The role of serum osteoprotegerin and S-100 protein levels in patients with acute ischaemic stroke: determination of stroke subtype, severity and mortality

Role of osteoprotegerin rs3102735 gene polymorphism in acute ischemic stroke patients

Background

Ischemic stroke ranks third among leading causes of death and disability. Both endothelial and vascular smooth muscle cells generate osteoprotegerin (OPG). Ischemic stroke and its severity may be enhanced by the OPG rs3102735 gene polymorphism. Our research aims to investigate OPG rs3102735 gene polymorphism role in ischemic stroke risk and to assess its association with stroke severity at presentation and degree of vascular stenosis and evaluate its potential as a predictor of stroke severity. Fifty people with acute ischemic stroke as well as fifty controls were studied. The NIHSS and ASPECTS were utilized to evaluate stroke severity and the infarction size, respectively. All subjects underwent extracranial carotid duplex study and molecular assessment for genotyping of OPG rs3102735) gene polymorphism.

Results

Stroke patients had markedly higher concentrations of OPG in the plasma than controls (311.60 ± 109.48 versus 240.20 ± 75.96 mmol/ml, p = 0.001). The optimal plasma OPG cutoff value for the predicting the occurrence of stroke was determined to be > 250 mmol/ml, the 95% confidence interval (CI) was (0.625–0.843), sensitivity was 68% and specificity was 72%. Ischemic stroke had a significantly different genotype distribution for the OPG rs3102735 gene polymorphism than did controls (36 CC, 13 CT, and 1 TT) versus (28 CC, 15 CT, and 7 TT) respectively. Stroke patients had a significantly greater CC + CT genotype than controls did (P = 0.041), also they had a higher propensity for carrying the C allele than the T allele (P = 0.017). Carotid intima medium thickness and the NIHSS both had positive correlations with OPG serum level (r = 0.39, p = 0.02 and r = 0.4, p = 0.02, respectively), whereas ASPECTS had an inversed correlation (r = − 0.65, p = 0.001).

Conclusions

The current study shows that as an independent risk factor, increased plasma OPG level, may participate in the atherothrombotic ischemic stroke pathophysiology, in addition, genetic variants in the OPG gene (rs3102735) are a separate risk factor for large artery atherosclerosis and plasma OPG level can serve as a biomarker to determine the severity of a stroke.

Osteoprotegerin and Ischemic Stroke Prognosis: A Prospective Multicenter Study and Mendelian Randomization Analysis

BACKGROUND

Osteoprotegerin was implicated in vascular injury and inflammatory responses, but its prognostic value in ischemic stroke remained unclear. We aimed to prospectively investigate the association between plasma osteoprotegerin and ischemic stroke prognosis combined with a Mendelian randomization analysis.

METHODS

Our prospective study follows the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) reporting guideline. We measured baseline plasma osteoprotegerin levels for 3490 ischemic stroke patients recruited between August 2009 and May 2013 in 26 hospitals across China. The primary outcome was a composite outcome of death and major disability at 3 months after ischemic stroke.

RESULTS

After adjustment for age, sex, admission National Institutes of Health Stroke Scale score, and other important covariates, elevated osteoprotegerin levels were associated with increased risks of primary outcome (odds ratio, 1.40 [95% CI, 1.05-1.88]), death (hazard ratio, 2.05 [95% CI, 1.04-4.08]), and composite outcome of death and vascular events (hazard ratio, 2.00 [95% CI, 1.15-3.48]) when 2 extreme quartiles were compared. Each 1-SD higher log-osteoprotegerin was associated with a 18% (95% CI, 6%-32%) increased risk of primary outcome, 69% (95% CI, 31%-118%) increased risk of death, and 53% (95% CI, 24%-89%) increased risk of composite outcome of death and vascular events, respectively. Multiple-adjusted spline regression model showed a linear association of osteoprotegerin with primary outcome (P for linearity <0.001). Adding osteoprotegerin to conventional risk factors did not significantly improve discriminatory power (C statistics, 0.817 versus 0.818; P=0.232) but did slightly improve the risk reclassification of primary outcome (net reclassification improvement: 13.68%, P<0.001; integrated discrimination improvement: 0.23%, P=0.039). In Mendelian randomization analysis, genetically determined high plasma osteoprotegerin was associated with increased risk of primary outcome (odds ratio, 5.74 [95% CI, 1.12-29.44]; P=0.036).

CONCLUSIONS

Elevated plasma osteoprotegerin was associated with poor prognosis of ischemic stroke, and genetically determined high plasma osteoprotegerin was associated with an increased risk of primary outcome in Mendelian randomization analysis.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01840072.

The association of plasma osteoprotegerin levels and functional outcomes post endovascular thrombectomy in acute ischemic stroke patients: a retrospective observational study

Background

Osteoprotegerin (OPG), also known as osteoclastogenesis inhibitory factor, is a tumor necrosis factor receptor superfamily component. There is an established relationship between OPG and cardiovascular disease. We hypothesized that plasma OPG levels are associated with functional outcomes in acute ischemic stroke patients who have undergone endovascular thrombectomy (EVT).

Methods

From April 2014 through December 2020, a total of 360 acute ischemic stroke patients who underwent EVT were prospectively included in this retrospective observational study. Plasma OPG was measured after fasting for 12 postoperative hours after EVT. A modified Rankin Scale (mRS) was used to assess functional outcomes 3 months after index stroke occurrence. Univariate and multivariate binary logistic regression and ordinal logistic regression analyses were performed to investigate the association of plasma OPG levels with poor functional outcomes.

Results

Overall, 145 (40.2%) patients had poor (mRS > 2) outcomes. The mean ± standard deviation plasma OPG level was 200.2 ± 74.4 pg/mL. Multivariate analysis after adjusting for sex, body mass index, and variables with p < 0.1 in the preceding univariate analysis revealed high plasma OPG levels were independently associated with poor functional outcomes (highest tertile vs. lowest tertile of OPG; odds ratios (OR) 2.121, 95% confidence interval (CI) [1.089-4.191], p = 0.037 in binary logistic regression, OR 2.102, 95% CI [1.301-3.412], p = 0.002 in ordinal logistic regression analysis).

Conclusions

This study demonstrated that higher plasma OPG levels were associated with poor functional outcomes in acute ischemic stroke patients who underwent EVT.

Plasma osteoprotegerin levels are associated with the presence and burden of cerebral small vessel disease in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Osteoprotegerin (OPG) is a component of the tumor necrosis factor receptor superfamily. Several studies have shown a relationship between OPG and cardiovascular diseases. We hypothesized that there is a relationship between plasma OPG levels and cerebral small vessel disease (SVD).

METHODS

Patients diagnosed with their first cerebral ischemic infarction between April 2014 and March 2017 were enrolled. All the enrolled patients were evaluated through the hospital stroke protocol, including routine blood tests, brain imaging, and measuring the plasma OPG levels. The presence and burden of cerebral SVD [cerebral microbleeds (CMBs), asymptomatic lacunar infarction (ALI), high-grade perivascular space (HPVS), high-grade white matter hyperintensity (HWMH)], and total SVD score were assessed through brain magnetic resonance imaging.

RESULTS

Of the 270 patients included in our study, 158 (58.5%) were men. The mean age of the patients was 63.8 ± 11.6 years. In multivariable analysis, plasma OPG levels were positively associated with the presence and burden of each cerebral SVD. The odds ratios (OR) of CMBs, ALI, HPVS, and HWMH for the association of OPG per standard deviation (SD) increase were 1.58 [95% confidence interval (CI), 1.09-2.27], 1.40 (95% CI, 1.04-1.88), 1.88 (95% CI, 1.27-2.78), and 1.47 (95% CI, 1.04-2.08), respectively. Plasma OPG levels were positively correlated with total SVD score (beta = 0.211, standard error = 0.061, p-value = 0.009, R² = 0.275).

CONCLUSIONS

Plasma OPG levels correlate with the presence and burden of cerebral SVD in patients with acute ischemic stroke.

Circulating Osteoprotegerin in Chronic Kidney Disease and All-Cause Mortality

BACKGROUND

Chronic kidney disease (CKD) is associated with cardiovascular disease (CKD), mineral and bone disorder (CKD-MBD) and high mortality. Bone-related factors such as osteopontin (OPN), osteocalcin (OC), osteoprotegerin (OPG) and fibroblast growth factor 23 (FGF23) were linked to cardiovascular complications of CKD and are expected to have predictive value in CKD patients.

PURPOSE

The aim of this study was to assess the relationship of OPN, OC, OPG and FGF23 to clinical characteristics and to evaluate their ability to predict mortality in patients with different CKD stages.

METHODS

The following study groups were enrolled: subjects with end-stage renal disease (38 ESRD), CKD stages 3 and 4 (19 CKD3-4) and non-CKD controls (19), respectively. Blood was withdrawn once to perform the measurements and cardiac computed tomography was used to evaluate coronary calcium score (CS). Patients were followed for 5 years for the ascertainment of their all-cause mortality.

RESULTS

Serum OPN, OC and OPG concentrations increased significantly along with the progression of renal disease. We found a significant positive correlation among these proteins. Additionally, OPN and OPG were significantly and positively correlated to CS. Serum OPG revealed the strongest correlation to the calcium turnover markers of GFR decline and was significantly associated with an increased risk of death in subjects with CKD3-4 or ESRD (HR 5.8, CI 95%).

CONCLUSION

Single measurement of osteoprotegerin is associated with 5-year all-cause mortality in patients with CKD3-4 or ESRD. We suggest assessing its concentration, preferably in combination with calcium score, to stratify mortality risks in CKD patients.

The role of the RANKL/RANK/OPG system in the central nervous systems (CNS)

The receptor-activator of NF-κB ligand (RANKL) and its specific receptor RANK have essential roles in regulating bone metabolism and the immune system. Besides, the RANKL/RANK system plays important roles in multiple physiological and pathophysiological processes such as mammary gland development during pregnancy, cancer development, and bone metastasis. While it has long been known that RANKL and RANK are expressed in the central nervous system (CNS), the physiological roles of RANKL/RANK system in the CNS and the underlying molecular mechanisms have been elucidated recently. Over the last decade, several reports showed that the central RANKL/RANK system plays important roles in regulating body temperature, brain ischemia, autoimmune encephalopathy, feeding behavior, and energy metabolism. In this review, it is provided an updated information regarding the roles of RANKL/RANK system in the CNS.

Serum osteoprotegerin level is positively associated with peripheral artery disease in patients with peritoneal dialysis

Osteoprotegerin (OPG) is a potential biomarker of cardiovascular disease complications and severity. Peripheral arterial disease (PAD) is associated with an increased risk of death in patients on peritoneal dialysis (PD). Therefore, this study aimed to evaluate the relationship between serum OPG levels and PAD by measuring the ankle-brachial index (ABI) of patients on PD. A commercial enzyme-linked immunosorbent assay kit was used to measure OPG values. Left or right ABI values of <0.9 were categorized as the low ABI group. Among 70 patients on PD, 13 (18.6%) were categorized in the low ABI group. Patients in the low ABI group had higher prevalence of diabetes mellitus (p = .044) and higher serum C-reactive protein (CRP) (p < .001) and OPG levels (p < .001) but lower creatinine (p = .013) and peritoneal Kt/V (p = .048) levels than those in the normal ABI group. Results of multivariable logistic regression analysis revealed that OPG [adjusted odds ratio (aOR) 1.027, 95% confidence interval (CI) 1.010-1.045, p = .002] and CRP (aOR 1.102, 95% CI 1.006-1.207, p = .037) levels were independent predictors of PAD in patients on PD. OPG can also be used to predict PAD development with the area under the receiver operating characteristic curve of 0.823 (95% CI: 0.714-0.904, p < .001) in patients on PD. Therefore, serum OPG and CRP levels can be considered as risk factors for PAD development in patients on PD.

Osteoprotegerin SNP associations with coronary artery disease and ischemic stroke risk: a meta-analysis

Osteoprotegerin (OPG) is involved in the development of atherosclerosis and cardio-cerebrovascular disease. The goal of this meta-analysis was to evaluate the association of OPG single nucleotide polymorphisms (SNPs) with coronary artery disease (CAD) and ischemic stroke. A total of 15 eligible studies were extracted from electronic databases. Odds ratios (ORs) were presented, with 95% confidence intervals (CIs), to assess the associations. Meta-analysis was conducted using MetaGenyo, STATA, and Comprehensive Meta-Analysis. Meta-analysis of our data showed that the OPG SNP T950C was significantly associated with increased CAD risk among Asians via recessive (OR 1.55, 95% CI 1.18–2.04, P=0.002), CC vs TT (OR 1.57, 95% CI 1.16–2.11, P=0.003) and allelic (OR 1.21, 95% CI 1.05–1.38, P=0.007) models. No strong associations were observed for the OPG SNP G1181C, T245G and G209A with CAD risk. When evaluating the OPG SNP T245G and T950C associations with ischemic stroke, we found the OPG SNP T245G to be significantly associated with increased risk of ischemic stroke among Chinese via recessive (OR 1.53, 95% CI 1.02–2.29, P=0.039) and CC vs AA (OR 1.61, 95% CI 1.07–2.42, P=0.021) models. Our results suggested that the OPG SNP T950C was associated with increased risk of CAD among Asians, and the OPG SNP T245G was associated with enhanced ischemic stroke risk among Chinese.

Plasma Osteoprotegerin Correlates with Stroke Severity and the Occurrence of Microembolic Signals in Patients with Acute Ischemic Stroke

Background

Instability of atherosclerotic plaques is associated with the occurrence of stroke. Microembolic signals (MESs) are an indicator of unstable plaque. A relationship between plasma osteoprotegerin (OPG) and ischemic stroke has already been identified. The aim of this study was to investigate whether plasma OPG levels have a relationship with MESs and to evaluate the feasibility of OPG as a biomarker of stroke severity and occurrence of MESs.

Methods

Our study consisted of 127 patients with large artery atherosclerosis stroke and 56 controls. Patients were classified into subgroups based on stroke severity and the occurrence of MESs. MES-monitoring was performed for 60 min using transcranial Doppler within 72 h of stroke onset. Stroke severity at admission was assessed by the National Institutes of Health Stroke Scale.

Results

Plasma OPG levels were significantly associated with stroke, MESs, and stroke severity at admission (adjusted OR [95% CI]: 1.002 [1.001–1.003] p < 0.001; 1.002 [1.001–1.003] p = 0.001; 1.001 [1.000–1.002] p = 0.028). When plasma OPG levels were used to determine the stroke severity, the area under the receiver-operating characteristic curve (AUC) was 0.734 (95% CI: 0.625-0.843) based on a cutoff value of 1998.44 pg/ml; the sensitivity and specificity of this test were 80.6% and 65.6%, respectively. Furthermore, when the levels of OPG were used to distinguish the presence of MESs, the AUC was 0.766 (95% CI: 0.672-0.860); the cutoff value was 2107.91 pg/ml. The sensitivity of this cutoff value was 68.8% and the specificity was 73.7%.

Conclusions

Plasma OPG levels correlate with stroke severity and the occurrence of MESs.

The Role of Osteoprotegerin as a Cardioprotective Versus Reactive Inflammatory Marker: the Chicken or the Egg Paradox

Cardiovascular disease is one of the most frequent causes of mortality and morbidity worldwide. Several variables have been identified as risk factors for cardiovascular disease. Recently, the role of receptor activator of nuclear factor kappa B, receptor activator of nuclear factor kappa B ligand, and the osteoprotegerin system has been recognized as more important in the pathogenesis of cardiovascular disease. Besides their roles in the regulation of bone resorption, these molecules have been reported to be associated with the pathophysiology of cardiovascular disease. There are conflicting data regarding the impact of osteoprotegerin, a glycoprotein with a regulatory role in the cardiovascular system. The aim of this review is to discuss the current knowledge and the role of osteoprotegerin in cardiovascular disease.

Significant Association between OPG/TNFRSF11B Variant and Common Complex Ischemic Stroke

BACKGROUND

The serum level of osteoprotegerin (encoded by OPG or TNFRSF11B) was previously shown to be increased in patients with ischemic stroke. A single nucleotide polymorphism rs3134069 in the TNFRSF11B gene was previously associated with ischemic stroke in a population of diabetic patients in Italy. It remains to be determined whether rs3134069 is associated with ischemic stroke in the general population or populations without diabetes.

MATERIALS AND METHODS

We genotyped rs3134069 and performed a case-control association study to test whether rs3134069 is associated with ischemic stroke in 2 independent Chinese Han populations, including a China-Central population with 1629 cases and 1504 controls and a China-Northern population with 1206 cases and 720 controls.

RESULTS

rs3134069 showed significant association with ischemic stroke in the China-Central population (P = 9.24 × 10^-3, odds ratio [OR] = 1.50). The association was replicated in the independent China-Northern population (P = 2.45 × 10^-4, OR = 1.53). The association became more significant in the combined population (P = 7.09 × 10^-6, OR = 1.41). The associations remained significant in the male population, female population, and population without type 2 diabetes. Our expression quantitative trait loci analysis found that the minor allele C of rs3134069 was significantly associated with a decreasedexpression level of TNFRSF11B (P = .002).

CONCLUSIONS

This study demonstrates that rs3134069 in TNFRSF11B increases risk of ischemic stroke by decreasing TNFRSF11B expression.

Update on Inflammatory Biomarkers and Treatments in Ischemic Stroke

After an acute ischemic stroke (AIS), inflammatory processes are able to concomitantly induce both beneficial and detrimental effects. In this narrative review, we updated evidence on the inflammatory pathways and mediators that are investigated as promising therapeutic targets. We searched for papers on PubMed and MEDLINE up to August 2016. The terms searched alone or in combination were: ischemic stroke, inflammation, oxidative stress, ischemia reperfusion, innate immunity, adaptive immunity, autoimmunity. Inflammation in AIS is characterized by a storm of cytokines, chemokines, and Damage-Associated Molecular Patterns (DAMPs) released by several cells contributing to exacerbate the tissue injury both in the acute and reparative phases. Interestingly, many biomarkers have been studied, but none of these reflected the complexity of systemic immune response. Reperfusion therapies showed a good efficacy in the recovery after an AIS. New therapies appear promising both in pre-clinical and clinical studies, but still need more detailed studies to be translated in the ordinary clinical practice. In spite of clinical progresses, no beneficial long-term interventions targeting inflammation are currently available. Our knowledge about cells, biomarkers, and inflammatory markers is growing and is hoped to better evaluate the impact of new treatments, such as monoclonal antibodies and cell-based therapies.

Serum osteopontin levels are upregulated and predict disability after an ischaemic stroke

BACKGROUND

After an acute ischaemic stroke (AIS), several inflammatory biomarkers have been investigated, but their predictive role on functional recovery remains to be validated. Here, we investigated the prognostic relevance of biomarkers related to atherosclerotic plaque calcification, such as osteopontin (OPN), osteoprotegerin (OPG) and the receptor activator of nuclear factor kappa-B ligand (RANKL) in a cohort of patients with AIS (n = 90) during 90-day follow-up.

MATERIALS AND METHODS

Radiological and clinical examinations as well as blood sampling were performed at admission and at days 1, 7 and 90 from the event. Validated scores [such as modified Rankin scale (mRS) and the National Institutes of Health Stroke Scale (NIHSS)] were used to assess poststroke outcome. Serum levels of OPN, OPG and RANKL were measured by colorimetric enzyme-linked immunosorbent assay (ELISA).

RESULTS

When compared to the admission, OPN serum levels increased at day 7. Serum OPN levels at this time point were positively correlated with both ischaemic lesion volume and NIHSS at days 7 and 90. A cut-off of 30.53 ng/mL was identified for serum OPN by receiver operating characteristic (ROC) curve analysis. Adjusted logistic regression showed that serum OPN levels at day 7 predicted worse mRS at day 90 [OR 4.13 (95% CI 1.64-10.36); P = 0.002] and NIHSS [1.49 (95% CI 1.16-1.99); P = 0.007], independently of age, gender, hypertension and thrombolysis.

CONCLUSIONS

Serum levels of OPN, but not OPG and RANKL, peaked at day 7 after AIS and predicted worse neurological scores. Therefore, OPN might have a pathophysiological and clinical relevance after AIS.

OPG/RANKL/RANK axis is a critical inflammatory signaling system in ischemic brain in mice

Osteoprotegerin (OPG) is a soluble secreted protein and a decoy receptor, which inhibits a receptor activator of nuclear factor κB (NF-κB) ligand (RANKL)/the receptor activator of NF-κB (RANK) signaling. Recent clinical studies have shown that a high-serum-OPG level is associated with unfavorable outcome in ischemic stroke, but it is unclear whether OPG is a culprit or an innocent bystander. Here we demonstrate that enhanced RANKL/RANK signaling in OPG(-/-) mice or recombinant RANKL-treated mice contributed to the reduction of infarct volume and brain edema via reduced postischemic inflammation. On the contrary, infarct volume was increased by reduced RANKL/RANK signaling in OPG(-/-) mice and WT mice treated with anti-RANKL neutralizing antibody. OPG, RANKL, and RANK mRNA were increased in the acute stage and were expressed in activated microglia and macrophages. Although enhanced RANKL/RANK signaling had no effects in glutamate, CoCl2, or H2O2-stimulated neuronal culture, enhanced RANKL/RANK signaling showed neuroprotective effects with reduced expression in inflammatory cytokines in LPS-stimulated neuron-glia mixed culture, suggesting that RANKL/RANK signaling can attenuate inflammation through a Toll-like receptor signaling pathway in microglia. Our findings propose that increased OPG could be a causal factor of reducing RANKL/RANK signaling and increasing postischemic inflammation. Thus, the OPG/RANKL/RANK axis plays critical roles in controlling inflammation in ischemic brains.

Association of plasma osteoprotegerin levels with stroke severity and functional outcome in acute ischaemic stroke patients

Osteoprotegerin (OPG) is known to regulate processes involved in vascular injury and inflammation. We investigated the relationship between plasma OPG levels and stroke subtype, stroke severity at admission and functional outcome at 3 months in 172 patients with acute ischaemic stroke. Patients with large artery atherosclerosis and those with multiple causes had higher plasma OPG levels than patients with lacune. Increased plasma OPG levels were independently associated with more severe stroke and poor functional outcome. These results suggest pleiotropic roles of OPG in mediating atherosclerosis and ischaemic brain injury. OPG is a potential biomarker for predicting neurologic outcome in stroke.

Osteoprotegerin as a marker of atherosclerosis: a systematic update

OBJECTIVE

Osteoprotegerin (OPG) may be involved in development of atherosclerosis. To evaluate plasma concentrations of OPG in individuals with stable coronary artery disease (CAD), acute coronary syndrome (ACS), peripheral artery disease (PAD), and cerebrovascular disease (CBVD) a systematic literature review was performed.

DESIGN AND METHODS

Studies investigating OPG concentrations in stable CAD, ACS, PAD, and CBVD were extracted from PubMed and the Cochrane Library, retrieving 280 articles. Nonrelevant articles were excluded and after thorough evaluation, and only 14 studies with clearly defined cohorts qualified for this review.

RESULTS

In 11 studies, OPG concentrations were elevated. Severity of atherosclerosis was significantly associated with higher OPG concentrations compared to healthy controls. No association between PAD and OPG concentrations was observed.

CONCLUSION

OPG concentrations are associated with the presence and severity of stable CAD, ACS, and CBVD. Larger studies are needed to reach conclusions concerning OPG concentrations in PAD. Studies addressing a putative role for OPG in suspected CAD and CBVD are warranted.