Association of interleukin-6 (IL-6)-174G/C gene polymorphism with cardiovascular disease in patients with rheumatoid arthritis: the role of obesity and smoking

Characterization of clinical, laboratory, IL-6 serum levels, and IL-6-174 G/C genetic polymorphisms in patients with rheumatoid arthritis and Sjögren's syndrome

OBJECTIVE

This study aimed to characterize the clinical (disease activity and exocrine gland function), laboratory, interleukin 6 (IL-6) serum levels, and IL-6-174G/C (rs1800795) genetic polymorphisms among rheumatoid arthritis (RA), RA plus Sjögren's syndrome (RA+SS), and control subjects.

METHODS

A case-control study enrolling 137 women (52±11 years old) were divided into three groups as follows: RA (n=70), RA+SS (n=29), and healthy control (C, n=38). Individuals underwent clinical evaluation composed of Schirmer's test, unstimulated salivary flow rate, and evaluation of disease activity and functional capacity (Disease Activity Score [DAS28] and Health Assessment Questionnaire [HAQ]). IL-6 serum levels and IL-6-174G/C polymorphisms were assessed.

RESULTS

RA and RA+SS presented higher serum levels of IL-6 than controls (p<0.001). Also, higher IL-6 levels were related to swollen joints (p=0.038), limited functional capacity (p=0.004), and disease activity (p≤0.001). However, neither IL-6-174G/C genetic polymorphism nor its allele frequency was associated with RA or RA+SS.

CONCLUSION

IL-6 serum is an important marker of RA activity and functional incapacity, but IL-6-174G/C genetic polymorphism did not differ among healthy controls and cases.

Cytokine Levels at Birth in Children Who Developed Acute Lymphoblastic Leukemia

BACKGROUND

Prenatal immune development may play an important role in the etiology of childhood acute lymphoblastic leukemia (ALL).

METHODS

Seven cytokines, IL1β, IL4, IL6, IL8, GM-CSF, TNFα, and VEGF, were analyzed in blood spots collected at birth from 1,020 ALL cases and 1,003 controls participating in the California Childhood Leukemia Study. ORs and 95% confidence intervals (95% CI) associated with an interquartile range increment in cytokine levels were calculated using logistic regression, adjusting for sociodemographic and birth characteristics.

RESULTS

We found that patients with ALL were born with higher levels of a group of correlated cytokines than controls [IL1β: OR of 1.18 (95% confidence interval [CI], 1.03-1.35); IL8: 1.19 (1.03-1.38); TNFα: 1.15 (1.01-1.30); VEGF: 1.16 (1.01-1.33)], especially among children of Latina mothers (ORs from 1.31 to 1.40) and for ALL with high hyperdiploidy (ORs as high as 1.27). We found that neonatal cytokine levels were correlated with neonatal levels of endogenous metabolites which had been previously associated with ALL risk; however, there was no evidence that the cytokines were mediating the relationship between these metabolites and ALL risk.

CONCLUSIONS

We posit that children born with altered cytokine levels are set on a trajectory towards an increased risk for subsequent aberrant immune reactions that can initiate ALL.

IMPACT

This is the first study to evaluate the interplay between levels of immunomodulatory cytokines at birth, prenatal exposures, and the risk of childhood ALL.

Relationship Between Interleukin-6 -174G/C Genetic Variant and Efficacy of Methotrexate Treatment in Psoriatic Arthritis Patients

Introduction

The purpose of the study was to investigate whether single-nucleotide polymorphisms (SNPs) IL-6 −174 G/C and IL-6R Asp358Ala are associated with susceptibility to psoriatic arthritis (PsA) or affect response to treatment with methotrexate (MTX).

Patients and Methods

Seventy-four patients diagnosed with PsA and qualified for MTX treatment were enrolled to the study. The control group consisted of 120 healthy individuals. Polymorphisms IL-6 −174 G/C and IL-6R Asp358Ala were genotyped using a polymerase chain reaction (PCR) amplification employing LightSNiP assays.

Results

A significant association between the IL-6 −174 CC genotype and an improved clinical outcome of MTX therapy was observed. A good response was more frequently observed among PsA patients bearing the IL-6 −174 CC genotype than patients with the GC or GG genotypes (P = 0.007). On the other hand, patients carrying the IL-6 −174 GC genotype less frequently responded to MTX treatment as compared to patients with other genotypes (P = 0.006). With respect to the IL-6R Asp358Ala SNP, there were no significant differences in genotype and allelic frequencies in relation to clinical outcome of MTX treatment. No association was found between the IL-6 −174 G/C or IL-6R Asp358Ala SNPs and PsA susceptibility.

Conclusion

Results from this study provide evidence that the IL-6 −174 G/C polymorphism might influence efficacy of MTX treatment.

Smoking cessation is associated with lower disease activity and predicts cardiovascular risk reduction in rheumatoid arthritis patients

Objectives

Smoking is a major risk factor for the development of both cardiovascular disease (CVD) and RA and may cause attenuated responses to anti-rheumatic treatments. Our aim was to compare disease activity, CVD risk factors and CVD event rates across smoking status in RA patients.

Methods

Disease characteristics, CVD risk factors and relevant medications were recorded in RA patients without prior CVD from 10 countries (Norway, UK, Netherlands, USA, Sweden, Greece, South Africa, Spain, Canada and Mexico). Information on CVD events was collected. Adjusted analysis of variance, logistic regression and Cox models were applied to compare RA disease activity (DAS28), CVD risk factors and event rates across categories of smoking status.

Results

Of the 3311 RA patients (1012 former, 887 current and 1412 never smokers), 235 experienced CVD events during a median follow-up of 3.5 years (interquartile range 2.5–6.1). At enrolment, current smokers were more likely to have moderate or high disease activity compared with former and never smokers (P < 0.001 for both). There was a gradient of worsening CVD risk factor profiles (lipoproteins and blood pressure) from never to former to current smokers. Furthermore, former and never smokers had significantly lower CVD event rates compared with current smokers [hazard ratio 0.70 (95% CI 0.51, 0.95), P = 0.02 and 0.48 (0.34, 0.69), P < 0.001, respectively]. The CVD event rates for former and never smokers were comparable.

Conclusion

Smoking cessation in patients with RA was associated with lower disease activity and improved lipid profiles and was a predictor of reduced rates of CVD events.

Cardiovascular Risk in Rheumatoid Arthritis and Mechanistic Links: From Pathophysiology to Treatment

Rheumatoid arthritis (RA) is an autoimmune inflammatory arthritis. Inflammation, however, can spread beyond the joints to involve other organs. During the past few years, it has been well recognized that RA associates with increased risk for cardiovascular (CV) disease (CVD) compared with the general population. This seems to be due not only to the increased occurrence in RA of classical CVD risk factors and comorbidities like smoking, obesity, hypertension, diabetes, metabolic syndrome, and others but also to the inflammatory burden that RA itself carries. This is not unexpected given the strong links between inflammation and atherosclerosis and CVD. It has been shown that inflammatory cytokines which are present in abundance in RA play a significant role in every step of plaque formation and rupture. Most of the therapeutic regimes used in RA treatment seem to offer significant benefits to that end. However, more studies are needed to clarify the effect of these drugs on various parameters, including the lipid profile. Of note, although pharmacological intervention significantly helps reduce the inflammatory burden and therefore the CVD risk, control of the so-called classical risk factors is equally important. Herein, we review the current evidence for the underlying pathogenic mechanisms linking inflammation with CVD in the context of RA and reflect on the possible impact of treatments used in RA.

Polymorphisms Involved in Response to Biological Agents Used in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic disease that leads to joint destruction. During the last decade, the therapy of RA has been principally based on biological drugs. Although the efficacy of biological therapy has been established, patients demonstrated a high heterogeneity in clinical response to treatment. Several genetic polymorphisms play a part in the different response to biological drugs. This review summarizes the pharmacogenetics of biological agents approved for clinical RA treatment. We reviewed PubMed papers published over the past 20 years (2000-2020), inserting as the search term "rheumatoid arthritis and polymorphisms". Despite some studies showing important correlations between genetic polymorphisms and response to biological therapy in RA patients, most of these findings are still lacking and inconsistent. The personalized treatment according to a pharmacogenetics approach is promising but the available pharmacogenetics data on biological treatment in RA are not adequate and reliable to recommend pharmacogenetic tests before starting biological therapy in RA patients.

Associations between IL-6 Variations and Congenital Heart Disease Incidence among Chinese Han People

Background

Our research explored if Interleukin-6 (IL-6) variants held substantial connection to congenital heart disease (CHD) susceptibility among Chinese Han children.

Material/Methods

A total of 102 CHD children were recruited as the case group while 98 healthy persons were recruited as the control group. We used polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) completed genotyping for IL-6 variants rs1800795 and rs1800796. The Hardy-Weinberg equilibrium (HWE) among controls was tested using χ² analysis. Genotype and allele frequencies for variants were compared between groups. Odds ratio (OR) accompanied by 95% confidence interval (CI) reflected the potential link of IL-6 variants to CHD occurrence.

Results

A remarkable increased trend of rs1800795 CC genotype and C allele was detected in the CHD patient group (P<0.05). Individuals carrying rs1800795 CC genotype showed higher risk for CHD (OR=3.763, 95% CI=1.162–12.190). In addition, rs1800795 C allele could increase CHD incidence (OR=1.766, 95% CI=1.101–2.832). No significant differences were detected in IL-6 gene rs1800796 polymorphism in both genotype and allele distributions between the case group and the control group (P>0.05). These associations had no significant alteration after the adjustment of age, gender, maternal smoking history, and maternal history of diabetes.

Conclusions

IL-6 variant rs1800795 exhibited a close relation to CHD susceptibility among Chinese Han people while the mutant C allele promoted CHD incidence. But rs1800796 variant showed no such influence.

Relationship between polymorphisms in -572G/C interleukin 6 promoter gene polymorphisms (rs1800796) and risk of rheumatoid arthritis: A meta-analysis

AIMS

This meta-analysis was aimed to investigate the association between -572G/C interleukin (IL)-6 gene polymorphism and occurrence risk of rheumatoid arthritis (RA).

METHODS

Literature search was conducted in PubMed, Embase, Springer and Google Scholar up to November 2018. The pooled odds ratios (ORs) and 95% confidence interval (CI) were calculated by Revman 5.3.

RESULTS

A total of six case-control studies were included in this meta-analysis. In the allele model (G vs C), homozygous gene model (GG vs CC), recessive gene model (GG vs GC + CC), and dominant gene model (GG + GC vs CC), the pooled estimate indicated there was significant association between -572G/C IL-6 gene polymorphism and risk of RA. However, no significant statistical results were found in meta-analyses of heterozygote gene models.

CONCLUSIONS

The -572G/C IL-6 gene polymorphism is associated with the risk of RA. The GG genotype may be the main contributor in increasing susceptibility to RA.

Interleukin-6 and body mass index, tobacco use, and sleep in gynecologic cancers

OBJECTIVE

Elevated body mass index (BMI), tobacco use, and sleep disturbance are common health concerns among women with gynecologic cancers. The extent to which these factors are associated with systemic inflammation in gynecologic cancers is unknown. This is a significant literature gap given that (a) chronic, systemic inflammation may mediate relationships between behavioral health factors and cancer outcomes; and (b) elevated BMI, tobacco use, and sleep disturbances can be modified via behavioral interventions. This study examined Interleukin-6 (IL-6) relations with BMI, tobacco use history, and sleep disturbances in patients undergoing surgery for suspected gynecologic cancer.

METHOD

Participants were 100 women (M age = 58.42 years, SD = 10.62 years) undergoing surgery for suspected gynecologic cancer. Smoking history was determined by participant self-report. Sleep quality/disturbance was assessed via the Pittsburgh Sleep Quality Index. BMI was abstracted from electronic health records. Presurgical serum IL-6 concentrations were determined using Enzyme-Linked Immunosorbent Assay.

RESULTS

Controlling for the cancer type and stage, regression analyses revealed higher BMI, β = 0.258, p = .007, and former/current smoking status, β = 0.181, p = .046, were associated with higher IL-6. IL-6 did not differ between former and current smokers, β = 0.008, p = .927. Global sleep quality, sleep latency, and sleep efficiency were not associated with IL-6.

CONCLUSIONS

Higher BMI and any history of tobacco use predicted higher IL-6 among women undergoing surgery for suspected gynecologic cancers. Cognitive-behavioral interventions targeting primary and secondary obesity and tobacco use prevention may reduce systemic inflammation and optimize cancer outcomes in this population. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Plasma Leptin Does Not Reflect the Effect of High Body Mass Index on Disease Activity in Rheumatoid Arthritis

Background: The effect of obesity on disease severity in rheumatoid arthritis (RA) remains controversial. Adipocytes secrete pro-inflammatory cytokines and adipokines which may contribute to RA disease activity. The goal of the present study is to address the association between body mass index (BMI) with plasma levels of leptin, pro-inflammatory cytokines, and RA disease severity.Methods: Fifty RA patients (20 newly diagnosed and 30 under treatment) as well as 30 age- and sex-matched healthy subjects were included in this survey. The plasma levels of leptin and pro-inflammatory cytokines, including TNF-α and IL-6, were measured, and the results were compared among the patients in the three different categories of BMI, including <25, ≥25-30, and ≥30.Results: In our study, a significant positive correlation was observed between disease activity score-28 (DAS-28) and BMI in overweight (OW) RA patients (p = .036 r = 0.440). The plasma levels of leptin were significantly higher in patients group, compared to healthy subjects (p < .05); moreover, leptin levels were significantly higher in OW and obese patients compared to RA patients with normal BMI (p = .011, p = .001, respectively) and also BMI had positive correlation with leptin concentrations just in the newly diagnosed patients (p < .0001, r = 0.748). There was no correlation between leptin and DAS-28. The plasma IL-6 and TNF-α did not show significant differences between RA patients and healthy subjects, and also the plasma leptin did not have any correlation with plasma levels of IL-6 and TNF-α.Conclusion: BMI contribution to RA disease severity is independent of systemic levels of leptin and pro-inflammatory cytokines.

Interleukin 6 (rs1800795) gene polymorphism is associated with cardiovascular diseases: a meta-analysis of 74 studies with 86,229 subjects

Cardiovascular diseases (CVD) are group of complex and multifactorial pathologies, in which interleukin-6 (IL-6) gene polymorphisms have been associated with several components of the CVD. Thus, in this study, we thoroughly reviewed and meta-analyzed evidence on the association between the IL-6 (rs1800795) gene polymorphism and CVD. We systematically searched in the PubMed, Web of Sciences, and Scopus databases. The analyses were performed using five study groups based on (1) a combined pool of the overall populations, (2) the country of birth, (3) the continent of birth, (4) the diagnosis and (5) both location (country or continent) and diagnosis. The analysis included the allelic, homozygote, heterozygote, dominant and recessive models. The meta-analysis showed that -174G>C (rs1800795) is a risk factor for CVD (allelic: OR=1.06, CI 95%=1.02-1.10. Z p value <0.0001; homozygous: OR=1.11, CI 95%=1.03-1.19, Z p value= 0.002; heterozygous: OR=1.08, CI 95%=1.03-1.21, Z p value= 0.003; dominant: OR= 1.12, CI 95%= 1.07-1.18, Z p value= 0.001) and that this risk increases in the Chinese population. Additionally, we found that carriers of the C allele of 174G>C (rs1800795) polymorphism have an increase in the risk of coronary artery disease under the hereditary models assessed in the study. Using robust data, we found that IL-6 (rs1800795) -174G>C gene polymorphism is associated with CVD risk.

Association between -174G>C polymorphism in the IL-6 promoter region and the risk of obesity: A meta-analysis

BACKGROUND

Many researchers have suggested that the -174G>C polymorphism in the interleukin-6 (IL-6) promoter region contributes to the risk of obesity; however, this hypothesis is still inconclusive. Therefore, we conducted a meta-analysis to combine the data from several studies to arrive at a conclusion regarding the association between -174G>C polymorphism and the risk of obesity.

METHODS

The PubMed and Embase databases were searched up to February 20, 2018. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using a random-effects model. Subgroup analysis and sensitivity were also performed.

RESULTS

Ten eligible studies involving 7210 cases were performed to identify the association strength. The association strength was measured by the ORs and 95% CIs. By pooling the eligible studies, we found a significant association between the -174G>C polymorphism and obesity risk (C vs G: OR = 1.37; 95% CI, 1.08-1.74; Pheterogeneity < .01). Overall, individuals with the variant CC (OR = 1.58; 95% CI, 1.09-2.28; Pheterogeneity < 0.01) and GC/CC (OR = 1.61; 95% CI, 1.13-2.29; Pheterogeneity < .01) were associated with a significantly increased risk of obesity.

CONCLUSION

The meta-analysis results suggested that the polymorphism -174G>C in the IL-6 promoter region was associated with a significantly increased risk of obesity.

Interleukin 6 gene polymorphism is associated with protein serum level and disease activity in Polish patients with rheumatoid arthritis

Interleukin 6 (IL-6) is a pro-inflammatory cytokine involved in the development of rheumatoid arthritis (RA). The present study aimed to determine the possible association of the IL6 (rs1800795, G > C) polymorphism with RA susceptibility, disease progression and protein serum levels. Distribution of IL6 alleles and genotypes was similar in RA patients and controls. As expected, patients before induction of anti-tumour necrosis factor agents had significantly higher IL-6 levels as compared with controls (P = 0.002). The CC homozygous patients were characterised with the highest average concentrations of this pro-inflammatory cytokine before treatment (P = 0.028), and they also more frequently presented with more active disease (P = 0.048). These results imply that the IL6 rs1800795 CC homozygosity may play a rather unfavourable role in RA.

Streptococcal pharyngitis and rheumatic heart disease: the superantigen hypothesis revisited

Streptococcus pyogenes is a human-specific and globally prominent bacterial pathogen that despite causing numerous human infections, this bacterium is normally found in an asymptomatic carrier state. This review provides an overview of both bacterial and human factors that likely play an important role in nasopharyngeal colonization and pharyngitis, as well as the development of acute rheumatic fever and rheumatic heart disease. Here we highlight a recently described role for bacterial superantigens in promoting acute nasopharyngeal infection, and discuss how these immune system activating toxins could be crucial to initiate the autoimmune process in rheumatic heart disease.

Impact of anti-rheumatic treatment on cardiovascular risk in Asian patients with rheumatoid arthritis

OBJECTIVES

To estimate the incidence of cardiovascular disease (CVD) in Asian patients with rheumatoid arthritis (RA) and to evaluate the impact of anti-rheumatic treatment on the development of CVD.

METHODS

A retrospective cohort of Asian patients with RA was established to identify the incidence rate (IR) of CVD in RA patients. The cohort was generated using the Korean National Healthcare claims database, which contained claims from Jan 2009 to Dec 2013. A total of 137,512 RA patients were identified; individuals with a history of CVD for 6 months or more before the index date were excluded. Nested case-control samples were drawn from the full study population with a case:control ratio of 1:4 (n = 7102 cases; n = 27,018 controls without CVD). A conditional multivariate regression model was used to evaluate the impact of anti-rheumatic treatment on the development of CVD in RA patients after matching for age, sex, RA index date, comorbidities, and drug use (e.g., antiplatelet agents and cholesterol-lowering agents).

RESULTS

The IR for development of overall CVD in RA patients was 182.1 (95% CI: 178.4-185.9) per 10,000 person-years. In models adjusted for other CVD risk factors, disease-modifying anti-rheumatic drugs (DMARDs) (OR = 0.79) were protective against CVD, and biologic DMARDs were not significantly associated with CVD risk (OR = 0.85). Corticosteroids (OR = 1.26) and NSAIDs (nonselective NSAIDs: OR = 1.32, Cox-2 inhibitors: OR = 1.31) were risk factors for CVD in RA patients.

CONCLUSIONS

The use of DMARDs is protective against CVD, while corticosteroids and NSAIDs increased the risk of CVD in RA patients.

Sudden cardiac death in patients with rheumatoid arthritis

An increased cardiovascular morbidity and mortality, including the risk of sudden cardiac death (SCD), has been shown in patients with rheumatoid arthritis (RA). Abnormalities in autonomic markers such as heart rate variability and ventricular repolarization parameters, such as QTc interval and QT dispersion, have been associated with sudden death in patients with RA. The interplay between these parameters and inflammation that is known to exist with RA is of growing interest. In this article, we review the prevalence and predictors of SCD in patients with RA and describe the potential underlying mechanisms, which may contribute to this. We also review the impact of biologic agents on arrhythmic risk as well as cardiovascular morbidity and mortality.

Coronary Artery Calcification and Rheumatoid Arthritis: Lack of Relationship to Risk Alleles for Coronary Artery Disease in the General Population

OBJECTIVE

Coronary artery disease (CAD) in the general population is characterized by an increased frequency of particular susceptibility single-nucleotide polymorphisms (SNPs). Because the frequency of CAD is increased among patients with rheumatoid arthritis (RA), we sought to determine whether the frequency of these SNPs is increased in RA patients with CAD, hypothesizing that RA could enhance CAD risk by acting through established genetic pathways predisposing to CAD.

METHODS

Coronary artery calcification (CAC) as detected by computed tomography was used as a measure of CAD in 561 patients with RA. One hundred SNPs associated with CAD in the general population were genotyped or imputed, and their relationship to CAC was established through multiple regression analysis for individual SNPs and a genetic risk score representing their cumulative effect.

RESULTS

Ninety-one CAD-related SNPs were genotyped successfully; of these, 81 exhibited no association with CAC (Agatston units) or different CAC categorizations, either individually or collectively, in the genetic risk score. Only rs579459 (ABO) and rs17676451 (HAL) had a consistent positive association between genotype and CAC, with a significant increase in the frequency of the effect allele in both homozygous and heterozygous genotype distributions. Five were variably negatively associated. Furthermore, a positive association between the Disease Activity Score in 28 joints and CAC was observed, and after adjustment for traditional cardiovascular risk factors, it was not modified by correcting for the CAD-related SNP genetic risk score.

CONCLUSION

The increased risk of CAC in patients with RA does not appear to operate primarily through established genetically regulated atherogenic mechanisms that are preponderant in the general population.

The -174G/C Interleukin-6 Gene Promoter Polymorphism as a Genetic Marker of Differences in Therapeutic Response to Methotrexate and Leflunomide in Rheumatoid Arthritis

Objective. To evaluate the association of -174G/C IL-6 polymorphism with failure in therapeutic response to methotrexate (MTX) or leflunomide (LEF). This prospective, observational cohort included 96 Mexican-Mestizo patients with moderate or severe rheumatoid arthritis (RA), initiating MTX or LEF, genotyped for IL-6 -174G/C polymorphism by PCR-RFLP. Therapeutic response was strictly defined: only if patients achieved remission or low disease activity (DAS-28 < 3.2). Results. Patients with MTX or LEF had significant decrement in DAS-28 (p < 0.001); nevertheless, only 14% and 12.5% achieved DAS-28 < 3.2 at 3 and 6 months. After 6 months with any of these drugs the -174G/G genotype carriers (56%) had higher risk of therapeutic failure compared with GC (RR: 1.19, 95% CI: 1.07-1.56). By analyzing each drug separately, after 6 months with LEF, GG genotype confers higher risk of therapeutic failure than GC (RR = 1.56; 95% CI = 1.05-2.3; p = 0.003), or CC (RR = 1.83; 95% CI = 1.07-3.14; p = 0.001). This risk was also observed in the dominant model (RR = 1.33; 95% CI = 1.03-1.72; p = 0.02). Instead, in patients receiving MTX no genotype was predictor of therapeutic failure. We concluded that IL-6 -174G/G genotype confers higher risk of failure in therapeutic response to LEF in Mexicans and if confirmed in other populations this can be used as promissory genetic marker to differentiate risk of therapeutic failure to LEF.

[Interleukin-6 inhibition and cardiovascular disease in patients with rheumatoid arthritis]

Rheumatoid arthritis (RA) is a' disease conferring high risk for cardiovascular events (CVE). Systemic inflammation underlying RA favors development of CVE. The safety of biological agents, acting on the cardiovascular system has been inadequately investigated. On the one hand, they decrease RA activity and, on the other, may increase the risk of CVE. This review analyzes' the literature data predominantly published in recent years on the effect of an IL-6 receptor inhibitor on the cardiovascular system. Tocilizumab is shown to be a promising agent to reduce cardiovascular risk the findings need to be clinically verified. Long-term prospective investigations should be conducted to determine more exactly the impact of IL-6 receptor inhibition on. the development of CVE.

Circulating interleukin-6 and rheumatoid arthritis: A Mendelian randomization meta-analysis

Interleukin-6 (IL-6), as a pleiotropic cytokine, has been demonstrated to be closely associated with the pathogenisis of rheumatoid arthritis (RA). However, whether this association is causal or not remains unclear, because of the multifactorial role of IL-6 and related confounding factors. We aimed to evaluate the causal relevance between circulating IL-6 levels and the risk of RA through meta-analytical Mendelian randomization approach. IL-6 gene -174G/C variant was selected as an instrument in this Mendelian randomization meta-analysis. Article identification and data collection were conducted in duplicate and independently by 2 authors. The STATA software was used for data analysis. In total, 15 and 5 articles on the association of the -174G/C variant with RA risk and circulating IL-6 level, respectively, were included. The overall analysis showed that C allelic and GC+CC genotype were significantly with 1.59-fold (95% CI: 1.19-2.14) and 1.63-fold (95% CI: 1.17-2.26) increased risk of developing RA, respectively. Asian populations showed stronger association with 4.55-fold (95% CI: 1.62-12.75), 1.84-fold (95% CI: 1.13-2.99), and 4.69-fold (95% CI: 1.68-13.14) increased RA risk in carriers of -174C allelic, CC, and GC+CC genotype, respectively. Carriers of GC+CC genotype showed significant reduction in the circulating IL-6 level compared with GG carriers (WMD = -0.77; 95% CI: -1.16 to -0.38; P = 0.000) in overall populations. Mendelian randomization presented 6% and 22% increased risk of RA with 0.1 pg/mL reduction of circulating IL-6 level in overall and Asian populations, respectively. This Mendelian randomization meta-analysis demonstrated that the long-term genetically reduced circulating IL-6 level might be causally related to a higher risk of RA, especially in Asian populations.

Genetic polymorphism directs IL-6 expression in fibroblasts but not selected other cell types

Interleukin (IL)-6 blockade is an effective treatment for rheumatoid arthritis (RA), and synovial fibroblasts are a major IL-6 producer in the inflamed joint. We found that human RA and osteoarthritis (OA) synovial fibroblasts derived from independent donors reproducibly segregated into low, medium, and high IL-6 producers, independent of stimulus, cell passage, or disease state. IL-6 expression pattern correlated strongly with total mRNA expression, not mRNA stability, suggesting transcriptional rather than posttranscriptional regulation. High-fibroblast IL-6 expression was significantly associated with the IL-6 proximal promoter single nucleotide polymorphism (SNP) rs1800795 minor allele (CC) genotype. In contrast, no association between this SNP and IL-6 production was detected in CD14(+) monocytes, another major producer of synovial IL-6. Luciferase expression assays confirmed that this SNP was associated with differential IL-6 expression in fibroblasts. To date, several association studies examining rs1800795 allele frequency and disease risk have reported seemingly conflicting results ranging from no association to association with either the major or minor allele across a spectrum of conditions, including cancer and autoimmune, cardiovascular, infectious, and metabolic diseases. This study points to a prominent contribution from promoter genetic variation in fibroblast IL-6 regulation, but not in other IL-6-producing cell types. We propose that some of the heterogeneity in these clinical studies likely reflects the cellular source of IL-6 in specific diseases, much of which may be produced by nonhematopoietic cells. These results highlight that functional analysis of disease-associated SNPs on gene expression and pathologic processes must consider variation in diverse cell types.

Interleukin-6 promoter haplotypes are associated with etanercept response in patients with rheumatoid arthritis

Indices prognosticating anti-tumor necrosis factor (TNF) response in patients with rheumatoid arthritis are a matter of interest. Differential outcome under anti-TNF and anti-interleukin-6 (IL-6) therapy raises the question whether genetic polymorphisms that have previously been linked to IL-6 production are associated with response to anti-TNF therapy. Fifty (50) rheumatoid arthritis (RA) patients were treated with etanercept (median 36 weeks, range 4-52). In terms of the EULAR response criteria, 25 patients responded well, 17 patients moderately and 8 patients not. By direct sequencing, the patients and 91 matched healthy controls were genotyped for the IL-6 promoter SNPs -597G > A (rs1800797), -572G > C (rs1800796) and -174G > C (rs1800795) and for an AnTn microsatellite tract at -373. Alleles and haplotypes were tested for association with disease susceptibility and therapy response. No significant difference was seen in the genotype distribution between patients and healthy controls. Confirming the results of previous studies, we observed a trend of -174G being more frequent in patients with a good or moderate therapy response. Beyond that, carriage of the A9T11 microsatellite allele within the -174G haplotype was associated most closely with a favourable response (relative risk 1.31; 95 % confidence interval 1.02-1.68). A subtle analysis of the IL-6 promoter giving respect to its complex haplotypic structure results in more precise information as to the association of genotypes with the long-term etanercept response. Despite a conclusive hypothesis that a genetically determined IL-6-dominated RA responds less well to anti-TNF, more work has to be done to provide us with reliable information regarding the functional aspects of these genetic polymorphisms.

Influence of Promoter Polymorphisms of the TNF-α (-308G/A) and IL-6 (-174G/C) Genes on Therapeutic Response to Etanercept in Rheumatoid Arthritis

Background

The study was undertaken to assess the influence of functional -308G/A TNF-α (rs 1800629) and -174G/C IL-6 (rs1800795) promoter polymorphisms on the therapeutic response to etanercept, a TNF-α blocker, in patients with rheumatoid arthritis (RA).

Methods

Seventy-three patients suffering from active RA were studied, at baseline and 6 and 12 months after therapy. The therapeutic response was estimated according to the European League Against Rheumatism response criteria. Patients were genotyped for -308G/A TNF-α and -174G/C IL-6 polymorphisms by the PCR-RFLP method, and the influence of genotype on etanercept response was assessed.

Results

No difference in the percentage of responders (patients who had DAS28 improvement > 1.2) between patients with the TNF-α-308GG and GA and AA genotype was detected after 6 and 12 months of treatment. After 12 months of treatment the percentage of responders was significantly increased in patients with the IL-6 -174GG genotype compared with those with the GC or CC genotype (p=0.006 by Chi-square test). Evaluation of the patients according to their combined IL-6/TNF-α genotypes showed that patients with the IL-6 -174GG / TNF-α-308GG genotype were more frequent among the responders compared to those with other combined genotypes (p=0.022 by Chi-square test). More precisely, all patients with the combined IL-6 -174GG / TNF-α-308GG genotype were responders after 12 months of etanercept treatment.

Conclusions

The study suggests that patients who are genetically low TNF-α and IL-6 producers are the best responders to etanercept therapy.

The -308 TNFα and the -174 IL-6 promoter polymorphisms associate with effective anti-TNFα treatment in seronegative spondyloarthritis

The genetic predisposition to a long-term efficacy of anti-tumor necrosis factor (TNF)α treatment in seronegative spondyloarthritis (SpA) was investigated by analysing the possible correlation between several single nucleotide gene polymorphisms and the retention rate of anti-TNFα therapies. We compared patients needing to switch the first anti-TNFα (Sw, No. 64) within at least 12 months of follow-up with patients not needing to switch (NSw, No. 123), observing at least 6 months of treatment to establish anti-TNFα failure, leading to treatment change. Response to treatment was evaluated by standardised criteria (BASDAI for axial involvement, DAS28-EULAR for peripheral involvement). The TNFα -308 A allele and the interleukin (IL)-6 -174GG homozygosis resulted as independent biomarkers predicting survival of the first anti-TNFα therapy in SpA patients (P=0.007, odds ratio (OR): 4.4, 95% confidence interval (CI)=1.5-13.1 and P=0.035, OR: 2.1, 95% CI=1.1-4.4). Also, the male gender (P=0.001, OR: 3.4, 95% CI=1.6-7.1) associated with the NSw phenotype, whereas no association was found either with the specific diagnosis or the predominant joint involvement.

Circulating miRNAs as potential biomarkers of therapy effectiveness in rheumatoid arthritis patients treated with anti-TNFα

Introduction

The advent of anti-tumor necrosis factor alpha (anti-TNFα) drugs has considerably improved medical management in rheumatoid arthritis (RA) patients, although it has been reported to be ineffective in a fraction of them. MicroRNAs (miRNAs) are small, non-coding RNAs that act as fine-tuning regulators of gene expression. Targeting miRNAs by gain or loss of function approaches have brought therapeutic effects in various disease models. The aim of this study was to investigate serum miRNA levels as predictive biomarkers of response to anti-TNFα therapy in RA patients.

Methods

In total, 95 RA patients undergoing anti-TNFα/disease-modifying antirheumatic drugs (anti-TNFα/DMARDs) combined treatments were enrolled. Serum samples were obtained at 0 and 6 months and therapeutic efficacy was assessed. miRNAs were isolated from the serum of 10 patients before and after anti-TNFα/DMARDs combination therapy, cDNA transcribed and pooled, and human serum miRNA polymerase chain reaction (PCR) arrays were performed. Subsequently, selected miRNAs were analyzed in a validation cohort consisting of 85 RA patients. Correlation studies with clinical and serological variables were also performed.

Results

Ninety percent of RA patients responded to anti-TNFα/DMARDs combination therapy according to European League Against Rheumatism (EULAR) criteria. Array analysis showed that 91% of miRNAS were overexpressed and 9% downregulated after therapy. Functional classification revealed a preponderance of target mRNAs involved in reduction of cells maturation - especially on chondrocytes - as well as in immune and inflammatory response, cardiovascular disease, connective tissue and musculoskeletal system. Six out of ten miRNAs selected for validation were found significantly upregulated by anti-TNFα/DMARDs combination therapy (miR-16-5p, miR-23-3p, miR125b-5p, miR-126-3p, miRN-146a-5p, miR-223-3p). Only responder patients showed an increase in those miRNAs after therapy, and paralleled the reduction of TNFα, interleukin (IL)-6, IL-17, rheumatoid factor (RF), and C-reactive protein (CRP). Correlation studies demonstrated associations between validated miRNAs and clinical and inflammatory parameters. Further, we identified a specific plasma miRNA signature (miR-23 and miR-223) that may serve both as predictor and biomarker of response to anti-TNFα/DMARDs combination therapy.

Conclusions

miRNA levels in the serum of RA patients before and after anti-TNFα/DMARDs combination therapy are potential novel biomarkers for predicting and monitoring therapy outcome.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0555-z) contains supplementary material, which is available to authorized users.

Muscle wasting in rheumatoid arthritis: The role of oxidative stress

Rheumatoid arthritis (RA), the commonest inflammatory arthritis, is a debilitating disease leading to functional and social disability. In addition to the joints, RA affects several other tissues of the body including the muscle. RA patients have significantly less muscle mass compared to the general population. Several theories have been proposed to explain this. High grade inflammation, a central component in the pathophysiology of the disease, has long been proposed as the key driver of muscle wasting. More recent findings however, indicate that inflammation on its own cannot fully explain the high prevalence of muscle wasting in RA. Thus, the contribution of other potential confounders, such as nutrition and physical activity, has also been studied. Results indicate that they play a significant role in muscle wasting in RA, but again neither of these factors seems to be able to fully explain the condition. Oxidative stress is one of the major mechanisms thought to contribute to the development and progression of RA but its potential contribution to muscle wasting in these patients has received limited attention. Oxidative stress has been shown to promote muscle wasting in healthy populations and people with several chronic conditions. Moreover, all of the aforementioned potential contributors to muscle wasting in RA (i.e., inflammation, nutrition, and physical activity) may promote pro- or anti-oxidative mechanisms. This review aims to highlight the importance of oxidative stress as a driving mechanism for muscle wasting in RA and discusses potential interventions that may promote muscle regeneration via reduction in oxidative stress.

IL6 genotype, tumour ER-status, and treatment predicted disease-free survival in a prospective breast cancer cohort

Background

In breast cancer, high levels of the inflammatory cytokine interleukin-6 (IL-6) have been associated with disease-free survival and treatment resistance. Increased serum levels of IL-6 have been correlated with increased levels of NF-κβ and aromatase expression in adipose tissue. Several IL6 single nucleotide polymorphisms have been associated with breast cancer prognosis, but the impact may differ depending on tumour oestrogen receptor (ER) status. This translational study investigated the association between IL6 genotypes, ER-status, and treatment on the risk of early events among breast cancer patients.

Methods

The study included 634 25- to 99-year-old primary breast cancer patients in Sweden from 2002–2008. Genotyped IL6 single nucleotide polymorphisms rs1800797, rs1800796, rs1800795, and rs2069849 were analysed separately and as diplotypes. Disease-free survival was assessed for 567 patients. Clinical data, patient-, and tumour-characteristics were obtained from questionnaires, patient charts, population registries, and pathology reports.

Results

The median follow-up time was 5.1 years. IL6 diplotype was not associated with early events for all 567 patients, but AGCC/AGCC diplotype-carriers with ER-negative tumours had an increased risk, (adjusted Hazard Ratio (HR) = 5.91, 95% CI: 1.28–27.42). Any C-carriers (rs1800795) with ER-negative tumours had a higher risk of early events than GG-carriers with ER-negative tumours, (adjusted HR = 3.76, 95% CI: 1.05–13.43), particularly after radiotherapy (adjusted HR = 7.17, 95% CI: 1.16–32.28). Irrespective of ER-status, chemotherapy-treated Any C-carriers had a higher risk of early events than GG-carriers (adjusted HR = 3.42, 95% CI: 1.01–11.54).

Conclusions

The main finding of the present study was that IL6 genotype was strongly associated with early events among patients with ER-negative tumours, particularly among radiotherapy-treated patients, and among chemotherapy-treated patients irrespective of ER-status. The high risk for early events observed in these subgroups of patients suggests that combined information on IL6 genotype, tumour ER-status, and breast cancer treatment may represent a tool for identifying patients who require more personalised treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-759) contains supplementary material, which is available to authorized users.

RADB: a database of rheumatoid arthritis-related polymorphisms

Rheumatoid arthritis (RA) is an autoimmune disease that has a complex genetic basis. Therefore, it is important to explore the genetic background of RA. The extensive recent application of polymorphic genetic markers, especially single nucleotide polymorphisms, has presented us with a large quantity of genetic data. In this study, we developed the Database of Rheumatoid Arthritis-related Polymorphisms (RADB), to integrate all the RA-related genetic polymorphisms and provide a useful resource for researchers. We manually extracted the RA-related polymorphisms from 686 published reports, including RA susceptibility loci, polymorphisms associated with particular clinical features of RA, polymorphisms associated with drug response in RA and polymorphisms associated with a higher risk of cardiovascular disease in RA. Currently, RADB V1.0 contains 3235 polymorphisms that are associated with 636 genes and refer to 68 countries. The detailed information extracted from the literature includes basic information about the articles (e.g. PubMed ID, title and abstract), population information (e.g. country, geographic area and sample size) and polymorphism information (e.g. polymorphism name, gene, genotype, odds ratio and 95% confidence interval, P-value and risk allele). Meanwhile, useful annotations, such as hyperlinks to dbSNP, GenBank, UCSC, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway, are included. In addition, a tool for meta-analysis was developed to summarize the results of multiple studies. The database is freely available at http://www.bioapp.org/RADB.

Database URL:http://www.bioapp.org/RADB.

Polymorphisms of tumor necrosis factor-alpha and interleukin-6 gene and C-reactive protein profiles in patients with idiopathic dilated cardiomyopathy

BACKGROUND AND OBJECTIVES

The tumor necrosis factor-alpha (TNF-a) and interleukin (IL)-6 gene polymorphism has a controversial role in the pathogenesis of cardiovascular disease among different populations. The effect of the cytokine's gene polymorphism on idiopathic dilated cardiomyopathy (IDCM) is still unresolved. The current study aimed to evaluate the association of the TNF-a -308 G/A and IL-6 -174 G/C polymorphism with IDCM in a Pakistani population.

DESIGN AND SETTINGS

Blood samples for this case-control study were collected from the cardiology out.patient department of multiple cardiology centers of Rawalpindi/Islamabad, Pakistan, between July 2012 and December 2012.

PATIENTS AND METHODS

IDCM cases (number [n]=250) and healthy controls (n=300) were genotyped using polymerase chain reaction and restriction fragment length polymorphism.

RESULTS

The TNF-a -308 variant genotypes GA and AA were more prevalent in patients compared with the control group (P < .0001). Similarly, the IL-6 -174 variant genotypes GC and CC showed a high prevalence in patients with IDCM compared with healthy controls (P=.0019). IDCM cases had a higher prevalence of the TNFa-308A (P < .0001) and the IL-6 -174C (P=.0008) mutant alleles than did the control group. The IDCM cases bearing the TNF-a-308 and IL-6 variant genotypes revealed elevated levels of high-sensitivity C-reactive protein (hs-CRP) when compared with the corresponding controls (P < .05).

CONCLUSION

The TNF-a -308 G/A and IL-6 -174 G/C gene polymorphisms and high levels of hs-CRP may be associated with the pathogenesis of IDCM in the study population.

Cardiovascular involvement in autoimmune diseases

Autoimmune diseases (AD) represent a broad spectrum of chronic conditions that may afflict specific target organs or multiple systems with a significant burden on quality of life. These conditions have common mechanisms including genetic and epigenetics factors, gender disparity, environmental triggers, pathophysiological abnormalities, and certain subphenotypes. Atherosclerosis (AT) was once considered to be a degenerative disease that was an inevitable consequence of aging. However, research in the last three decades has shown that AT is not degenerative or inevitable. It is an autoimmune-inflammatory disease associated with infectious and inflammatory factors characterized by lipoprotein metabolism alteration that leads to immune system activation with the consequent proliferation of smooth muscle cells, narrowing arteries, and atheroma formation. Both humoral and cellular immune mechanisms have been proposed to participate in the onset and progression of AT. Several risk factors, known as classic risk factors, have been described. Interestingly, the excessive cardiovascular events observed in patients with ADs are not fully explained by these factors. Several novel risk factors contribute to the development of premature vascular damage. In this review, we discuss our current understanding of how traditional and nontraditional risk factors contribute to pathogenesis of CVD in AD.

Association between interleukin-6 gene polymorphisms and rheumatoid arthritis in Chinese Han population: a case-control study and a meta-analysis

The aim of this study was to investigate the possible association in the interleukin-6 (IL-6) gene with Rheumatoid arthritis (RA) in Chinese Han population from Shandong Province. Target regions of IL-6 gene were amplified by polymerase chain reaction (PCR) and genotyped. A logistic regression analysis was performed to detect potential associations in our case-control sample, the odd ratio(OR) and 95% confidence intervals(CIs) were calculated. Furthermore, we systematically tracked all the published studies in the field and performed a meta-analysis for the single nucleotide polymorphisms (SNPs) under study. 256 RA patients and 331 healthy controls were recruited into the case-control study. We found allele frequencies of rs1800795, rs1800797 and rs1474347 in RA patients differ from control subjects (P = 0.016, 0.024, 0.020, respectively). Significant difference was observed in haplotype frequencies of GCCGCT between RA patients and controls (P = 0.0001, OR = 4.066, 95%CI = 1.891 ~ 8.746), while GGCGCT frequencies was found lower in RA than controls (P = 0.006, OR = 0.669, 95%CI = 0.501 ~ 0.894). The results of the meta-analysis showed association polymorphism within the IL-6 promoter with RA. These findings suggest that rare IL-6 gene polymorphisms may associate with RA susceptibility in Han Chinese populations; however further studies are needed to assess the validity of the association of IL-6 with RA.

Interleukin-4, interleukin-4 receptor, and interleukin-18 polymorphisms and rheumatoid arthritis: a meta-analysis

OBJECTIVE

The aim of this study was to determine whether the functional interleukin-4 (IL-4) -590 C/T, IL-4 receptor (IL-4R) 1902 G/A, IL-18 -607 C/A, and -137 G/C polymorphisms polymorphisms confer susceptibility to rheumatoid arthritis (RA).

METHODS

Meta-analysis was conducted on the associations between these IL-4, IL-4R, and IL-18 polymorphisms and RA.

RESULTS

A total of 12 comparative studies were included in this meta-analysis. Meta-analysis of the IL-4 -590 C/T polymorphism showed an association in all study subjects and Europeans (OR for the TT genotype = 2.280, 95% CI = 1.315-3.952, p = 0.003; OR = 2.139, 95% CI = 1.089-4.199, p = 0.027). However, meta-analysis showed no association between RA and the IL-4R 1902 G allele in all study subjects and Europeans. Meta-analysis showed no association between RA and the IL-18 -607 C allele (OR = 1.159, 95% CI = 0.967-1.387, p = 0.110). Meta-analysis of the IL-18 -137 G/C polymorphism revealed no association between RA and the IL-18 -137 G/C polymorphism.

CONCLUSIONS

This meta-analysis demonstrates that the IL-4 -590 T/C polymorphism is associated with susceptibility to RA in Europeans, but the IL-4R + 1902 G/A, IL-18 -607 C/A and -137 G/C polymorphisms are not associated with RA.

Rheumatoid arthritis and cardiovascular disease: an update on treatment issues

PURPOSE OF REVIEW

This review examines thresholds for treatment of traditional cardiovascular disease (CVD) risk factors among patients with rheumatoid arthritis (RA) and whether RA-specific treatment modulates cardiovascular risk.

RECENT FINDINGS

There are substantial data demonstrating an increased CVD risk among patients with RA. Both traditional CVD risk factors and inflammation contribute to this risk. Recent epidemiologic studies strengthen the case that aggressive immunosuppression with biologic disease-modifying anti-rheumatic drugs (DMARDs), such as tumour necrosis factor (TNF) antagonists, is associated with a reduced risk of CVD events. However, to date, there are no randomized controlled trials published regarding the management of CVD in RA.

SUMMARY

Epidemiologic evidence continues to accumulate regarding the relationship between the effects of traditional CVD risk factors and RA-specific treatments on cardiovascular outcomes in RA. The field needs randomized controlled trials to better guide management.

Circulating concentrations of GLP-1 are associated with coronary atherosclerosis in humans

Background

GLP-1 is an incretine hormone which gets secreted from intestinal L-cells in response to nutritional stimuli leading to pancreatic insulin secretion and suppression of glucagon release. GLP-1 further inhibits gastric motility and reduces appetite which in conjunction improves postprandial glucose metabolism. Additional vasoprotective effects have been described for GLP-1 in experimental models. Despite these vasoprotective actions, associations between endogenous levels of GLP-1 and cardiovascular disease have yet not been investigated in humans which was the aim of the present study.

Methods

GLP-1 serum levels were assessed in a cohort of 303 patients receiving coronary CT-angiography due to typical or atypical chest pain.

Results

GLP-1 was found to be positively associated with total coronary plaque burden in a fully adjusted model containing age, sex, BMI, hypertension, diabetes mellitus, smoking, triglycerides, LDL-C (low density lipoprotein cholesterol), hsCRP (high-sensitive C-reactive protein), and eGFR (estimated glomerular filtration rate) (OR: 2.53 (95% CI: 1.12 – 6.08; p = 0.03).

Conclusion

Circulating GLP-1 was found to be positivity associated with coronary atherosclerosis in humans. The clinical relevance of this observation needs further investigations.

TGF-β1 limits the onset of innate lung inflammation by promoting mast cell-derived IL-6

TGF-β1 is an important suppressive mediator of inflammation, but it can also drive fibrosis and remodeling in the lung. In response to intratracheal LPS, neutrophils migrate into the lung, and TGF-β1 was suggested to protect against the ensuing injury. However, the mechanisms for this protective role remain unknown. Using a model of acute lung injury, we demonstrate that TGF-β1 decreases neutrophil numbers during the onset of injury. This was due to increased apoptosis rather than reduced migration. We demonstrate that TGF-β1 does not directly regulate neutrophil apoptosis but instead functions through IL-6 to promote neutrophil clearance. rIL-6 is sufficient to promote neutrophil apoptosis and reduce neutrophilia in bronchoalveolar lavage fluid, while IL-6 increases rapidly following LPS-induced injury. Mast cells are a critical source of IL-6, because mast cell-deficient mice exhibit increased neutrophil numbers that are reduced by reconstitution with wild-type, but not IL-6(-/-), mast cells. Although IL-6 diminishes neutrophilia in mast cell-deficient mice, TGF-β1 is ineffective, suggesting that these effects were mast cell dependent. Taken together, our findings establish a novel pathway through which TGF-β1, likely derived from resident regulatory T cells, controls the severity and magnitude of early innate inflammation by promoting IL-6 from mast cells.

Body composition and serum levels of adiponectin, vascular endothelial growth factor, and interleukin-6 in patients with rheumatoid arthritis

Aim

To investigate differences in body composition and body mass index (BMI) in patients with rheumatoid arthritis (RA) and their correlations with serum production of adiponectin, interleukin-6 (IL-6), and vascular endothelial growth factor (VEGF).

Methods

The study included 83 patients (age 53 ± 5 years) with RA treated with methotrexate. We determined their BMI, fat mass, and fat-free mass using bioimpedance analysis, and serum concentrations of adiponectin, VEGF, and IL-6 using immunoassay analysis.

Results

Normal BMI was found in 39 (47%), overweight and obesity in 26 (31%), and underweight in 18 (22%) patients. Concentration of adiponectin was lower in overweight/obese patients than in patients with normal BMI (2.1 [0.8-3.9] μg/mL vs 8.9 (7.2-11.3) μg/mL). In underweight patients, it was moderately increased (12.7 [9.3-14.8] μg/mL) and the correlation between the concentrations of adiponectin and IL-6 was positive (r = 0.4; P = 0.01). Concentrations of VEGF and IL-6 were increased in all groups with RA. The overweight/obese group showed a negative correlation between the concentrations of adiponectin and VEGF (r = - 0.34; P = 0.04), a positive correlation between VEGF concentration and fat mass (r = 0.39; P = 0.02), and a negative correlation between adiponectin concentration and fat mass (r = - 0.23; P = 0.02).

Conclusion

Inflammatory and angiogenesis activation was found in RA patients with all types of body composition, but only in those with obesity and overweight there was a direct antagonism between adiponectin and VEGF. Further research is needed to identify possible regimens of metabolic correction in different variations of body composition.

Health behaviors predict higher interleukin-6 levels among patients newly diagnosed with head and neck squamous cell carcinoma

BACKGROUND

Health behaviors have been shown to be associated with recurrence risk and survival rates in patients with cancer and are also associated with interleukin-6 (IL-6) levels, but few epidemiologic studies have investigated the relationship of health behaviors and IL-6 among cancer populations. The purpose of the study is to look at the relationship between five health behaviors, viz.: smoking, alcohol problems, body mass index (BMI; a marker of nutritional status), physical activity, and sleep and pretreatment IL-6 levels in persons with head and neck cancer.

METHODS

Patients (N = 409) were recruited in otolaryngology clinic waiting rooms and invited to complete written surveys. A medical record audit was also conducted. Descriptive statistics and multivariate analyses were conducted to determine which health behaviors were associated with higher IL-6 levels controlling for demographic and clinical variables among patients with newly diagnosed head and neck cancer.

RESULTS

While smoking, alcohol problems, BMI, physical activity, and sleep were associated with IL-6 levels in bivariate analysis, only smoking (current and former) and decreased sleep were independent predictors of higher IL-6 levels in multivariate regression analysis. Covariates associated with higher IL-6 levels were age and higher tumor stage, whereas comorbidities were marginally significant.

CONCLUSION

Health behaviors, particularly smoking and sleep disturbances, are associated with higher IL-6 levels among patients with head and neck cancer.

IMPACT

Treating health behavior problems, especially smoking and sleep disturbances, may be beneficial to decreasing IL-6 levels, which could have a beneficial effect on overall cancer treatment outcomes.

-174G/C interleukin-6 gene promoter polymorphism predicts therapeutic response to etanercept in rheumatoid arthritis

To examine whether -174G/C interleukin-6 (IL-6) gene polymorphism, previously reported to correlate with IL-6 level, influences response to etanercept therapy in patients with rheumatoid arthritis. Seventy-seven patients with active RA were studied, at baseline and 6- and 12-month follow-up after etanercept therapy. Treatment response was estimated according to the European League Against Rheumatism response criteria. RA patients were genotyped for -174G/C IL-6 gene polymorphism by the PCR-RFLP method, and influence of genotype at this polymorphism to clinical response to etanercept was assessed. After 12 months of treatment, the percentage of responders (patients who had DAS28 improvement >1.2) was significantly increased in patients carrying the IL-6 -174G/G genotype (95.7 %) compared with those with the G/C (75.6 %) or CC (44.4 %) genotype (p = 0.006 by Chi-square test). No significant difference in the mean values of DAS28 improvement was observed between groups with different genotype. RA patients with an IL-6 -174GG genotype respond to etanercept better than patients with GC or CC genotype. This finding, if confirmed in future studies, suggests that the -174G/C IL-6 polymorphism may be a genetic marker of responsiveness to tumor necrosis factor-alpha (TNF-α) blockers in RA.

Genetic markers of cardiovascular disease in rheumatoid arthritis

Cardiovascular (CV) disease is the most common cause of premature mortality in patients with rheumatoid arthritis (RA). It is the result of an accelerated atherosclerotic process. Both RA and atherosclerosis are complex polygenic diseases. Besides traditional CV risk factors and chronic inflammation, a number of studies have confirmed the role of genetic factors in the development of the atherogenesis observed in RA. In this regard, besides a strong association between the HLA-DRB1∗04 shared epitope alleles and both endothelial dysfunction, an early step in the atherosclerotic process, and clinically evident CV disease, other polymorphisms belonging to genes implicated in inflammatory and metabolic pathways, located inside and outside the HLA region, such as the 308 variant (G > A, rs1800629) of the TNFA locus, the rs1801131 polymorphism (A > C; position + 1298) of the MTHFR locus, or a deletion of 32 base pairs on the CCR5 gene, seem to be associated with the risk of CV disease in patients with RA. Despite considerable effort to decipher the genetic basis of CV disease in RA, further studies are required to better establish the genetic influence in the increased risk of CV events observed in patients with RA.