Biomarkers predict hemorrhagic transformation and stroke severity after acute ischemic stroke.

OBJECTIVES: Hemorrhagic transformation (HT) is a complication occurring in patients with acute ischemic stroke (AIS) either spontaneously or post-thrombolysis leading to significant morbidity and mortality. We assessed circulating matrix metalloproteinase-9 (MMP-9), Claudin-5, and soluble serum stimulation-2 (sST2) in HT and stroke severity in AIS based on their temporal distribution. MATERIALS AND METHODS: We prospectively enrolled 111 AIS patients within 12 h from onset. Patient demographic, clinical, and imaging details were documented. Follow-up imaging was conducted 24-48 h after admission. Blood samples were taken at three time-points from stroke onset. HT was classified according to the European Co-operative Acute Stroke Study-III(ECASS-III). Stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS). Multiple logistic regression and receiver operating characteristic curve were conducted to determine the discriminative capacity. RESULTS: Mean age was 62.3 ± 11.7 years and median baseline NIHSS was 12[IQR 8.0-18.0]. HT was detected in 30(27%) patients. Biomarker levels at 12 h were elevated with median MMP-9 concentration of 153.9 ng/mL[IQR 110.6-309 ng/mL] indicating a trend toward significant positive correlation with HT(P = 0.05). Claudin-5 levels at 12 h was elevated but was not statistically significant (43.1 pg/mL[IQR:26.7-72.6 pg/mL] vs 59.4 pg/mL[IQR:24.5-100.8 pg/mL];P = 0.4). Multiple logistic regression indicated Claudin-5 levels at 12 h (OR 9.46;95% CI:1.97-64.6;P = 0.010) and baseline low ASPECTS score(OR 20.3;95% CI:3.46-193; P = 0.003) independently predicted HT. MMP-9 at 12 h was significantly elevated in patients with moderate to severe strokes (P = 0.04). CONCLUSIONS: Claudin-5 and low ASPECTS independently predicted HT. MMP-9 was positively correlated with baseline stroke severity.

Biomarkers in the Prediction of Hemorrhagic Transformation in Acute Stroke: A Systematic Review and Meta-Analysis.

BACKGROUND: Hemorrhagic transformation (HT) is a complication that occurs spontaneously or after thrombolysis in acute ischemic stroke (AIS) and can increase morbidity and mortality. The association of biomarkers with the risk of HT has been variably reported. We conducted a systematic review of the literature and meta-analysis and sought to compare blood biomarkers associated with HT and its subtypes by evaluating its predictability and correlation with outcome in AIS. METHODS: The study protocol was registered in the PROSPERO database (CRD42020201334) and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Among 2,230 articles identified from Cochrane Library, PubMed, and Web of Science databases, 30 quality-appraised articles were found eligible. Meta-analysis was conducted for matrix metalloproteinase-9 (MMP-9), cellular fibronectin (c-Fn), ferritin, S100 calcium-binding protein B (S100B), and neutrophil-lymphocyte ratio (NLR). We also reviewed biomarkers for correlation with the functional outcome at 90 days from stroke onset (poor outcome modified Rankin scale >2). RESULTS: The pooled diagnostic odds ratio (DORpooled) was the highest for baseline c-Fn levels (299.253 [95% CI, 20.508-4,366.709]), followed by MMP-9 (DORpooled, 29.571 [95% CI 17.750-49.267]) and ferritin (DORpooled, 24.032 [95% CI 2.557-225.871]). However, wide confidence intervals for ferritin and c-Fn suggested lesser reliability of the markers. Patients with MMP-9 levels ≥140 ng/mL were 29.5 times at higher risk of developing symptomatic HT after AIS (area under the curve = 0.881). S100B (DORpooled, 6.286 [95% CI, 1.861-21.230]) and NLR (DORpooled, 5.036 [95% CI, 2.898-8.749]) had lower diagnostic accuracies. Among the markers not included for meta-analysis, caveolin-1, thrombin-activated fibrinolysis inhibitor, plasminogen activator inhibitor-1, and soluble ST2 were highly sensitive. Elevated levels of MMP-9, ferritin, and NLR were found to be associated with poor functional outcomes and mortality. CONCLUSION: Of the 5 biomarkers, there was enough evidence that MMP-9 has higher diagnostic accuracy for predicting the risk of HT before thrombolysis. MMP-9, ferritin, and NLR also predicted poor short-term outcomes.

Apolipoproteins B and A1 in Ischemic Stroke Subtypes.

INTRODUCTION: Elevated serum apolipoprotein B and the apolipoprotein B/A1 ratio have been associated with ischemic stroke and intracranial atherosclerotic disease. We sought to assess the relationship between serum levels of apolipoprotein B, apolipoprotein A1, and the apolipoprotein B/A1 ratio with ischemic stroke subtypes and large artery atherosclerosis location. MATERIALS AND METHODS: We evaluated serum apolipoprotein B and apolipoprotein A1 levels in consecutive, statin-naïve, adult ischemic stroke patients admitted to an academic medical center in southern India. We evaluated for differences in the mean serum levels of apolipoprotein B, apolipoprotein A1, and the apolipoprotein B/A1 ratio between patients with ischemic stroke attributed to intracranial atherosclerotic disease, extracranial atherosclerotic disease, small vessel disease, and cardioembolism. In secondary analysis, we assessed for differences in these serum apolipoproteins between patients with moderate-severe intracranial atherosclerotic disease and extracranial atherosclerotic disease, irrespective of ischemic stroke subtype. RESULTS: Among the 156 ischemic stroke patients enrolled in this study, there were no significant differences in serum levels of apolipoprotein B, apolipoprotein A1, and the apolipoprotein B/A1 ratio between patients with distinct ischemic stroke subtypes. No significant differences were found in serum levels of apolipoprotein B, A1 and the apolipoprotein B/A1 ratio between patients with moderate-severe intracranial atherosclerotic disease and moderate-severe extracranial atherosclerotic disease. DISCUSSION: Serum levels of apolipoprotein B and A1 did not differ between ischemic stroke subtypes. Additional studies are needed to validate our findings and to better understand the relationship between serum apolipoproteins and stroke.

Soluble ST2 Predicts Poor Functional Outcome in Acute Ischemic Stroke Patients.

INTRODUCTION: There are very limited data on the role of biomarkers correlating with the outcome in acute ischemic stroke (AIS). We evaluated the predictive values of the plasma concentrations of soluble serum stimulation-2 (sST2), matrix metalloproteinase-9 (MMP-9), and claudin-5 in AIS. METHODS: The biomarker levels in the plasma samples of consecutive AIS patients collected at baseline, 12 h, and 24 h from stroke onset were quantified using immunoassays. Stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS) and functional outcome at 90 days using the modified Rankin Scale (mRS), with scores above 3 defined as poor outcome. Receiver operating characteristic curve analysis and multiple logistic regression were performed for evaluating the discriminative power of each marker. RESULTS: We included 108 patients in the study (mean age 62.3 ± 11.7 years). Median NIHSS score was 12 (interquartile range 8-18). High baseline glucose levels, systolic blood pressure, baseline NIHSS, low Alberta Stroke Program Early CT Score, and hemorrhagic transformation were associated with poor outcomes. Elevated sST2 at 12 h (50.4 ± 51.0 ng/mL; p = 0.047) and 24 h (81.8 ± 101.3 ng/mL; p = 0.001) positively correlated with poor outcomes. MMP-9 (p = 0.086) and claudin-5 (p = 0.2) were not significantly associated with the outcome, although increased expressions of both markers were observed at 12 h. Multiple logistic regression showed that sST2 levels ≥71.8 ng/mL at 24 h, with a specificity of 96.9%, emerged as an independent predictor of poor functional outcome (OR: 6.44; 95% CI: 1.40-46.3; p = 0.029). CONCLUSION: Evaluation of sST2 may act as a reliable biomarker of functional outcome in AIS.

Increased high­density lipoprotein­oxidant index in ischemic stroke patients.

High-density lipoprotein (HDL) is known to have atheroprotective properties which could become dysfunctional under certain disease conditions, particularly during the atherosclerotic progression. The present study sought to assess HDL functionality in acute ischemic stroke (AIS) patients in comparison with controls and the functional alteration among the ischemic stroke subtypes. The HDL functionality was evaluated in 71 statin-naïve, adult patients of South Indian descent, admitted with AIS and were compared with that of 25 age- and sex-matched healthy volunteers. Functional assay of HDL was based on its antioxidant ability to inhibit low-density lipoproteins (LDL) oxidation by air using a dichlorodihydrofluorescein-based fluorescent assay and expressed as HDL oxidant index (HOI). The HOI was higher in ischemic stroke patients as compared with controls (1.07±0.32 vs. 0.51±0.12; P<0.001) indicating high oxidative stress and dysfunctionality in HDL. Regarding the stroke subtypes, HOI was >1 in all stroke subtypes: 1.05±0.301 for Cardioembolic subtype, 1.15±0.41 for large vessel disease, and 1.01±0.25 for small vessel disease when compared with controls. However, no significant difference was noted in HOI values among the three stroke subtypes in the post hoc analysis. It was found that HDL in all ischemic stroke subtypes had less antioxidant capacity, indicating dysfunctional HDL. Functional alteration occurred in HDL of patients even in the presence of normal HDL-cholesterol levels suggesting that dysfunctionality in HDL is unrelated to cholesterol content.

An interleukin-6 ZnO/SiO(2)/Si surface acoustic wave biosensor.

A novel high sensitivity ZnO/SiO(2)/Si Love mode surface acoustic wave (SAW) biosensor for the detection of interleukin-6 (IL-6), is reported. The biosensors operating at 747.7 MHz and 1.586 GHz were functionalized by immobilizing the monoclonal IL-6 antibody onto the ZnO biosensor surface both through direct surface adsorption and through covalent binding on gluteraldehyde. The morphology of the IL-6 antibody-protein complex was studied using scanning electron microscopy (SEM), and the mass of the IL-6 protein immobilized on the surface was measured from the frequency shift of the SAW resonator biosensor. The biosensor was shown to have extended linearity, which was observed to improve with higher sensor frequency and for IL-6 immobilization through the monoclonal antibody. Preliminary results of biosensor measurements of low levels of IL-6 in normal human serum are reported. The biosensor can be fully integrated with CMOS Si chips and developed as a portable real time detection system for the interleukin family of proteins in human serum.

Morphological and binding properties of interleukin-6 on thin ZnO films grown on (100) silicon substrates for biosensor applications.

To develop effective protein immobilization technology with minimal amounts of protein for high sensitivity surface acoustic wave biosensors, we determined the binding properties, and morphological characteristics of human interleukin-6 (IL-6), a pro-inflammatory cytokine, on the surface of ZnO, and SiO(2) films grown onto (100) Si substrates, for the first time. Interleukin-6 was immobilized in the range of 0.276-10 pg/ml on the surface of ZnO and SiO(2), and visualized at each stage, while protein-protein interactions were measured with the antigen/antibody immunoassay of solid-phase ELISA, which we modified for these types of substrates. A relative mass value was determined in each case. ELISA detected upward of 1 and 6 ng/ml of protein applied on ZnO and SiO(2), respectively. It is concluded that the more reactive ZnO surface is a new and more effective template for protein immobilization.

Dopamine D3 receptor Ser9Gly variant is associated with impulse control disorders in Parkinson's disease patients.

INTRODUCTION: Impulse control disorders (ICD) are reported to occur at variable frequencies in different ethnic groups. Genetic vulnerability is suspected to underlie the individual risk for ICD. We investigated whether the allelic variants of dopamine (DRD3), glutamate (GRIN2B) and serotonin (HTR2A) receptors are linked to ICD in Indian Parkinson's disease (PD) patients. METHODS: We conducted a prospective, case-control study which included PD patients (70 with ICD, 100 without ICD categorized after direct psychiatric interview of patient and caregiver) and 285 healthy controls. Single nucleotide polymorphism (SNP) variants of DRD3 p.S9G (rs6280), GRIN2B c.2664C>T (rs1806201) and HTR2A c.102T>C (rs6313) were genotyped. RESULTS: Multivariate regression analysis revealed that DRD3 p.Ser9Gly (rs6280) heterozygous variant CT (OR = 2.22, 95% CI: 1.03-4.86, p = 0.041), higher daily Levodopa equivalent doses (LED) of drugs (for 100 mg LED, OR = 1.14, 95% CI: 1.01-1.29, p = 0.041), current dopamine agonist but not Levodopa use (OR = 2.16, 95% CI: 1.03-4.55, p = 0.042) and age of onset of motor symptoms under 50 years (OR 2.09, 95% CI: 1.05-4.18, p = 0.035) were independently associated with ICD. CONCLUSION: DRD3 p.Ser9Gly (rs6280) CT genotype is associated with ICD in Indian PD patients and this association is novel. Enhanced D3 receptor affinity due to gain-of-function conferred by the glycine residues could impair reward-risk assessment in the mesolimbic system and contribute to development of impulsive behaviour, in carriers of this genotype.