmune and inflammatory processes.

Subjects and methods

To confirm our hypothesis, we studied the polymorphisms and cytokine levels of 120 patients with GD and GO using PCR-RFLP and ELISA methods, respectively.

Results

We found that patients with GG genotype and carriers of G allele of PARP-1 G1672A polymorphism are at risk in the group having GD (p = 0.0007) while having GA genotype may be protective against the disease. PARP-1 C410T polymorphism was found to be associated with GO by increasing the risk by 1.7 times (p = 0.004). Another risk factor for development of GO was the polymorphism of del/ins of NFkB1 gene (p = 0.032) that increases the risk by 39%. Levels of cytokines were also elevated in patients with GD, but no association was found between levels of cytokines and the development of GO as there was no change in levels of cytokines.

Conclusions

We suggest that, PARP-1 and NFkB1 gene polymorphisms may be risk factors for developing Graves Disease and Ophthalmopathy.     

Genome-Wide Association Study of Genetic Variants in LPS-Stimulated IL-6, IL-8, IL-10, IL-1ra and TNF-α Cytokine Response in a Danish Cohort

Background

Cytokine response plays a vital role in various human lipopolysaccharide (LPS) infectious and inflammatory diseases. This study aimed to find genetic variants that might affect the levels of LPS-induced interleukin (IL)-6, IL-8, IL-10, IL-1ra and tumor necrosis factor (TNF)-α cytokine production.

Methods

We performed an initial genome-wide association study using Affymetrix Human Mapping 500 K GeneChip® to screen 130 healthy individuals of Danish descent. The levels of IL-6, IL-8, IL-10, IL-1ra and TNF-α in 24-hour LPS-stimulated whole blood samples were compared within different genotypes. The 152 most significant SNPs were replicated using Illumina Golden Gate® GeneChip in an independent cohort of 186 Danish individuals. Next, 9 of the most statistical significant SNPs were replicated using PCR-based genotyping in an independent cohort of 400 Danish individuals. All results were analyzed in a combined study among the 716 Danish individuals.

Results

Only one marker of the 500 K Gene Chip in the discovery study showed a significant association with LPS-induced IL-1ra cytokine levels after Bonferroni correction (P<10⁻⁷). However, this SNP was not associated with the IL-1ra cytokine levels in the replication dataset. No SNPs reached genome-wide significance for the five cytokine levels in the combined analysis of all three stages.

Conclusions

The associations between the genetic variants and the LPS-induced IL-6, IL-8, IL-10, IL-1ra and TNF-α cytokine levels were not significant in the meta-analysis. This present study does not support a strong genetic effect of LPS-stimulated cytokine production; however, the potential for type II errors should be considered.