Serum interleukin-6 soluble receptor in relation to interleukin-6 in stroke patients

IL-6 and stroke recurrence in ischemic stroke

Objective: This study aimed to evaluate the predictive value of IL-6 for stroke recurrence in acute ischemic stroke.Methods: Patients who were admitted within 48 h of onset were included. At 3-month, stroke recurrence was assessed. IL-6 levels were measured in serum samples taken upon admission.Results: Out of the 305 patients, 47 (15.4%) experienced a stroke recurrence. The risk of stroke recurrence increased by 8% (OR: 1.08; 95% CI: 1.04-1.11; p < 0.001) for every 1 pg/ml increase in IL-6 serum level, both in unadjusted and adjusted analyses (6%; OR: 1.06; 95% CI: 1.02-1.10; p = 0.001).Conclusion: The study supports the usefulness of IL-6 as a predictive biomarker for stroke recurrence after acute ischemic stroke.

Association between interleukin-6 levels and stroke: a systematic review and meta-analysis

OBJECTIVES

We aimed to evaluate the association of interleukin-6 (IL-6) expression levels with stroke.

METHODS

According to the set search strategy, we systematically screened relevant studies using PubMed and extracted study results regarding IL-6 from the literature for comprehensive quantitative analysis to explore the relationship between IL-6 level and stroke risk.

RESULTS

This study included 15 publications with a total of 1696 participants, with 975 cases in the case group and 721 cases in the control group. Meta-analysis showed that IL-6 levels were significantly higher in the stroke population than those in the control group (standardized mean difference = 1.22, 95% confidence interval = 0.79-1.64). Subgroup analysis showed that there was no significant difference in heterogeneity for IL-6 detection methods between the two groups (I2 = 0, P = 0.47). The difference in heterogeneity test results regarding geographic region was statistically significant (I2 = 89.7%, P < 0.01). The results of heterogeneity testing for mean participant age were also statistically significant (I2 = 84.3%, P = 0.01).

CONCLUSION

The present study results showed that IL-6 may be significantly associated with stroke development.

Biomarkers and the outcomes of ischemic stroke

Biomarkers are measurable substances that could be used as objective indicators for disease diagnosis, responses to treatments, and outcomes predictions. In this review, we summarized the data on a number of important biomarkers including glutamate, S100B, glial fibrillary acidic protein, receptor for advanced glycation end-products, intercellular adhesion molecule-1, von willebrand factor, matrix metalloproteinase-9, interleukin-6, tumor necrosis factor-a, activated protein C, copeptin, neuron-specific enolase, tau protein, gamma aminobutyric acid, blood glucose, endothelial progenitor cells, and circulating CD34-positive cells that could be potentially used to indicate the disease burden and/or predict clinical outcome of ischemic stroke. We examined the relationship between specific biomarkers and disease burden and outcomes and discussed the potential mechanisms underlying the relationship. The clinical significance and implications of these biomarkers were also discussed.

Post-stroke inflammation-target or tool for therapy?

Inflammation is currently considered a prime target for the development of new stroke therapies. In the acute phase of ischemic stroke, microglia are activated and then circulating immune cells invade the peri-infarct and infarct core. Resident and infiltrating cells together orchestrate the post-stroke inflammatory response, communicating with each other and the ischemic neurons, through soluble and membrane-bound signaling molecules, including cytokines. Inflammation can be both detrimental and beneficial at particular stages after a stroke. While it can contribute to expansion of the infarct, it is also responsible for infarct resolution, and influences remodeling and repair. Several pre-clinical and clinical proof-of-concept studies have suggested the effectiveness of pharmacological interventions that target inflammation post-stroke. Experimental evidence shows that targeting certain inflammatory cytokines, such as tumor necrosis factor, interleukin (IL)-1, IL-6, and IL-10, holds promise. However, as these cytokines possess non-redundant protective and immunoregulatory functions, their neutralization or augmentation carries a risk of unwanted side effects, and clinical translation is, therefore, challenging. This review summarizes the cell biology of the post-stroke inflammatory response and discusses pharmacological interventions targeting inflammation in the acute phase after a stroke that may be used alone or in combination with recanalization therapies. Development of next-generation immune therapies should ideally aim at selectively neutralizing pathogenic immune signaling, enhancing tissue preservation, promoting neurological recovery and leaving normal function intact.

Systemic inflammation as a therapeutic target in acute ischemic stroke

Acute systemic inflammatory reaction superimposed on chronic low-grade inflammation accompanies acute ischemic stroke. Elevated blood levels of systemic inflammatory markers such as IL-6 or C-reactive protein are associated with an unfavorable functional outcome and increased mortality after stroke. Animal studies have demonstrated a causal relationship between systemic inflammation and ischemic brain damage. The mechanisms linking systemic inflammation with poor outcome include increased neutrophil infiltration of cerebral cortex, disruption of the blood-brain barrier, impaired tissue reperfusion, increased platelet activation and microvascular coagulation and complement-dependent brain injury. Non-selective (e.g., by statins) or selective (e.g., by inhibition of IL-6) attenuation of systemic inflammation, enhancement of systemic anti-inflammatory response (e.g., by infusion of IL-1 receptor antagonist), prevention of infections that exacerbate systemic inflammation or inhibition of neuronal pathways triggering inflammatory reaction are potential therapeutic targets in stroke patients. This review discusses the relationship between systemic inflammation, cerebral ischemia and prognosis in the context of therapeutic strategies.

Higher C-reactive protein and soluble tumor necrosis factor receptor levels are associated with poor physical function and disability: a cross-sectional analysis of a cohort of late middle-aged African Americans

BACKGROUND

This cohort of "late middle-aged" African Americans has an excess of disability. We aimed to determine associations of circulating cytokine receptors (sTNFR1, sTNFR2, and sIL-6R) and C-reactive protein (CRP) with disability, physical function, and body composition.

METHODS

Stratified sampling of two socioeconomically diverse strata of St Louis, Missouri, occurred in 2000-2001. Inclusion criteria were self-reported black or African American race, born 1936-1950 inclusive, and Mini-Mental State Examination score of 16 or greater. In-home evaluations of handgrip strength, lean body mass percentage (LBM%), physical performance, upper and lower body functional limitations (UBFLs and LBFLs), and basic and instrumental activities of daily living (BADLs and IADLs) were collected. Of the 998 participants, 368 had blood sampled at baseline. Serum was stored and assayed in 2006.

RESULTS

Absolute risks were LBFLs of 2 or more, 46%; UBFLs of 1 or more, 23.5%; BADLs of 2 or more, 20.6%; and IADLs of 2 or more, 22.5%. Independent of age, sex, and underlying comorbid conditions, higher CRP and sTNFR were associated with poorer physical performance (beta = -1.462, p < .001 and beta = -0.618, p = .003), UBFLs (odds ratio [OR] 2.26, 95% confidence interval [CI] 1.1-4.64 and OR 1.39, 95% CI 0.96-2.02), LBFLs (OR 2.30, 95% CI 1.19-4.45 and OR 1.91, 95% CI 1.26-2.91), BADLs (OR 2.79, 95% CI 1.03-5.96 and OR 1.66, 95% CI 1.11-2.46), and IADLs (OR 2.13, 95% CI 1.03-4.41 and OR 1.43, 95% CI 0.99-2.08). Higher CRP (beta = -3.251, p <.001), sIL-6R (beta = -6.152, p = .013), and lower adiponectin (beta = 2.947, p = .052) were associated with lower LBM%.

CONCLUSIONS

Higher CRP and sTNFR are independently associated with disability and physical dysfunction. Higher sIL-6R, CRP, and lower adiponectin associate with lower LBM%.

Risk of stroke with typical and atypical anti-psychotics: a retrospective cohort study including unexposed subjects

The purpose of the study was to investigate the risk of stroke with typical and atypical anti-psychotics in elderly subjects, weighting for a number of known risk factors, including dementia. Data were retrospectively drawn from the primary care setting from the Health Search Database, which stores information on about 1.5% of the total Italian population served by general practitioners. All elderly patients (65+ years) prescribed an anti-psychotic in monotherapy from January 2000 to June 2003 were selected for the study. A cohort of patients not exposed to anti-psychotics was taken from the same database. Subjects who had previously had a stroke were excluded. The main outcome measure was the incidence of first-ever stroke during exposure to an anti-psychotic.The sample included non-users (69,939), users of atypicals (599), butyrophenones (749), phenotiazines (907) and substituted benzamides (1,968). The crude incidence of stroke in subjects not exposed to anti-psychotics was 12.0/1000 person-years. Risk was significantly higher for those on butyrophenones (47.1/1000), phenotiazines (72.7/1000) and in the atypical anti-psychotic group (47.4/1000). Substituted benzamides had an almost significant higher risk (25.0/1000). Cox regression modelling, weighting for demographic and clinical variables with non-users as the reference group, showed that the risk for stroke was 5.79 times for phenotiazines, 3.55 times for butyrophenones, and 2.46 times for atypicals. Clinicians should be cautious in prescribing phenotiazines and butyrophenones in elderly patients, since the risk for stroke would seem comparable or even greater than with atypicals.

Interleukin 1 beta polymorphism (-511) and risk of stroke due to small vessel disease

BACKGROUND

Interleukin 1 (IL-1) is a proinflammatory cytokine involved in atherogenesis and thrombosis. The aim of this study was to investigate the association between the IL-1beta gene polymorphism (-511) and the risk of large vessel disease (LVD) stroke, small vessel disease (SVD) stroke and cardioembolic (CE) stroke.

METHODS

We genotyped 115 patients with LVD stroke and 194 matched controls, 122 patients with SVD stroke and 227 controls and 221 patients with CE stroke and 219 controls. The IL-1beta polymorphism was analyzed by a polymerase chain reaction followed by a restriction enzyme digestion.

RESULTS

The allele T distribution did not change significantly between patients with LVD stroke and their controls nor between patients with CE stroke and their controls. The frequency of the T allele was higher in patients with SVD stroke than in the control group (37.7 vs. 30.4%, p = 0.05). After adjustment for vascular risk factor, the TT genotype was an independent risk factor for SVD stroke (OR: 2.40, 95% CI: 1.17-4.94).

CONCLUSIONS

The TT genotype of the IL-1beta gene may be associated with an increased risk of SVD stroke.