Plasma sIL-2R Research Articles

Circulating IL-6 and not its circulating signaling components sIL-6R and sgp130 demonstrate clinical significance in NSCLC patients treated with immune checkpoint inhibitors.

Introduction: Clinical roles of plasma IL-6 levels have been reported in patients with various cancers, including non-small cell lung cancer (NSCLC), treated with immune checkpoint inhibitors (ICIs). However, the roles of other IL-6 signaling components, soluble IL-6 receptor (sIL-6R) and soluble gp130 (sgp130), in the plasma have not been elucidated. Methods: Blood was collected from 106 patients with NSCLC before initiation of ICI treatment (anti-PD-1 or anti-PD-L1 antibody). Plasma levels of IL-6, sIL-6R, sgp130, and their complexes were assessed by Cox regression hazard model to evaluate their clinical significance. The clinical role of IL-6 or IL-6R genetic polymorphisms was also analyzed. Results: Cox regression analysis showed that higher plasma IL-6 levels significantly predicted unfavorable overall survival (OS; hazard ratio [HR] 1.34, 95% confidence interval [CI] 1.05-1.68, p = 0.012) in NSCLC patients treated with ICIs. However, plasma sIL-6R and sgp130 levels showed no prognostic significance (p = 0.882 and p = 0.934, respectively). In addition, the estimated concentrations of binary IL-6:sIL-6R and ternary IL-6:sIL-6R:sgp130 complexes and their ratios (binary/ternary complex) were not significantly associated with OS (p = 0.647, p = 0.727, and p = 0.273, respectively). Furthermore, the genetic polymorphisms of IL-6 (-634G>C) and IL-6R (48892A>C) showed no clinical role by Kaplan-Meier survival analysis (p = 0.908 and p = 0.639, respectively). Discussion: These findings demonstrated the clinical significance of plasma levels of IL-6, but not of other IL-6 signaling components, sIL-6R and sgp130, suggesting that classical IL-6 signaling, but not trans-signaling, may be related to anti-tumor immune responses in cancer patients treated with ICIs.

Investigation of the causal relationship between Interleukin-6 signaling and gastrointestinal tract cancers: A Mendelian randomization study

BackgroundObservational studies indicate that interleukin-6(IL-6) has been associated with gastrointestinal tract cancers. However, the causal association is still confusing. Thus, we aimed to putative the causality between IL-6 signaling and gastrointestinal tract cancers. MethodsWe conducted a two-sample Mendelian randomization analysis to assess the causal effects. Two groups of IL-6 signaling-related single nucleotide polymorphisms were chosen from two Genome-wide association studies. Summary-level data for gastrointestinal tract cancers including esophageal, gastric, and colorectal cancer, were obtained from the FinnGen consortium and UK Biobank study. We also performed survival analysis to explore the prognostic value of IL-6 in gastrointestinal tract cancers. ResultsGenetically predicted plasma sIL6R level, which inhibits IL-6 Signaling, was associated with a reduced risk of gastric cancer in FinnGen. In the combined analysis of the two sources, genetically predicted sIL6R was associated with a decreased risk of gastric cancer (OR = 0.943, 95%CI: 0.904,0.983, p = 0.006). Survival analysis results indicated the prognostic value of IL-6 in gastric cancer. ConclusionsThese results present evidence indicating that genetically-determined reduced IL-6 signaling lowers the risk of gastric cancer, which may provide potential prevention and therapeutic strategies for gastric cancer. Additionally, IL-6 may be a prognostic biomarker for gastric cancer.

Frequency of HLA-DR+CD38hi T cells identifies and quantifies T-cell activation in hemophagocytic lymphohistiocytosis, hyperinflammation, and immune regulatory disorders

Quantifying T-cell activation is essential for the diagnosis and evaluation of treatment response in various hyperinflammatory and immune regulatory disorders, including hemophagocytic lymphohistiocytosis. Plasma soluble IL-2 receptor (sIL-2R) is a well-established biomarker for evaluating systemic T-cell activation. However, the limited availability of sIL-2R testing could result in delayed diagnosis. Furthermore, high sIL-2R levels may not always reflect T-cell activation. To address these limitations, this study investigated whether cell surface markers of T-cell activation, HLA-DR, and CD38, as assessed by flow cytometry, could be used to quantify systemic T-cell activation in a variety of inflammatory disease states and examine its correlation with sIL-2R levels. Results for sIL-2R, CXCL9, and ferritin assays were obtained from patient's medical records. Frequency of HLA-DR+CD38high(hi) T-cells was assessed in different T-cell subsets using flow cytometry. In this study's cohort, activation in total CD8+ T (r=0.65; P< .0001) and CD4+ (r= 0.42; P< .0001) T-cell subsets significantly correlated with plasma sIL-2R levels. At the disease onset, the frequency of HLA-DR+CD38hi T cells in CD8+ T (r= 0.65, P< .0001) and CD4+ T (r= 0.77; P< .0001) effector memory (TEM) compartments correlated strongly with sIL-2R levels. Evaluation of T-cell activation markers in follow-up samples also revealed a positive correlation for both CD4+ TEM and CD8+ TEM activation with sIL-2R levels; thus, attesting its utility in initial diagnosis and in evaluating treatment response. The frequency of HLA-DR+CD38hi T-cells in the CD8+ TEM compartment also correlated with plasma CXCL9 (r= 0.42; P= .0120) and ferritin levels (r= 0.32; P=.0037). This study demonstrates that flow cytometry-based direct T-cell activation assessed by HLA-DR+CD38hi Tcells accurately quantifies T-cell activation and stronglycorrelates with sIL-2R levels across a spectrum ofhyperinflammatory and immune dysregulation disorders.

The utility of HLA-DR+CD38high expression in quantifying the amplitude of T cell activation in HLH and immune dysregulation disorders

IntroductionIdentifying T-cell activation, the hallmark of multiple hyperinflammatory diseases like HLH and immune dysregulation disorders (IDS) like LRBA deficiency, is critical for diagnosis, management, and monitoring treatment response for patients with immune activation driven disease processes. Soluble Interleukin 2 Receptor (sIL2R) is an established systemic marker for T-cell activation but the clinical availability of sIL2R testing is limited. sIL2R is also not a reliable marker of T-cell activation in patients with eosinophilia or T-cell lymphoma. A recent study by Chaturvedi et.al has demonstrated the utility of flow-based T-cell activation assessment in differentiating HLH from sepsis. However, its utility in defining and quantifying T-cell activation across the hyperinflammatory spectrum and its correlation with sIL2R has not yet been established. MethodsA total of 125 samples were collected either at disease onset (n = 81) or at follow-up (n = 44) from 85 human subjects. Paired plasma sIL2R and T-cell activation markers were prospectively evaluated in patients with suspected HLH (n = 79) or IDS (n = 46). Flow cytometry-based T-cell activation was evaluated in different T-cell sub-compartments by the coexpression of HLA-DR and CD38 surface markers. ResultsEvaluation of T-cell activation measured by HLADR+CD38high in healthy controls (HCs) and different hyperinflammatory/ immune regulatory disorders revealed that HCs have less than 8% of T-cell activation in CD8 + Teffector memory (TEM) and less than 4% for activation in the CD4+ TEM compartments. In patients with suspected hyperinflammatory/ immune regulatory disorders, we identified significant correlation of direct T-cell activation with plasma sIL2R level in different T-cell subsets, CD3 (r = 0.44, p < 0.0001), CD4 (r = 0.41, p < 0.0001), CD8 (r = 0.45, p < 0.001), CD4 TEM (Teffector memory) (r = 0.53, p < 0.001), and CD8 TEM (r = 0.53, p < 0.0001).The strongest correlation between HLADR+CD38high with sIL2R level was noted in CD4+ TEM and CD8+ TEM compartments (Figure 1). [Display omitted] [Display omitted] ConclusionsFlow cytometry-based direct assessment of HLADR+ CD38high in T cells subsets can reliably quantify T-cell activation and strongly correlate with sIL2R level across a spectrum of different hyperinflammatory and immune dysregulation disorders.

HLA-DR+ CD38high Expression in T Cells Is Excellent in Quantifying the Amplitude of T-Cell Activation in a Spectrum of Hyperinflammatory Disorders Including HLH

Introduction: T cell activation is the hallmark of several hyperinflammatory states such as HLH and immune dysregulation disorders like LRBA deficiency. Identifying T-cell activation and quantifying the amplitude of T-cell activation is critical for diagnosis, management, and monitoring treatment response in patients with hyperinflammatory and immune regulatory disorders. Soluble Interleukin 2 Receptor (sIL2R) is one of the established systemic T-cell activation markers for diagnosing and monitoring HLH and other hyperinflammatory disorders. However, the clinical availability of sIL2R testing is limited, and it may not be a reliable marker of T-cell activation in patients with eosinophilia and T-cell lymphoma. A recent study by Chaturvedi et.al has demonstrated the utility of flow-based T-cell activation assessment in differentiating HLH from sepsis. However, its utility in defining and quantifying T-cell activation across the hyperinflammatory spectrum and its correlation with sIL2R has not yet been established. Methods: A total of 125 samples were collected either at disease onset (n = 81) or at follow-up (n = 44) from 85 human subjects. Paired plasma sIL2R and T-cell activation markers were prospectively evaluated in patients with suspected HLH (n = 79) or immune dysregulation disorders (n = 46). Out of 85 patients, 21 patients were diagnosed with either primary HLH (p-HLH), Epstein-Barr virus infection-associated HLH (EBV-HLH), malignancy-associated HLH (m-HLH), or macrophage activation syndrome (MAS). The rest of the patients were diagnosed with either sepsis, multisystem inflammatory syndrome in children (MIS-C), hyperinflammatory conditions, hepatitis, or acute liver failure. Flow cytometry-based T-cell activation was evaluated in different T-cell sub-compartments by the co-expression of HLA-DR and CD38 surface markers. Plasma sIL2R levels and CXCL9 (a chemokine driven by IFN-g) were determined independently in CLIA certified clinical diagnostic laboratory. Research personnel who analyzed the flow cytometry data were blinded to the corresponding sIL2R test results and clinical diagnosis. Longitudinal follow-up was performed for a subset of patients with HLH or immune dysregulation with evidence of T-cell activation. We also evaluated T-cell activation in 30 healthy controls (HC) to establish a reference range. In addition, the correlation between T-cell activation markers with plasma levels of sIL2R and CXCL9 was also investigated. Results: Evaluation of T-cell activation measured by HLADR+CD38high in HCs and different hyperinflammatory/ immune regulatory disorders revealed that HCs have less than 8% of T-cell activation in CD8+ T effector memory (TEM) and less than 4% for activation in the CD4+ TEM compartments. In patients with suspected hyperinflammatory/ immune regulatory disorders, we identified significant correlation of direct T-cell activation with plasma sIL2R level in different T-cell subsets, CD3 (r = 0.44, p < 0.0001), CD4 (r = 0.41, p < 0.0001), CD8 (r = 0.45, p <0.001), CD4 TEM (T effector memory) (r =0.53, p < 0.001), and CD8 TEM (r =0.53, p < 0.0001). The strongest correlation between HLADR+CD38high with sIL2R level was noted in CD4+ TEM and CD8+ TEM compartments (Figure 1). The correlation is even more robust at disease onset (r = 0.69, p <0.0001 for CD4+ TEM and r = 0.64, p < 0.0001 for CD8+ TEM). However, at follow up, only activation in CD8+ TEM correlated with sIL2R levels (r = 0.4, p = 0.0069). Moreover, T-cell activation in CD8+ TEM correlated well with CXCL9 and ferritin levels. Among the cohort of patients with the confirmed final diagnosis, we found that both p-HLH and EBV-HLH have CD8+ TEM activation > 70%, whereas MAS and m-HLH have a median T cell activation of 37.8% (10.5-67) and 48.1% (4.9-80.6) respectively. Immune dysregulation patients had T-cell activation range from 8.0 to 46.0 % and sepsis group has 0% to 10.8% (Figure 2). A similar trend was also validated using corresponding plasma sIL2R levels in different hyperinflammatory states. Conclusions: Flow cytometry-based direct assessment of HLADR+CD38high in T cells subsets can reliably quantify T-cell activation and strongly correlate with sIL2R level across a spectrum of different hyperinflammatory and immune dysregulations disorders. If validated, this could be used as a real-time assessment of T-cell activation at disease onset and monitoring response to therapy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Soluble Interleukin-6 Receptor Regulates Interleukin-6-Dependent Vascular Remodeling in Long-Distance Runners.

Little is known about the effects of training load on exercise-induced plasma increase of interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6R) and their relationship with vascular remodeling. We sought to evaluate the role of sIL 6R as a regulator of IL-6-induced vascular remodeling. Forty-four male marathon runners were recruited and allocated into two groups: low-training (LT, <100 km/week) and high-training (HT, ≥100 km/week), 22 athletes per group. Twenty-one sedentary participants were used as reference. IL-6, sIL-6R and sgp130 levels were measured in plasma samples obtained before and immediately after finishing a marathon (42.2-km). Aortic diameter was measured by echocardiography. The inhibitory effect of sIL-6R on IL-6-induced VSMC migration was assessed using cultured A7r5 VSMCs. Basal plasma IL-6 and sIL-6R levels were similar among sedentary and athlete groups. Plasma IL-6 and sIL-6R levels were elevated after the marathon, and HT athletes had higher post-race plasma sIL-6R, but not IL-6, level than LT athletes. No changes in sgp130 plasma levels were found in LT and HT groups before and after running the marathon. Athletes had a more dilated ascending aorta and aortic root than sedentary participants with no differences between HT and LT athletes. However, a positive correlation between ascending aorta diameter and plasma IL-6 levels corrected by training load and years of training was observed. IL-6 could be responsible for aorta dilation because IL-6 stimulated VSMC migration in vitro, an effect that is inhibited by sIL-6R. However, IL-6 did not modify cell proliferation, collagen type I and contractile protein of VSMC. Our results suggest that exercise induces vascular remodeling. A possible association with IL-6 is proposed. Because sIL-6R inhibits IL-6-induced VSMC migration, a possible mechanism to regulate IL-6-dependent VSMC migration is also proposed.

Soluble IL-6R-mediated IL-6 trans-signaling activation contributes to the pathological development of psoriasis.

IL-6 has been suggested to function as an autocrine mitogen in the psoriatic epidermis. The biological activity of IL-6 relies on interactions with its receptors, including the membrane-bound IL-6 receptor (mIL-6R) and soluble IL-6 receptor (sIL-6R). Our study presents data showing that the levels of plasma IL-6 and sIL-6R were elevated in psoriatic patients. Genotyping of two single-nucleotide polymorphisms (SNPs) in IL-6R (rs4845617 and rs2228145) demonstrated that the SNP IL-6R (rs4845617) rather than IL-6R (rs2228145) shows a significant association with psoriasis (P = 0.006). To verify the functions of sIL-6R, cultured keratinocytes and imiquimod (IMQ)-induced psoriatic model mice were treated with sIL-6R. We found that the presence of sIL-6R in the HaCaT cell culture medium enhanced the IL-6-induced Stat3 activation, which resulted in abnormal keratinocyte proliferation and aberrant differentiation. Furthermore, the application of sIL-6R in vivo accelerated the pathological development of the disease. Our results demonstrate for the first time that genetic polymorphisms in the IL-6R gene are associated with psoriasis disease phenotypes in a Chinese psoriatic patient population; sIL-6R-mediated trans-signaling pathway plays a pivotal role in keratinocyte proliferation and differentiation, suggesting potential therapeutics for psoriasis. KEY MESSAGES: Patients with psoriasis displayed higher levels of IL-6 and sIL-6R compared with healthy controls. Analysis of genotypes revealed that IL-6R rs4845617 GG genotype associated with the risk of psoriasis. Supplement of sIL-6R further enhanced IL-6-induced Stat3 activation in keratinocytes. In vivo administration of sIL-6R accelerated, whereas sgp130FC alleviated, the pathological development of psoriasis.

Expression of Interleukin 6 signaling receptors in carotid atherosclerosis.

Interleukin (IL) 6 contributes to atherosclerotic plaque development through IL6 membrane-bound (IL6R and gp130) and soluble (sIL6R and sgp130) receptors. We investigated IL6 receptor expression in carotid plaques and its correlation with circulating IL6 and soluble receptor levels. Plasma samples and carotid plaques were obtained from 78 patients in the Biobank of Karolinska Endarterectomies study. IL6, sIL6R, and sgp130 were measured in plasma and IL6, IL6R, sIL6R, GP130, and sGP130-RAPS (sGP130) gene expression assessed in carotid plaques. Correlations between plaque IL6 signaling gene expression and plasma levels were determined by Spearman’s correlation. Differences in plasma and gene expression levels between patients with (n = 53) and without (n = 25) a history of a cerebral event and statin-treated (n = 65) and non-treated (n = 11), were estimated by Kruskal–Wallis. IL6 and its receptors were all expressed in carotid plaques. There was a positive, borderline significant, moderate correlation between plasma IL6 and sIL6R and the respective gene expression levels (rho 0.23 and 0.22, both p = 0.05). IL6R expression was higher in patients with a history of a cerebrovascular event compared to those without (p = 0.007). Statin-treated had higher IL6R, sIL6R, and sGP130 expression levels and plasma sIL6R compared to non-treated patients (all p < 0.05). In conclusion, all components of the IL6 signaling pathways are expressed in carotid artery plaques and IL6 and sIL6R plasma levels correlate moderately with IL6 and sIL6R. Our data suggest that IL6 signaling in the circulation might mirror the system activity in the plaque, thus adding novel perspectives to the role of IL6 signaling in atherosclerosis.

Prognostic significance of plasma IL-2 and sIL-2R\u03b1 in patients with first-ever ischaemic stroke

BackgroundAn imbalance between circulating neuroprotective and neurotoxic T cell subsets leads to poor prognosis in acute ischaemic stroke (AIS). Preclinical studies have indicated that the soluble form of the interleukin-2 receptor α (sIL-2Rα)-IL-2 complex regulates T cell differentiation. However, the association between sIL-2Rα levels and AIS remains unclear.MethodsA total of 201 first-ever AIS patients within 24 h after stroke onset and 76 control subjects were recruited. The National Institutes of Health Stroke Scale (NIHSS) score and 3-month functional outcome (modified Rankin Scale [mRS] score) at admission were assessed. Plasma sIL-2Rα and IL-2 levels at admission were measured. Prognostic significance was identified by using univariate and multivariate logistic regression analyses.ResultsPatients with poor functional outcomes at 3 months had significantly higher levels of sIL-2Rα and lower levels of IL-2 than patients with good outcomes. Moreover, sIL-2Rα levels showed a strong positive correlation with NIHSS and mRS scores (p < 0.0001), whereas IL-2 levels were negatively correlated with mRS scores (p < 0.01). Univariate analyses showed that higher sIL-2Rα and IL-2 levels were associated with an increased and reduced risk of unfavourable outcomes, respectively. After adjusting for confounding variables, the sIL-2Rα level remained independently associated with an increased risk of an unfavourable outcome, and adding sIL-2Rα levels to the conventional risk factor model significantly improved risk reclassification (net reclassification improvement 17.56%, p = 0.003; integrated discrimination improvement 5.78%, p = 0.0003).ConclusionssIL-2Rα levels represent a novel, independent prognostic marker that can improve the currently used risk stratification of AIS patients. Our findings also highlight that elevated plasma sIL-2Rα and IL-2 levels manifested opposite correlations with functional outcome, underlining the importance of IL-2/IL-2R autocrine loops in AIS.

Risk, Diagnostic and Predictor Factors for Classical Hodgkin Lymphoma in HIV-1-Infected Individuals: Role of Plasma Exosome-Derived miR-20a and miR-21

The incidence of classical Hodgkin lymphoma (cHL) in the HIV-1 setting has increased 5–25-fold compared to that observed in the general population. This study aimed to determine whether selected micro RNAs (miRs) and other soluble biomarkers and cellular subsets are dysregulated in cHL and could be used as biomarkers. This was a retrospective and longitudinal matched case-control study of 111 Caucasian, HIV-1-infected adult individuals, including 37 individuals with cHL and 74 with no type of cancer. Immunovirological data, plasma exosome-derived miR-16, miR-20a, miR-21, miR-221, miR-223, miR-106a, miR-185, miR-23, miR-30d, miR-222, miR-146a and miR-324, plasma IL-6, sCD14, sCD27, sCD30, sIL-2R, TNFR1, and cell phenotyping of T and B lymphocytes and natural killer (NK) cells were analyzed. Before cHL diagnosis, miR-20a, miR-21, and sCD30 were higher in cHL (p = 0.008, p = 0.009 and p = 0.042, respectively), while miR-16 was down-regulated (p = 0.040). miR-20a and miR-21 were independently associated with cHL (p = 0.049 and p = 0.035, respectively). The combination of miR-20a and miR-21 showed a good AUC value of 0.832 with a moderate likelihood ratio positive (LR+) value of 5.6 and a slight likelihood ratio negative (LR−) value of 0.23. At cHL diagnosis, miR-20a, miR-21 and miR-324 were overexpressed in cHL (p = 0.005, p = 0.024, and p = 0.001, respectively), while miR-223, miR-16, miR-185 and miR-106a were down regulated (p = 0.042, p = 0.007, p = 0.006, and p = 0.002, respectively). In addition, sCD14, sCD27, sCD30 and IL2R levels were higher in these individuals (p = 0.038, p = 0.010, p = 0.030, p = 0.006, respectively). miR-20a was independently associated with cHL (p = 0.011). The diagnostic value of miR-20a showed good AUC value of 0.754 (p = 0.074) with a slight LR+ value of 2 and a slight LR− of 0.25. After chemotherapy, miR-20a was higher in those individuals who had an adverse outcome (p < 0.001), while sCD14 and sCD30 were higher (p < 0.001). A specific signature of miRs and cytokines associated with a subsequent cHL diagnosis was found in this study, especially miR-20a and miR-21. Also, another biomarker signature was found at cHL diagnosis, with a relevant discriminant disease value for miR-20a. Of note, miR-20a expression was higher in those individuals who had an adverse clinical outcome after chemotherapy.

Evidence for Persistent Monocyte and Immune Dysregulation After Prolonged Viral Suppression Despite Normalization of Monocyte Subsets, sCD14 and sCD163 in HIV-Infected Individuals.

Background:People living with HIV on antiretroviral therapy (HIV/ART) experience excess non-AIDS comorbidities, and also remain at increased risk for certain infections and viral malignancies. Monocytes/macrophages are central to many of these comorbidities, and elevated plasma cytokines and immune activation during untreated infection are often incompletely reversed by ART and are also associated with comorbidities.Methods:We investigated monocyte surface markers, gene expression, and plasma cytokines in 11 HIV-infected older individuals (median 53 years) who started therapy with low CD4 counts (median 129 cells/µl), with elevated hsCRP (≥ 2mg/L) despite long-term ART (median 7.4 years), along with matched controls.Results:Frequency of monocyte subsets (based on CD14/CD16/CD163), were not different from controls, but surface expression of CD163 was increased (P = 0.021) while PD1 was decreased (P = 0.013) along with a trend for higher tissue factor (P = 0.096). As a group, HIV/ART participants had elevated plasma CCL2 (MCP-1; P = 0.0001), CXCL9 (MIG; P = 0.04), and sIL2R (P = 0.015), which were correlated, while sCD14 was not elevated. Principal component analysis of soluble markers revealed that 6/11 HIV/ART participants clustered with controls, while 5 formed a distinct group, driven by IL-10, CCL11, CXCL10, CCL2, CXCL9, and sIL2R. These individuals were significantly older than those clustering with controls. Transcriptomic analysis revealed multiple genes linked to immune functions including inflammation, immune cell development, and cell-cell signaling that were downregulated in HIV/ART monocytes and distinct from patterns in untreated subjects.Conclusions:Long-term ART-treated individuals normalize monocyte subsets but exhibit immune dysregulation involving both aberrant inflammation and monocyte dysfunction, as well as inter-individual heterogeneity, suggesting complex mechanisms linking monocytes and HIV/ART comorbidities.

Plasma levels of pro-inflammatory molecules and their expressions are associated with severity of heart failure: An investigation in Chinese cohort

Heart failure (HF) is a syndrome with multiple clinical phenotypes affecting around 1%–2% of adult population worldwide, and about 230 million Chinese are affected by cardiovascular diseases. The important role of pro-inflammatory plasma cytokines with HF has been demonstrated in different populations. The aim of this study was to investigate importance of pro-inflammatory cytokines in Chinese HF patients. In all, 134 HF patients were enrolled in this study and further classified in to four clinical distinct groups according to New York Heart Association classification criteria (NYHA-I: n = 34, NYHA-II: n = 35, NYHA-III: n = 22 and NYHA-IV: n = 43). Sixty-eight healthy Chinese were enrolled as controls. Plasma levels of tumour necrosis factor-α (TNF-α), TNF-receptor 1 (TNFRI), TNF-receptor 2 (TNFRII), interleukin 6 (IL-6), soluble IL-6 receptor (sIL-6R), C-reactive protein (CRP), soluble cluster of differentiation 14 (sCD14) and interleukin 1 beta (IL-1β) were quantified by enzyme-linked immunosorbent assay (ELISA). Plasma levels of all parameters investigated in this study remained comparable among healthy controls and NYHA-I group. Plasma levels of TNF-α, TNFRI, TNFRII, IL-6, sIL-6R, CRP, sCD14 and IL-1β were significantly higher in NYHA-III and NYHA-IV clinical categories compared to other HF phenotype (NYHA-I and NYHA-II). Interestingly, TNFR-II levels were significantly higher in NYHA-II compared to NYHA-I. No significant difference of plasma sIL-6R was observed among various clinical categories. In conclusion, plasma levels of pro-inflammatory molecules are elevated in severe HF patients and may be used as possible biomarkers for accessing severity of HF.

Role of Interleukin-6 and Its Receptor in Endometriosis.

BackgroundStudies have shown that the concentration of interleukin (IL)-6 in peritoneal fluid is increased in patients with endometriosis; however, whether the disorders involving IL-6 contribute to the development of endometriosis is still unclear. In the present study, we evaluated the potential role of IL-6 and IL-6 receptor (IL-6R) in the pathogenesis of endometriosis.Material/MethodsWe examined activated macrophages and the expression of membrane-binding receptor (mIL-6R) in peritoneal fluid using flow cytometry. The levels of IL-6 and the IL-6 soluble receptor (sIL-6R) in peritoneal fluid and plasma in patients with endometriosis was measured by an enzyme-linked immunosorbent assay.ResultsActivated macrophages and mIL-6R in peritoneal fluid were increased in patients with endometriosis. IL-6 and sIL-6R in peritoneal fluid were also increased in patients with endometriosis; however, there was an increase in plasma IL-6 and a decrease in plasma sIL-6R. The endometriosis group was categorized into 2 groups according to the retrospective American Fertility Society Score (r-AFS): group A and group B. Peritoneal fluid sIL-6R in endometriosis group B was significantly higher than in endometriosis group A and the control group.ConclusionsDisorders involving IL-6 and IL-6R are correlated with the etiology of endometriosis. An increase in sIL-6R in peritoneal fluid promotes the development of endometriosis by enhancing the bioactivity of IL-6.

227 Infarct size in a rat model of acute myocardial infarction is reduced by interleukin-6 trans-signalling blockade using sgp130fc but not an anti-il-6r monoclonal antibody

IntroductionInterleukin-6 (IL-6) is elevated during acute myocardial infarction (AMI) particularly after reperfusion with primary percutaneous coronary intervention (PPCI). Higher circulating levels of IL-6 and its soluble receptor (sIL-6R) are associated...

The contribution of the functional IL6R polymorphism rs2228145, eQTLs and other genome-wide SNPs to the heritability of plasma sIL-6R levels.

The non-synonymous SNP rs2228145 in the IL6R gene on chromosome 1q21.3 is associated with a wide range of common diseases, including asthma, rheumatoid arthritis, type 1 diabetes and coronary heart disease. We examined the contribution of this functional IL6R gene polymorphism rs2228145 versus other genome-wide SNPs to the variance of sIL-6R levels in blood plasma in a large population-based sample (N ~5,000), and conducted an expression QTL analysis to identify SNPs associated with IL6R gene expression. Based on data from 2,360 twin families, the broad heritability of sIL-6R was estimated at 72 and 51% of the total variance was explained by the functional SNP rs2228145. Converging findings from GWAS, linkage, and GCTA analyses indicate that additional variance of sIL-6R levels can be explained by other variants in the IL6R region, including variants at the 3'-end of IL6R tagged by rs60760897 that are associated with IL6R RNA expression.

Interleukin-6 and soluble interleukin-6 receptor levels in posttraumatic stress disorder: Associations with lifetime diagnostic status and psychological context

This study correlated lifetime PTSD diagnostic status with interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6R) levels, and tested whether these correlations are sensitive to psychological context. Midlife women attended two research visits where blood was drawn (beginning of visits) and saliva and oral mucosal transudate were collected (beginning and end of visits) to measure IL-6 and sIL-6R. Women were classified as PTSD−/− (past and current symptoms below subsyndromal levels), PTSD+/− (past symptoms at or above subsyndromal levels), or PTSD+/+ (past and current symptoms at or above subsyndromal levels). PTSD+/+ women, compared to the other women, showed more negative emotion at the beginning of the visits, higher salivary IL-6 levels at the beginning versus end of visits, and positive correlations between negative emotion, salivary IL-6, and plasma sIL-6R. Their plasma sIL-6R levels exceeded those of the PTSD+/− women. Overall, IL-6 sensitivity to anticipation and to negative emotions, and higher sIL-6R levels, differentiated persistent versus remitted PTSD.

Association of plasma IL-6 and soluble IL-6 receptor levels with the Asp358Ala polymorphism of the IL-6 receptor gene in schizophrenic patients

Recent studies indicate a role of excessive interleukin-6 (IL-6) signaling in the pathogenesis of schizophrenia. A previous study reported a significant association of schizophrenia with the IL-6 receptor (IL-6R) gene Asp358Ala polymorphism, which is known to regulate circulating IL-6 and soluble IL-6R (sIL-6R) levels in healthy subjects. To further examine the influence of the polymorphism in schizophrenic patients, we compared the plasma levels of IL-6 and sIL-6R between schizophrenic patients and healthy controls for each genotype of the Asp358Ala polymorphism. Asp358Ala genotyping and plasma IL-6 level measurements were performed in 104 patients with schizophrenia and 112 healthy controls. Of these participants, 53 schizophrenic patients and 49 controls were selected for the measurement of plasma sIL-6R levels. A two-way factorial analysis of covariance was performed with the transformed plasma levels as the dependent variable, diagnosis and genotype as independent variables, and sex and age as covariates. No significant diagnosis × genotype interaction was observed for IL-6 and sIL-6R levels. The Ala allele of Asp358Ala was significantly associated with higher levels of both IL-6 and sIL-6R. IL-6 levels were significantly elevated in schizophrenic patients compared to those in controls, whereas no significant difference in sIL-6R levels was observed between schizophrenic patients and controls. Our findings suggest that the presence of schizophrenia is associated with elevated IL-6 levels, whereas sIL-6R levels are mainly predetermined by the Asp358Ala genotype and are not associated with the disease status. Increased IL-6 levels without alterations in sIL-6R levels may result in excessive IL-6 signaling in schizophrenia.

Soluble interleukin-2 receptor levels correlated with positive symptoms during quetiapine treatment in schizophrenia-spectrum disorders

Some but not all antipsychotics have been shown to modulate plasma cytokine levels in schizophrenia patients. Thus far, the most consistent finding has been the increase in plasma levels of soluble interleukin (IL)-2 receptor (sIL-2R) associated with clozapine treatment. Quetiapine is a second-generation antipsychotic with a pharmacological profile similar to that of clozapine, but its immunomodulatory effects have not been investigated in schizophrenia yet. The purpose of this exploratory study was to examine the changes in plasma levels of sIL-2R in schizophrenia during quetiapine treatment and association with psychopathology. Participants were 29 schizophrenia-spectrum disorder patients (DSM-IV criteria), and 28 healthy controls. Patients had a comorbid substance use disorder (cannabis>alcohol>cocaine), since quetiapine is increasingly used in this population of dual diagnosis. No participant suffered from infection or overt inflammatory diseases. On baseline, patients taking mostly second-generation antipsychotics were switched to quetiapine for a 12-week open-label trial. Five patients were drop-outs. Mean dose of quetiapine for trial completers (n=24) was 466.6mg±227.3. Psychiatric variables were evaluated with the Positive and Negative Syndrome Scale and the Calgary Depression Scale for Schizophrenia. Plasma sIL-2R levels were assessed at baseline, weeks 6 and 12 in patients, and in healthy controls, using sandwich immunoassay. Plasma IL-6 and IL-1 receptor antagonist (IL-1RA) were measured for comparison purposes. On baseline, plasma sIL-2R, IL-6 and IL-1RA levels were higher in dual-diagnosis patients, compared to controls. Plasma sIL-2R further increased after quetiapine treatment (p=0.037), while plasma IL-6 and IL-1RA did not change. Clinical improvements were observed in positive, negative and depressive symptoms, and substance abuse severity (all p<0.01). Interestingly, changes in sIL-2R levels during treatment were inversely correlated with changes in positive symptoms (r=-0.524; p=0.009). That is, increases in sIL-2R levels were associated with reductions in positive symptoms. These data show that quetiapine elevates, like clozapine, sIL-2R levels in schizophrenia. Furthermore, the results suggest that sIL-2R alterations in schizophrenia rely on complex interplays between antipsychotics and the positive symptoms of the disorder. Future randomized controlled trials involving larger samples of schizophrenia patients are warranted to determine whether changes in plasma sIL-2R are quetiapine-related.

Roles of circulating soluble interleukin (IL)-6 receptor and IL-6 receptor expression on CD4+ T cells in patients with chronic hepatitis B

The objective of this study was to investigate the potential clinical roles of circulating soluble interleukin (IL)-6 receptor (sIL-6R) and IL-6R expression on CD4+ T cells (CD4+ IL-6R+ T cells) in chronic hepatitis B (CHB) patients. One hundred and thirty-three subjects, including 72 CHB patients, 27 asymptomatic carriers, eight acute hepatitis B (AHB) patients, and 26 healthy donors were included in this study. Plasma IL-6 and sIL-6R levels were measured by enzyme-linked immunosorbent assay (ELISA); the frequency of CD4+ IL-6R+ T cells was detected by flow cytometry analysis. Our data showed a significant increase in plasma sIL-6R levels and the frequency of CD4+ IL-6R+ T cells in peripheral blood in CHB patients compared to asymptomatic carriers and healthy controls (both p<0.05). The elevated prevalence of CD4+ IL-6R+ T cells was positively associated with increased serum alanine aminotransferase levels in CHB patients (r = 0.316, p = 0.007), but was not correlated with serum hepatitis B virus (HBV) DNA load. Moreover, CHB patients with an HBV DNA load >1.0 × 10(6) copies/ml had a lower level of plasma sIL-6R than those with an HBV DNA load <1.0 × 10(6) copies/ml. Circulating sIL-6R and CD4+ IL-6R+ T cells were increased in CHB patients. Elevated plasma sIL-6R is probably associated with HBV elimination, and CD4+ IL-6R+ T cells in peripheral blood might contribute to the pathogenesis of liver injury in CHB patients.

Plasma soluble IL-6 receptor concentration in rheumatoid arthritis: associations with the rs8192284 IL6R polymorphism and with disease activity

Soluble interleukin-6 receptor α subunit (sIL-6R) is primarily generated by shedding of the membrane-bound form. This process is influenced by the single nucleotide polymorphism rs8192284 (A>C) resulting in an aspartic acid to alanine substitution (D358A) at the proteolytic cleavage site. The aim of this study was to determine whether plasma levels of sIL6R are influenced by the rs8192284 polymorphism in patients with rheumatoid arthritis and to assess the association between plasma sIL-6R levels and disease activity as reflected by anti-CCP status. Thirty-nine patients were randomly selected from a cohort of patients with RA of Spanish descent. Plasma sIL-6R concentrations were measured using sandwich ELISA. Genotyping of the rs8192284 (A>C) polymorphism was done using a Fast Real-Time PCR System. DAS 28 scores were used to assess disease activity. Plasma sIL-6R levels were positively associated with the number of C alleles (AA: 35.27 (3.50)ng/ml, AC: 45.50 (4.58)ng/ml, CC: 52.55 (3.18)ng/ml, P=0.0001). DAS28 and plasma sIL-6R levels were positively associated in the anti-CCP-positive subgroup (r (2)=0.45, P=0.0336) and negatively associated in the anti-CCP-negative subgroup (r (2)=-0.45, P=0.0825). No association between anti-CCP status and sIL-6R level was found. Our findings show that the rs8192284 polymorphism is operative in patients with RA. The presence of anti-CCP antibodies determines the relationship between sIL-6R concentration and disease activity.