Interleukin-6 gene -174g>c and -572g>c promoter polymorphisms are strong predictors of plasma interleukin-6 levels after coronary artery bypass surgery

Frequency of Tumor Necrosis Factor-α, Interleukin-6, and Interleukin-10 Gene Polymorphisms in Mexican Patients with Diabetic Retinopathy and Diabetic Kidney Disease

BACKGROUND/OBJECTIVES

Two of the microvascular complications in type 2 diabetes (T2D) are diabetic retinopathy (DR), which is the most common cause of non-traumatic blindness, and diabetic kidney disease (DKD); the latter generally requires renal replacement therapy. The aim of the present study was to determine the frequency of polymorphisms of Tumor Necrosis Factor-α, interleukin-6, and interleukin-10 (TNF-α, IL-10, and IL-6), as well as to describe the clinical and laboratory characteristics of T2D association with these microvascular complications.

METHODS

This study included 203 patients with T2D, of which 102 had microvascular complications: 95 with DR, 50 with DKD, and 15 with diabetic neuropathy (the latter were not included in the statistical analysis); those with T2D without confirmed microvascular complications were considered as controls. Clinical and laboratory data were collected from the patient's medical records. Polymorphism typing of TNF-α rs361525 and rs1800629 and IL-10 rs1800872 and rs1800871 were obtained using MALDI-TOF MS. IL-10 rs1800896 and IL-6 rs1800795 were typed using a quantitative real-time polymerase chain reaction.

RESULTS

The results of age, HbA1c, fasting glucose, and arterial hypertension are significantly associated in every group. The TNF-α rs1800629A allele and TNF-α rs1800629G/A genotype were associated with microvascular complications and DR. For IL-10-rs1800896, all the models were associated in DKD. The TNF-α rs361525-rs1800629GA haplotype was associated with microvascular complications and DR, while the IL-10 haplotype, rs1800872-rs1800871-rs1800896 GGC, showed susceptibility in every group.

CONCLUSIONS

Our results show the contributions of the variants of these cytokines to these microvascular complications, but more studies are required to reach relevant conclusions.

Strategies to attenuate maladaptive inflammatory response associated with cardiopulmonary bypass

Cardiopulmonary bypass (CPB) initiates an intense inflammatory response due to various factors: conversion from pulsatile to laminar flow, cold cardioplegia, surgical trauma, endotoxemia, ischemia-reperfusion injury, oxidative stress, hypothermia, and contact activation of cells by the extracorporeal circuit. Redundant and overlapping inflammatory cascades amplify the initial response to produce a systemic inflammatory response, heightened by coincident activation of coagulation and fibrinolytic pathways. When unchecked, this inflammatory response can become maladaptive and lead to serious postoperative complications. Concerted research efforts have been made to identify technical refinements and pharmacologic interventions that appropriately attenuate the inflammatory response and ultimately translate to improved clinical outcomes. Surface modification of the extracorporeal circuit to increase biocompatibility, miniaturized circuits with sheer resistance, filtration techniques, and minimally invasive approaches have improved clinical outcomes in specific populations. Pharmacologic adjuncts, including aprotinin, steroids, monoclonal antibodies, and free radical scavengers, show real promise. A multimodal approach incorporating technical, circuit-specific, and pharmacologic strategies will likely yield maximal clinical benefit.

The Interleukin-6 gene variants may protect against SARS-CoV-2 infection and the severity of COVID-19: a case-control study in a Moroccan population

The symptoms of SARS-CoV-2 infection vary widely, ranging from asymptomatic cases to severe forms marked by acute respiratory distress syndrome, multi-organ damage, and fatalities. Studies indicate a correlation between specific genes and susceptibility to SARS-CoV-2 infection and disease severity, particularly involving variants in genes linked to inflammation and immune responses. The objective of this study is to investigate the association between rs1800795 (- 174 G > C) and rs1800797 (- 597 A > G) variants in the interleukin-6 (IL-6) promoter region and susceptibility to SARS-CoV-2 infection. Additionally, we aim to explore their correlation with COVID-19 severity in a Moroccan population. In this case-control study, we enrolled 270 unvaccinated COVID-19 patients, consisting of 132 with severe COVID-19 and 138 with asymptomatic-moderate COVID-19. Additionally, we included 339 SARS-CoV-2-negative group. Genotyping of rs1800795 and rs1800797 polymorphisms of the IL-6 gene was performed using predesigned TaqMan SNP genotyping. The median age of SARS-CoV-2-negative controls was 50 years, while severe COVID-19 cases exhibited a median age of 61 years. Additionally, individuals with asymptomatic to moderate COVID-19 had a median age of 36 years. We observed a significant age difference between severe and mild COVID-19 patients (p < 0.0001), and an association was noted between gender and the severity of COVID-19 (p = 0.011). The allele and genotype frequencies of the IL-6 - 597G > A and - 174G > C variants did not show significant associations with susceptibility to SARS-CoV-2 infection (p > 0.05). However, further analysis revealed that the linkage disequilibrium between rs1800797 and rs1800795 indicated that individuals with the GC* haplotype (OR = 0.04, 95% CI 0.01-0.30, p = 0.001) and AG* haplotype (OR = 0.11, 95% CI 0.03-0.46, p = 0.002) were significantly associated with protection against SARS-CoV-2 infection. Moreover, in the overdominant model, the IL-6 - 174 G/C genotype was found to be protective against the development of severe disease compared to those with the G/G-C/C genotypes (p = 0.03; OR = 0.41, 95% CI 0.18-0.96). However, correlations between complete blood count markers, hematological markers, D-dimer, C-reactive protein, and ferritin levels according to - 597 A > G and - 174G > C genotypes showed no significant differences (all p > 0.05). Our findings provide valuable insights into the pathogenesis of COVID-19, suggesting that genetic variations at the IL-6 gene may contribute to the susceptibility to severe SARS-CoV-2 infection within the Moroccan population.

Determination of IL-6 Gene Promoter Polymorphism in Patients with Hepatitis C and Its Impact on RNA Secondary Structure

Background and Objectives: A polymorphism in the promoter region of the IL-6 gene would influence the level of IL-6 expression in patients with HCV, resulting in a pro-inflammatory response. Few studies have shown the association between -174G>C (rs1800795) and -1363G>T (rs2069827) polymorphisms and HCV infection, and their results have been contradictory. There are no data published in our population to study such an IL-6 stimulus against HCV infection and its impact on RNA secondary structure. Therefore, we isolated human subjects from the province of Punjab, Pakistan. The objective was to screen for IL-6 gene promoter polymorphisms -174G/C and -1363G/T and those correlated with serum concentrations of IL-6 in patients with HCV and compared with a control. Materials and Methods: In conventional PCR, measurement of serum IL-6 by CLIA and statistical analysis were performed to observe the genotype association studies. By integrating bioinformatics and computational tools, our study aimed to provide a comprehensive understanding of how variations in the promoter region of IL-6 may have functional implications on gene expression. Results: The -174G>C and -1363G>T genotypes in the promoter region of patients with HCV were in strong allelic association (Δ = 0.97, p < 0.001). Interestingly, the bioinformatics analysis was well aligned with our experimental data. Conclusions: Based on the data, it can be inferred that IL-6 gene promoter polymorphisms are important in the dysregulation of IL-6 levels in patients with HCV.

Host Genetic Impact on Infectious Diseases among Different Ethnic Groups

Infectious diseases such as malaria, tuberculosis (TB), human immunodeficiency virus (HIV), and the coronavirus disease of 2019 (COVID-19) are problematic globally, with high prevalence particularly in Africa, attributing to most of the death rates. There have been immense efforts toward developing effective preventative and therapeutic strategies for these pathogens globally, however, some remain uncured. Disease susceptibility and progression for malaria, TB, HIV, and COVID-19 vary among individuals and are attributed to precautionary measures, environment, host, and pathogen genetics. While studying individuals with similar attributes, it is suggested that host genetics contributes to most of an individual's susceptibility to disease. Several host genes are identified to associate with these pathogens. Interestingly, many of these genes and polymorphisms are common across diseases. This paper analyzes genes and genetic variations within host genes associated with HIV, TB, malaria, and COVID-19 among different ethnic groups. The differences in host-pathogen interaction among these groups, particularly of Caucasian and African descent, and which gene polymorphisms are prevalent in an African population that possesses protection or risk to disease are reviewed. The information in this review could potentially help develop personalized treatment that could effectively combat the high disease burden in Africa.

Cerebral Aneurysm and Interleukin-6: a Key Player in Aneurysm Generation and Rupture or Just One of the Multiple Factors?

Intracranial aneurysm (IA) rupture is a common cause of subarachnoid hemorrhage (SAH) with high mortality and morbidity. Inflammatory interleukins (IL), such as IL-6, play an important role in the occurrence and rupture of IA causing SAH. With this review we aim to elucidate the specific role of IL-6 in aneurysm formation and rupture in preclinical and clinical studies. IL-6 is a novel cytokine in that it has pro-inflammatory and anti-inflammatory signaling pathways. In preclinical and clinical studies of IA formation, elevated and reduced levels of IL-6 are reported. Poor post-rupture prognosis and increased rupture risk, however, are associated with higher levels of IL-6. By better understanding the relationships between IL-6 and IA formation and rupture, IL-6 may serve as a biomarker in high-risk populations. Furthermore, by better understanding the IL-6 signaling mechanisms in IA formation and rupture, IL-6 may optimize surveillance and treatment strategies. This review examines the association between IL-6 and IA, while also suggesting future research directions.

Increased Frequencies of the ‒174G and ‒572C IL6 Alleles in Populations of Indigenous Peoples of Siberia Compared to Russians

Abstract-The study of immune response and inflammation gene polymorphisms in a genogeographic context is relevant in the study of human populations. Here, in the indigenous populations of Siberia the frequencies of polymorphic variants ‒174G/C (rs1800795) and ‒572C/G (rs1800796) of the IL6 gene encoding the proinflammatory cytokine IL-6 were determined. For the first time, it was shown that the frequencies of the ‒174G and ‒572C alleles, which determine increased inflammatory response and are also associated with several diseases were statistically significantly higher in ethnic groups of Buryats, Teleuts, Yakuts, Dolgans and Tuvinians than in Russians living in Siberia. These values were in the intermediate position between those in the European and East-Asian groups. We hypothesize an adaptive role of these IL6 genetic variants in human settlement from Africa to the Eurasian continent. However, due to the departure from the traditional way of life and the increasing anthropogenic environmental pollution, the risk of diseases whose pathogenesis is based on inflammation in indigenous Siberian populations is likely increased.

An interleukin 6-based genetic risk score strengthened with interleukin 10 polymorphisms associated with long-term kidney allograft outcomes

Of all kidney transplants, half are still lost in the first decade after transplantation. Here, using genetics, we probed whether interleukin 6 (IL-6) could be a target in kidney transplantation to improve graft survival. Additionally, we investigated if a genetic risk score (GRS) based on IL6 and IL10 variants could improve prognostication of graft loss. In a prospective cohort study, DNA of 1271 donor-recipient kidney transplant pairs was analyzed for the presence of IL6, IL6R, IL10, IL10RA, and IL10RB variants. These polymorphisms and their GRS were then associated with 15-year death-censored allograft survival. The C|C-genotype of the IL6 polymorphism in donor kidneys and the combined C|C-genotype in donor-recipient pairs were both associated with a reduced risk of graft loss (p = .043 and p = .042, respectively). Additionally, the GRS based on IL6, IL6R, IL10, IL10RA, and IL10RB variants was independently associated with the risk of graft loss (HR 1.53, 95%-CI [1.32-1.84]; p < .001). Notably, the GRS improved risk stratification and prediction of graft loss beyond the level of contemporary clinical markers. Our findings reveal the merits of a polygenic IL-6-based risk score strengthened with IL-10- polymorphisms for the prognostication and risk stratification of late graft failure in kidney transplantation.

Analysis of Gene Single Nucleotide Polymorphisms in COVID-19 Disease Highlighting the Susceptibility and the Severity towards the Infection

Many factors may influence the risk of being infected by SARS-CoV-2, the coronavirus responsible for coronavirus disease 2019 (COVID-19). Exposure to the virus cannot explain the variety of an individual's responses to the virus and the high differences of effect that the virus may cause to some. While a person's preexisting condition and their immune defenses have been confirmed to play a major role in the disease progression, there is still much to learn about hosts' genetic makeup towards COVID-19 susceptibility and risk. The host genetic makeup may have direct influence on the grade of predisposition and outcomes of COVID-19. In this study, we aimed to investigate the presence of relevant genetic single nucleotide polymorphisms (SNPs), the peripheral blood level of IL6, vitamin D and arterial blood gas (ABG) markers (pH, oxygen-SpO₂ and carbon dioxide-SpCO₂) on two groups, COVID-19 (n = 41, study), and the healthy (n = 43, control). We analyzed cytokine and interleukin genes in charge of both pro-inflammatory and immune-modulating responses and those genes that are considered involved in the COVID-19 progression and complications. Thus, we selected major genes, such as IL1β, IL1RN (IL-1 β and α receptor) IL6, IL6R (IL-6 receptor), IL10, IFNγ (interferon gamma), TNFα (tumor necrosis factor alpha), ACE2 (angiotensin converting enzyme), SERPINA3 (Alpha-1-Antiproteinase, Antitrypsin member of Serpin 3 family), VDR (vitamin D receptor Tak1, Bsm1 and Fok1), and CRP (c-reactive protein). Though more research is needed, these findings may give a better representation of virus pleiotropic activity and its relation to the immune system.

The NESHIE and CP Genetics Resource (NCGR): A database of genes and variants reported in neonatal encephalopathy with suspected hypoxic ischemic encephalopathy (NESHIE) and consequential cerebral palsy (CP)

Neonatal encephalopathy (NE) with suspected hypoxic ischaemic encephalopathy (HIE) (NESHIE) is a complex syndrome occurring in newborns, characterised by altered neurological function. It has been suggested that genetic variants may influence NESHIE susceptibility and outcomes. Unlike NESHIE, for which a limited number of genetic studies have been performed, many studies have identified genetic variants associated with cerebral palsy (CP), which can develop from severe NESHIE. Identifying variants in patients with CP, as a consequence of NESHIE, may provide a starting point for the identification of genetic variants associated with NESHIE outcomes. We have constructed NCGR (NESHIE and CP Genetics Resource), a database of genes and variants reported in patients with NESHIE and CP (where relevant to NESHIE), for the purpose of collating and comparing genetic findings between the two conditions. In this paper we describe the construction and functionality of NCGR. Furthermore, we demonstrate how NCGR can be used to prioritise genes and variants of potential clinical relevance that may underlie a genetic predisposition to NESHIE and contribute to an understanding of its pathogenesis.

Quantile-Dependent Expressivity of Serum Interleukin-6 Concentrations as a Possible Explanation of Gene-Disease Interactions, Gene-Environment Interactions, and Pharmacogenetic Effects

Interleukin 6 (IL-6) is a moderately heritable pleiotropic cytokine whose elevated concentrations in coronary artery disease, peripheral arterial disease, pulmonary arterial hypertension, Eales' disease, Sjògren's syndrome, osteoarthritis, adenocarcinoma, neuroblastoma, polymyalgia rheumatica, pulmonary tuberculosis, and enterovirus 71 infection, and following coronary artery bypass graft show larger genetic effects than in unaffected low IL-6 controls. We hypothesize that genetic effects may depend upon whether average IL-6 concentrations are high or low, i.e., quantile-dependent expressivity. Quantile-specific offspring-parent (βOP) and full-sib regression slopes (βFS) were estimated by applying quantile regression to the age- and sex-adjusted serum IL-6 concentrations in families surveyed in the Framingham Heart Study. Quantile-specific heritabilities were calculated as h2 = 2βOP / (1 + rspouse) and h2 = {(1 + 8rspouseβFS)0.5 -1} / (2rspouse)). Heritability (h2 ± SE) of IL-6 concentrations increased from 0.01 ± 0.01 at the 10th percentile (NS), 0.02 ± 0.01 at the 25th (P = 0.009), 0.03 ± 0.01 at the 50th (P = 0.007), 0.04 ± 0.02 at the 75th (P = 0.004), and 0.13 ± 0.05 at the 90th percentile (P = 0.03), or 0.0005 ± 0.0002 for each 1% increase in the offspring's phenotype distribution (Plinear trend = 0.02) when estimated from βOP and from 0.02 ± 0.02 at the 10th (NS), 0.02 ± 0.02 at the 25th (NS), 0.06 ± 0.02 at the 50th (P = 0.01), 0.12 ± 0.04 at the 75th (P = 0.001), and 0.30 ± 0.03 at the 90th percentile (P < 10-16), or 0.0015 ± 0.0007 for each 1% increase in the sibling phenotype distribution (Plinear trend = 0.02) when estimated from βFS. Thus the heritability of serum IL-6 concentrations is quantile dependent, which may contribute in part to the larger genetic effect size reported for diseases and environmental conditions that elevate IL-6 concentrations vis-à-vis unaffected controls.

The dynamic changes in autophagy activity and its role in lung injury after deep hypothermic circulatory arrest

Deep hypothermic circulatory arrest (DHCA) can cause acute lung injury (ALI), and its pathogenesis mimics ischaemia/reperfusion (I/R) injury. Autophagy is also involved in lung I/R injury. The present study aimed to elucidate whether DHCA induces natural autophagy activation and its role in DHCA‐mediated lung injury. Here, rats were randomly assigned to the Sham or DHCA group. The sham group (n = 5) only received anaesthesia and air intubation. DHCA group rats underwent cardiopulmonary bypass (CPB) followed by the DHCA procedure. The rats were then sacrificed at 3, 6 and 24 h after the DHCA procedure (n = 5) to measure lung injury and autophagy activity. Chloroquine (CQ) was delivered to evaluate autophagic flux. DHCA caused lung injury, which was prominent 3–6 h after DHCA, as confirmed by histological examination and inflammatory cytokine quantification. Lung injury subsided at 24 h. Autophagy was suppressed 3 h but was exaggerated at 6 h. At both time points, autophagic flux appeared uninterrupted. To further assess the role of autophagy in DHCA‐mediated lung injury, the autophagy inducer rapamycin and its inhibitor 3‐methyladenine (3‐MA) were applied, and lung injury was reassessed. When rapamycin was administered at an early time point, lung injury worsened, whereas administration of 3‐MA at a late time point ameliorated lung injury, indicating that autophagy contributed to lung injury after DHCA. Our study presents a time course of lung injury following DHCA. Autophagy showed adaptive yet protective suppression 3 h after DHCA, as induction of autophagy caused worsening of lung tissue. In contrast, autophagy was exaggerated 6 h after DHCA, and autophagy inhibition attenuated DHCA‐mediated lung injury.

Candidates for smart cardiovascular medical device coatings: A comparative study with endothelial and smooth muscle cells

Stent-induced vascular injury is manifested by removal of the endothelium and phenotypic changes in the underlying medial smooth muscle cells layer. This results in pathological vascular remodelling primarily contributed to smooth muscle cell proliferation and leads to vessel re-narrowing; neointimal hyperplasia. Current drug-eluting stents release non-selective anti-proliferative drugs such as paclitaxel from the stent surface that not only inhibit growth of smooth muscle cells but also delay endothelial healing, potentially leading to stent thrombosis. This highlights the need for novel bioactive stent coating candidates with the ability to target key events in the pathogenesis of in-stent restenosis. Citric acid, a molecule with anti-coagulant properties, was investigated against L-ascorbic acid, an antioxidant molecule reported to preferentially promote endothelial growth, and paclitaxel, a typically used anti-proliferative stent coating. Citric acid was found to exhibit growth supporting properties on endothelial cells across a range of concentrations that were significantly better than the model stent coating drug paclitaxel and better than the ascorbic acid which inhibited endothelial proliferation at concentrations ≥100 μg/ml. It was demonstrated that a citric acid-paclitaxel combination treatment significantly improves cell viability in comparison to paclitaxel only treated cells, with endothelial cells exhibiting greater cell recovery over smooth muscle cells. Furthermore, cell treatment with citric acid was found to reduce inflammation in a lipopolysaccharide (LPS)-induced in vitro inflammation model by significantly reducing interleukin 6 expression. Thus, this study demonstrates that citric acid is a promising candidate for use as a coating in stents and other endovascular devices.

Donor genetic variants in interleukin-6 and interleukin-6 receptor associate with biopsy-proven rejection following kidney transplantation

Rejection after kidney transplantation remains an important cause of allograft failure that markedly impacts morbidity. Cytokines are a major player in rejection, and we, therefore, explored the impact of interleukin-6 (IL6) and IL-6 receptor (IL6R) gene polymorphisms on the occurrence of rejection after renal transplantation. We performed an observational cohort study analyzing both donor and recipient DNA in 1271 renal transplant‐pairs from the University Medical Center Groningen in The Netherlands and associated single nucleotide polymorphisms (SNPs) with biopsy-proven rejection after kidney transplantation. The C-allele of the IL6R SNP (Asp358Ala; rs2228145 A > C, formerly rs8192284) in donor kidneys conferred a reduced risk of rejection following renal transplantation (HR 0.78 per C-allele; 95%-CI 0.67–0.90; P = 0.001). On the other hand, the C-allele of the IL6 SNP (at position-174 in the promoter; rs1800795 G > C) in donor kidneys was associated with an increased risk of rejection for male organ donors (HR per C-allele 1.31; 95%-CI 1.08–1.58; P = 0.0006), but not female organ donors (P = 0.33). In contrast, neither the IL6 nor IL6R SNP in the recipient showed an association with renal transplant rejection. In conclusion, donor IL6 and IL6R genotypes but not recipient genotypes represent an independent prognostic marker for biopsy-proven renal allograft rejection.

Polymorphisms of Interleukin-6 and Interleukin-8 Are Not Associated with Parkinson's Disease in Taiwan

Background: Studies have suggested that cytokines are crucial mediators in the pathogenesis of Parkinson’s disease (PD). The multifunctional cytokine interleukin (IL)-6 and its single nucleotide polymorphisms (SNPs) were found to have an impact on the development of PD. However, different studies in associations of IL-6 genetic variants with PD showed inconsistent results and it has never been explored in a Taiwanese population. Both IL-1α and IL-8 contribute to the same inflammation pathway. IL-1α genetic polymorphism has an effect on late-onset PD in Taiwan, whereas the associations of IL-8 genetic variants with PD in Taiwan remain to be investigated. Methods: This study examined the frequencies of polymorphisms within the critical promoter areas of the proinflammatory cytokine genes: IL-6 G-174C (rs1800795) and IL-8 A-251T (rs4073) in Taiwanese PD patients compared with age-and gender-matched healthy subjects. Comparisons were also made in genotype and allele frequencies of IL-6 G-174C (rs1800795) and IL-8 A-251T (rs4073) among different populations in previous studies. Results: In total, 1120 subjects, including 509 PD patients (female/male: 259/250) and 511 control subjects (female/male: 252/259), were recruited. We found no statistically significant differences in IL-6 G-174C (rs1800795) or IL-8 A-251T (rs4073) genotypic and allelic distribution between PD and controls, even after being stratified by age at onset and gender. Conclusions: The results did not demonstrate any association of IL-6 G-174C (rs1800795) or IL-8 A-251T (rs4073) with PD in a Taiwanese population. Despite the negative results, this is the first study in associations of IL-6 G-174C (rs1800795) and IL-8 A-251T (rs4073) with PD in Taiwan. The relevance of genetic variants of IL-6 G-174C (rs1800795) or IL-8 A-251T (rs4073) on PD susceptibility warrants further investigation.

Genetics Insight for COVID-19 Susceptibility and Severity: A Review

Coronavirus disease (COVID-19) presents a broad spectrum of clinical manifestations ranging from an asymptomatic to a severe clinical course. The host genetic background influence on the susceptibility and outcome of multiples infectious diseases has been previously reported. Herein, we aimed to describe relevant identified genetic variants and those potentially related to the inter-individual variability of COVID-19 susceptibility and/or severity considering the physiopathological pathway of the disease The HLA-A*25:01, -B*15:27, -B*46:01, -C*01:02, and -C*07:29 alleles have been associated with COVID-19 susceptibility; while HLA-A*02:02, -B*15:03, and -C*12:03 have been identified as low-risk alleles. Variants in cytokine genes such as IL1B, IL1R1, IL1RN, IL6, IL17A, FCGR2A, and TNF could be related to disease susceptibility and cytokine storm, and/or COVID-19 complications (e.g., venous thrombosis). Several variants in ACE2 and TMPRSS2 affecting the expression of the receptors related to COVID-19 have been associated with the disease susceptibility and risk factors. Finally, two GWAS have identified the loci 3p21.31 (LZTFL1, SLC6A20, CCR9, FYCO1, CXCR6, and XCR1) and 9q34.2 (ABO) with COVID-19 severity. Heterogeneous results in the association of genetic variants with COVID-19 susceptibility and severity were observed. The mechanism of identified risk-genes and studies in different populations are still warranted.

The role of IL-6-174 G/C polymorphism and intraocular IL-6 levels in the pathogenesis of ocular diseases: a systematic review and meta-analysis

Interleukin-6 (IL-6) is one of the key regulators behind the inflammatory and pathological process associated with ophthalmic diseases. The role of IL-6-174 G/C polymorphism as well as intraocular IL-6 levels among various eye disease patients differ across studies and has not been systematically reviewed. Thus, this study aims to provide a summary to understand the relationship between IL-6 and ophthalmic disease. In total, 8,252 and 11,014 subjects for IL-6-174 G/C and intraocular levels of IL-6, respectively, were retrieved from PubMed, Scopus and Web of Science. No association was found between IL-6-174 G/C polymorphisms with ocular diseases. Subgroup analyses revealed a suggestive association between the GC genotype of IL-6-174 G/C with proliferative diabetic retinopathy (PDR). Further, the level of intraocular IL-6 among ocular disease patients in general was found to be higher than the control group [standardized mean difference (SMD) = 1.41, 95% confidence interval (CI) 1.24-1.58, P < 0.00001]. Closer examination through subgroup analyses yielded similar results in several ocular diseases. This study thus indicates that the IL-6-174 G/C polymorphism does not predispose patients to ocular disease, although the GC genotype is likely to be a genetic biomarker for PDR. Moreover, intraocular IL-6 concentrations are related to the specific manifestations of the ophthalmic diseases. Further studies with larger sample sizes are warranted to confirm this conclusion.

Uncovering Outcome Disparities of β2 Adrenergic Agonists in Blacks: A Systematic Review

PURPOSE

Outcome differences driven by variation in Blacks' biologic response to treatment may contribute to persistent racial disparities in asthma morbidity and mortality. This review assessed systematic variation in β₂ agonist treatment outcomes among Blacks compared to other groups.

METHODS

We conducted a systematic review of studies reporting differential response to β₂ agonists among Blacks, including studies identifying pharmacogenetic variants.

RESULTS

Of 3158 papers, 20 compared safety or efficacy of β₂ agonists among Blacks as compared with other subgroups. Six papers evaluating efficacy of short-acting β₂ agonists (SABA) found similar or improved results among Blacks compared with other groups, while one small study found reduced response to SABA therapy among Blacks. Reports of safety and efficacy of long-acting β₂ agonists (LABA) indicated similar results among Blacks in four papers, while four reports found reduced safety among Blacks, as compared with other groups. Four papers assessed genomic variation and relative treatment response in Blacks, with two finding significant effects of the p.Arg16Gly variant in ADRB2 on β₂ agonist response and one finding significant gene-gene IL6/IL6R interaction effects on albuterol response.

CONCLUSIONS

Evidence suggests the potential for differences in β₂ agonist outcomes among Blacks compared with other groups. This literature, however, remains small and significantly underpowered for substantive conclusions. There are notable opportunities for adequately-powered investigations exploring safety and efficacy of β₂ agonists among Blacks, including pharmacogenomic modifiers of response.

The Association between Interleukin-6 Gene Polymorphisms and Risk of Systemic Lupus Erythematosus: A Meta-analysis with Trial Sequential Analysis

BACKGROUND

Molecular epidemiological studies have sought associations between interleukin-6 (IL-6) polymorphisms and the risk of systemic lupus erythematosus (SLE); however, the results are controversial. Therefore, we conducted a meta-analysis with trial sequential analysis to evaluate a more accurate estimation of the associations.

METHODS

Published literatures reporting the relationships of two IL-6 polymorphisms (G-174C and G-572C) and SLE risk were retrieved from electronic databases such as PubMed and EMBASE. The most appropriate genetic model was chosen for each polymorphism. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Trial sequential analysis (TSA) was introduced to assess the information size and the positive results.

RESULTS

With 17 studies (2780 cases and 3100 controls) included, a dominant association (CC+GC vs. GG) was suggested for G-174C polymorphism, and compared with the GG genotype, the CC+GC genotype of G-174C was associated with a decreased SLE risk (OR = 0.71; 95% CI = 0.56-0.88, P =.02). No association was found for G-572C under all genetic models (e.g. OR and 95%CI for CC+GC vs. GG: 0.89, 0.73-1.08, P =.22). Subgroup analyses indicated that SLE risk decreased in G-174C polymorphism by subgroups of Caucasian population, publications after 2010, studies with high quality, and studies complied with Hardy-Weinberg equilibrium (HWE). TSA suggested that the sample sizes used for G-572C were insufficient.

CONCLUSION

We found that the minor allele C of IL6G-174C polymorphism is a protective factor in SLE. Further studies with a larger sample size are needed to confirm the null association for G-572C.

Interleukin-6 Receptor Asp358 A>C Polymorphism Is Associated With Postoperative Atrial Fibrillation

BACKGROUND

This study examined the associations of single-nucleotide polymorphisms in the interleukin-6 receptor gene (Asp358 A>C) and the interleukin-6 promoter (-174G>C and -597G>A) with interleukin-6 levels and postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG).

METHODS

The study enrolled 371 Chinese Han patients who were undergoing CABG. Serum interleukin-6 levels were measured preoperatively and at 6, 12, and 18 hours postoperatively. Genotypes for the 3 polymorphisms were determined.

RESULTS

Overall, POAF developed in 30.2% of patients. The CC genotype and C allele frequencies for the interleukin-6 receptor Asp358 A>C polymorphism were significantly higher in patients with POAF than in patients without POAF (P = .003), and the interleukin-6 levels were significantly higher in patients with the CC genotype compared with A allele carriers at 6, 12, and 18 hours in the overall cohort and at 12 and 18 hours in the POAF subgroup, but there were no significant differences in the non-POAF subgroup. However, the allele and genotype frequencies of the interleukin-6 -174G>C and -597G>A polymorphisms were similar among groups, and there were no differences in interleukin-6 levels at any time point between the C/A allele carriers and the patients with GG genotypes. Univariate analysis showed that the CC genotype for interleukin-6 receptor Asp358 A>C, age, and history of cerebrovascular disease were associated with POAF. Multivariable regression showed that the CC genotype was independently related to the development of POAF (odds ratio, 2.01; 95% confidence interval: 1.15 to 3.52; P = .014).

CONCLUSIONS

The interleukin-6 receptor Asp358 A>C polymorphism may contribute to genetic susceptibility to POAF after CABG.

Regulation of interleukin 6 by a polymorphic CpG within the frontal cortex in Alzheimer's disease

The cytokine interleukin 6 (IL-6) has been linked to the pathogenesis of Alzheimer's disease (AD). This is the first study to investigate the genetic and epigenetic interactions in the control of IL-6 in human brain and its relation to AD neuropathology in prefrontal cortex tissues from AD and controls genotyped for the SNP -174 C/G rs1800795, a polymorphic CpG in which the G allele creates a CpG site. Within CC homozygotes there were significantly higher brain levels of IL-6 protein compared to G allele carriers. The C allele that resulted in an absence of methylation at a CpG was also associated with significant changes in methylation at neighboring CpGs. Furthermore, there were significant differences in methylation between CC and CG/GG at CpG sites in the AD and control groups. That DNA methylation was altered in the brains by the presence of rs1800795, which further correlated with protein levels suggests the presence of a polymorphic CpG and genetic-epigenetic interactions in the regulation of IL-6 in the prefrontal cortex within AD brains.

Interleukin-6 gene -572 G > C polymorphism and myocardial infarction risk

INTRODUCTION

The association between interleukin-6 (IL-6) gene -572 G^C polymorphism and myocardial infarction (MI) risk has not been established. We adopted this meta-analysis for further insight into the case-control studies.

MATERIALS AND METHODS

To investigate the genetic association, we searched multiple databases, including Web of Science, EMbase, CBM disc, PubMed and CNKI. Also, we manually identified the searched references. All the statistical analyses were conducted using Stata 11.0.

RESULTS

A total of five studies were identified, involving 2,526 MI cases and 3,027 controls. The results revealed a significant association between IL-6 gene -572 G^C polymorphism and MI, implying that the IL-6 gene -572 C allele may be a protective factor for MI (for C allele vs K allele: OR = 0.85, 95% CI = 0.73-0.99, p = 0.041; for C/C vs G/G: OR = 0.55, 95% CI = 0.31-0.98, p = 0.044; for C/C vs G/C + G/G: OR = 0.60, 95% CI = 0.41-0.89, p = 0.011). However, in the subgroup analysis with regard to ethnicity, no significant correlation was identified between IL-6 gene -572 G^C polymorphism and MI among Europeans.

CONCLUSION

The IL-6 gene -572 C allele may be a protective factor for MI. Future studies involving larger sample bases are still recommended.

Epigenetic landscapes suggest that genetic risk for intracranial aneurysm operates on the endothelium

BACKGROUND

Genetics play an important role in intracranial aneurysm (IA) pathophysiology. Genome-wide association studies have identified several single nucleotide polymorphisms (SNPs) that are linked to IA but how they affect disease pathobiology remains poorly understood. We used Encyclopedia of DNA Elements (ENCODE) data to investigate the epigenetic landscapes surrounding genetic risk loci to determine if IA-associated SNPs affect functional elements that regulate gene expression and if those SNPs are most likely to impact a specific type of cells.

METHODS

We mapped 16 highly significant IA-associated SNPs to linkage disequilibrium (LD) blocks within the human genome. Within these regions, we examined the presence of H3K4me1 and H3K27ac histone marks and CCCTC-binding factor (CTCF) and transcription-factor binding sites using chromatin immunoprecipitation-sequencing (ChIP-Seq) data. This analysis was conducted in several cell types relevant to endothelial (human umbilical vein endothelial cells [HUVECs]) and inflammatory (monocytes, neutrophils, and peripheral blood mononuclear cells [PBMCs]) biology. Gene ontology analysis was performed on genes within extended IA-risk regions to understand which biological processes could be affected by IA-risk SNPs. We also evaluated recently published data that showed differential methylation and differential ribonucleic acid (RNA) expression in IA to investigate the correlation between differentially regulated elements and the IA-risk LD blocks.

RESULTS

The IA-associated LD blocks were statistically significantly enriched for H3K4me1 and/or H3K27ac marks (markers of enhancer function) in endothelial cells but not in immune cells. The IA-associated LD blocks also contained more binding sites for CTCF in endothelial cells than monocytes, although not statistically significant. Differentially methylated regions of DNA identified in IA tissue were also present in several IA-risk LD blocks, suggesting SNPs could affect this epigenetic machinery. Gene ontology analysis supports that genes affected by IA-risk SNPs are associated with extracellular matrix reorganization and endopeptidase activity.

CONCLUSION

These findings suggest that known genetic alterations linked to IA risk act on endothelial cell function. These alterations do not correlate with IA-associated gene expression signatures of circulating blood cells, which suggests that such signatures are a secondary response reflecting the presence of IA rather than indicating risk for IA.

Interactions Between Diet Quality and Interleukin-6 Genotypes Are Associated With Metabolic and Renal Function Parameters in Mexican Patients With Type 2 Diabetes Mellitus

OBJECTIVE

The aim of this study was to evaluate the interaction between diet quality and interleukin (IL)-6 genotypes and its association with metabolic and renal function parameters in Mexican patients with type 2 diabetes mellitus (T2DM).

DESIGN AND METHODS

Using an analytical cross-sectional design, 219 patients with T2DM (92 men; age 62 ± 10 years) were evaluated for selected metabolic and renal function parameters. Diet quality according to the Healthy Eating Index was evaluated and classified as good diet or poor diet in all patients. IL-6 serum concentrations and genotypes and haplotypes for IL6-597G > A (rs180097), -572G > C (rs180096), and -174G > C (rs180095) polymorphisms were determined.

RESULTS

Eighty-two percent of patients reported having a poor diet. Carriers of alleles -572C and -174C showed higher high-density lipoprotein cholesterol levels (44 ± 12 vs. 40 ± 9 mg/dL; P = .01) and lower total cholesterol levels (184 ± 33 vs. 197 ± 42 mg/dL; P = .03) than did those homozygous for G/G. Neither IL6 genotypes nor haplotypes were significantly associated with serum concentrations of IL-6. Some significant interactions between IL6 genotypes/haplotypes and diet quality were associated with body mass index, waist circumference, high-density lipoprotein cholesterol levels, and estimated glomerular filtration rate.

CONCLUSIONS

Interactions between diet quality and IL6 genotypes/haplotypes were associated with the main metabolic and renal function parameters in Mexican patients with T2DM. It will be important to consider genetic profiles in designing dietary portfolios and nutritional interventions for the management of such patients.

Genetic Variants Associated with Cancer Pain and Response to Opioid Analgesics: Implications for Precision Pain Management

OBJECTIVE

To review the current knowledge on the association of genetic variants with cancer pain.

DATA SOURCES

Data-based publications and review articles retrieved from PubMed, CINAHL, and Web of Science, as well as an additional search in Google Scholar.

CONCLUSION

Genetic variability can influence differential pain perception and response to opioids in cancer patients, which will have implications in the optimal personalized treatment of cancer pain. More studies are warranted to replicate findings.

IMPLICATIONS FOR NURSING PRACTICE

Nurses are poised to educate patients on biomarker testing and interpretation and to use precision pain management strategies based on this information.

Arterial Hypertension and Interleukins: Potential Therapeutic Target or Future Diagnostic Marker?

Hypertension as a multifactorial pathology is one of the most important cardiovascular risk factors, affecting up to 30-40% of the general population. Complex immune responses are involved in the inflammatory mechanism of hypertension, with evidence pointing to increased inflammatory mediators even in prehypertensive patients. Increased vascular permeability, thrombogenesis, and fibrosis, effects that are associated with sustained hypertension, could be attributed to chronic inflammation. Chronic inflammation triggers endothelial dysfunction via increased production of ROS through proinflammatory cytokines. Increased serum level of proinflammatory cytokines such as IL-1β, IL-6, IL-8, IL-17, IL-23, TGFβ, and TNFα in hypertensive patients has been associated with either increased blood pressure values and/or end-organ damage. Moreover, some cytokines (i.e., IL-6) seem to determine a hypertensive response to angiotensin II, regardless of blood pressure values. Understanding hypertension as an inflammatory-based pathology gives way to new therapeutic targets. As such, conventional cardiovascular drugs (statins, calcium channels blockers, and ACEIs/ARBs) have shown additional anti-inflammatory effects that could be linked to their blood pressure lowering properties. Moreover, anti-inflammatory drugs (mycophenolate mofetil) have been shown to decrease blood pressure in hypertensive patients or prevent its development in normotensive individuals. Further research is needed to evaluate whether drugs targeting hypertensive-linked proinflammatory cytokines, such as monoclonal antibodies, could become a new therapeutic option in treating arterial hypertension.

Association of genetic polymorphisms with acute kidney injury after cardiac surgery in a Southeast Asian population

Introduction

Genetic polymorphisms are important in explaining the wide interpatient variability that exists in the development of acute kidney injury (AKI) post cardiac surgery. We hypothesised that polymorphisms in 4 candidate genes, namely angiotensin-converting enzyme (ACE), apolipoprotein-E (ApoE), interleukin-6 (IL-6), and tumour necrosis factor-alpha (TNF-α) are associated with AKI.

Methods

870 patients who underwent cardiac surgery in Singapore were analysed. All patients who fulfilled stage 1 KDIGO criteria and above were considered to have AKI. This was investigated against various demographic, clinical and genetic factors.

Results

Increased age, history of hypertension, anaemia and renal impairment remained important preoperative risk factors for AKI. Intraoperatively, longer cardiopulmonary bypass (CPB) time and the use of intra-aortic balloon pump (IABP) were shown to be associated with AKI. Among the genetic factors, ACE-D allele was associated with an increased risk of AKI while IL6-572C allele was associated with a decreased risk of AKI.

Conclusion

ACE-D allele was associated with the development of AKI similar to other studies. On the other hand, IL6-572C was shown to have a protective role against the development of AKI, contradictory to studies done in the Caucasian population. This contradictory effect of IL6-572C is a result of a complex interplay between the gene and population specific modulating factors. Our findings further underscored the necessity of taking into account population specific differences when developing prediction models for AKI.

The impact of antihypertensive pharmacotherapy on interplay between protein-bound uremic toxin (indoxyl sulfate) and markers of inflammation in patients with chronic kidney disease

PURPOSE

Indoxyl sulfate (IS) is one of the most potent uremic toxins involved in chronic kidney disease (CKD) progression, induction of inflammation, oxidative stress, and cardiovascular diseases occurrence. It is proved that hypertension is a common CVD complication and a major death risk factor as well as contributes for decline in a renal function. The aim of our study was to investigate how implementing of antihypertensive therapy impact IS concentrations and the associations between IS and markers of renal function, inflammation and oxidative stress.

METHODS

Study was conducted on 50 patients diagnosed with CKD and hypertension, divided into three groups: without hypotensive therapy (CKD-NONE), hypotensive monotherapy (CKD-MONO), and hypotensive polypharmacotherapy (CKD-POLI), and 18 healthy volunteers. The markers of inflammation [interleukin-6, tumor necrosis factor-alpha (TNF-α), high-sensitive C-reactive protein (hs-CRP), neopterin, ferritin], oxidative status [superoxide dismutase (Cu/Zn-SOD), antibodies against oxidized low-density lipoprotein (oxLDL-abs)], and selectins were determinate using immunoenzymatic methods. IS levels were assayed using high-performance liquid chromatography and other parameters were analysed using routine laboratory techniques. Then cross-sectional analysis was performed.

RESULTS

Elevated levels of IS, indicators of kidney function, markers of inflammation and blood pressure values were observed in each CKD subgroups. There was no effect of antihypertensive therapy on IS levels between studied groups, as well as there was no clear relationship between IS and blood pressure values in each studied group. The positive associations between IS and Cu/Zn SOD, neopterin, hs-CRP, creatinine and neutrophils/lymphocytes ratio were observed in CKD-NONE and CKD-POLI subgroups. Additionally, in CKD-POLI group IS positively correlated with TNF-α, ferritin and neutrophils. In CKD-MONO group, IS was positively related to oxLDL-abs, neopterin, E-selectin and creatinine, whereas it was inversely associated with hs-CRP.

CONCLUSIONS

Our study showed for the first time that the antihypertensive therapy has no impact on IS levels in CKD patients with hypertension. However, the introduction of the antihypertensive therapy modified the dependencies between IS and the studied markers of kidney function, inflammation, oxidative stress and hematological parameters that are crucial for mortality and morbidity amongst the CKD patients with hypertension.

Association of interleukin-6 gene promoter polymorphism with acne vulgaris and its severity

BACKGROUND

Acne vulgaris (AV) is an inflammatory disorder with a possible genetic background. Different cytokines and mediators are involved in its pathogenesis.

AIM

Our aim was to investigate the interleukin (IL)-6 572 polymorphism in patients with AV and its relation to patient sex and acne severity.

METHODS

In total, 30 patients with acne and 20 healthy controls (HCs) were enrolled. The Global Acne Grading System was used to assess acne severity. The IL-6 572 gene promoter polymorphism was assessed using the PCR-restriction fragment length polymorphism method.

RESULTS

There was a significantly higher association of IL-6 572 variants genotypes in patients with acne (93%) compared with the HC group (45%) (P < 0.001), with a higher incidence of the IL-6 572 CC polymorphism in patients with acne. A significant difference (P < 0.001) between C and G alleles in patients vs. HCs was detected. There were no significant associations between the IL-6 572 variant genotypes and either patient sex or AV severity.

CONCLUSION

IL-6 gene promoter polymorphism might have a role in AV susceptibility but it is not related to AV severity.

Gene polymorphisms in the interleukins gene and the risk of acute pancreatitis: A meta-analysis

Single nucleotide polymorphisms (SNPs) within the interleukins (IL) gene may affect the risk of acute pancreatitis. Many epidemiological studies have reported an association between the IL gene and acute pancreatitis risk, but the results remain inconsistent. Given the controversial available data, we carried out a meta-analysis to systematically evaluate and clarify the association between IL gene polymorphisms and AP. A systematic search of studies for this association was obtained from the PubMed, EMBASE, Web of Science and Chinese National Knowledge Infrastructure (CNKI) databases until June 1, 2017. We also searched the references of the included studies to identify additional studies. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were used to pool the effect size. Stata12.0 was used for whole statistical analysis. Fifteen studies that contained 3371 AP cases and 3506 controls were included in final combination. Overall, a significant association was found between the IL-8-251 T/A (rs4073) polymorphism, the IL-10-1082 A/G (rs1800896) polymorphism and the AP risk in four genetic models (homozygote model, recessive model, dominant model, allele model). Meanwhile, individuals with IL-1β+3954 C/T (rs1143634, (homozygote model, recessive model)), IL-1β -511 C/T (rs16944, (dominant model)) and IL-6-634C/G (rs1800796, (allele model)) polymorphism were associated with an increased risk of AP. No evidence of an association was found between IL and 10-592 C/A (rs1800872) and IL-10-819 C/T (rs1800871) polymorphism and AP risk.

IL6/IL6R genetic diversity and plasma IL6 levels in bipolar disorder: An Indo-French study

Reports of association of genetic variants of IL6 and its receptor (IL6R) with psychiatric disorders are inconsistent, and there are few population-based studies thus far in bipolar disorder (BD). We genotyped the IL6 rs1800795 and IL6R rs2228145 polymorphisms in two independent sets of patients exposed to different environmental stimuli such as climatic conditions or specific infectious burden - a French sample and a south Indian Tamil sample of BD with quantitation of circulating plasma IL-6 levels in the latter sub-sample. In both populations, allele and genotype frequencies did not differ significantly between cases and controls for either polymorphism. Upon stratifying based on age at onset, we found no associations with the IL6 rs1800795 variant. However, the IL6R rs2228145 C allele and CC genotype were associated with early onset of disease in the French sample when compared to late onset BD. A similar trend was observed in the Indian population where we also found that plasma IL-6 levels were significantly higher in BD and also in patients who were in residual phase or remission both as compared to controls. Our findings are in favour of a possible trans-ethnic implication of the IL6R genetic diversity in BD and reinforce the notion that IL-6 is an important marker of the operating inflammatory processes in the disease.

Influence of Interleukin-6 (IL-6) Promoter Gene Polymorphisms (-174G>C, -572G>C, and -597G>A) on IL-6 Plasma Levels and Their Impact in the Development of Acute Ischemic Stroke in Young Indians

This study aimed to determine whether there is an influence of interleukin 6 (IL-6) gene promoter polymorphisms on IL-6 plasma levels and its role in the development of ischemic stroke in young Indians. One hundred young patients with ischemic stroke (age ≥ 45 years) and equal number of age- and sex-matched controls were genotyped for 174G>C, -572G>C, and -597G>A promoter polymorphisms by polymerase chain reaction-restriction fragment length polymorphism. Plasma IL-6 levels were measured by enzyme-linked immunosorbent assay. Plasma IL-6 levels were significantly higher in patients as compared to controls (patients: 28.61 ± 8.61 pg/mL, controls: 7.60 ± 4.10 pg/mL, P = .001). Both -174G>C (allelic χ2/P value: 4.79/.028, genotypic χ2/P value: 5.3/.021) and -572G>C (allelic χ2/P value: 9.63/.00113 Genotypic χ2/P value: 74/.0002) polymorphisms exhibited genotypic as well as allelic significant association with the disease phenotype. Comparison was made between patients and controls for all 3 polymorphisms using a recessive model with respect to plasma IL-6 levels; no polymorphism showed any significant correlative association with the increased IL-6 levels (P = .31, .51, .32). Interleukin 6 is an inflammatory marker that is considerably influenced by nongenetic factors and is not a good candidate gene for studying genetic components associated with ischemic stroke. It seems that the variability in IL-6 levels is an integrated effect of nongenetic influences and the inflammatory events that follow ischemic stroke instead of being its cause. It is suggested that there is no direct association between -174G>C, -572G>C, and -597G>A polymorphisms and elevated IL-6 levels in the development of ischemic stroke.

An Evidence-Based Meta-Analysis on the Roles of Functional Interleukin-6 Polymorphisms in Coronary Artery Disease

Recently, the relationship between functional interleukin-6 (IL-6) polymorphisms and coronary artery disease (CAD) was extensively studied, with controversial findings. Therefore, we conducted this meta-analysis to better elucidate the relationship between these polymorphisms and the risk of CAD. A total of 57 case-control studies were finally included. The overall analyses showed that IL-6 -174G>C and -572G>C polymorphisms were significantly associated with the risk of CAD, the C allele of -174G>C (G versus C, odds ratio [OR] = 0.82, confidence interval [95% CI] = 0.75-0.89) and -572G>C polymorphisms (G versus C, OR = 0.82, 95% CI = 0.74-0.92) conferred an increased susceptibility to CAD. Further subgroup analyses yielded similar positive results for -174G>C polymorphism in Asian and Caucasian populations, and for -572G>C polymorphism in Asian and African populations. In conclusion, our findings suggest that IL-6 -174G>C and -572G>C polymorphisms may serve as potential genetic markers of CAD.

Impact of interleukin 6 promoter polymorphisms (-174 G > C, -572 G > C and -597 G > A) on plasma IL-6 levels and their influence on the development of DVT: a study from India

OBJECTIVES

To evaluate the association of interleukin 6 (IL-6) levels with deep vein thrombosis (DVT) and to assess the impact of IL-6 promoter polymorphisms (-174G > C, -572G > C and -597G > A) on its plasma levels and their influence in the development of DVT in India.

METHODS

One hundred DVT patients and 100 age and sex-matched healthy controls were study subjects. IL-6 polymorphisms were identified by polymerase chain reaction-restriction fragment length polymorphism. IL-6 levels were detected by enzyme-linked immunosorbent assay.

RESULTS

Significantly raised IL-6 levels were observed in patients as compared to controls. (Patients: 13.73 ± 6.30 pg/ml, Controls: 11.83 ± 4.47 pg/ml, p = 0.014). The prevalence of C allele of -572G > C polymorphism was significantly higher in patients than controls (Patients: 39.5%, Controls: 27.5%, p = 0.011, χ²=6.463). Subjects with GC and CC genotype had significantly higher IL-6 levels than GG genotype (p=<0.001). Patients with GC and CC genotype increased the DVT risk by 1.39 fold (OR^a: 1.39, CI: 0.74-2.62) and 2.69 fold (OR^a: 2.42, CI: 1.08-6.70), respectively. IL-6 -174G > C and -597G > A polymorphisms were not associated with raised IL-6 levels and nor with thrombotic risk (-174G > C: p = 0.823 χ²=0.369; -597G > A: p = 0.678 χ²=1.08).

CONCLUSION

Our study emphasizes the importance of -572G > C polymorphism in increasing IL-6 levels, thereby showing its significant role in DVT in India. IL-6 -174G > C and -597G > A were neither associated with raised plasma IL-6 levels nor with thrombotic risk. Thus -572G > C polymorphism detection may be one of the connecting links between IL-6 and thrombotic risk in Indian DVT patients.

The Role of Interleukins and Inflammatory Markers in the Early Restenosis of Covered Stents in the Femoropopliteal Arterial Segment

BACKGROUND

The objective of this study was to evaluate the relationship between inflammatory markers, such as interleukin (IL)-1β, IL-6, IL-8, IL-10, tumor necrosis factor α (TNF-α), transforming growth factor β (TGF-β), and highly sensitive C-reactive protein, and the development of arterial restenosis 6 months after femoropopliteal percutaneous transluminal angioplasty (PTA) with covered stent implantation.

METHODS

We recruited 27 patients of a tertiary hospital in Brazil who were treated with covered stents for atherosclerotic peripheral arterial disease. Serum samples were collected before stent implantation, then 24 hr later, and 6 months after the procedure.

RESULTS

At 6-month follow-up, 4 patients (15%) presented restenosis. IL1- β, IL-6, IL-8, and TNF-α levels showed a statistically significant reduction after both 24 hr and 6 months compared with pretreatment levels (P < 0.01). There were increased levels of IL-10 and TGF-β both 24 hr and 6 months after PTA and stenting compared with pretreatment levels (P < 0.01). None of the cytokines studied were correlated with restenosis.

CONCLUSIONS

This study demonstrated a significant increase in anti-inflammatory TGF-β and IL-10 and a decrease in proinflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α 6 months after the procedure, but no inflammatory marker was independently identified as a risk factor for in-stent restenosis.

Minimally invasive heart valve surgery: influence on coagulation and inflammatory response

OBJECTIVES

Minimally invasive valve surgery (MIVS) is associated with improved clinical outcome but longer cardiopulmonary bypass (CPB) time. The aim of the present study is to compare inflammatory and coagulation parameters in patients undergoing minimally invasive or standard valve surgery.

METHODS

A prospective non-randomized study was performed enrolling 79 patients undergoing mitral (20 right mini-thoracotomy and 18 standard sternotomy) and aortic valve (20 mini-sternotomy and 21 standard sternotomy) procedures. Blood samples were collected perioperatively to measure prothrombin fragment 1.2 (PF1.2, thrombin generation), plasmin antiplasmin complex (PAP, fibrinolysis), interleukin-6 (IL-6, inflammation). Plasma free haemoglobin (f-Hb) was assessed to evaluate haemolysis.

RESULTS

Patients in the minimally invasive group were younger and had less comorbidities CPB and cross-clamp times were comparable considering both aortic and mitral procedures, but longer in the mini-thoracotomy group. IL-6 and PAP were reduced in the minimally invasive group, particularly 2 h after CPB (respectively 102 ± 114 vs 34 ± 49 pg/ml, P < 0.001 and 2137 ± 1046 vs 1207 ± 675 ng/ml, P < 0.001), PF1.2 was also reduced during and after the operation (688 ± 514 vs 571 ± 470, P = 0.02; 1600 ± 1185 vs 1042 ± 548, P < 0.001; 1487 ± 676 vs 1042 ± 541). Despite the use of vacuum-assisted active venous drainage (VAVD) f-Hb was significantly reduced in the minimally invasive group. The other routine biomarkers such as C-reactive protein, fibrinogen and cTnI were also reduced in the minimally invasive group.

CONCLUSIONS

In a selected cohort of patients MIVS is associated to reduced inflammatory reaction and coagulopathy, supporting the clinical evidence of reduced postoperative bleeding and lower transfusion rate. Our data offer further suggestion supporting the adoption of minimally invasive approaches.

Impact of cytokine genetic polymorphisms on the risk of renal parenchymal infection in children

BACKGROUND

Acute pyelonephritis is associated with renal scarring in up to 30% of patients. Renal scarring may cause significant long-term morbidity. The pathogenesis of acute pyelonephritis remains unclear, although it involves interaction among uroepithelium, the immune system cells, and the locally produced cytokines. That some UTI-prone children develop acute pyelonephritis, and eventually renal parenchymal scarring, suggests a genetic role. Interleukin-6, interleukin-8, chemokine receptor-1 (CXCR1), and tumor necrosis factor-alpha (TNFα), the key regulators of the host immune responses, are proteins whose secretion is controlled by genes. We postulated that functional polymorphic variants of their genes might have a role in APN susceptibility.

OBJECTIVES

We sought to investigate a possible association of the common functional polymorphisms in genes encoding IL-6, IL-8, CXCR1, and TNFα with the risk of APN in children.

METHODS

Urine culture was used to diagnose 300 children with UTI, of mean age of 51.31 ± 37.4 months (2-180 months). 99Tc-DMSA scans diagnosed 86 children with APN. Follow-up scans identified new renal scars in 18 children. Six functional single-nucleotide polymorphisms (SNPs) in genes encoding IL-6, IL-8, CXCR1, and TNFα were genotyped in all subjects (IL-6 rs1800795 (-174G/C), IL-6 rs1800796 (-572G/C), IL-8 rs2227306 (781C/T), IL8 rs4073 (-251A/T), CXCR1 rs2234671 (2607G/C), and TNFα rs1800629 (-308G/A)).

RESULTS

TT genotype of IL-8 -251A/T polymorphism was significantly higher in APN patients (26.7%) than those with lower UTI (11.7%, p = 0.01) and control individuals (12.2%, p = 0.002). T allele was significantly more common in APN than in lower UTI (p = 0.025) and was significantly more common in APN (46%) than in the controls (p = 0.001). Similarly, TT genotype of IL-8 781C/T polymorphism was significantly more common in APN patients (31.4%) than those with lower UTI (17.3%, p = 0.003) and the controls (14.3%, p = 0.001). T allele was significantly more common in APN (55%) than lower UTI (40%, p = 0.005) and controls (37%, p = 0.001). However, IL-8 -251A/T and +781C/T SNPs did not qualify as an independent risk for parenchymal infection (OR 1.9, 95% CI 0.68-2.6, p = 0.13 and OR 2.3, 95% CI 0.89-3.7, p = 0.091, respectively). Lower UTI did not differ from the controls. The frequency of the genotypes and alleles of IL-6, CXCR1, and TNFα SNPs did not differ significantly among the different groups of the study.

CONCLUSION

IL-8 -251A/T and +781C/T SNPs are associated with susceptibility to renal parenchymal infection in children and could be implicated in APN risk. However, none of these variants could clearly and independently predict this risk.

Association between interleukin-6/6R gene polymorphisms and coronary artery disease in Russian population: influence of interleukin-6/6R gene polymorphisms on inflammatory markers

This study determined the genotype effects of interleukin (IL)-6/IL-6R single nucleotide polymorphisms (SNPs) on circulating levels of different cytokines in healthy and coronary artery disease (CAD) patients with different allele frequencies. In the control patients, rs1800795 showed significant differences in IL-18 concentrations between CC and CG and CC and GG genotypes (P=0.003 and 0.004, respectively). Furthermore, circulatory IL-1β was significantly different between GC and GG genotypes from the same SNP (P=0.038). In the diseased patients, significance was determined only for IL-2 (P=0.021) between the C and G homozygote allele carriers of rs1800795. The diseased GC and GG genotype carriers were statistically different for IL-2 (P=0.049) from the rs1800796 and for IL-4 (P=0.049) from the rs2228044. IL-4 was also statistically significant between the GC and CC genotypes from the rs2228043 of the IL-6R gene (P=0.025). The last combination of genotypes in the same gene for the same SNP was statistically significant for IL-10 (P=0.036). According to the logistic regression, only gender (odds ratio [OR] =2.43) and triglycerides (OR =1.98) could be taken as determinants of CAD, while examined SNPs genotypes were not identified as risk factors for CAD. In general, the IL-6 polymorphism genotypes were mainly associated with inflammatory cytokines, while the IL-6R polymorphism genotypes were associated with anti-inflammatory cytokines.

The profile of selected single nucleotide polymorphisms in patients with hypertension and heart failure with preserved and mid-range ejection fraction

The study aimed to assess the clinical significance of selected single nucleotide polymorphisms (SNPs) in patients with diastolic heart failure (HF): inflammation [-174 G/C Interleukin -6 (IL-6) rs1800795, tumor necrosis factor (TNF)-608 G/A rs1800629], fibrosis [Arg25Pro transforming growth factor β (TGF β) rs1800471], endothelial function [-786 T/C nitric oxide synthase (NOS) rs2070744], glucose and lipid metabolism [Pro12Ala peroxisome proliferator activated receptor (PPAR)γ rs1801282], and vitamin D metabolism [cytochrome P450 27B1 (CYP27B1) C-1260A].110 patients with HF with preserved and mid-range ejection fraction (HFpEF and HFmrEF) were recruited. GG homozygotes in 174 G/C of IL6 polymorphism are characterized by higher values of estimated glomerular filtration rate based on the study Modification of Diet in Renal Disease (eGFR MDRD) and C allele in the NOS polymorphism and AA profile in C-1260A of CYP27B1 polymorphism correlated with a lower eGFR (MDRD). In multivariate analysis the CG genotype for 174 G/C of IL-6 and allele A in C-1260A of CYP27B1 are the only SNPs independently associated with worse course of HFpEF and HFmrEF. These data confirm the importance of the selected SNPs in aggravation and complications of hypertension.

Clinical response to non-surgical periodontal treatment in patients with interleukin-6 and interleukin-10 polymorphisms

Background

Genetic polymorphisms are commonly associated with altered transcriptional activity and possibly make individuals more susceptible to periodontal disease development, increased disease severity and poor treatment outcome. The study aimed to determine the effect of Interleukin-6 (IL-6) -572 G/C (rs1800796) and IL-10 -592 C/A (rs1800872) polymorphisms on the outcomes of non-surgical periodontal therapy in a Caucasian population.

Material and Methods

Sixty-eight patients with chronic periodontal disease were grouped according to their genotype: IL-6, IL-10, IL-6 and IL-10 susceptible (SCP) and non-susceptible (NSCP). All individuals were clinically evaluated at the first visit, and blood sample were collected from patients after checking the inclusion and exclusion criteria of the study. All patients received non-surgical periodontal therapy from a single-blinded periodontist. Clinical periodontal measurements were repeated 45 days after therapy.

Results

This population mean aged 47.63 years included 52.2% females and 58.2% non-smokers. Following DNA separation and genotyping, 65.7% of patients were homozygous carriers of the IL-6 - 572G; 49.3% were carriers of the IL-10 -592A- allele (AA and CA genotypes); and 35.8% carried SCP genotypes for both polymorphisms. The clinical parameters after therapy were not associated with the genotype status. The multiple logistic regression analysis did not show any statistically significant association between the genotypes and the variables tested.

Conclusions

Within the limitations of this longitudinal study, it can be suggested that IL-6 -572 G/C and IL-10 -592 C/A polymorphisms as well as their combination do not influence the outcome of nonsurgical periodontal therapy in Caucasian patients diagnosed with chronic periodontal disease.

Key words:Gene polymorphism, genetics, interleukins, periodontal disease, treatment outcome.

Predicting acute kidney injury: current status and future challenges

Acute kidney injury (AKI) is characterized by an acute decline in renal function and is associated to increased mortality rate, hospitalization time, and total health-related costs. The severity of this ‘fearsome’ clinical complication might depend on, or even be worsened by, the late detection of AKI, when the diagnosis is based on the elevation of serum creatinine (SCr). For these reasons, in recent years a great number of new tools, biomarkers and predictive models have been proposed to clinicians in order to improve diagnosis and prevent the development of AKI. The purpose of this narrative paper is to review the current state of the art in prediction and early detection of AKI and outline future challenges.

Association of Gene Polymorphisms in Interleukin 6 in Infantile Bronchial Asthma

INTRODUCTION

The genetic background of bronchial asthma is complex, and it is likely that multiple genes contribute to its development both directly and through gene-gene interactions. Cytokines contribute to different aspects of asthma, as they determine the type, severity and outcomes of asthma pathogenesis. Allergic asthmatics undergoing an asthmatic attack exhibit significantly higher levels of pro-inflammatory cytokines, such as interleukins and chemokines. In recent years, cytokines and their receptors have been shown to be highly polymorphic, and this prompted us to investigate interleukin 6 promoter polymorphisms at position -174G/C (rs1800795) and at -572G/C (rs1800796) in relation to asthma in children.

METHODS

Interleukin 6 promoter polymorphisms were analyzed in bronchial asthma patients and healthy children using polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS

We observed a significant association between polymorphism at -174G/C and bronchial asthma (OR=3.4, 95% CI: 2.045-5.638, P<.001). Higher associations between polymorphism at IL-6 -174G/C and bronchial asthma were observed in atopic patients (OR=4.1, 95% CI: 2.308-7.280, P<8.10^-7).

CONCLUSIONS

Interleukin 6 polymorphism is associated with bronchial asthma, particularly its atopic phenotype. Expression and secretion of interleukins in asthmatic patients may be affected by genetic polymorphisms, and could have a disease-modifying effect in the asthmatic airway and modify the therapeutic response.

Assessment of genetic diversity in IL-6 and RANTES promoters and their level in Saudi coronary artery disease patients

BACKGROUND

The present study consisted of a total of 200 subjects (100 confirmed coronary artery disease (CAD) patients), both men and women, and 100 healthy control individuals.

METHODS

Serum concentration of IL-6 and RANTES were measured by enzyme-linked immunosorbent assay kit. For SNPs analysis, sanger method of DNA sequencing was followed.

RESULTS

We observed variable numbers of SNP sites at -174 G/C, -572 G/C, and -597 G/A in IL-6 and -28 C/G and -109 C/T in RANTES promoters in CAD patients compared with control individuals. However, the observed changes in the number of SNPs were found to be non-significant compared with control individuals. The IL-6 level was found to be significantly (P<.001) elevated in CAD patients compared with control. Moreover, RANTES serum level did not show any significant change in CAD patients.

CONCLUSION

Based on our result, it is quite clear that inflammation has a role in the pathogenesis of CAD but does not lead to significant changes at the genetic level in our population. As far as our knowledge goes, this is the first report that shows the genetic diversity in IL-6 and RANTES promoters and their respective levels in Saudi CAD patients.