Genotype at a promoter polymorphism of the interleukin-6 gene is associated with baseline levels of plasma C-reactive protein

A tale of two functions: C-reactive protein complement-ary structures and their role in rheumatoid arthritis

C-reactive protein (CRP) is an inflammatory biomarker with associated clinical utility in a wide number of inflammatory disorders, including rheumatoid arthritis (RA). The interaction of CRP with pro-inflammatory cytokines has been explored before, however its role in complement regulation is more subtle, where CRP is capable of both up and downregulating the complement cascade. CRP is produced in a pentameric form and can dissociate to a monomeric form in circulation which has significant implications for its ability to interact with receptors and binding partners. This dichotomy of CRP structure could have relevance in patients with RA who have significant dysfunction in their complement cascade and also widely varying CRP levels including at the time of flare. This review aims to bring together current knowledge of CRP in its various forms, its effects on complement function and how this could influence pathology in the context of RA.

Whole Genome Sequencing Based Analysis of Inflammation Biomarkers in the Trans-Omics for Precision Medicine (TOPMed) Consortium

Inflammation biomarkers can provide valuable insight into the role of inflammatory processes in many diseases and conditions. Sequencing based analyses of such biomarkers can also serve as an exemplar of the genetic architecture of quantitative traits. To evaluate the biological insight, which can be provided by a multi-ancestry, whole-genome based association study, we performed a comprehensive analysis of 21 inflammation biomarkers from up to 38,465 individuals with whole-genome sequencing from the Trans-Omics for Precision Medicine (TOPMed) program. We identified 22 distinct single-variant associations across 6 traits - E-selectin, intercellular adhesion molecule 1, interleukin-6, lipoprotein-associated phospholipase A2 activity and mass, and P-selectin - that remained significant after conditioning on previously identified associations for these inflammatory biomarkers. We further expanded upon known biomarker associations by pairing the single-variant analysis with a rare variant set-based analysis that further identified 19 significant rare variant set-based associations with 5 traits. These signals were distinct from both significant single variant association signals within TOPMed and genetic signals observed in prior studies, demonstrating the complementary value of performing both single and rare variant analyses when analyzing quantitative traits. We also confirm several previously reported signals from semi-quantitative proteomics platforms. Many of these signals demonstrate the extensive allelic heterogeneity and ancestry-differentiated variant-trait associations common for inflammation biomarkers, a characteristic we hypothesize will be increasingly observed with well-powered, large-scale analyses of complex traits.

Genetic Polymorphisms of Ischemic Stroke in Asians

The increasing incidence of ischemic stroke emphasizes the necessity for early detection and preventive strategies. Diagnostic biomarkers currently available for ischemic stroke only become detectable shortly before the manifestation of stroke symptoms. Genetic variants associated with ischemic stroke offer a potential solution to address this diagnostic limitation. However, it is crucial to acknowledge that genetic variants cannot be modified in the same way as epigenetic changes. Nevertheless, individuals carrying risk or protective variants can modify their lifestyle to potentially influence the associated epigenetic factors. This study aims to summarize specific variants relevant to Asian populations that may aid in the early detection of ischemic stroke and explore their impact on the disease's pathophysiology. These variants give us important information about the genes that play a role in ischemic stroke by affecting things like atherosclerosis pathway, blood coagulation pathway, homocysteine metabolism, transporter function, transcription, and the activity of neurons regulation. It is important to recognize the variations in genetic variants among different ethnicities and avoid generalizing the pathogenesis of ischemic stroke.

Genetic analyses of circulating PUFA-derived mediators identifies heritable dihydroxyeicosatrienoic acid species

Estimates of heritability are the first step in identifying a trait with substantial variation due to genetic factors. Large-scale genetic analyses can identify the DNA variants that influence the levels of circulating lipid species and the statistical technique Mendelian randomisation can use these DNA variants to address potential causality of these lipids in disease. We estimated the heritability of plasma eicosanoids, octadecanoids and docosanoids to identify those lipid species with substantial heritability. We analysed plasma lipid mediators in 31 White British families (196 participants) ascertained for high blood pressure and deeply clinically and biochemically phenotyped over a 25-year period. We found that the dihydroxyeicosatrienoic acid (DHET) species, 11,12-DHET and 14,15-DHET, products of arachidonic acid metabolism by cytochrome P450 (CYP) monooxygenase and soluble epoxide hydrolase (sEH), exhibited substantial heritability (h2 = 33%-37%; Padj<0.05). Identification of these two heritable bioactive lipid species allows for future large-scale, targeted, lipidomics-genomics analyses to address causality in cardiovascular and other diseases.

The Influence of Treatment with PCSK9 Inhibitors and Variants in the CRP (rs1800947), TNFA (rs1800629), and IL6 (rs1800795) Genes on the Corresponding Inflammatory Markers in Patients with Very High Lipoprotein(a) Levels

Chronic inflammation contributes significantly to the development and progression of atherosclerosis. However, the factors that lead to an inflammatory imbalance towards a proinflammatory state are not yet fully understood. The CRP rs1800947, TNFA rs1800629, and IL6 rs1800795 polymorphisms may play a role in the pathogenesis of atherosclerosis and were therefore selected to investigate the influence of genetic variability on the corresponding plasma levels after treatment with a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor. A group of 69 patients with stable coronary artery disease after myocardial infarction before the age of 50 years and very high lipoprotein(a) levels were enrolled in the study. All patients received a PCSK9 inhibitor (evolocumab or alirocumab). Genotyping was performed using TaqMan assays (CRP rs1800947, TNFA rs1800629, and IL6 rs1800795). Consistent with previous studies, no significant change in levels of inflammatory biomarkers was observed after 6 months of treatment with PCSK9 inhibitors. We also did not detect any significant association between single nucleotide polymorphisms CRP rs1800947, TNFA rs1800629, and IL6 rs1800795 and plasma levels of high-sensitivity C-reactive protein (hsCRP), tumor necrosis factor-α (TNF-α), or interleukin 6 (IL6), respectively, at enrollment. However, the difference in IL6 levels after treatment with PCSK9 inhibitors was statistically significant (p = 0.050) in patients with IL6-74CC genotype, indicating the possible role of the IL6 rs1800795 polymorphism in modulating inflammation.

C-reactive protein in adult Samoans: Population variation and physiological correlates

OBJECTIVES

C-reactive protein (CRP) has been associated with adiposity and cardiometabolic disease risk in many populations but remains remarkably understudied in Pacific Islander populations. Here, we provide the first examination of correlates of CRP in adult Samoans (n = 108, ages 35-55 years) to test the hypotheses that CRP exhibits sex-dependent associations with measures of BMI, adiposity, and cardiometabolic disease risks.

METHODS

We analyzed associations between measures of adiposity (total fat mass, visceral fat mass, percent total body fat), body mass index (BMI), cardiometabolic risks, behaviors, demographics, and CRP. Unadjusted analyses of CRP were undertaken using Pearson's pairwise, and Spearman's rank correlations; one-way analysis of variance and Kruskal-Wallis tests assessed variables by CRP quartiles. Adjusted analyses of CRP correlates were examined using generalized linear regression.

RESULTS

Serum CRP ranged from 0.08 to 13.3 mg/L (median 1.4 mg/L) and varied significantly by sex t (108) = -2.47, p = .015. CRP was weakly to moderately associated with measures of adiposity and BMI (r and ρ ranged between 0.25 and 0.50, p < .05) and some cardiometabolic markers (including HbA1c, fasting insulin, and insulin resistance). CRP was significantly associated with percent body fat in women and men, adjusting for other variables.

CONCLUSIONS

These data are among the first to demonstrate CRP correlates in a sample of adult Samoans. CRP differed by sex and was associated with BMI, adiposity, and some cardiometabolic risk markers. These data align with findings in other populations.

Heritability and family-based GWAS analyses of the N-acyl ethanolamine and ceramide plasma lipidome

Signalling lipids of the N-acyl ethanolamine (NAE) and ceramide (CER) classes have emerged as potential biomarkers of cardiovascular disease (CVD). We sought to establish the heritability of plasma NAEs (including the endocannabinoid anandamide) and CERs, to identify common DNA variants influencing the circulating concentrations of the heritable lipids, and assess causality of these lipids in CVD using 2-sample Mendelian randomization (2SMR). Nine NAEs and 16 CERs were analyzed in plasma samples from 999 members of 196 British Caucasian families, using targeted ultra-performance liquid chromatography with tandem mass spectrometry. All lipids were significantly heritable (h2 = 36-62%). A missense variant (rs324420) in the gene encoding the enzyme fatty acid amide hydrolase (FAAH), which degrades NAEs, associated at genome-wide association study (GWAS) significance (P < 5 × 10-8) with four NAEs (DHEA, PEA, LEA and VEA). For CERs, rs680379 in the SPTLC3 gene, which encodes a subunit of the rate-limiting enzyme in CER biosynthesis, associated with a range of species (e.g. CER[N(24)S(19)]; P = 4.82 × 10-27). We observed three novel associations between SNPs at the CD83, SGPP1 and DEGS1 loci, and plasma CER traits (P < 5 × 10-8). 2SMR in the CARDIoGRAMplusC4D cohorts (60 801 cases; 123 504 controls) and in the DIAGRAM cohort (26 488 cases; 83 964 controls), using the genetic instruments from our family-based GWAS, did not reveal association between genetically determined differences in CER levels and CVD or diabetes. Two of the novel GWAS loci, SGPP1 and DEGS1, suggested a casual association between CERs and a range of haematological phenotypes, through 2SMR in the UK Biobank, INTERVAL and UKBiLEVE cohorts (n = 110 000-350 000).

Association Between Promoter Polymorphisms of IL-1B, IL-4 and IL-6 Genes and a Viral Load Infected Women with Human Papillomavirus

Background:

The purpose of this study was to investigate the association between IL-4 -589C>T, IL-6 -174G>C, IL-1β -31T>C and IL-1β -511C>T genes polymorphism with high concentrations of human papillomavirus (HPV), and the influence of gene-gene interactions on persistent human papillomavirus infection.

Methods:

In this study, 101 infected women with high HPV viral load and 93 healthy women were involved in a case-control study. Genotyping of SNPs for IL-4 -589C>T, IL-6 -174G>C, IL-1β -31T>C and IL-1β -511C>T genes was carried out by allele-specific PCR. Quantitative analysis of HPV-DNA was performed by Amplisens HPV HCR genotype-titer software. Gene-gene interactions were analyzed using multifactor dimensionality reduction (MDR) algorithm. Haplotype interactions were analyzed by HaploView 4.2 tool.

Results:

The study of single individual SNPs in promoters of IL-4 -589C>T, IL-6 -174G>C and IL-1β -31T>C genes did not reveal statistically significant difference in genotypes and allele frequencies among women with high HPV viral load and control group. The frequency of -511T allele and TT genotype of the IL-1β gene in case group was significantly higher than the one in control group (OR=1.71, p=0.012 and OR=2.02, p=0.046, respectively). Haplotype analysis revealed that -511C/-31T haplotype for IL-1β gene is significantly less common among women with high HPV viral load (p=0.018).

Conclusion:

The haplotype -511C/-31T for IL-1β gene is associated with a protective effect against increasing HPV viral load. The frequencies of -511T allele and -511TT genotype of the IL-1β -511C>T were significantly higher among women with HPV in comparison to control group.

Quantile-dependent expressivity of serum C-reactive protein concentrations in family sets

Background

“Quantile-dependent expressivity” occurs when the effect size of a genetic variant depends upon whether the phenotype (e.g., C-reactive protein, CRP) is high or low relative to its distribution. We have previously shown that the heritabilities (h²) of coffee and alcohol consumption, postprandial lipemia, lipoproteins, leptin, adiponectin, adiposity, and pulmonary function are quantile-specific. Whether CRP heritability is quantile-specific is currently unknown.

Methods

Serum CRP concentrations from 2,036 sibships and 6,144 offspring-parent pairs were analyzed from the Framingham Heart Study. Quantile-specific heritability from full-sib (β_FS, h² ={(1 + 8r_spouseβ_FS)^0.5 − 1}/(2r_spouse)) and offspring-parent regression slopes (β_OP, h² = 2β_OP/(1 + r_spouse)) were estimated robustly by quantile regression with nonparametric significance determined from 1,000 bootstrap samples.

Results

Quantile-specific h² (±SE) increased with increasing percentiles of the offspring’s age- and sex-adjusted CRP distribution when estimated from β_OP (P_trend = 0.0004): 0.02 ± 0.01 at the 10th, 0.04 ± 0.01 at the 25th, 0.10 ± 0.02 at the 50th, 0.20 ± 0.05 at the 75th, and 0.33 ± 0.10 at the 90th percentile, and when estimated from β_FS (P_trend = 0.0008): 0.03±0.01 at the 10th, 0.06 ± 0.02 at the 25th, 0.14 ± 0.03 at the 50th, 0.24 ± 0.05 at the 75th, and 0.53 ± 0.21 at the 90th percentile.

Conclusion

Heritability of serum CRP concentration is quantile-specific, which may explain or contribute to the inflated CRP differences between CRP (rs1130864, rs1205, rs1800947, rs2794521, rs3091244), FGB (rs1800787), IL-6 (rs1800795, rs1800796), IL6R (rs8192284), TNF-α (rs1800629) and APOE genotypes following CABG surgery, stroke, TIA, curative esophagectomy, intensive periodontal therapy, or acute exercise; during acute coronary syndrome or Staphylococcus aureus bacteremia; or in patients with chronic rheumatoid arthritis, diabetes, peripheral arterial disease, ankylosing spondylitis, obesity or inflammatory bowel disease or who smoke.

Meta-analysis of association between il-6-174 g/c polymorphism and female infertility related disorders

Female infertility continues to increase in prevalence annually and factors causing it need to be researched. As IL-6-174 G/C polymorphism is known to alter the plasma levels of IL-6, abnormal levels of IL-6 found in infertile females could be due to genetic reasons. With the understanding of the importance of IL-6 in reproductive physiology, several individual studies done so far to find the association of this polymorphism with female infertility related disorders were systematically combined for meta-analysis. Articles were searched using electronic data base sources and were included based on specific criteria. Finally, eight articles which includes polycystic ovarian syndrome (PCOS; n = 4), endometriosis (n = 3) and tubal damage (n = 1) were selected for the analysis. Results showed statistically significant heterogeneity across studies under the allele model (p < 0.0001, I² = 78 %) and dominant model (p < 0.00001, I² = 82%) but not under recessive model (p = 0.31, I² = 16%). This difference could be possibly due to variation in ethnicity, lifestyle, age or BMI related factors. The pooled odds ratio under the three genetic models were 0.87(CI = 0.75-1.02), 0.77 (CI = 0.63-0.94) and 1.05 (CI = 0.76-1.46) respectively. Sub group analysis showed statistical significant (P < 0.01) for PCOS under allele and dominant model, but not for endometriosis and tubal damage. By this meta-analysis, we can say that IL-6-174 G/C polymorphism can be considered as a potential genetic marker for PCOS but not for endometriosis and tubal damage disorders. However, more studies with adequate sample sizes are required to be done in endometriosis, tubal disease and other female infertility disorders to arrive at a definite conclusion.

INTERACTIONS AMONG INTERLEUKIN-6, C-REACTIVE PROTEIN AND INTERLEUKIN-6 (-174) G/C POLYMORPHISM IN THE PATHOGENESIS OF CROHN'S DISEASE AND ULCERATIVE COLITIS

Inflammatory bowel diseases are multifactorial disorders the clinical manifestation of which depends on the interaction among immune response, genetic and environmental factors. There is growing evidence that cytokines and gene polymorphisms have an important role in disease pathogenesis in various populations although molecular mechanism of their signaling and interactions is not fully understood yet. The present study aimed at exploring the effects of interleukin-6, C-reactive protein and interleukin-6 rs1800795 polymorphism on the development of Crohn’s disease, ulcerative colitis and inflammatory bowel diseases overall and at determining differences between inflammatory bowel disease patients and healthy controls. A total of 132 inflammatory bowel disease patients and 71 healthy blood donors were investigated. In order to assess the clinical relevance of interleukin-6 and C-reactive protein serum concentration and interleukin-6 rs1800795 single nucleotide polymorphism in patients with Crohn’s disease and ulcerative colitis, we performed a cross-sectional, case-control study. Quantitative assessment of serum interleukin-6 and C-reactive protein was performed with solid-phase, enzyme-labeled, chemiluminescent sequential immunometric and immunoturbidimetric assay, respectively. A real-time fluorescence resonance energy transfer-based method on a LightCyclerTM PCR 1.2 was used for genotyping of IL-6 rs1800795 polymorphism. Both interleukin-6 and C-reactive protein serum levels were elevated in Crohn’s disease and ulcerative colitis patients. Positive correlations were observed between C-reactive protein and interleukin-6 serum concentration and ulcerative colitis activity index as measured by modified Truelove-Witt’s severity index scale. C-reactive protein serum level was higher in Crohn’s disease patients without intestinal resection than in Crohn’s disease patients with prior intestinal resection. In ulcerative colitis patients, interleukin-6 and C-reactive protein serum levels were statistically significantly higher in CC interleukin-6 genotype in comparison to GG+GC genotype. Analysis of the promoter region of the interleukin-6 rs1800795 gene polymorphism showed no statistically significant difference in allele frequency either between inflammatory bowel disease patients and healthy controls or between the two inflammatory bowel disease phenotypes and healthy controls. Associations presented in this study give a potentially important insight into the role of interleukin-6 and C-reactive protein signaling and interleukin-6 polymorphism in the pathogenesis of Crohn’s disease and ulcerative colitis disease.

Allelic Heterogeneity at the CRP Locus Identified by Whole-Genome Sequencing in Multi-ancestry Cohorts

Whole-genome sequencing (WGS) can improve assessment of low-frequency and rare variants, particularly in non-European populations that have been underrepresented in existing genomic studies. The genetic determinants of C-reactive protein (CRP), a biomarker of chronic inflammation, have been extensively studied, with existing genome-wide association studies (GWASs) conducted in >200,000 individuals of European ancestry. In order to discover novel loci associated with CRP levels, we examined a multi-ancestry population (n = 23,279) with WGS (∼38× coverage) from the Trans-Omics for Precision Medicine (TOPMed) program. We found evidence for eight distinct associations at the CRP locus, including two variants that have not been identified previously (rs11265259 and rs181704186), both of which are non-coding and more common in individuals of African ancestry (∼10% and ∼1% minor allele frequency, respectively, and rare or monomorphic in 1000 Genomes populations of East Asian, South Asian, and European ancestry). We show that the minor (G) allele of rs181704186 is associated with lower CRP levels and decreased transcriptional activity and protein binding in vitro, providing a plausible molecular mechanism for this African ancestry-specific signal. The individuals homozygous for rs181704186-G have a mean CRP level of 0.23 mg/L, in contrast to individuals heterozygous for rs181704186 with mean CRP of 2.97 mg/L and major allele homozygotes with mean CRP of 4.11 mg/L. This study demonstrates the utility of WGS in multi-ethnic populations to drive discovery of complex trait associations of large effect and to identify functional alleles in noncoding regulatory regions.

Interleukin-6 serum level and -597 A/G gene polymorphism in moderate and severe chronic obstructive pulmonary disease

Inflammation is a major pathogenic pathway in pulmonary chronic obstructive disease (COPD). Interleukin-6 (IL-6) mediates the local and systemic immune response. The aim consisted in investigating the relationship between IL-6 serum levels and IL-6 -597A/G gene polymorphism (rs1800797) with COPD. Serum levels of IL-6 were determined using an enzyme-linked immune-sorbent assay, in 120 participants (60 COPD patients and 60 healthy subjects), from Transylvanian region. The IL-6 -597A/G gene polymorphism was investigated by high molecular weight genomic DNA extracted from the peripheral blood leukocytes, and subsequently analyzed by the Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP) technique. Smoking history, the severity of the disease, expressed by the GOLD stages, and arterial blood partial pressure of oxygen (PaO2) levels were also investigated. COPD patients had significantly elevated blood levels of IL-6 when compared to the control group ( p < 0.05). The frequencies of AA, AG, and GG genotypes were 61.6%, 26.6%, and 11.6% in the COPD cases and 70%, 23.3%, and 6.7% in healthy subjects, respectively. There were no statistically significant differences in IL-6 rs1800797 genotypes and allele frequencies between cases and controls ( χ2 = 0.54, OR = 1.29 and χ2 = 0.21, OR = 1.48, respectively). Higher serum levels of IL-6 were found in the GG genotype subgroup in COPD patients. IL 6 levels are higher in COPD patients, where positively correlate with pack-year index, but not with clinical features. Although COPD patients did not have statistically different rs1800797 allele distribution compared to healthy subjects, the GG genotype is associated with higher IL6 serum levels.

Genetic study in patients operated dentally and anesthetized with articaine-epinephrine

Aims: In this study we wanted to figure out if there was a correlation between OPRM1 N40D, TRPV1 I316M, TRPV1 I585V, NOS3 −786T>C and IL6 −174C>G polymorphisms and the response to locally applied articaine-epinephrine anesthetic.

Methods: In this observational study, 114 oral cell samples of patients anesthetized with articaine-epinephrine (54 from men 60 from women), were collected from dental centers in Madrid (Spain). High molecular weight DNA was obtained from oral mucosa cells. The analysis of OPRM1 N40D (rs1799971), TRPV1 I316M (rs222747), TRPV1 I585V (rs8065080) and IL6 −174C>G polymorphism was performed through real-time PCR allelic discrimination using TaqMan probes. Polymorphism NOS3 −786T> C (rs2070744) was analyzed using RFLP-PCR.

Results: The studied polymorphisms are involved neither in the response to the anesthetic, nor in the intensity of perceived dental pain. However, in a subset of female patients we found that TRPV1 I316M was associated with a delayed onset of anesthesia.

Conclusions: There is no association among these polymorphisms and the time elapsed between the application of the anesthetic and the onset of its effect.

Trajectories of inflammatory biomarkers over the eighth decade and their associations with immune cell profiles and epigenetic ageing

BACKGROUND

Epigenetic age acceleration (an older methylation age compared to chronological age) correlates strongly with various age-related morbidities and mortality. Chronic systemic inflammation is thought to be a hallmark of ageing, but the relationship between an increased epigenetic age and this likely key phenotype of ageing has not yet been extensively investigated.

METHODS

We modelled the trajectories of the inflammatory biomarkers C-reactive protein (CRP; measured using both a high- and low-sensitivity assay) and interleukin-6 (IL-6) over the eighth decade in the Lothian Birth Cohort 1936. Using linear mixed models, we investigated the association between CRP and immune cell profiles imputed from the methylation data and examined the cross-sectional and longitudinal association between the inflammatory biomarkers and two measures of epigenetic age acceleration, derived from the Horvath and Hannum epigenetic clocks.

RESULTS

We found that low-sensitivity CRP declined, high-sensitivity CRP did not change, and IL-6 increased over time within the cohort. CRP levels inversely associated with CD8+T cells and CD4+T cells and positively associated with senescent CD8+T cells, plasmablasts and granulocytes. Cross-sectionally, the Hannum, but not the Horvath, measure of age acceleration was positively associated with each of the inflammatory biomarkers, including a restricted measure of CRP (≤ 10 mg/L) likely reflecting levels relevant to chronic inflammation.

CONCLUSIONS

We found a divergent relationship between inflammation and immune system parameters in older age. We additionally report the Hannum measure of epigenetic age acceleration associated with an elevated inflammatory profile cross-sectionally, but not longitudinally.

Genetic variations in key inflammatory cytokines exacerbates the risk of diabetic nephropathy by influencing the gene expression

BACKGROUND

Diabetic nephropathy is the single strongest predictor of mortality in patients with diabetes. The development of overt nephropathy involves important inter-individual variations, even after adjusting for potential confounding influences of modifiable and non-modifiable risk factors. Genome-wide transcriptome studies have reported the activation of inflammatory signaling pathways and there is mounting indication of the role of genetic factors.

METHODS

We screened nine genetic variations in three cytokine genes (TNF-α, IL-6 and IL-β) in 1326 unrelated subjects comprising of healthy controls (n = 464), type 2 diabetics with nephropathy (DN, n = 448) and type 2 diabetes without nephropathy (T2D, n = 414) by sequence-specific amplification. Functional implication of SNPs was elucidated by correlation studies and relative gene expression using Realtime-Quantitative PCR (RT-qPCR).

RESULTS

Individual SNP analysis showed highest association of IL-1β rs16944-TT genotype (OR = 3.51, 95%CI = 2.36-5.21, P = 0.001) and TNF-α rs1800629-AA genotype (OR = 2.75, 95% CI = 1.64-4.59, P = 0.001) with T2D and DN respectively. The haplotype frequency showed significant risk of seven combinations among T2D and four combinations among DN subjects. The highest risk of T2D and DN was associated with GGTGAGTTT (OR = 4.25, 95%CI = 3.3-14.20, P = 0.0016) and GACGACCTT (OR = 21.3, 95%CI = 15.1-28.33, P = 0.026) haplotypes respectively. Relative expression by RT-qPCR showed increased cytokine expression in cases as compared to controls. TNF-α expression was increased by more than four-folds (n-fold = 4.43 ± 1.11) in DN. TNF-α, IL-6 and IL-1β transcript levels were significantly modulated by promoter region SNPs.

CONCLUSIONS

The present study implicates a strong association between cytokine TNF-α, IL-6 and IL-1β gene promoter polymorphisms and modulation of transcript levels with susceptibility to nephropathy in diabetes subjects.

Genetic polymorphisms of IL-6 promoter in cancer susceptibility and prognosis: a meta-analysis

IL-6 is critical for tumorigenesis. However, previous studies on the association of IL-6 promoter polymorphisms with predisposition to different cancer types are somewhat contradictory. Therefore, we performed this meta-analysis regarding the relationship between IL-6 promoter single nucleotide polymorphisms and cancer susceptibility and prognosis. Up to April 2017, 97 original publications were identified covering three IL-6 promoter SNPs. Our results showed statistically significant association between IL-6 promoter and cancer risk and prognosis. Subgroup analysis indicated that rs1800795 was significantly associated with increased risk of cervical cancer, colorectal cancer, breast cancer, prostate cancer, lung cancer, glioma, non-Hodgkin’s lymphoma and Hodgkin’s lymphoma but not gastric cancer and multiple myeloma. Furthermore, rs1800796 was significantly associated with increased risk of lung cancer, prostate cancer and colorectal cancer but not gastric cancer. Additionally, rs1800797 was significantly association with breast cancer, non-Hodgkin’s lymphoma, B-cell lymphoma and diffuse large B-cell lymphoma but not gastric cancer. Simultaneously, rs1800795 and rs1800796 were associated with a significantly higher risk of cancer in Asia and Caucasian, rs1800797 was associated with a significantly risk of cancer in Caucasian but not in Asia. Furthermore, IL-6 promoter polymorphisms were significantly associated with the prognosis of cancer. Considering these promising results, IL-6 promoter including rs1800795, rs1800796 and rs1800797 may be a tumor marker for cancer therapy.

Association between variants in genes involved in the immune response and prostate cancer risk in men randomized to the finasteride arm in the Prostate Cancer Prevention Trial

BACKGROUND

We reported that some, but not all single nucleotide polymorphisms (SNPs) in select immune response genes are associated with prostate cancer, but not individually with the prevalence of intraprostatic inflammation in the Prostate Cancer Prevention Trial (PCPT) placebo arm. Here, we investigated whether these same SNPs are associated with risk of lower- and higher-grade prostate cancer in men randomized to finasteride, and with prevalence of intraprostatic inflammation among controls. Methods A total of 16 candidate SNPs in IL1β, IL2, IL4, IL6, IL8, IL10, IL12(p40), IFNG, MSR1, RNASEL, TLR4, and TNFA and 7 tagSNPs in IL10 were genotyped in 625 white prostate cancer cases, and 532 white controls negative for cancer on an end-of-study biopsy nested in the PCPT finasteride arm. We used logistic regression to estimate log-additive odds ratios (OR) and 95% confidence intervals (CI) adjusting for age and family history.

RESULTS

Minor alleles of rs2243250 (T) in IL4 (OR = 1.46, 95% CI 1.03-2.08, P-trend = 0.03), rs1800896 (G) in IL10 (OR = 0.77, 95% CI 0.61-0.96, P-trend = 0.02), rs2430561 (A) in IFNG (OR = 1.33, 95% CI 1.02-1.74; P-trend = 0.04), rs3747531 (C) in MSR1 (OR = 0.55, 95% CI 0.32-0.95; P-trend = 0.03), and possibly rs4073 (A) in IL8 (OR = 0.81, 95% CI 0.64-1.01, P-trend = 0.06) were associated with higher- (Gleason 7-10; N = 222), but not lower- (Gleason 2-6; N = 380) grade prostate cancer. In men with low PSA (<2 ng/mL), these higher-grade disease associations were attenuated and/or no longer significant, whereas associations with higher-grade disease were apparent for minor alleles of rs1800795 (C: OR = 0.70, 95% CI 0.51-0.94, P-trend = 0.02) and rs1800797 (A: OR = 0.72, 95% CI 0.53-0.98, P-trend = 0.04) in IL6. While some IL10 tagSNPs were associated with lower- and higher-grade prostate cancer, distributions of IL10 haplotypes did not differ, except possibly between higher-grade cases and controls among those with low PSA (P = 0.07). We did not observe an association between the studied SNPs and intraprostatic inflammation in the controls.

CONCLUSION

In the PCPT finasteride arm, variation in genes involved in the immune response, including possibly IL8 and IL10 as in the placebo arm, may be associated with prostate cancer, especially higher-grade disease, but not with intraprostatic inflammation. We cannot rule out PSA-associated detection bias or chance due to multiple testing.

A Common Interleukin-6 Promoter Polymorphism in Patients With Vulvar Cancer

OBJECTIVE

Besides its important role in immune response and inflammatory processes the cytokine interleukin-6 (IL-6) is crucially involved in carcinogenesis. A common polymorphism within the gene encoding IL-6 (IL6) is known to alter IL-6 protein expression and has been associated with patients' prognosis in various malignancies. No data are available with respect to vulvar cancer. Therefore, we determined the prognostic potential of the common -174(G-->C) single nucleotide polymorphism in the promoter region of IL6 in a series of patients with this disease.

METHODS

The IL6 promoter polymorphism was investigated in 81 Caucasian patients with surgically treated squamous cell vulvar cancer using pyrosequencing. Results were correlated with clinical data.

RESULTS

No association was ascertained between the IL6 promoter polymorphism and the investigated clinicopathologic parameters, ie, tumor stage, lymph node involvement, tumor grade, and patient's age at diagnosis. In an univariate analysis, lymph node involvement and patients' age at diagnosis were associated with patient prognosis. In a multivariate analysis, including tumor stage and lymph node involvement as established prognostic factors and the IL6 promoter polymorphism, lymph node involvement, and the presence of at least one mutant allele, but not tumor stage, were associated with increased disease-free and overall survival.

CONCLUSION

Our data suggest that the IL6 -174(G-->C) promoter polymorphism might serve as an additional prognostic parameter in patients with vulvar cancer.

An lnterleukin-6 Gene Promoter Polymorphism and Unexplained Late Intrauterine Fetal Death: A Multicenter Study

OBJECTIVE

Interleukin-6 (IL-6)-mediated inflammatory processes have been proposed to be involved in the pathogenesis of pregnancy-associated complications such as late unexplained intrauterine fetal death (IUFD). Therefore we determined whether a common guanine/cytosine polymorphism at position -174 of the promoter of the IL-6 gene (IL6) known to affect in vivo protein activity can serve as candidate gene for this condition.

METHODS

In a multicenter case-control study, we evaluated the IL6 promoter polymorphism by pyrosequencing in 92 women with IUFD. Ninety-four healthy women with at least one uncomplicated full-term pregnancy and no history of IUFD served as the control group.

RESULTS

No significant association was found between the presence of at least one mutant allele of the IL6 promoter polymorphism (P = .2; odds ratio = 1.5 [95% confidence interval, 0.8-2.7]) and the incidence of IUFD. In women with IUFD, the presence of at least one mutant allele of the IL6 promoter polymorphism did not influence timing of fetal death (33.9 [5.1] gestational weeks vs 34.1 [4.9] gestational weeks, P = .8) or birth weight (2055 [1119] g vs 1963 [992] g, P = .7).

CONCLUSION

To our knowledge, we are the first to report on a common polymorphism of the IL6 promoter gene in women with late IUFD. The investigated IL6 promoter polymorphism can not be seen as candidate gene for IUFD in Caucasian women.

Genetic markers: Potential candidates for cardiovascular disease

The effective prevention of cardiovascular disease depends upon the ability to recognize the high-risk individuals at an early stage of the disease or long before the development of adverse events. Evolving technologies in the fields of proteomics, metabolomics, and genomics have played a significant role in the discovery of cardiovascular biomarkers, but so far these methods have achieved the modest success. Hence, there is a crucial need for more reliable, suitable, and lasting diagnostic and therapeutic markers to screen the disease well in time to start the clinical aid to the patients. Gene polymorphisms associated with the cardiovascular disease play a decisive role in the disease onset. Therefore, the genetic marker evaluation to classify high-risk patients from low-risk patients trends an effective approach to patient management and care. Currently, there are no genetic markers available for extensive adoption as risk factors for coronary vascular disease, yet, there are numerous promising, biologically acceptable candidates. Many of these gene biomarkers, alone or in combination, can play an essential role in the prediction of cardiovascular risk. The present review highlights some putative emerging genetic biomarkers that could facilitate more authentic and fast diagnosis of CVD. This review also briefly describes few technological approaches employed in the biomarker search.

Association study of inflammatory genes with rheumatic heart disease in North Indian population: A multi-analytical approach

Rheumatic heart disease (RHD) is an inflammatory, autoimmune disease; occurring as a consequence of group A streptococcal infection complicated by rheumatic fever (RF). An inappropriate immune response is the central signature tune to the complex pathogenesis of RHD. However, some of those infected develop RHD, and genetic host susceptibility factors are thought to play a key role in diseasedevelopment. Therefore, the present study was designed to explore the role of genetic variants in inflammatory genes in conferring risk of RHD. The study recruited total of 700 subjects, including 400 RHD patients and 300 healthy controls. We examined the associations of 8 selected polymorphisms in seven inflammatory genes: IL-6 [rs1800795G/C], IL-10 [rs1800896G/A], TNF-A [rs1800629G/A], IL-1β [rs2853550C/T], IL-1VNTR [rs2234663], TGF-β1 [rs1800469C/T]; [rs1982073T/C], and CTLA-4 [rs5742909C/T] with RHD risk. Genotyping for all the polymorphisms was done using PCR-ARMS/PCR/RFLP methods. Multifactor dimensionality reduction and classification and regression tree approaches were combined with logistic regression to discover high-order gene-gene interactions in studiedgenes involved in RHD susceptibility.In univariate logistic regression analysis, we found significant association of variant-containing genotypes (CT&TT) of TGF-β1 869T/C [rs1982073]; [p=0.0.004 & 0.001, OR (95% CI)=1.65 (1.2-2.3) & 2.25 (1.4-3.6) respectively], variant genotype (CC) of IL-1β -511C/T [rs2853550]; [p=0.001, OR (95% CI)=2.33 (1.4-3.8)] and IL-1 VNTR [rs2234663]; [p=0.03, OR (95% CI)=5.25 (1.2-23.4)] SNPs with RHD risk. CART analysis revealed that individuals with the combined genotypes of TGF-β1T/C_ rs1982073 (CT/TT) and IL-1 β_ rs2853550 (CC) had significantly higher susceptibility for RHD [p=0.0005, OR (95% CI)=5.91 (2.9-12.5)]. In MDR analysis, TGF-β1 869T>C yielded the highest testing accuracy of 0.562. In conclusion, using multi-analytical approaches, our study revealed important role of TGF-β1 869T/C [rs1982073] in RHD susceptibility.

Genetic epidemiology of coronary artery disease: an Asian Indian perspective

Coronary artery disease (CAD) has emerged as a major cause of morbidity and mortality worldwide. Recent findings on the role of genetic factors in the aetiopathology of CAD have implicated novel genes and variants in addition to those involved in lipid and lipoprotein metabolism. However, our present knowledge is limited due to lack of clarity on their exact identity and the quantum of impact on disease susceptibility, and incident risk. It is a matter of great interest to understand the role of genetic factors in ethnic populations that have a strong underlying predisposition to CAD such as the South Asian populations, particularly among Asian Indians living in India and abroad. Although, a number of isolated studies do implicate certain gene polymorphisms towards enhanced disease susceptibility, the available data remains scanty and inconclusive as they have not been validated in large, prospective cohorts. The present review aims to consolidate the available literature on the genetics of CAD in Asian Indians and seeks to provide insights on the concerns that need to be addressed in future studies to generate information having clinical value.

Effects of NSAIDs on the risk factors of colorectal cancer: a mini review

Evidence from epidemiological and experimental studies has shown that non-steroidal anti-inflammatory drugs (NSAIDs) reduce the risk of colorectal cancer (CRC). The function of NSAIDs and the molecular targets for chemopreventive effects on CRC have been extensively studied and their data were reported. However, the relation between NSAIDs and the risk factors of CRC have not been fully elucidated yet. Thus, relations between NSAIDs and the risk factors of CRC, such as overweight and obesity, alcohol, aging, hypertriglyceridemia and smoking, are summarized with our data and with recent reported data in this review.

Significant impact of IL-6 -174G/C but inverse relation with -634 C/G polymorphism in patients with non-small cell lung cancer in Kashmiri population

To study the possible role of proinflammatory interleukin 6 -174 G>C (rs 1800795) and -634 C>G (rs 1800796) polymorphism in the pathogenesis of non-small cell lung cancer (NSCLC). A total of 190 NSCLC patients and 200 healthy controls were evaluated for polymorphic analysis of -174 G/C and -634 C/G by PCR-RFLP followed by DNA sequencing. A significant association was observed in the genotypic and allelic distribution of IL-6 -174 G/C in the NSCLC group as compared to control group [OR = 2.7 (1.77-4.11), p < 0.0001]. Smokers with the -174C allele were found to be significantly associated with NSCLC (p = 0.01), while 634C/G SNP showed an inverse relation [OR-0.4, p < 0.0001]. The present investigation revealed a significant association of the IL6 -174 G/C gene promoter polymorphism with NSCLC, and thus, the IL-6 -174G/C genotype can be considered as one of the biological markers in the etiology of NSCLC.

Shared genetic susceptibility of vascular-related biomarkers with ischemic and recurrent stroke

OBJECTIVE

To investigate the genetic contributors to cerebrovascular disease and variation in biomarkers of ischemic stroke.

METHODS

The Vitamin Intervention for Stroke Prevention Trial (VISP) was a randomized, controlled clinical trial of B vitamin supplementation to prevent recurrent stroke, myocardial infarction, or death. VISP collected baseline measures of C-reactive protein (CRP), fibrinogen, creatinine, prothrombin fragments F1+2, thrombin-antithrombin complex, and thrombomodulin prior to treatment initiation. Genome-wide association scans were conducted for these traits and follow-up replication analyses were performed.

RESULTS

We detected an association between CRP single nucleotide polymorphisms (SNPs) and circulating CRP levels (most associated SNP, rs2592902, p = 1.14 × 10(-9)) in 2,100 VISP participants. We discovered a novel association for CRP level in the AKR1D1 locus (rs2589998, p = 7.3 × 10(-8), approaching genome-wide significance) that also is an expression quantitative trait locus for CRP gene expression. We replicated previously identified associations of fibrinogen with SNPs in the FGB and LEPR loci. CRP-associated SNPs and CRP levels were significantly associated with risk of ischemic stroke and recurrent stroke in VISP as well as specific stroke subtypes in METASTROKE. Fibrinogen levels but not fibrinogen-associated SNPs were also found to be associated with recurrent stroke in VISP.

CONCLUSIONS

Our data identify a genetic contribution to inflammatory and hemostatic biomarkers in a stroke population. Additionally, our results suggest shared genetic contributions to circulating CRP levels measured poststroke and risk for incident and recurrent ischemic stroke. These data broaden our understanding of genetic contributors to biomarker variation and ischemic stroke risk, which should be useful in clinical risk evaluation.

PPARγ and IL-6 - 174G>C gene variants in Croatian patients with ischemic stroke

AIM

Etiology of ischemic stroke (IS) is multifactorial and includes interaction of genetic and environmental factors. Different genes, their polymorphisms, host susceptibility, and inflammation processes play a role in IS development. The aim of this study was to evaluate the effect of PPAR-γ and IL-6 gene variants on IS onset.

MATERIAL AND METHODS

A total of 301 subjects (144 males, 157 females) participated in the study, 114 patients with IS and 187 healthy controls.

RESULTS

Statistically significant predictors of IS were male gender (OR 7.13, 95% CI 2.92-17.39, p<0.001), hypertension (OR 7.82. 95% CI 2.53-24.19, p<0.001), lowered HDL cholesterol (OR 8.20, 95% CI 2.41-27.94, p=0.001), elevated C-reactive protein (OR 5.26, 95% CI 1.92-14.41) and IL-6 -174 GC (OR 2.44 95% CI 1.01-5.91, p=0.0048) genotype. Males, compared to females, had 7 times higher odds for stroke. IL6 -174G/C genotype increased the odds for IS for 2.4 times. PPARγ was not statistically significantly associated with stroke.

CONCLUSION

We can point to the IL-6 -174G>C polymorphisms as candidate gene marker and risk factor for the prediction of ischemic stroke.

Single nucleotide polymorphisms in interleukin-6 and their association with venous thromboembolism

The aim of the present study was to reveal the contribution of single nucleotide polymorphisms of the interleukin‑6 (IL‑6) gene and the progression of venous thromboembolism (VTE). A case‑control study composed of 246 VTE patients, including 160 from the Han population (76 males and 84 females, mean age 57.41±13.25 years), 86 from the Uyghur population (41 males and 45 females, mean age 51.61±13.73 years) and 292 gender and ethnicity‑matched control participants, including 170 from the Han population (91 males and 79 females, mean age 55.82±11.83 years) and 122 from the Uyghur population (64 males and 58 females, mean age 53.52±13.64 years) were enrolled in the present study. The results demonstrated that the serum levels of IL‑6, C‑reactive protein (CRP), D‑dimer, fibrinogen, plasminogen activator inhibitor‑1 and leptin were significantly higher in the VTE group compared with the control group (P<0.05). The frequencies of the ‑572C/G promoter polymorphisms of the IL‑6 genotypes CC, CG and GG were identified to be 34, 48 and 18% in the Han population and 33, 47 and 20% in the Uyghur population, respectively. The allele frequency distributions of the C and G alleles were 58 and 42% in the Han population and 56 and 43% in the Uyghur population, respectively. Significant differences were identified in the ‑572C/G promoter polymorphisms between the VTE group and the control group (P<0.05). For the ‑597G/A polymorphism, all individuals carried the GG and GA genotype; AA genotypes were not detected. Logistic regression analysis was used to identify the risk factors for VTE, adjusting by confounding factors, the results of which demonstrated that the CC homozygote of the IL‑6 ‑572G/C, CRP, IL‑6 and high‑density lipoprotein‑cholesterol were independent risk factors of VTE (P<0.05). In conclusion, the ‑572G/C genotype of IL‑6 may be a genetic marker of VTE in the Han and Uyghur populations.

Detection of pleiotropy through a Phenome-wide association study (PheWAS) of epidemiologic data as part of the Environmental Architecture for Genes Linked to Environment (EAGLE) study

We performed a Phenome-wide association study (PheWAS) utilizing diverse genotypic and phenotypic data existing across multiple populations in the National Health and Nutrition Examination Surveys (NHANES), conducted by the Centers for Disease Control and Prevention (CDC), and accessed by the Epidemiological Architecture for Genes Linked to Environment (EAGLE) study. We calculated comprehensive tests of association in Genetic NHANES using 80 SNPs and 1,008 phenotypes (grouped into 184 phenotype classes), stratified by race-ethnicity. Genetic NHANES includes three surveys (NHANES III, 1999-2000, and 2001-2002) and three race-ethnicities: non-Hispanic whites (n = 6,634), non-Hispanic blacks (n = 3,458), and Mexican Americans (n = 3,950). We identified 69 PheWAS associations replicating across surveys for the same SNP, phenotype-class, direction of effect, and race-ethnicity at p<0.01, allele frequency >0.01, and sample size >200. Of these 69 PheWAS associations, 39 replicated previously reported SNP-phenotype associations, 9 were related to previously reported associations, and 21 were novel associations. Fourteen results had the same direction of effect across more than one race-ethnicity: one result was novel, 11 replicated previously reported associations, and two were related to previously reported results. Thirteen SNPs showed evidence of pleiotropy. We further explored results with gene-based biological networks, contrasting the direction of effect for pleiotropic associations across phenotypes. One PheWAS result was ABCG2 missense SNP rs2231142, associated with uric acid levels in both non-Hispanic whites and Mexican Americans, protoporphyrin levels in non-Hispanic whites and Mexican Americans, and blood pressure levels in Mexican Americans. Another example was SNP rs1800588 near LIPC, significantly associated with the novel phenotypes of folate levels (Mexican Americans), vitamin E levels (non-Hispanic whites) and triglyceride levels (non-Hispanic whites), and replication for cholesterol levels. The results of this PheWAS show the utility of this approach for exposing more of the complex genetic architecture underlying multiple traits, through generating novel hypotheses for future research.

Human interleukin-27: wide individual variation in plasma levels and complex inter-relationships with interleukin-17A

Although it is widely believed that interleukin (IL)-27 is anti-inflammatory, its role in controlling human immune responses is not fully established. In particular, its interactions with T helper type 17 (Th)17 cytokines are unclear. Our aims were to establish the relationships between IL-27 and proinflammatory cytokines, including IL-17A, in human sera and cultures of peripheral blood mononuclear cells. Plasma IL-27 levels in 879 healthy humans from 163 families varied widely, but with relatively low heritability (19%). Despite IL-27 including a subunit encoded by Epstein-Barr virus-induced gene 3 (EBI3), there was no correlation of levels with serological evidence of infection with the virus. Although IL-27 has been reported to inhibit IL-17A production, we demonstrated a strong positive correlation in sera, but lower correlations of IL-27 with other proinflammatory cytokines. We verified that IL-27 inhibited IL-17A production by human peripheral blood T cells in vitro, but not that it stimulated IL-10 secretion. Importantly, addition of IL-17A decreased IL-27 production by stimulated T cells but had the opposite effect on resting T cells. Together, these data suggest a model whereby IL-27 and IL-17A exerts complex reciprocal effects to boost inflammatory responses, but restrain resting cells to prevent inappropriate activation.

[Genetic polymorphisms and lung cancer risk: a case-control study]

BACKGROUND AND OBJECTIVE

The smoke fume, principal factor in the development of lung cancer, causes the expression of certain cytokines, including interleukin 4, 6, 8 and 10, which may act by inhibiting apoptosis and interfere cellular repair mechanisms and angiogenesis. To determine the possible relationship between gene polymorphisms of these cytokines and lung cancer.

PATIENTS AND METHOD

To achieve this objective we designed a case-control study, which included 400 patients who had come to the consultation for rapid diagnosis of lung cancer at the Pneumology Department, University Hospital of Salamanca, and whose main criterion exclusion was the lack of active contact with smoke fume. Patients were divided into 2 groups, each consisting of 200 patients: cases (patients diagnosed with lung cancer) and controls (patients without lung cancer).

RESULTS

A percentage of 62.8 of men were former smokers at diagnosis compared with 55.5% of women, although the former still had a greater cumulative consumption. Squamous cell carcinoma predominated in diagnosis (48.9% of patients) and more than half were in advanced stages (28.5% in stage iiiB and 25.5% in stage iv). No statistical significance was observed by linking the existence of tumor to the prevalence of any of the analyzed polymorphisms.

CONCLUSIONS

Polymorphisms in the study did not modify the risk of developing lung cancer.

Variants in C-reactive protein and IL-6 genes and susceptibility to obstructive sleep apnea in children: a candidate-gene association study in European American and Southeast European populations

BACKGROUND

Preliminary evidence indicates that variants of the C-reactive protein (CRP) and IL-6 genes might be associated with the presence of obstructive sleep apnea (OSA) in childhood. Thus a candidate-gene association study was conducted to investigate the association of four variants of the CRP gene (1444C/T, -717T/C, 1861C/T, and 1919A/T) and two variants of the IL-6 gene (-174G/C and 597G/A) with OSA in a cohort of European American and Greek children.

METHODS

The genetic risk effects were estimated based on the odds ratio (OR) of the allele contrast and the generalized odds ratio (ORG), which is a model-free approach. The mode of inheritance was assessed using the degree of dominance index. The impact of haplotypes was also examined.

RESULTS

In the American population, the allele contrast and the model-free approach produced significant ORs for the CRP 1444C/T variant (OR, 3.82 [95% confidence interval {CI}, 1.91-7.63] and ORG, 4.37 [95% CI, 1.96-9.76]), respectively, and the mode of inheritance was recessiveness of allele T. Significance was also shown for the CRP 1919A/T variant (OR, 2.45 [95% CI, 1.23-4.85] and ORG, 2.76 [95% CI, 1.26-6.03]) with the mode of inheritance being nondominance of allele T. For the IL-6-174G/C variant, there was an indication of recessiveness of allele C. Finally, the IL-6-174C/IL-6 597A haplotype was associated with OSA. In the Greek population, no association was detected for any variant or haplotype.

CONCLUSIONS

Genetic variation in the IL-6/CRP pathway was associated with increased risk for OSA in European American children and may account for the higher CRP levels in the context of pediatric OSA compared to Greek children.

Association of interleukin-6 gene promoter polymorphism with coronary artery disease in Pakistani families

Interleukin-6 (IL-6) is a well-known inflammatory cytokine and suggested to be involved in the development of coronary artery disease (CAD). IL-6 gene expression has been investigated with controversy in CAD patients. This study investigates the association of the IL-6 gene expression with CAD, the molecular basis for the regulation of interleukin-6 expression in a Pakistani population. Our data show that the serum IL-6 levels were increased in patients with CAD compared with healthy controls and that the IL-6 gene polymorphism at -174 was more prevalent in CAD cases. There was a statistically significant association between the IL-6 gene polymorphism and CAD, which may be associated with an increased risk for the disease. Moreover, circulating IL-6 and hs-CRP levels were significantly higher in patients with CC genotype (P < 0.0001 and P < 0.0001, resp.). In a binary logistic-regression model, an independent association was found between CAD and increased serum IL-6 and hs-CRP levels and -174G>C polymorphism. This is the first report on the IL-6 expression and the IL-6 gene polymorphism in patients with CAD from Pakistan, and hence it highlights a novel risk factor for the disease.

The role of Interleukin-6, its -174 G>C polymorphism and C-reactive protein in idiopathic cardiac arrhythmias in children

ABSTRACT Purpose: Knowledge about the role of inflammation in the pathogenesis of arrhythmias in children is limited. Several studies have suggested a relationship between plasma IL-6 levels and/or the -174G>C IL-6 gene polymorphism and atrial fibrillation in adults. Our present study was performed to investigate whether serum IL-6, -174G>C IL-6 polymorphism and C-reactive protein (CRP) are associated with arrhythmias of unknown origin in children.

METHODS

The study included 126 children diagnosed with supraventricular or ventricular arrhythmia. Patients with congenital heart defects as well as arrhythmias of known origin were excluded from the study. The control group comprised 37 healthy children. The 24 hour Holter electrocardiography monitoring was performed. Serum IL-6, -174 GC IL-6 polymorphism and CRP concentrations were measured on admission.

RESULTS

There were no differences in IL-6, CRP and -174 G>C IL-6 genotype distribution between the control and patient groups. No significant differences in IL-6, CRP and -174 G>C IL-6 genotypes were observed between children with supraventricular or ventricular arrhythmias. The severity of arrhythmias showed also no associations with IL-6, CRP or -174 G>C IL-6 genotypes.

CONCLUSION

The results suggest that idiopathic cardiac arrhythmias of unknown origin in children are not associated with selected pro-inflammatory markers of infections i.e. elevated IL-6, CRP or -174 G>C IL-6 polymorphism. This new information can effectively reduce the total financial cost of unnecessary diagnosis and treatment of children affected by cardiac arrhythmias.

The interleukin-6 -147 g/c polymorphism is associated with increased risk of coronary artery disease in young South African Indian men

BACKGROUND

Interleukin-6 (IL-6) is a proinflammatory cytokine involved in the pathogenesis of chronic inflammatory diseases such as coronary artery disease (CAD). The -174 IL-6 G/C promoter polymorphism influences mRNA levels and protein expression and is implicated in CAD. The Indian population in South Africa, unlike the black community, has a high prevalence of premature CAD. This polymorphism has not been fully explored in this population. The present study assessed the -174 IL-6 G/C polymorphism in young Indian patients with angiographically documented CAD and compared them with age- and gender-matched Indian and black control subjects.

METHODS

Polymorphic variants were assessed by polymerase chain reaction-restriction fragment length polymorphism, and IL-6 levels were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

The -174 IL-6 C allele was found with a higher frequency (23%) in the total Indian group compared to 2% in the black participants [P<0.0001, odds ratio (OR)=0.05, 95% confidence interval (CI) 0.018-0.14). The difference in frequency was more pronounced when Indian controls were compared to black controls (29% vs. 2%, respectively) (P<0.0001, OR=0.05, 95% CI 0.02-0.17). A significant association between the -174 IL-6 G allele and CAD was found in Indian patients compared to Indian controls (84% in cases vs. 71% in Indian controls; P=0.043, OR=0.47 95% CI 0.23-0.95). Levels of IL-6 in circulation were higher in black controls (6.62±0.63 pg/mL) compared to Indian controls (2.51±0.57 pg/mL) and CAD patients (1.46±0.36 pg/mL) (P<0.0001). Levels of IL-6 were higher in all groups with homozygous -174 IL-6 C alleles, but only significant in the healthy Indian control group (GG 3.73±0.94 pg/mL vs. GC/CC 0.89±0.5 pg/mL, P=0.0001).

CONCLUSION

The presence of the IL-6 -174 G allele influences levels of IL-6 and increases the risk of CAD in South African Indians.

The association of IL-6 and IL-6R gene polymorphisms with chronic periodontitis in a Chinese population

OBJECTIVE

The aim of our investigation is to reveal the association of interleukin-6 (IL-6) and interleukin-6 receptor (IL-6R) gene polymorphisms with chronic periodontitis in Northwestern Chinese Han Population.

MATERIAL AND METHODS

A case-control study of 199 cases of chronic periodontitis patients and 216 healthy controls was performed. Genomic DNA was isolated from whole venous blood, and four single nucleotide polymorphisms (IL-6 -572 G/C and -1363 G/T, IL-6R -183 G/A and +48892 A/C) were analysed using polymerase chain reaction, followed by restriction fragment length polymorphism analysis and sequencing methods.

RESULTS

Our SNP analyses showed that the distribution of the IL-6 -572 G/C and IL-6R -183 G/A polymorphisms did not differ between patients and controls. The frequency of the IL-6 -1363 G/T genotype GG was significantly increased chronic periodontitis cases (P = 0.023, odds ratio (OR) = 2.825 adjusted for gender and age.) The IL-6R +48892 A/C polymorphisms genotype CC was found to be protective against chronic periodontitis (P = 0.004, OR = 0.318 adjusted for gender and age.). In addition, compared with the other haplotypes, haplotype A(+48892) A(-183) was significantly associated with chronic periodontitis, with an odds ratio of 0.720 (P = 0.0235).

CONCLUSION

Our results suggest that the IL-6 -1363 G/T and IL-6R +48892 A/C polymorphisms may contribute to genetic susceptibility to chronic periodontitis in Northwestern Chinese Han population.

The -174G/C variant of IL6 as risk factor for mortality and technique failure in a large cohort of peritoneal dialysis patients

BACKGROUND

Functional variants in the IL6 gene, in particular the -174G/C polymorphism (rs1800795), affect the mortality risk in dialysis patients. Peritoneal dialysis (PD) patients harbouring the C allele of the -174G/C polymorphism of IL6 showed faster peritoneal transport. The aim of this study was to investigate this IL6 variant as risk factor for mortality and technique failure in a large cohort of Caucasian PD patients.

METHODS

A Dutch multicentre cohort of 398 incident PD patients (NECOSAD) was analysed. Survival analysis was performed for death and technique failure with a maximum follow-up of 5 years. A combined PD cohort from Amsterdam (Academic Medical Center, N = 71) and Brussels (Université catholique de Louvain Medical School, N = 102) was used for independent replication.

RESULTS

In NECOSAD, 105 patients died on dialysis [incidence rate 10.3/100 person-years (py)], and 138 patients experienced technique failure (16.2/100 py), with peritonitis as important cause. Patients with the C/C genotype had a 71% increased mortality risk compared to patients with the G/G genotype (95% confidence interval 0.98-2.98); this effect was mainly a long-term effect: a 2.7-fold increased mortality risk was found in patients having survived 2 years since the start on dialysis, and a 1.7-fold increased risk for the combined end point (mortality or technique failure). In the combined replication cohort, no increased risks were found in patients with the C/C genotype.

CONCLUSIONS

The C/C genotype of the -174G/C polymorphism was associated with an increased mortality risk in 398 Dutch incident PD patients. The existence of substantial differences between the two academic replication cohorts and the discovery cohort from NECOSAD and the limited power of these cohorts prevented an independent replication of the NECOSAD findings.

Plasma concentrations but not serum concentrations of brain-derived neurotrophic factor are related to pro-inflammatory cytokines in patients undergoing major abdominal surgery

OBJECTIVES

To investigate peripheral brain-derived neurotrophic factor (BDNF) concentrations in the perioperative period, their relationship with transforming growth factor-β1 (TGF-β1 tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-6 genetics.

DESIGN AND METHODS

Prospective, observational study. BDNF, TGF-β1, IL-6 and TNF-α were analysed at baseline (T0), 5 h (T1), 24 h (T2) and 5 days (T3) after surgery, in 21 patients. The IL-6 -174 G/C polymorphism was genotyped.

RESULTS

Serum BDNF concentrations decreased (P=0.048), correlated with TGF-β1 (r=0.610 at T1, r=0.493 at T2, r=0.554 at T3). Plasma BDNF concentrations raised (P=0.049), correlated with IL-6 and TNF-α at T1 (r=0.495 and r=0.441, respectively). BDNF response was predictable from TNF-α and IL-6 concentrations and the IL-6 -174 G/C genotype.

CONCLUSION

Serum and plasma BDNF concentrations could relate to platelet activation and inflammatory response, respectively. IL-6 genetics played a role in the BDNF acute response.

Acute phase inflammatory markers in patients with non-steroidal anti-inflammatory drugs (NSAIDs)-induced acute urticaria/angioedema and after aspirin challenge

BACKGROUND

Active chronic urticaria, identified as a mast cell- and basophil-dependent inflammatory disorder of the skin is able to elicit acute phase response (APR). However, systemic inflammatory response in different types of urticaria is poorly characterized.

AIM

To determine APR pattern in a clearly defined group of patients with acute urticaria and/or angioedema - induced by NSAIDs.

METHODS

Plasma IL-6 and serum C-reactive protein (CRP) concentrations were studied in 17 patients with NSAIDs-induced acute urticaria/angioedema (NSAIDsAU) and in 20 healthy controls. Eleven patients who used NSAIDs were presented at the emergency room with acute urticaria/angioedema while the remaining six manifested the symptoms during the aspirin challenge test. Patients were examined in a dynamic manner: during the acute phase, and next, after subsidence of the symptoms.

RESULTS

CRP and IL-6 concentrations increased significantly in patients with NSAIDsAU as compared with their asymptomatic period and the healthy subjects. In addition, NSAIDsAU patients showed elevated concentration of the biomarkers following aspirin provocation with the baseline values recovered in the asymptomatic period.

CONCLUSION

These results indicate that an acute systemic inflammatory response is activated in patients with NSAIDs-induced urticaria and/or angioedema. The study supports the evidence proving that up-regulation of CRP and IL-6 in urticaria/angioedema does not necessarily reflect any concomitant infection or other inflammatory processes, but may be due to the disease itself.

C-reactive protein induces interleukin-6 and thrombospondin-1 protein and mRNA expression through activation of nuclear factor-ĸB in HK-2 cells

BACKGROUND

Although C-reactive protein (CRP) is significantly increased in patients with diabetic nephropathy, whether CRP exerts direct proinflammatory effects on human renal tubular epithelial cells (HK-2 cells) is still unclear.

METHODS

HK-2 cells were incubated with purified CRP at clinically relevant concentrations (0, 5, 10, 20 and 40 μg/ml). The protein and transcript levels of thrombospondin-1 (TSP-1) and interleukin-6 (IL-6) were determined by ELISA and RT-PCR. Phosphorylation of p38MAPK was investigated through Western blot analysis in HK-2 cells induced by CRP. The activation of nuclear factor-kappa B (NF-κB) was studied via EMSA. A specific p38MAPK inhibitor (SB203580) and an NF-κB inhibitor (PDTC; pyrrolidine dithiocarbamate) were used to analyze the signal transduction in CRP induction. To explore the direct or indirect role of CRP in HK-2 cells, IL-6 or TSP-1 antibodies were used. The expression of IL-6, TSP-1 and transforming growth factor-β(1 )(TGF-β(1)) were determined through Western blot analysis in HK-2 cells.

RESULTS

In HK-2 cells, purified CRP significantly induced protein release and mRNA expression of IL-6 and TSP-1 in a dose- and time-dependent manner. TGF-β(1) protein was overexpressed in HK-2 cells induced by CRP, which cannot be inhibited by IL-6 or TSP-1 antibodies. CRP triggered phosphorylation of p38MAPK and activation of NF-κB-mediated signal transduction. SB203580 (5 μM) and PDTC (50 μM) efficiently suppressed those effects of CRP in HK-2 cells.

CONCLUSIONS

CRP induces IL-6 and TSP-1 protein release and mRNA expression from HK-2 cells via activation of the p38MAPK and NF-κB signaling pathways and TGF-β(1) was highly expressed in HK-2 cells, suggesting that CRP plays an important role in the propagation and prolongation of inflammation in renal fibrosis.

Acute-phase response in chronic urticaria

The patterns of acute-phase response (APR) biomarkers differ upon various inflammatory conditions. Little information is available on the systemic inflammatory response in urticaria/angio-oedema. It has been shown that concentrations of circulating APR biomarkers, IL-6 and C-reactive protein (CRP), are elevated more in severe chronic urticaria (CU) than in patients showing milder urticarial symptoms. It is not clear whether the increase of IL-6 and CRP is merely an epiphenomenon or may contribute to the pathogenesis of CU. It is tempting to speculate that mediators of APR may enhance urticarial inflammation. In addition, there is some association between APR and activation of coagulation/fibrinolysis in CU. It is well known that even slight elevation in CRP baseline concentration is enough to produce significant increase in cardiovascular risk. In this light, one should ask whether CU patients, in particular those showing stronger systemic inflammatory response and long-lasting course are more vulnerable to the cardiovascular events. Apart from highly troublesome symptoms and low quality of life, CU may then involve some remote, serious systemic consequences. Taken together, CU can be identified as a mast cell- and basophil-dependent inflammatory disorder of the skin, which is accompanied by APR. Characterization of APR in CU may appear essential for an insight into the activity of this disease and for assessment of the inflammation degree. Moreover, measurement of these biomarkers might be particularly relevant while assessing CU patients demanding an anti-inflammatory or immunosuppressive therapy. This review summarizes information regarding APR in the course of urticaria/angio-oedema.

Associations between inflammatory markers, candidate polymorphisms and physical performance in older Danish twins

Inflammation may play an essential role in the decline of physical performance. In this study we investigated the associations between inflammatory markers, candidate polymorphisms and physical performance in elderly people. Plasma levels of TNF-α, IL-6, CRP, fibrinogen, sICAM-1 and candidate polymorphisms were measured in 600 twin individuals aged 73 years and older participating in the Longitudinal Study of Aging Danish Twins. Physical performance was assessed using a self-reported measure. The inclusion of twins allowed both traditional and within-twin-pair analysis which permitted control for shared environment and genetic factors. Higher levels of inflammatory markers were generally associated with a lower level of physical performance. The TNFα-238G/A polymorphism was significantly associated with physical performance in men, with A allele carriers having significantly better performance than GG homozygotes. However, this gene variation seems to have only a minor role in explaining the associations between the levels of inflammatory markers and physical performance. When using twin pair analysis to test whether genetic factors in general account for this association, results showed that the association between the level of fibrinogen and physical performance could be caused by genetic factors. Also the association between the level of TNF-α and physical performance in males could be caused by genetic factors. However, other gene variations than the candidate gene polymorphisms studied here seem to explain the major part of the genetic proportion of this association.

Study of C-reactive protein and myocardial infarction in the Indian population

To analyse the association of high sensitivity C-reactive (hsCRP) protein levels and -717A/G single nucleotide polymorphism of CRP with acute myocardial infarction (AMI) in the Indian population. Study population included 100 MI cases wherein 32 patients had experienced previous MI (MI-Group-1), 68 MI cases were recruited at presentation (MI-Group-2) and equal number of age and gender matched healthy individuals. hsCRP levels were determined by ELISA and genotyping of -717A/G was carried out by polymerase chain reaction-based restriction digestion method. The -717A/G genotypes did not influence hsCRP level and their distribution did not differ between groups. However, in the present study hsCRP demonstrated significant correlation with BMI in controls of both the genders and with triglycerides in females of AMI at presentation who otherwise are with low risk profile. Identifying traditional risk factors associated with inflammation may help in controlling the acute event.