Ischemia, Immunosuppression and Infection--Tackling the Predicaments of Post-Stroke Complications

The clinical value of nutritional and inflammatory indicators in predicting pneumonia among patients with intracerebral hemorrhage

Immunosuppression and malnutrition play pivotal roles in the complications of intracerebral hemorrhage (ICH) and are intricately linked to the development of stroke-associated pneumonia (SAP). Inflammatory markers, including NLR (neutrophil-to-lymphocyte ratio), SII (systemic immune inflammation index), SIRI (systemic inflammatory response index), and SIS (systemic inflammation score), along with nutritional indexes such as CONUT (controlling nutritional status) and PNI (prognostic nutritional index), are crucial indicators influencing the inflammatory state following ICH. In this study, our objective was to compare the predictive efficacy of inflammatory and nutritional indices for SAP in ICH patients, aiming to determine and explore their clinical utility in early pneumonia detection. Patients with severe ICH requiring ICU admission were screened from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The outcomes included the occurrence of SAP and in-hospital death. Receiver operating characteristic (ROC) analysis, multivariate logistic regression, smooth curve analysis, and stratified analysis were employed to investigate the relationship between the CONUT index and the clinical outcomes of patients with severe ICH. A total of 348 patients were enrolled in the study. The incidence of SAP was 21.3%, and the in-hospital mortality rate was 17.0%. Among these indicators, multiple regression analysis revealed that CONUT, PNI, and SIRI were independently associated with SAP. Further ROC curve analysis demonstrated that CONUT (AUC 0.6743, 95% CI 0.6079-0.7408) exhibited the most robust predictive ability for SAP in patients with ICH. Threshold analysis revealed that when CONUT < 6, an increase of 1 point in CONUT was associated with a 1.39 times higher risk of SAP. Similarly, our findings indicate that CONUT has the potential to predict the prognosis of patients with ICH. Among the inflammatory and nutritional markers, CONUT stands out as the most reliable predictor of SAP in patients with ICH. Additionally, it proves to be a valuable indicator for assessing the prognosis of patients with ICH.

Myeloperoxidase to high-density lipoprotein ratio: Potential predictor of severity and outcome in patients with acute ischemic stroke

OBJECTIVE

As a new marker of inflammation and lipid metabolism, the ratio of myeloperoxidase to high density lipoprotein (MPO/HDL) has been reported in the field of cardiovascular disease. However, the effect of MPO/HDL on acute ischemic stroke (AIS) is not clear. The purpose of this study was to explore the prognostic value of MPO/HDL level in patients with AIS.

METHODS

This study conducted a retrospective analysis of 363 patients diagnosed with AIS. Stroke severity was assessed by National Institutes of Health Stroke Scale (NIHSS). The short-term functional outcome was evaluated with modified Rankin Scale (mRS) 90 days after admission. Spearman correlation analysis was used to evaluate the correlation between MPO/HDL and NIHSS scores. The predictive value of MPO, HDL and MPO/HDL to AIS was evaluated by receiver operating characteristic curve (ROC).

RESULTS

The level of MPO/HDL in patients with NIHSS score ≥ 4 was significantly higher than that in patients with NIHSS score < 4 (P < 0.001). MPO and MPO/HDL were positively correlated with NIHSS score (P < 0.001), while HDL was negatively correlated with NIHSS score (P < 0.001). During 90-day follow-up, multivariate Logistic regression analysis showed that increased MPO/HDL levels were associated with 90-day functional outcomes. ROC showed that compared with MPO and HDL, MPO/HDL had the highest predictive value for 90-day functional prognosis in patients with AIS (AUC = 0.9825).

CONCLUSION

The level of serum MPO/HDL may be potential prognostic biomarker in AIS 90 days.

The Clinical Value of the Neutrophil-to-Lymphocyte Ratio, the C-Reactive Protein-to-Albumin Ratio, the Systemic Inflammatory Index, and the Systemic Inflammatory Response Index in Patients with the Anti-Synthetase Syndrome

Objective

There are no studies examining the role of the neutrophil-to-lymphocyte ratio (NLR), the C-reactive protein-to-albumin ratio (CAR), the systemic inflammatory index (SII), and the systemic inflammatory response index (SIRI) in anti-synthetase syndrome (ASS). We aim to compare NLR, CAR, SII, and SIRI in ASS and dermatomyositis/polymyositis (DM/PM), as well as to examine potential correlations between NLR, CAR, SII, and SIRI and clinical features and laboratory parameters in ASS.

Methods

Retrospective collection of data from 111 patients with ASS and 175 patients with DM/PM. A Spearman rank correlation analysis was utilized to analyze the correlation between NLR, CAR, SII, and SIRI and inflammatory indexes. Receiver operating characteristic (ROC) curves were used to assess the diagnostic value. Univariate logistic regression analysis was performed to assess risk factors for interstitial lung disease (ILD).

Results

Compared with DM/PM, NLR, CAR, SII, and SIRI were significantly greater in ASS patients (p < 0.05). NLR, CAR, SII, and SIRI were correlated with albumin, lactic dehydrogenase (LDH), C-reactive protein (CRP), ferritin, white blood cell (WBC), platelets, and myositis disease activity assessment visual analog scales (MYOACT) score (p < 0.05). The ROC curves analysis showed that NLR, SII, and SIRI were all highly predictive of the occurrence of ASS. Comparisons based on clinical characteristics showed elevated levels of NLR, CAR, SII, and SIRI in ASS patients with ILD, fever, and infection (p < 0.05). Univariate logistic regression analysis revealed that NLR, CAR, and SII were significant risk factors for ASS-ILD (p < 0.05).

Conclusion

The levels of NLR, CAR, SII, and SIRI were higher in ASS than in DM/PM and correlated with disease activity and specific clinical features. NLR, CAR, SII, and SIRI may be an aid in differentiating ASS from DM/PM and maybe promising biomarkers for ASS.

Blocking cerebral lymphatic system reduces central and peripheral inflammatory response in ischemic stroke

Reduced blood supply to the brain activates the intracranial inflammatory response, a key contributor to secondary brain damage in ischemic stroke. Post-stroke, activation of peripheral immune cells leads to systemic inflammatory responses. Usingin vivo approaches, we investigated meningeal lymphatics' role in central immune cell infiltration and peripheral immune cell activation. The bilateral deep cervical lymph nodes (dCLNs) were removed 7 days before right middle cerebral artery occlusion in Sprague Dawley (SD) rats. At 3, 24, and 72 h post-intervention, brain immune cell infiltration and microglial and astrocyte activation were measured, while immune cells were classified in the spleen and blood. Inflammatory factor levels in peripheral blood were analyzed. Simultaneously, reverse verification was conducted by injecting AAV-vascular endothelial growth factor C (AAV-VEGFC) adenovirus into the lateral ventricle 14 days before middle cerebral artery occlusion (MCAO) induction to enhance meningeal lymph function. Blocking meningeal LVs in MCAO rats significantly reduced infarct area and infiltration, and inhibited microglia and pro-inflammatory astrocytes activation. After removing dCLNs, CD4+ T lymphocytes, CD8+ T lymphocytes, B lymphocytes, macrophages, and neutrophils in the spleen and blood of MCAO rats decreased significantly at different time points. The levels of inflammatory factors IL-6, IL-10, IL-1β, and TNF-α in plasma decreased significantly. Tests confirmed the results, and AAV-VEGFC-induced MCAO rats provided reverse validation.

Pannexin1 Channel-Mediated Inflammation in Acute Ischemic Stroke

Emerging evidence suggests that inflammation mediated by the pannexin1 channel contributes significantly to acute ischemic stroke. It is believed that the pannexin1 channel is key in initiating central system inflammation during the early stages of acute ischemic stroke. Moreover, the pannexin1 channel is involved in the inflammatory cascade to maintain the inflammation levels. Specifically, the interaction of pannexin1 channels with ATP-sensitive P2X7 purinoceptors or promotion of potassium efflux mediates the activation of the NLRP3 inflammasome, triggering the release of pro-inflammatory factors such as IL-1 and IL-18, exacerbating and sustaining inflammation of brain. Also, increased release of ATP induced by cerebrovascular injury activates pannexin1 in vascular endothelial cells. This signal directs peripheral leukocytes to migrate into ischemic brain tissue, leading to an expansion of the inflammatory zone. Intervention strategies targeting pannexin1 channels may greatly alleviate inflammation after acute ischemic stroke to improve this patient population's clinical outcomes. In this review, we sought to summarize relevant studies on inflammation mediated by the pannexin1 channel in acute ischemic stroke and discussed the possibility of using brain organoid-on-a-chip technology to screen miRNAs that exclusively target the pannexin1 channel to provide new therapeutic measures for targeted regulation of pannexin1 channel to reduce inflammation in acute ischemic stroke.

Fibrinaloid Microclots and Atrial Fibrillation

Atrial fibrillation (AF) is a comorbidity of a variety of other chronic, inflammatory diseases for which fibrinaloid microclots are a known accompaniment (and in some cases, a cause, with a mechanistic basis). Clots are, of course, a well-known consequence of atrial fibrillation. We here ask the question whether the fibrinaloid microclots seen in plasma or serum may in fact also be a cause of (or contributor to) the development of AF. We consider known 'risk factors' for AF, and in particular, exogenous stimuli such as infection and air pollution by particulates, both of which are known to cause AF. The external accompaniments of both bacterial (lipopolysaccharide and lipoteichoic acids) and viral (SARS-CoV-2 spike protein) infections are known to stimulate fibrinaloid microclots when added in vitro, and fibrinaloid microclots, as with other amyloid proteins, can be cytotoxic, both by inducing hypoxia/reperfusion and by other means. Strokes and thromboembolisms are also common consequences of AF. Consequently, taking a systems approach, we review the considerable evidence in detail, which leads us to suggest that it is likely that microclots may well have an aetiological role in the development of AF. This has significant mechanistic and therapeutic implications.

Experimental Models of Hospital-Acquired Infections After Traumatic Brain Injury: Challenges and Opportunities

Patients hospitalized after a moderate or severe traumatic brain injury (TBI) are at increased risk of nosocomial infections, including bacterial pneumonia and other upper respiratory tract infections. Infections represent a secondary immune challenge for vulnerable TBI patients that can lead to increased morbidity and poorer long-term prognosis. This review first describes the clinical significance of infections after TBI, delving into the known mechanisms by which a TBI can alter systemic immunological responses towards an immunosuppressive state, leading to promotion of increased vulnerability to infections. Pulmonary dysfunction resulting from respiratory tract infections is considered in the context of neurotrauma, including the bidirectional relationship between the brain and lungs. Turning to pre-clinical modeling, current laboratory approaches to study experimental TBI and lung infections are reviewed, to highlight findings from the limited key studies to date that have incorporated both insults. Then, practical decisions for the experimental design of animal studies of post-injury infections are discussed. Variables associated with the host animal, the infectious agent (e.g., species, strain, dose, and administration route), as well as the timing of the infection relative to the injury model are important considerations for model development. Together, the purpose of this review is to highlight the significant clinical need for increased pre-clinical research into the two-hit insult of a hospital-acquired infection after TBI to encourage further scientific enquiry in the field.

The associations between peripheral inflammatory and lipid parameters, white matter hyperintensity, and cognitive function in patients with non-disabling ischemic cerebrovascular events

BACKGROUND

The global prevalence of VCI has increased steadily in recent years, but diagnostic biomarkers for VCI in patients with non-disabling ischemic cerebrovascular incidents (NICE) remain indefinite. The primary objective of this research was to investigate the relationship between peripheral serological markers, white matter damage, and cognitive function in individuals with NICE.

METHODS

We collected clinical data, demographic information, and medical history from 257 patients with NICE. Using the MoCA upon admission, patients were categorized into either normal cognitive function (NCF) or VCI groups. Furthermore, they were classified as having mild white matter hyperintensity (mWMH) or severe WMH based on Fazekas scores. We then compared the levels of serological markers between the cognitive function groups and the WMH groups.

RESULTS

Among 257 patients with NICE, 165 were male and 92 were female. Lymphocyte count (OR = 0.448, P < 0.001) and LDL-C/HDL-C (OR = 0.725, P = 0.028) were protective factors for cognitive function in patients with NICE. The sWMH group had a higher age and inflammation markers but a lower MoCA score, and lymphocyte count than the mWMH group. In the mWMH group, lymphocyte count (AUC = 0.765, P < 0.001) and LDL-C/HDL-C (AUC = 0.740, P < 0.001) had an acceptable diagnostic value for the diagnosis of VCI. In the sWMH group, no significant differences were found in serological markers between the NCF and VCI groups.

CONCLUSION

Lymphocyte count, LDL-C/HDL-C were independent protective factors for cognitive function in patients with NICE; they can be used as potential biological markers to distinguish VCI in patients with NICE and are applicable to subgroups of patients with mWMH.

Risk Factors for the Development of Pneumonia in Stroke Patients: A Systematic Review and Meta-Analysis

Pneumonia is one of the most prevalent medical complications post-stroke. It can have negative impacts on the prognosis of stroke patients. This study aimed to determine the predictors of pneumonia in stroke patients. The authors devised, reviewed, and enhanced the search strategy in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were gathered from various electronic databases, including Medline, CINAHL, Cochrane, Embase, and Web of Science, from January 1st, 2011, to February 25th, 2024. The review encompassed studies involving patients aged 18 years and older who were hospitalized for acute stroke care. Inclusion criteria required patients to have received a clinical diagnosis of stroke, confirmed via medical imaging (CT or MRI), hospital primary diagnosis International Classification of Diseases 10th Revision discharge codes, or pathology reporting. A total of 35 studies met the criteria and were included in our pooled analysis. Among them, 23 adopted a retrospective design, while the remaining 12 were prospective. The pooled incidence of pneumonia among patients with stroke was found to be 14% (95% confidence interval = 13%-15%). The pooled analysis reported that advancing age, male gender, a history of chronic obstructive pulmonary disease (COPD), the presence of a nasogastric tube, atrial fibrillation, mechanical ventilation, stroke severity, dysphagia, and a history of diabetes were identified as significant risk factors for pneumonia development among stroke patients. Our results underscore the importance of proactive identification and management of these factors to mitigate the risk of pneumonia in stroke patients.

Predictive value of cytokines combined with human neutrophil lipocalinin acute ischemic stroke-associated pneumonia

OBJECTIVE

To explore the predictive value of interleukin-6 (IL-6) combined with human neutrophil lipocalin (HNL) of stroke-associated pneumonia (SAP) in patients who were diagnosed with acute ischemic stroke (AIS).

METHODS

108patients were divided into two groups: pneumonia group (52 cases) and non-pneumonia group (56 cases), according to whether the patients developed SAP within 7 days of admission. General information was compared between the two groups, like age, gender, history of hypertension, diabetes mellitus, cardiovascular disease, dysphagia, smoking and alcoholhistory. Clinical data were recorded and compared, including lipid profile, interleukin-6 (IL-6), homocysteine (Hcy), National Institutes of Health Stroke Scale (NIHSS) score, and HNL. Multivariate Logistic regression analysis was used to screen the risk factors of AIS-AP, and the predictive value of IL-6 and HNL alone and in combination was evaluated by receiver operating characteristic curve (ROC curve).

RESULTS

Logistic regression analysis showed that dysphagia (OR,0.018; 95% CI, 0.001 ~ 0.427; P = 0.013), increased NIHSS scores(OR,0.012; 95% CI, 0.000 ~ 0.434; P = 0.016), and high levels of IL-6 (OR,0.014; 95% CI, 0.000 ~ 0.695; P = 0.032)and HNL (OR,0.006; 95% CI, 0.000 ~ 0.280; P = 0.009) were independent risk factors for SAP with significant difference (all P < 0.05). According to the ROC curve analysis of IL-6, the area under the curve (AUC) was 0.881 (95% CI: 0.820 ~ 0.942), and the optimal cutoff value was 6.89 pg/mL with the sensitivity of 73.1% and specificity of 85.7%. As for the ROC curve analysis of HNL, the AUC was 0.896 (95% CI: 0.839 ~ 0.954), and the best cutoff value was 99.66ng/mL with the sensitivity of 76.9% and specificity of 89.3%. The AUC of the combination of IL-6 and HNL increased to 0.952 (95% CI: 0.914 ~ 0.989), and the sensitivity and specificity increased to 80.8% and 92.9%, respectively.

CONCLUSION

In this research, the levels of IL-6 ≥ 6.89 pg/mL and HNL ≥ 99.66ng/mL were considered as risk factors for AIS patients complicated with SAP. The combined detection had higher predictive value for patients with SAP, which may help to identify who were in highrisk.

Diagnostic value of coagulation index and serum inflammatory cytokines in hemorrhagic stroke patients with pulmonary infection in the sequelae stage

BACKGROUND

Stroke is the second reason for global deaths and a major reason for disabilities.

OBJECTIVE

To unravel the clinical value of the coagulation index and serum inflammatory cytokines in hemorrhagic stroke patients with pulmonary infection in the sequelae stage.

METHODS

Altogether, 130 hemorrhagic stroke patients who received treatment in Hebei General Hospital from April 2019 to December 2020 were selected. Patients were classified into the infection group (n= 65) and non-infection group (n= 65) according to whether they had a pulmonary infection in the sequelae stage of hemorrhagic stroke. Levels of coagulation index and serum inflammatory cytokines of patients in two groups were compared. Multiple linear regression analysis was used to analyze pulmonary infection-related factors of hemorrhagic stroke patients. The diagnostic value of the coagulation index and serum inflammatory cytokines in pulmonary infection was analyzed by the receiver operating characteristic (ROC) curve.

RESULTS

Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), D-dimer (D-D), platelet (PLT) related to coagulation function levels and interleukin 1β (IL-1β), interleukin 17 (IL-17) related to serum inflammatory cytokines levels of patients in the infection group were higher than those in non-infection groups (p< 0.05). Multiple linear regression analysis uncovered that FIB, D-D, PLT, and IL-17 were influencing factors of pulmonary infection in the sequelae of patients with hemorrhagic stroke (p< 0.05). Area under the curve (AUC) values of pulmonary infection in the sequelae stage of patients with hemorrhagic stroke diagnosed by FIB, D-D, PLT, and IL-17 were 0.823, 0.758, 0.660, and 0.755, respectively.

CONCLUSION

FIB, D-D, PLT, and IL-17 levels could be used for pulmonary infection diagnosis in the sequelae stage of hemorrhagic stroke patients.

Prevalence of Stroke-Associated Pneumonia and Its Predictors Among Hyperglycaemia Patients During Acute Ischemic Stroke

BACKGROUND

Hyperglycaemia (HG) during an acute ischemic stroke (AIS) is not only associated with unfavourable functional outcomes but also associated with stroke-associated pneumonia (SAP). This study aimed to determine the prevalence of SAP among Malaysian patients with AIS and the predictors of SAP among patients with HG during AIS.

METHODS

This is a retrospective cross-sectional study that included patients with AIS admitted to Hospital Sultanah Nur Zahirah, Malaysia from 2017 to 2020. SAP was defined as infection with pneumonia during the first seven days after IS. HG was defined as a blood glucose level > 7.8 mmol/L within 72 h after admission. Patients with SAP were divided into two groups according to HG status. Multivariate logistic regression analysis was performed using SPSS software, version 22 (IBM Corp., Armonk, NY) to identify SAP predictors among patients with HG. Kaplan-Meier log-rank test was used to compare the survival rate from unfavourable functional outcomes between hyperglycaemic patients with and without SAP.

RESULTS

Among 412 patients with AIS, 69 (16.74%) had SAP. The prevalence of SAP among patients with HG and normoglycemia during AIS was 20.98%, and 10.65%, respectively. Age above 60 years, leucocytosis, and National Institute of Health Stroke Scale (NIHSS) > 14 on admission were independent predictors of SAP with aOR of 2.08 (95% CI;1.01-4.30), 2.83 (95% CI; 1.41-5.67), and 3.67 (95% CI; 1.53-8.80), respectively. No significant difference in unfavourable functional outcomes survival was found among patients with and without SAP (p = 0.653).

CONCLUSION

This study demonstrated the prevalence of SAP was higher among patients with HG compared to normoglycemia during AIS. The patient being old, leucocytosis and severe stroke upon admission predict the occurrence of SAP among patients with HG during AIS.

Prediction of early neurological deterioration in acute ischemic stroke patients treated with intravenous thrombolysis

A proportion of acute ischemic stroke (AIS) patients suffer from early neurological deterioration (END) within 24 hours following intravenous thrombolysis (IVT), which greatly increases the risk of poor prognosis of these patients. Therefore, we aimed to explore the predictors of early neurological deterioration of ischemic origin (ENDi) in AIS patients after IVT and develop a nomogram prediction model. This study collected 244 AIS patients with post-thrombolysis ENDi as the derivation cohort and 155 patients as the validation cohort. To establish a nomogram prediction model, risk factors were identified by multivariate logistic regression analysis. The results showed that neutrophil to lymphocyte ratio (NLR) (OR 2.616, 95% CI 1.640-4.175, P < 0.001), mean platelet volume (MPV) (OR 3.334, 95% CI 1.351-8.299, P = 0.009), body mass index (BMI) (OR 1.979, 95% CI 1.285-3.048, P = 0.002) and atrial fibrillation (AF) (OR 8.012, 95% CI 1.341-47.873, P = 0.023) were significantly associated with ENDi. The area under the curve of the prediction model constructed from the above four factors was 0.981 (95% CI 0.961-1.000) and the calibration curve was close to the ideal diagonal line. Therefore, this nomogram prediction model exhibited good discrimination and calibration power and might be a reliable and easy-to-use tool to predict post-thrombolysis ENDi in AIS patients.

Molecular chaperones in stroke-induced immunosuppression

Stroke-induced immunosuppression is a process that leads to peripheral suppression of the immune system after a stroke and belongs to the central nervous system injury-induced immunosuppressive syndrome. Stroke-induced immunosuppression leads to increased susceptibility to post-stroke infections, such as urinary tract infections and stroke-associated pneumonia, worsening prognosis. Molecular chaperones are a large class of proteins that are able to maintain proteostasis by directing the folding of nascent polypeptide chains, refolding misfolded proteins, and targeting misfolded proteins for degradation. Various molecular chaperones have been shown to play roles in stroke-induced immunosuppression by modulating the activity of other molecular chaperones, cochaperones, and their associated pathways. This review summarizes the role of molecular chaperones in stroke-induced immunosuppression and discusses new approaches to restore host immune defense after stroke.

Research progress on the roles of neurovascular unit in stroke-induced immunosuppression

A complex pathophysiological mechanism is involved in brain injury following cerebral infarction. The neurovascular unit (NVU) is a complex multi-cellular structure consisting of neurons, endothelial cells, pericyte, astrocyte, microglia and extracellular matrix, etc. The dyshomeostasis of NVU directly participates in the regulation of inflammatory immune process. The components of NVU promote inflammatory overreaction and synergize with the overactivation of autonomic nervous system to initiate stroke-induced immunodepression (SIID). SIID can alleviate the damage caused by inflammation, however, it also makes stroke patients more susceptible to infection, leading to systemic damage. This article reviews the mechanism of SIID and the roles of NVU in SIID, to provide a perspective for reperfusion, prognosis and immunomodulatory therapy of cerebral infarction.

Post-stroke pneumonia: Factors associated with readmission within 90 days of stroke discharge

OBJECTIVE

The objective was to identify risk and protective factors associated with post-stroke pneumonia readmission.

METHOD

A retrospective chart review was conducted on 365 stroke patients who were admitted to Ascension Via Christi St. Francis Hospital in Wichita, Kansas from January 1, 2015 through January 30, 2020. This case control study used matching by age at a proportion of four control patients to one post-stroke pneumonia patient. Patients with and without post-stroke pneumonia readmission within 90 days of discharge were included in this study.

RESULTS

Of the 3,952 patients diagnosed with stroke, 1.8% (n=73) patients were readmitted with post-stroke pneumonia. Compared to patients who were not readmitted for post-stroke pneumonia, patients with post-stroke pneumonia readmission were more likely to: have used a nasogastric tube during index admission, have used mechanical ventilation during index admission, or have been placed on a nothing-by-mouth diet at discharge. Being placed on nothing-by-mouth for fluids was also a predictor of post-stroke pneumonia readmission. Lack of acquired infection during the index admission was a protective factor for post-stroke pneumonia readmission.

DISCUSSION

The pathophysiology of post-stroke pneumonia is multifactorial and includes consideration of dysphagia severity, bacterial colonization of the oropharynx and feeding tube, and an altered immune system.

CONCLUSION

During the index admission, patients on nothing-by-mouth were more likely to be readmitted, and infection-free patients were less likely to be readmitted with post-stroke pneumonia. By identifying at-risk patients, clinicians may be able to use this information to tailor future medical interventions to prevent post-stroke pneumonia readmissions.

Integrative Approaches in Acute Ischemic Stroke: From Symptom Recognition to Future Innovations

Among the high prevalence of cerebrovascular diseases nowadays, acute ischemic stroke stands out, representing a significant worldwide health issue with important socio-economic implications. Prompt diagnosis and intervention are important milestones for the management of this multifaceted pathology, making understanding the various stroke-onset symptoms crucial. A key role in acute ischemic stroke management is emphasizing the essential role of a multi-disciplinary team, therefore, increasing the efficiency of recognition and treatment. Neuroimaging and neuroradiology have evolved dramatically over the years, with multiple approaches that provide a higher understanding of the morphological aspects as well as timely recognition of cerebral artery occlusions for effective therapy planning. Regarding the treatment matter, the pharmacological approach, particularly fibrinolytic therapy, has its merits and challenges. Endovascular thrombectomy, a game-changer in stroke management, has witnessed significant advances, with technologies like stent retrievers and aspiration catheters playing pivotal roles. For select patients, combining pharmacological and endovascular strategies offers evidence-backed benefits. The aim of our comprehensive study on acute ischemic stroke is to efficiently compare the current therapies, recognize novel possibilities from the literature, and describe the state of the art in the interdisciplinary approach to acute ischemic stroke. As we aspire for holistic patient management, the emphasis is not just on medical intervention but also on physical therapy, mental health, and community engagement. The future holds promising innovations, with artificial intelligence poised to reshape stroke diagnostics and treatments. Bridging the gap between groundbreaking research and clinical practice remains a challenge, urging continuous collaboration and research.

Comparison of the Predictive Value of Inflammatory Biomarkers for the Risk of Stroke-Associated Pneumonia in Patients with Acute Ischemic Stroke

Purpose

To investigate the predictive value of various inflammatory biomarkers in patients with acute ischemic stroke (AIS) and evaluate the relationship between stroke-associated pneumonia (SAP) and the best predictive index.

Patients and Methods

We calculated the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), prognostic nutritional index (PNI), systemic inflammation response index (SIRI), systemic immune inflammation index (SII), Glasgow prognostic score (GPS), modified Glasgow prognostic score (mGPS), and prognostic index (PI). Variables were selectively included in the logistic regression analysis to explore the associations of NLR, PLR, MLR, PNI, SIRI, SII, GPS, mGPS, and PI with SAP. We assessed the predictive performance of biomarkers by analyzing receiver operating characteristic (ROC) curves. We further used restricted cubic splines (RCS) to investigate the association. Next, we conducted subgroup analyses to investigate whether specific populations were more susceptible to NLR.

Results

NLR, PLR, MLR, SIRI, SII, GPS, mGPS, and PI increased significantly in SAP patients, and PNI was significantly decreased. After adjustment for potential confounders, the association of inflammatory biomarkers with SAP persisted. NLR showed the most favorable discriminative performance and was an independent risk factor predicting SAP. The RCS showed an increasing nonlinear trend of SAP risk with increasing NLR. The AUC of the combined indicator of NLR and C-reactive protein (CRP) was significantly higher than those of NLR and CRP alone (DeLong test, P<0.001). Subgroup analyses suggested good generalizability of the predictive effect.

Conclusion

NLR, PLR, MLR, PNI, SIRI, SII, GPS, mGPS, and PI can predict the occurrence of SAP. Among the indices, the NLR was the best predictor of SAP occurrence. It can therefore be used for the early identification of SAP.

Association between red cell distribution width-to-platelet ratio and short-term and long-term mortality risk in patients with acute ischemic stroke

BACKGROUND

The objective of this study was to evaluate the association between red cell distribution width/platelet ratio (RPR) and 30-day and 1-year mortality in acute ischemic stroke (AIS).

METHODS

Data for the retrospective cohort study were collected from the Medical Information Mart for Intensive Care (MIMIC) III database. RPR was divided into two groups: RPR ≤ 0.11 and RPR > 0.11. The study outcomes were 30-day mortality and 1-year mortality from AIS. Cox proportional hazard models were utilized to assess the association between RPR and mortality. Subgroup analyses were applied based on age, tissue-type plasminogen activator (IV-tPA), endovascular treatment, and myocardial infarction.

RESULTS

A total of 1,358 patients were included in the study. Short- and long-term mortality occurred in 375 (27.61%) and 560 (41.24%) AIS patients, respectively. A high RPR was significantly associated with increased 30-day [hazard ratio (HR): 1.45, 95% confidence interval (CI): 1.10 to 1.92, P = 0.009] and 1-year mortality (HR: 1.54, 95%CI: 1.23 to 1.93, P < 0.001) in AIS patients. Meanwhile, RPR was found to be significantly related to 30-day mortality in AIS patients aged < 65 years (HR: 2.19, 95% CI: 1.17 to 4.10, P = 0.014), without IV-tPA use (HR: 1.42, 95% CI: 1.05 to 1.90, P = 0.021), without using endovascular treatment (HR: 1.45, 95% CI: 1.08 to 1.94, P = 0.012), and without myocardial infarction (HR: 1.54, 95% CI: 1.13 to 2.10, P = 0.006). Additionally, RPR was associated with 1-year mortality in AIS patients aged < 65 years (HR: 2.54, 95% CI: 1.56 to 4.14, P < 0.001), aged ≥ 65 years (HR: 1.38, 95% CI: 1.06 to 1.19, P = 0.015), with (HR: 1.46, 95% CI: 1.15 to 1.85, P = 0.002) and without using IV-tPA (HR: 2.30, 95% CI: 1.03 to 5.11, P = 0.041), without using endovascular treatment (HR: 1.56, 95% CI: 1.23 to 1.96, P < 0.001), and without myocardial infarction (HR: 1.68, 95% CI: 1.31 to 2.15, P < 0.001).

CONCLUSION

Elevated RPR is associated with a high risk of short-term and long-term mortality in AIS.

The Effect of Prognostic Nutritional Index on Infection in Acute Ischemic Stroke Patients

Objectives: Malnutrition is frequently seen in stroke patients. Malnutrition worsens the prognosis and increases the mortality rate in acute ischemic stroke patients. Malnutrition is a significant factor not only in the initiation of infection but also in its progression. The prognostic nutritional index (PNI) is a new index that evaluates the nutrition and inflammatory status. This study aims to investigate the relationship between PNI and stroke-related infection (SRI) development during hospitalization in patients with acute ischemic stroke. Materials and Methods: Acute ischemic stroke was the primary diagnosis for 158 patients who were admitted to the neurology intensive care unit. Patients' demographic, clinical, and laboratory parameters were recorded. PNI was calculated according to the formula given below. PNI: 10 × serum albumin (g/dL) + 0.005 × total lymphocyte count (mm³). PNI > 380 normal, PNI: 350-380 moderate malnutrition risk, PNI < 350 severe malnutrition risk. Results: A total of 158 patients with acute ischemic stroke were included in the study. There were 70 male and 88 female patients, whereas the mean age of the patients was 67.79 ± 14.0 years. Nosocomial infection developed in 34 (21%) of the patients. Compared to high PNI scores, patients with low PNI scores were generally older, and the National Institutes of Health Stroke Scale (NIHSS) score, atrial fibrillation, infection, mortality rate, and hospitalization rates were all significantly higher. Conclusions: In this study, we discovered that patients with poor PNI had a considerably increased rate of infection development. It is vital to evaluate the nutritional status of patients with acute ischemic stroke during hospitalization.

The efficacy and safety of prophylactic antibiotics for post-acute stroke infection: A systematic review and meta-analysis

AIMS

Infections are common complications after stroke and associated with unfavourable outcomes. We aimed to evaluate the efficacy and safety of prophylactic antibiotics for post-acute stroke infection.

METHODS

We searched PubMed, Embase, the Cochrane Library, SinoMed, China National Knowledge Infrastructure, WanFang Data, China Science and Technology Journal Database, and clinical trial register platforms from inception to 15 February 2022. We included randomized clinical trials that evaluated the efficacy and safety of prophylactic antibiotics. Primary outcomes were mortality rate and incidence of pneumonia. The pooled risk ratio (RR) and mean differences with 95% confidence interval (CI) were calculated using the random or fixed-effect model depending on heterogeneity. The quality of evidence was evaluated using the Grading of Recommendations, Assessment, Development and Evaluations.

RESULTS

Twelve studies (4809 participants) were included. There was no significant difference in the mortality rate (12 trials, n = 4740, RR 1.03 [95% Cl: 0.91-1.16], high-quality evidence), incidence of pneumonia (7 trials, n = 4352, RR 0.94 [95% CI: 0.79-1.11], high-quality evidence) and the incidence of adverse events between the prophylactic antibiotics and control groups. Prophylactic antibiotics significantly reduced the incidence of infections (8 trials, n = 4517, RR 0.72 [95% CI: 0.58-0.89], moderate-quality evidence) and urinary tract infections (7 trials, n = 4352, RR 0.39 [95% CI: 0.3-0.49], moderate-quality evidence). None of the subgroup analyses showed a significant difference in mortality or the incidence of pneumonia.

CONCLUSION

For acute stroke patients, prophylactic antibiotics were significantly associated with fewer incidences of any infections and urinary tract infections without significant differences in mortality rate and pneumonia.

Optimal time point for neutrophil-to-lymphocyte ratio to predict stroke-associated pneumonia

PURPOSE

This study aimed at the population receiving thrombolytic therapy and to explore the optimal time point for neutrophil-to-lymphocyte ratio (NLR) in predicting stroke-associated pneumonia (SAP).

METHODS

We assessed patients undergoing intravenous thrombolysis (IVT) for acute ischemic stroke. Blood parameters were sampled before thrombolysis (within 30 min after admission) and within 24-36 h after thrombolysis, respectively. The primary outcome measure was the occurrence of SAP. Multivariate logistic regression analysis was performed to analyze the association between admission blood parameters and the event of SAP. We also used receiver operating characteristic (ROC) curve analysis to assess the discriminative ability of blood parameters measured at different times in predicting SAP.

RESULTS

Among the 388 patients, SAP occurred in 60 (15%) patients. Multivariate logistic regression analysis showed that NLR was significantly associated with SAP (NLR before IVT: aOR = 1.288; 95%CI = 1.123-1.476; p < 0.001; NLR after IVT: (aOR = 1.127, 95%CI = 1.017-1.249; p = 0.023). The ROC curve showed that the predictive ability of NLR after IVT was better than NLR before IVT, not only in predicting the occurrence of SAP but also in predicting short-term and long-term functional outcomes, hemorrhagic transformation, and 1-year mortality.

CONCLUSION

Increased NLR measured within 24-36 h after IVT has a significant predictive effect on the occurrence of SAP and can be used to predict short-term and long-term poor functional outcomes, hemorrhagic transformation, and 1-year mortality.

The clinical value of neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), platelet-to-lymphocyte ratio (PLR) and systemic inflammation response index (SIRI) for predicting the occurrence and severity of pneumonia in patients with intracerebral hemorrhage

Background

Inflammatory mechanisms play important roles in intracerebral hemorrhage (ICH) and have been linked to the development of stroke-associated pneumonia (SAP). The neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), platelet-to-lymphocyte ratio (PLR) and systemic inflammation response index (SIRI) are inflammatory indexes that influence systemic inflammatory responses after stroke. In this study, we aimed to compare the predictive value of the NLR, SII, SIRI and PLR for SAP in patients with ICH to determine their application potential in the early identification of the severity of pneumonia.

Methods

Patients with ICH in four hospitals were prospectively enrolled. SAP was defined according to the modified Centers for Disease Control and Prevention criteria. Data on the NLR, SII, SIRI and PLR were collected at admission, and the correlation between these factors and the clinical pulmonary infection score (CPIS) was assessed through Spearman's analysis.

Results

A total of 320 patients were enrolled in this study, among whom 126 (39.4%) developed SAP. The results of the receiver operating characteristic (ROC) analysis revealed that the NLR had the best predictive value for SAP (AUC: 0.748, 95% CI: 0.695-0.801), and this outcome remained significant after adjusting for other confounders in multivariable analysis (RR=1.090, 95% CI: 1.029-1.155). Among the four indexes, Spearman's analysis showed that the NLR was the most highly correlated with the CPIS (r=0.537, 95% CI: 0.395-0.654). The NLR could effectively predict ICU admission (AUC: 0.732, 95% CI: 0.671-0.786), and this finding remained significant in the multivariable analysis (RR=1.049, 95% CI: 1.009-1.089, P=0.036). Nomograms were created to predict the probability of SAP occurrence and ICU admission. Furthermore, the NLR could predict a good outcome at discharge (AUC: 0.761, 95% CI: 0.707-0.8147).

Conclusions

Among the four indexes, the NLR was the best predictor for SAP occurrence and a poor outcome at discharge in ICH patients. It can therefore be used for the early identification of severe SAP and to predict ICU admission.

Impact of age group on bloodstream infection risk evaluation in immunosuppressed patients: a retrospective, single-centre, 5-year cohort study

INTRODUCTION

Elderly patients in immunosuppressive status may have an increased occurrence of illness and risk of poor prognosis. It is a generally overlooked population that we should pay more attention to their risk factors of sickness and mortality.

METHODS

Eight hundred and nine patients who were diagnosed with bloodstream infection in immunosuppressive states during accepting treatment in our hospital were selected from 2015 to 2019.The demographic data, underlying diseases, comorbidity, inducement, complications, pathogen sources, etiologies, and the antibiotics therapy were analyzed between ages > 65 years groups and ages < 65 years groups.

RESULTS

The clinical characteristics of totally 809 immunosuppressed people diagnosed with bloodstream infection were analyzed, and among those people about 371 were ages > 65 years. By univariate logistic regression analysis and multivariate logistic regression analysis, we found that hypertension (OR: 2.864, 95% CI 2.024-4.051, P < 0.0001), cerebral Infarction (OR: 4.687, 95% CI 2.056-10.686, P < 0.0001), coronary heart disease (OR: 1.942, 95% CI 1.168-3.230, P = 0.011), acute pancreatitis (OR: 3.964, 95% CI 2.059-7.632, P < 0.0001), infective endocarditis (OR: 6.846, 95% CI 1.828-25.644, P = 0.004), aortic dissection (OR: 9.131, 95% CI 3.190-26.085, P < 0.0001), chemotherapy (OR: 3.462, 95% CI 1.815-6.603, P < 0.0001), transplant status (OR: 20.031, 95% CI 4.193-95.697, P < 0.0001), and respiratory tract infection (OR: 2.096, 95% CI 1.269-3.461, P = 0.004) were significantly different between ages > 65 years groups and ages < 65 years groups.

CONCLUSION

Hypertension, cerebral Infarction, coronary heart disease, acute pancreatitis, infective endocarditis, aortic dissection, chemotherapy, transplant status, and pathogen source of respiratory tract were the independent risk factors of ages > 65 years in immunosuppressed patients, which would have the benefit to discriminate the prognostic factors in immunosuppressive elderly people with bloodstream infection.

Non-Neurological Complications after Mechanical Thrombectomy for Acute Ischemic Stroke: A Retrospective Single-Center Study

Introduction

The global burden of stroke is high and mechanical thrombectomy is the cornerstone of the treatment. Incidences of acute non-neurological-complications are poorly described. Improve knowledge about these complications may allow to better prevent, detect and/or manage them. The aim is to identify risk markers of death or poor evolution.

Method

We conducted a retrospective single-center study to analyzed the incidence of non-neurologicalcomplications after mechanical thrombectomy in acute ischemic stroke. Patients who had experienced a stroke and undergone thrombectomy were identified using a registry in which we prospectively collected data from each patient admitted to our hospital with a diagnosis of stroke. Quantitative and qualitative variables were analyses. The association between studied variables and hospital death was assessed using simple logistic regression models.

Result

361 patients were reviewed but 16 were excluded due to a lack of medical information. Between 2012 and 2019, 345 patients were included. The median admission NIHSS score was 15. Seven percent of the patients died in the ICU. The following independent risk markers of death in the ICU were identified by logistic regression: respiratory complication, hypotension, infectious complication, and hyperglycemia.

Conclusion

In this large retrospective study of stroke, respiratory complications and pulmonary infections represented the most important non-neurological adverse events encountered in the ICU and associated with a risk of death.

Correlations among peripheral blood markers, white matter hyperintensity, and cognitive function in patients with non-disabling ischemic cerebrovascular events

BACKGROUND

Both inflammation and cerebral white matter injury are closely associated with vascular cognitive impairment (VCI). The aim of this study was to analyze the correlation between peripheral serological markers, white matter injury, and cognitive function in patients with non-disabling ischemic cerebrovascular events (NICE); to identify potential biological markers for the diagnosis and prediction of VCI; and to provide a basis for the early diagnosis and intervention of VCI.

METHODS

We collected clinical data, along with demographic and medical history data, from 151 NICE patients. Fasting venous blood samples were collected. Based on the Montreal Cognitive Assessment (MoCA) after admission, we divided the patients into normal cognitive function (NCF) and VCI groups, and then classified them into mild white matter hyperintensity (mWMH) and severe white matter hyperintensity (sWMH) based on Fazekas scores. The differences in serological marker levels were compared between the cognitive function groups and the white matter hyperintensity groups. Binary logistic regression models and receiver operating characteristic curves were used to analyze the diagnostic predictive value of serological markers for VCI in patients with NICE and in the white matter hyperintensity subgroups.

RESULTS

Among 151 patients with NICE, 95 were male and 56 were female. Lymphocyte count (OR = 0.405, p = 0.010, 95% CI [0.201, 0.806]), red blood cell count (OR = 0.433, p = 0.010, 95% CI [0.228, 0.821]), and hemoglobin level (OR = 0.979, p = 0.046, 95% CI [0.958, 0.999]) were protective factors for cognitive function in patients with NICE. The sWMH group had a higher age, granulocyte/lymphoid ratio (NLR), and neutrophil percentage but a lower MoCA score, hemoglobin level, and lymphocyte count than the mWMH group. In the mWMH group, lymphocyte count (AUC = 0.713, p = 0.003, 95% CI [0.593, 0.833]) had an acceptable predictive value for the diagnosis of VCI, whereas white blood cell count (AUC = 0.672, p = 0.011, 95% CI [0.545, 0.799]), red blood cell count (AUC = 0.665, p = 0.014, 95% CI [0.545, 0.784]), and hemoglobin level (AUC = 0.634, p = 0.047, 95% CI [0.502, 0.765]) had marginal predictive value for the diagnosis of VCI. In the sWMH group, no significant differences were found in serological markers between the NCF and VCI groups.

CONCLUSION

Lymphocyte count, red blood cell count, and hemoglobin level were independent protective factors for cognitive function in patients with NICE; they can be used as potential biological markers to distinguish VCI in patients with NICE and are applicable to subgroups of patients with mWMH.

Systemic immune responses after ischemic stroke: From the center to the periphery

Ischemic stroke is a leading cause of disability and death. It imposes a heavy economic burden on individuals, families and society. The mortality rate of ischemic stroke has decreased with the help of thrombolytic drug therapy and intravascular intervention. However, the nerve damage caused by ischemia-reperfusion is long-lasting and followed by multiple organ dysfunction. In this process, the immune responses manifested by systemic inflammatory responses play an important role. It begins with neuroinflammation following ischemic stroke. The large number of inflammatory cells released after activation of immune cells in the lesion area, along with the deactivated neuroendocrine and autonomic nervous systems, link the center with the periphery. With the activation of systemic immunity and the emergence of immunosuppression, peripheral organs become the second “battlefield” of the immune response after ischemic stroke and gradually become dysfunctional and lead to an adverse prognosis. The purpose of this review was to describe the systemic immune responses after ischemic stroke. We hope to provide new ideas for future research and clinical treatments to improve patient outcomes and quality of life.

Day 1 neutrophil-to-lymphocyte ratio (NLR) predicts stroke outcome after intravenous thrombolysis and mechanical thrombectomy

Background

The neutrophil-to-lymphocyte ratio (NLR) is a biomarker reflecting the balance between inflammation (as indicated by the neutrophil count) and adaptive immunity (as indicated by the lymphocyte count). We aimed to estimate ability of NLR at admission and at day 1 for predicting stroke outcome after two reperfusion therapies: intravenous thrombolysis (IVT) and mechanical thrombectomy (MT).

Methods

A retrospective analysis was performed on patients who received recombinant human tissue plasminogen activator (IVT) and/or underwent MT for acute ischemic stroke (AIS) at the First Affiliated Hospital of Wenzhou Medical University (Wenzhou, China) from January 2018 to December 2020. Blood samples were taken on admission to hospital and on day 1 after stroke onset. Binary logistic regression models were applied to investigate potential associations between NLR at admission or day 1 and the following outcomes: symptomatic intracerebral hemorrhage (sICH), dependence, and mortality at 90 days. The ability of NLR to predict AIS outcome was analyzed using receiver operating characteristic (ROC) curves.

Results

Data for 927 patients (576 IVT and 351 MT) were reviewed. High admission NLR was associated with dependence in IVT treatment [adjusted odds ratio (OR) 1.21, 95% confidence interval (CI) 1.14–1.23] and 90-day mortality in MT patients (OR 1.09, 95% CI 1.04–1.13). In IVT patients, high NLR at day 1 predicted dependence (OR 1.09, 95% CI 1.02–1.11), sICH (OR = 1.07, 95% CI 1.01–1.12), and 90-day mortality (OR 1.06, 95% CI 1.01–1.15). In MT patients, high NLR at day 1 also predicted dependence (OR 1.08, 95% CI 1.02–1.11) and sICH (OR 1.03, 95% CI 1.01–1.09). ROC analysis confirmed that NLR at day 1 could predict dependence (cut-off 4.2; sensitivity 68.7%; specificity 79.6%), sICH (cut-off 5.1; sensitivity 57.9%, specificity 73.5%), and death (cut-off 5.4; sensitivity 78.8%; specificity 76.4%) in IVT patients. Z values of area under the curves were compared between admissioin and day 1 NLR in IVT patients and showed day 1 NLR can better predict dependence (Z = 2.8, p = 0.004) and 90-day death (Z = 2.8, p = 0.005).

Conclusions

NLR is a readily available biomarker that can predict AIS outcome after reperfusion treatment and day 1 NLR is even better than admission NLR.

Systemic immune inflammation index and system inflammation response index are potential biomarkers of atrial fibrillation among the patients presenting with ischemic stroke

Background

Chronic inflammatory disorders in atrial fibrillation (AF) contribute to the onset of ischemic stroke. Systemic immune inflammation index (SIII) and system inflammation response index (SIRI) are the two novel and convenient measurements that are positively associated with body inflammation. However, little is known regarding the association between SIII/SIRI with the presence of AF among the patients with ischemic stroke.

Methods

A total of 526 ischemic stroke patients (173 with AF and 353 without AF) were consecutively enrolled in our study from January 2017 to June 2019. SIII and SIRI were measured in both groups. Logistic regression analysis was used to analyse the potential association between SIII/SIRI and the presence of AF. Finally, the correlation between hospitalization expenses, changes in the National Institutes of Health Stroke Scale (NIHSS) scores and SIII/SIRI values were measured.

Results

In patients with ischemic stroke, SIII and SIRI values were significantly higher in AF patients than in non-AF patients (all p < 0.001). Moreover, with increasing quartiles of SIII and SIRI in all patients, the proportion of patients with AF was higher than that of non-AF patients gradually. Logistic regression analyses demonstrated that log-transformed SIII and log-transformed SIRI were independently associated with the presence of AF in patients with ischemic stroke (log-transformed SIII: odds ratio [OR]: 1.047, 95% confidence interval CI = 0.322–1.105, p = 0.047; log-transformed SIRI: OR: 6.197, 95% CI = 2.196–17.484, p = 0.001). Finally, a positive correlation between hospitalization expenses, changes in the NIHSS scores and SIII/SIRI were found, which were more significant in patients with AF (all p < 0.05).

Conclusions

Our study suggests SIII and SIRI are convenient and effective measurements for predicting the presence of AF in patients with ischemic stroke. Moreover, they were correlated with increased financial burden and poor short-term prognosis in AF patients presenting with ischemic stroke.

Interactions between the Autonomic Nervous System and the Immune System after Stroke

Acute stroke is one of the leading causes of morbidity and mortality worldwide. Stroke-induced immune-inflammatory response occurs in the perilesion areas and the periphery. Although stroke-induced immunosuppression may alleviate brain injury, it hinders brain repair as the immune-inflammatory response plays a bidirectional role after acute stroke. Furthermore, suppression of the systemic immune-inflammatory response increases the risk of life-threatening systemic bacterial infections after acute stroke. Therefore, it is essential to explore the mechanisms that underlie the stroke-induced immune-inflammatory response. Autonomic nervous system (ANS) activation is critical for regulating the local and systemic immune-inflammatory responses and may influence the prognosis of acute stroke. We review the changes in the sympathetic and parasympathetic nervous systems and their influence on the immune-inflammatory response after stroke. Importantly, this article summarizes the mechanisms on how ANS regulates the immune-inflammatory response through neurotransmitters and their receptors in immunocytes and immune organs after stroke. To facilitate translational research, we also discuss the promising therapeutic approaches modulating the activation of the ANS or the immune-inflammatory response to promote neurologic recovery after stroke. © 2022 American Physiological Society. Compr Physiol 12:3665-3704, 2022.

Neuroprotection by Ozanimod Following Intracerebral Hemorrhage in Mice

The destruction of the blood-brain barrier (BBB) after intracerebral hemorrhage (ICH) is associated with poor prognosis. Modulation of sphingosine 1-phosphate receptor (S1PR) may improve outcomes from ICH. Ozanimod (RPC-1063) is a newly developed S1PR regulator which can selectively modulate type 1/5 sphingosine receptors. Here, we studied the impact of Ozanimod on neuroprotection in an experimental mouse model of ICH, induced by injecting collagenase type VII into the basal ganglia. Ozanimod was administered by gavage 2 h after surgery and once a day thereafter until sacrifice. The results demonstrate that Ozanimod treatment improved neurobehavioral deficits in mice and decreased weight loss after ICH. Ozanimod significantly reduced the density of activated microglia and infiltrated neutrophils in the perihematoma region. Furthermore, Ozanimod reduced hematoma volume and water content of the ICH brain. The results of TUNEL staining indicate that Ozanimod mitigated brain cell death. The quantitative data of Evans blue (EB) staining showed that Ozanimod reduced EB dye leakage. Overall, Ozanimod reduces the destruction of the BBB and exert neuroprotective roles following ICH in mice.

Herb Formula (GCis) Prevents Pulmonary Infection Secondary to Intracerebral Hemorrhage by Enhancing Peripheral Immunity and Intestinal Mucosal Immune Barrier

Lung infection is a common complication induced by stroke and seriously affects the prognosis and life quality of patients. However, effective therapeutic strategies are still lacking. In the present study, the herb formula GCis was confirmed to prevent pulmonary infection induced by intracerebral hemorrhage (ICH). The animal model of lung infection induced by ICH, GCis (Ginseng Radix et Rhizoma, Aconiti Lateralis Radix Praeparata, and Cistanches Herba) was orally administrated every day for 7 days. Lung microbial biomass and pathological results showed that the GCis formula pretreatment significantly reduced lung bacterial biomass and alleviated pathological abnormalities. These results indicated that the GCis formula has a clear pharmacological effect on preventing lung infection induced by ICH. Immunosuppression induced by ICH seemed to be the main mechanism of lung infection. Our results showed that the spleen and thymus indexes, WBC, and LY% contents were significantly increased in the GCis formula group. Moreover, bone marrow cells were further analyzed by transcriptome sequencing, and GO and KEGG enrichment analysis results showed that immune function was the main pathway enriched by differential genes after GCis formula intervention. More importantly, our results showed that GCis pretreatment had no significant effect on the mRNA expression of IL-1β, IL-6, and TNF-α in the brain. These results indicated that the GCis formula could enhance immunity after ICH. The intestinal barrier function was further investigated in the present study, considering the origin of the source of infection. Our results showed that the mRNA expressions of intestinal ZO-1, SIgA, and MUC2 were significantly increased, villi structure was intact, inflammatory cell infiltration was reduced, and goblet cell number was increased after GCis formula treatment. These results suggest that the GCis formula can enhance the intestinal mucosal immune barrier. This study provides a herb formula (GCis) that could enhance peripheral immunity and intestinal mucosal immune barrier to prevent pulmonary infection induced by ICH. It would be beneficial in the prevention of severe clinical infections.

Lung Imaging Reveals Stroke-Induced Impairment in Pulmonary Intravascular Neutrophil Function, a Response Exacerbated with Aging

In stroke patients, infection is a significant contributor to morbidity and mortality. Moreover, older stroke patients show an increased risk of developing stroke-associated infection, although the mechanisms underlying this increased susceptibility to infection are unknown. In this study, using an experimental mouse model of ischemic stroke, we showed that older (12-15 mo of age) mice had elevated lung bacterial infection and inflammatory damage after stroke when compared with young (8-10 wk of age) counterparts, despite undergoing the same degree of brain injury. Intravital microscopy of the lung microvasculature revealed that in younger mice, stroke promoted neutrophil arrest in pulmonary microvessels, but this response was not seen in older poststroke mice. In addition, bacterial phagocytosis by neutrophils in the lung microvasculature was reduced by both aging and stroke, such that neutrophils in aged poststroke mice showed the greatest impairment in this function. Analysis of neutrophil migration in vitro and in the cremaster muscle demonstrated that stroke alone did not negatively impact neutrophil migration, but that the combination of increased age and stroke led to reduced effectiveness of neutrophil chemotaxis. Transcriptomic analysis of pulmonary neutrophils using RNA sequencing identified 79 genes that were selectively altered in the context of combined aging and stroke, and they were associated with pathways that control neutrophil chemotaxis. Taken together, the findings of this study show that stroke in older animals results in worsening of neutrophil antibacterial responses and changes in neutrophil gene expression that have the potential to underpin elevated risk of stroke-associated infection in the context of increased age.

A novel nomogram to predict mortality in patients with stroke: a survival analysis based on the MIMIC-III clinical database

Background

Stroke is a disease characterized by sudden cerebral ischemia and is the second leading cause of death worldwide. We aimed to develop and validate a nomogram model to predict mortality in intensive care unit patients with stroke.

Methods

All data involved in this study were extracted from the Medical Information Mart for Intensive Care III database (MIMIC-III). The data were analyzed using multivariate Cox regression, and the performance of the novel nomogram, which assessed the patient’s overall survival at 30, 180, and 360 days after stroke, was evaluated using Harrell’s concordance index (C-index) and the area under the receiver operating characteristic curve. A calibration curve and decision curve were introduced to test the clinical value and effectiveness of our prediction model.

Results

A total of 767 patients with stroke were randomly divided into derivation (n = 536) and validation (n = 231) cohorts at a 7:3 ratio. Multivariate Cox regression showed that 12 independent predictors, including age, weight, ventilation, cardiac arrhythmia, metastatic cancer, explicit sepsis, Oxford Acute Severity of Illness Score or OASIS score, diastolic blood pressure, bicarbonate, chloride, red blood cell and white blood cell counts, played a significant role in the survival of individuals with stroke. The nomogram model was validated based on the C-indices, calibration plots, and decision curve analysis results.

Conclusions

The plotted nomogram accurately predicted stroke outcomes and, thus may contribute to clinical decision-making and treatment as well as consultation services for patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12911-022-01836-3.

Low serum transthyretin levels predict stroke-associated pneumonia

BACKGROUND AND AIMS

Stroke-associated pneumonia (SAP) is commonly seen in ischemic stroke patients. Low transthyretin levels are found to be correlated with stroke. This study aims to investigate the potential relationship between transthyretin levels and SAP.

METHODS AND RESULTS

In total, 920 patients were involved in our study. Serum transthyretin levels were measured within 24 h at admission. We defined SAP according to the modified Centers for Disease Control criteria. In the study population, 123 (13.4%, 77 men, 46 women) were diagnosed with SAP. In the multivariable analysis, we found that serum transthyretin levels were significantly lower in SAP compared with non-SAP patients (231 ± 80 vs. 279 ± 75; P < 0.001) after adjusting for confounders. Meanwhile, we discovered that low transthyretin levels (≤252 mg/L) were independently associated with the development of SAP (OR 3.370; 95% CI: 1.763-6.441; P < 0.001). Moreover, patients with SAP had a worse clinical outcome than those without SAP at discharge. In addition, dysphagia, leukocyte count and NLR (neutrophil-to-lymphocyte ratio) were also found to be associated with SAP.

CONCLUSION

We found that low transthyretin levels significantly increased the risk of SAP. Patients with high risk of developing SAP could be early identified and prevented timely.

Is Immune Suppression Involved in the Ischemic Stroke? A Study Based on Computational Biology

Objective

To identify the genetic mechanisms of immunosuppression-related genes implicated in ischemic stroke.

Background

A better understanding of immune-related genes (IGs) involved in the pathophysiology of ischemic stroke may help identify drug targets beneficial for immunomodulatory approaches and reducing stroke-induced immunosuppression complications.

Methods

Two datasets related to ischemic stroke were downloaded from the GEO database. Immunosuppression-associated genes were obtained from three databases (i.e., DisGeNET, HisgAtlas, and Drugbank). The CIBERSORT algorithm was used to calculate the mean proportions of 22 immune-infiltrating cells in the stroke samples. Differential gene expression analysis was performed to identify the differentially expressed genes (DEGs) involved in stroke. Immunosuppression-related crosstalk genes were identified as the overlapping genes between ischemic stroke-DEGs and IGs. Feature selection was performed using the Boruta algorithm and a classifier model was constructed to evaluate the prediction accuracy of the obtained immunosuppression-related crosstalk genes. Functional enrichment analysis, gene-transcriptional factor and gene-drug interaction networks were constructed.

Results

Twenty two immune cell subsets were identified in stroke, where resting CD4 T memory cells were significantly downregulated while M0 macrophages were significantly upregulated. By overlapping the 54 crosstalk genes obtained by feature selection with ischemic stroke-related genes obtained from the DisGenet database, 17 potentially most valuable immunosuppression-related crosstalk genes were obtained, ARG1, CD36, FCN1, GRN, IL7R, JAK2, MAFB, MMP9, PTEN, STAT3, STAT5A, THBS1, TLR2, TLR4, TLR7, TNFSF10, and VASP. Regulatory transcriptional factors targeting key immunosuppression-related crosstalk genes in stroke included STAT3, SPI1, CEPBD, SP1, TP53, NFIL3, STAT1, HIF1A, and JUN. In addition, signaling pathways enriched by the crosstalk genes, including PD-L1 expression and PD-1 checkpoint pathway, NF-kappa B signaling, IL-17 signaling, TNF signaling, and NOD-like receptor signaling, were also identified.

Conclusion

Putative crosstalk genes that link immunosuppression and ischemic stroke were identified using bioinformatics analysis and machine learning approaches. These may be regarded as potential therapeutic targets for ischemic stroke.

Effects of the liaison nurse management on the infectious stroke complications: a randomized controlled trial

Background

Two of the most serious complications after stroke are pneumonia, and urinary tract infection. Liaison nurse, from hospital admission to discharge and then at home helps patients with complicated caring issues stroke. This study investigates the effect of liaison nurse management on the incidence of pneumonia and urinary tract infection in patients with stroke after discharge from the hospital.

Methods

This randomized controlled trial was conducted on 80 patients in a hospital in Iran. The intervention group was assessed and developed a caring program by the liaison nurse and the control group received routine care. Two weeks and two months after discharge, the patients were evaluated for the incidence of pneumonia and urinary tract infection. Collected data were analyzed using the Chi-square test. P < 0.05 was considered statistically significant.

Results

The two groups were homogenous in terms of mean age; gender frequently distribution and having urinary catheter. The incidence of pneumonia in intervention and control groups (11.6% vs. 19.2%, P = 0.35) had no statistically significant differences, but there was a significant difference in the incidence of urinary tract infection (0% vs. 24.6%, P < 0.001).

Conclusions

With liaison nurse performance, there was a significant difference in the incidence of urinary tract infection, in two months after discharge from hospital, but the incidence of pneumonia had no statistically significant differences in two groups. Nurse’s evaluation each patient individually according to needs, developing and monitoring the home-based care program, beyond overall education to these patients, could reduce some of complications of a stroke.

Trial registration

This study is retrospectively registered by Iranian Registry of Clinical Trials with decree code: IRCT20170605034330N3 on April 4, 2018.

Neutrophil Albumin Ratio is Associated with All-Cause Mortality in Stroke Patients: A Retrospective Database Study

Objective

The novel biomarker, neutrophil percentage-to-albumin ratio (NPAR), as a prognostic tool for inflammation in relation to all-cause mortality for patients afflicted by strokes has yet to be explored.

Methods

Data sets associated with patient files stored within the MIMIC-III V1.4 database were obtained. Data files from 940-patients were obtained for this retrospective analysis. Clinical endpoints were determined to represent a month (30-), three months (90-) and year (365-) all-cause mortality in stroke patients were determined. In order to determine NPAR and clinical endpoint relationships, Cox proportional hazards models were utilized.

Results

For all-cause mortality within a 30-day period, in an unadjusted model, the HR (95% CIs) in group B (NPAR 20.5–25.0) and C (NPAR >25.0) was 1.17 (0.85, 1.63) and 1.55 (1.13, 2.11) compared with group A (NPAR < 20.5). Proceeding adjustment for more confounding factors, higher NPAR still obtained significant predictive power for 30-day all-cause mortality (HR= 1.45, 95% CI: 1.05, 2.00). Statistical significance (P = 0.0196) was also observed for the other time-based subgroupings for all-cause mortality.

Conclusion

A strong correlation was present between increased levels of the novel biomarker NPAR and increased risk of mortality in stroke patients.

The mechanism of microglia-mediated immune inflammation in ischemic stroke and the role of natural botanical components in regulating microglia: A review

Ischemic stroke (IS) is one of the most fatal diseases. Neuroimmunity, inflammation, and oxidative stress play important roles in various complex mechanisms of IS. In particular, the early proinflammatory response resulting from the overactivation of resident microglia and the infiltration of circulating monocytes and macrophages in the brain after cerebral ischemia leads to secondary brain injury. Microglia are innate immune cells in the brain that constantly monitor the brain microenvironment under normal conditions. Once ischemia occurs, microglia are activated to produce dual effects of neurotoxicity and neuroprotection, and the balance of the two effects determines the fate of damaged neurons. The activation of microglia is defined as the classical activation (M1 type) or alternative activation (M2 type). M1 type microglia secrete pro-inflammatory cytokines and neurotoxic mediators to exacerbate neuronal damage, while M2 type microglia promote a repairing anti-inflammatory response. Fine regulation of M1/M2 microglial activation to minimize damage and maximize protection has important therapeutic value. This review focuses on the interaction between M1/M2 microglia and other immune cells involved in the regulation of IS phenotypic characteristics, and the mechanism of natural plant components regulating microglia after IS, providing novel candidate drugs for regulating microglial balance and IS drug development.

Microbiology and Outcomes of Institutionalized Patients With Stroke-Associated Pneumonia: An Observational Cohort Study

Background: The attributable mortality and microbial etiology of stroke-associated pneumonia (SAP) vary among different studies and were inconsistent. Purpose: To determine the microbiology and outcomes of SAP in the lower respiratory tract (LRT) for patients with invasive mechanical ventilation (MV). Methods: In this observational study, included patients were divided into SAP and non-SAP based on a comprehensive analysis of symptom, imaging, and laboratory results. Baseline characteristics, clinical characteristics, microbiology, and outcomes were recorded and evaluated. Results: Of 200 patients, 42.5% developed SAP after the onset of stroke, and they had a lower proportion of non-smokers (p = 0.002), lower GCS score (p < 0.001), higher serum CRP (p < 0.001) at ICU admission, and a higher proportion of males (p < 0.001) and hypertension (p = 0.039) than patients with non-SAP. Gram-negative aerobic bacilli were the predominant organisms isolated (78.8%), followed by Gram-positive aerobic cocci (29.4%). The main pathogens included K. pneumoniae, S. aureus, H. influenzae, A. baumannii, P. aeruginosa, E. aerogenes, Serratia marcescens, and Burkholderia cepacia. SAP prolonged length of MV (p < 0.001), duration of ICU stay (p < 0.001) and hospital stay (p = 0.027), shortened MV-free days by 28 (p < 0.001), and caused elevated vasopressor application (p = 0.001) and 60-day mortality (p = 0.001). Logistic regression analysis suggested that patients with coma (p < 0.001) have a higher risk of developing SAP. Conclusion: The microbiology of SAP is similar to early phase of HAP and VAP. SAP prolongs the duration of MV and length of ICU and hospital stays, but also markedly increases 60-day mortality.

Impact of mobile health and telehealth technology on medication adherence of stroke patients: a systematic review and meta-analysis of randomized controlled trials

Background Stroke patients have low medication adherence after discharge, which leads to a high recurrence rate and poor disease control. Various strategies have been explored to enhance medication adherence in this patient population. Aim To evaluate the effects of mobile health (mHealth) and telehealth technology on medication adherence in stroke patients. Method All English studies that met the inclusion criteria published before September 2021 were obtained from PubMed, EMBASE, Web of Science, and Cochrane Library. Two researchers independently screened articles, extracted data, and evaluated the quality of the included studies. All articles were about randomized controlled trials. Medication adherence was used as the outcome index of this review. Random or fixed-effect models were used in statistical methods. I² statistics were used to evaluate heterogeneity. Results A total of ten studies met the inclusion criteria, covering 2151 stroke patients. Compared with the Usual Care group, the medication adherence scores of the mHealth technology group were better (standard mean deviation 0.67, 95% confidence interval, CI [0.49, 0.85], P < 0.001). The medication adherence ratio of the mHealth technology group was higher (odds ratio, OR, 2.81, 95% CI [1.35, 5.85], P = 0.006). Subgroup analysis showed that application and messaging interventions were more effective than the telephone call intervention (OR 4.05, 95% CI [2.10, 7.80], P < 0.001). The shorter the interval of the intervention, the better the medication adherence of patients (OR 4.24, 95% CI [2.30, 7.81], P < 0.001). Conclusion Compared with Usual Care, mHealth can effectively improve the medication adherence of stroke patients.

High Neutrophil Percentage-To-Albumin Ratio Can Predict Occurrence of Stroke-Associated Infection

Purpose: Stroke-associated infection (SAI) is associated with adverse outcomes in patients with acute ischemic stroke (AIS). In this study, we aimed to evaluate the association between neutrophil percentage-to-albumin ratio (NPAR) and SAI occurrence in patients with AIS. Methods: We retrospectively analyzed all AIS patients who were admitted to the Neurology ward of The Second Hospital of Tianjin Medical University from November 2018 to October 2020. The relationship between NPAR and SAI was analyzed by multivariable analysis. The receiver operating characteristic (ROC) curve was used to compare the predicted value of albumin, neutrophil percentage, neutrophil-to-lymphocyte ratio (NLR), and NPAR. Results: We included 379 AIS patients out of which 51 (13.5%) developed SAI. The NPAR was independently associated with increased risk of SAI adjusting for confounders [adjusted odds ratio (aOR) = 10.52; 95% confidence interval (CI), 3.33-33.28; P <0.001]. The optimal cutoff value of NPAR for predicting SAI incidence was 1.64, with sensitivity and specificity of 90.2 and 55.8%, respectively. The area under the curve (AUC) value of NPAR [0.771 (0.725-0.812)] was higher than that of albumin [0.640 (0.590-0.689)], neutrophil percentage [0.747 (0.700-0.790)], and NLR [0.736 (0.689-0.780)], though the statistical significance appeared only between NPAR and albumin. Conclusions: We demonstrated that a higher NPAR could predict the occurrence of SAI. Thus, NPAR might be a more effective biomarker to predict SAI compared with albumin, neutrophil percentage, and NLR.

Stroke-associated pneumonia: A bibliometric analysis of worldwide trends from 2003 to 2020

Stroke-associated pneumonia (SAP) is a spectrum of pulmonary infections in patients within 7 days of stroke. Which is one of the most common complications after stroke and is significantly associated with a poor prognosis of stroke. To the best of our knowledge, a bibliometric method was not previously used to analyze the topic of SAP; we aim to describe the situation and evolution of SAP from 2003 to 2020, and to discuss the research hotspots and frontiers.A total of 151 articles were retrieved from the Scopus database. Bibliometric analysis was used to explore the dynamic trends of articles and the top subject areas, journals, institutes, citations, and co-keywords. VOS viewer software (version 1.6.15) was used to graphically map the hot topics of SAP based on the co-keywords.A total of 151 articles were identified. Articles have increased over the recent years and faster in the last 2 years (55 articles, 36.4%), the majority of subject areas are medicine (124 articles, 82.1%) and neuroscience (38 articles, 25.2%). The "Journal Of Stroke And Cerebrovascular Diseases" with 15 articles has been scored as the first rank followed by "Plos One." Regarding the geographical distribution of articles, China is the most productive country with 50 articles (33.1%), others are more prominent in Europe, and most institutes are universities. Citations have increased over time, the main country of the top five highly cited published articles are Germany and before 2008. The co-keywords are mainly divided into four aspects: risk factors, predictive scores, preventions, and outcomes.This study could provide practical sources for researchers to find the top subject areas, journals, institutes, citations, and co-keywords. Moreover, the study could pave the way for researchers to be engaged in studies potentially lead to more articles in this field.

Ischemic stroke and infection: A brief update on mechanisms and potential therapies

Ischemic stroke triggers a multifaceted inflammatory response in the brain that contributes to secondary brain injury and infarct expansion. In parallel with brain inflammation, ischemic stroke also leads to post-stroke immunosuppression. Stroke-induced leukopenia then predisposes patients to opportunistic infections potentially leading to pneumonia or unrinary tract infections and a worsened stroke outcome. There is evidence that the hypothalamic-pituitaryadrenal axis plays an important role in the etiology of post-stroke immunosuppression, by which prolonged glucocorticoid signalling leads to changes in immune responses. While opportunistic microbes in hospitals have been thought to be the source of infection, recent studies have reported that gut flora may also be a cause of post-stroke infection as a consequence of compromised integrity of the gut barrier after stroke. While antimicrobial drugs would appear to be a rational form of treatment for bacterial infections in stroke patients, the rise in drug-resistant bacteria and possible adverse effects of disrupting beneficial gut flora represent major challenges with these drugs. Considering the prominent role of gut microbiota in modulating immune responses, protecting and restoring the post-stroke gut bacteriome may provide significant benefit in the context of post-stroke infection. With such broad aspects of post-stroke infection occurring together with an extensive inflammatory response in the brain, a carefully considered administration of therapies for ischemic stroke is warranted.

Molecular Mechanisms of Neuroimmune Crosstalk in the Pathogenesis of Stroke

Stroke disrupts the homeostatic balance within the brain and is associated with a significant accumulation of necrotic cellular debris, fluid, and peripheral immune cells in the central nervous system (CNS). Additionally, cells, antigens, and other factors exit the brain into the periphery via damaged blood–brain barrier cells, glymphatic transport mechanisms, and lymphatic vessels, which dramatically influence the systemic immune response and lead to complex neuroimmune communication. As a result, the immunological response after stroke is a highly dynamic event that involves communication between multiple organ systems and cell types, with significant consequences on not only the initial stroke tissue injury but long-term recovery in the CNS. In this review, we discuss the complex immunological and physiological interactions that occur after stroke with a focus on how the peripheral immune system and CNS communicate to regulate post-stroke brain homeostasis. First, we discuss the post-stroke immune cascade across different contexts as well as homeostatic regulation within the brain. Then, we focus on the lymphatic vessels surrounding the brain and their ability to coordinate both immune response and fluid homeostasis within the brain after stroke. Finally, we discuss how therapeutic manipulation of peripheral systems may provide new mechanisms to treat stroke injury.

The role of P2Y12 receptor inhibition in ischemic stroke on microglia, platelets and vascular smooth muscle cells

P2Y12 receptors on platelets have long been the main target of antiplatelet drugs. However, a growing number of studies have revealed that P2Y12 receptor activation on microglia and vascular smooth muscle cells (VSMCs) also aggravates ischemic stroke injury. The proliferation and migration of VSMCs in the vascular wall have important influence on the early lesion of atherosclerosis, which may lead to the origin of cerebral ischemic attack of atherosclerosis. Blockage of cellular P2Y12 receptors could inhibit microglial activation, block formation of platelet-leukocyte aggregates, reduce proinflammatory cytokine levels and suppress migration and proliferation of VSMCs, implying that apart from anti-thrombotic effect, P2Y12 inhibitors have additional neuroprotective, anti-inflammatory and anti-atherosclerotic therapeutic benefits against ischemic stroke. In this review, we will summarize recent advances in studies on P2Y12 receptors and emphatically introduce their significance in microglia, platelets and VSMCs after ischemic stroke, discussing how to exert the beneficial effects of P2Y12 inhibition.

The Red Blood Cell Distribution Width-Albumin Ratio: A Promising Predictor of Mortality in Stroke Patients

Objective

Within this study we attempt to express a correlation between the mortality of stroke and stroke related infection to a novel biomarker represented by the red blood cell width-albumin levels ratio within the patient. We hypothesize that this novel biomarker could be utilized as better predictive tool for stroke associated infections.

Methods

Patient data sets were obtained via the Medical Information Mart for Intensive Care Database iii V1.4 (MIMIC-iii). Data from 1480 patients were obtained to serve the testing for the RA biomarker tests. Clinical endpoints of 30-, 60-, and 365-day all-cause mortality in stroke patients were used as subgroups within the analyzed population. Estimation of hazard ratios (HR) were obtained from Cox regression models for stroke-associated infection and all-cause mortality in relation to RA values.

Results

A high-RA was associated with increased mortality in ICU patients suffering from a stroke. After adjusting for age and sex, compared to the reference group (the first quartile), the high-RA group had the highest 30-day (HR, 95% CI: 1.88 (1.36, 2.58)), 90-day (HR, 95% CI: 2.12 (1.59, 2.82)), and one-year (HR, 95% CI: 2.15 (1.65, 2.80)) all-cause mortality. The RA values were independently associated with an increased risk of stroke-associated infection when adjusting for confounders.

Conclusions

Our data suggest RA may be an easily accessible, reproducible, and low-cost biomarker for predicting stroke-associated infections and mortality in patients who have suffered from a stroke.

Treelet transform analysis to identify clusters of systemic inflammatory variance in a population with moderate-to-severe traumatic brain injury

BACKGROUND

Inflammatory cascades following traumatic brain injury (TBI) can have both beneficial and detrimental effects on recovery. Single biomarker studies do not adequately reflect the major arms of immunity and their relationships to long-term outcomes. Thus, we applied treelet transform (TT) analysis to identify clusters of interrelated inflammatory markers reflecting major components of systemic immune function for which substantial variation exists among individuals with moderate-to-severe TBI.

METHODS

Serial blood samples from 221 adults with moderate-to-severe TBI were collected over 1-6 months post-injury (n = 607 samples). Samples were assayed for 33 inflammatory markers using Millipore multiplex technology. TT was applied to standardized mean biomarker values generated to identify latent patterns of correlated markers. Treelet clusters (TC) were characterized by biomarkers related to adaptive immunity (TC1), innate immunity (TC2), soluble molecules (TC3), allergy immunity (TC4), and chemokines (TC5). For each TC, a score was generated as the linear combination of standardized biomarker concentrations and cluster load for each individual in the cohort. Ordinal logistic or linear regression was used to test associations between TC scores and 6- and 12-month Glasgow Outcome Scale (GOS), Disability Rating Scale (DRS), and covariates.

RESULTS

When adjusting for clinical covariates, TC5 was significantly associated with 6-month GOS (odds ratio, OR = 1.44; p-value, p = 0.025) and 6-month DRS scores (OR = 1.46; p = 0.013). TC5 relationships were attenuated when including all TC scores in the model (GOS: OR = 1.29, p = 0.163; DRS: OR = 1.33, p = 0.100). When adjusting for all TC scores and covariates, only TC3 was associated with 6- and 12-month GOS (OR = 1.32, p = 0.041; OR = 1.39, p = 0.002) and also 6- and 12-month DRS (OR = 1.38, p = 0.016; OR = 1.58, p = 0.0002). When applying TT to inflammation markers significantly associated with 6-month GOS, multivariate modeling confirmed that TC3 remained significantly associated with GOS. Biomarker cluster membership remained consistent between the GOS-specific dendrogram and overall dendrogram.

CONCLUSIONS

TT effectively characterized chronic, systemic immunity among a cohort of individuals with moderate-to-severe TBI. We posit that chronic chemokine levels are effector molecules propagating cellular immune dysfunction, while chronic soluble receptors are inflammatory damage readouts perpetuated, in part, by persistent dysfunctional cellular immunity to impact neuro-recovery.

Orexin-A inhibits cerebral ischaemic inflammatory injury mediated by the nuclear factor-κB signalling pathway and alleviates stroke-induced immunodepression in mice

Cerebral ischaemia is accompanied by infectious complications due to immunosuppression, known as stroke-induced immunodepression (SIID). Orexin-A (OXA), a neuropeptide produced in the hypothalamus, has been reported to have neuroprotective properties after stroke and is known to modulate inflammatory processes in peripheral tissues. The aim of this study was to determine the effects of orexin-A (OXA) on cerebral ischaemic inflammatory injury and SIID following experimental stroke. Cerebral ischaemia was induced in C57/BL6 mice by middle cerebral artery occlusion (MCAO). A mouse model of pneumonia and poststroke pneumococcal pneumonia was established by intratracheal inoculation with S. pneumoniae in a normal mouse or MCAO mouse model on the third day. We found that OXA postconditioning inhibited cerebral ischaemic inflammatory injury. The mechanism involved downregulation of the NF-κB signalling pathway. In addition, OXA may serve as a potential treatment target for attenuating stroke-induced immunodepression in mice.

Usefulness of the Neutrophil-to-Lymphocyte Ratio as a Predictor of Pneumonia and Urinary Tract Infection Within the First Week After Acute Ischemic Stroke

Background: A high Neutrophil-to-Lymphocyte ratio (NLR) in patients with acute ischemic stroke (AIS) has been associated with post-stroke infections, but it's role as an early predictive biomarker for post-stroke pneumonia (PSP) and urinary tract infection (UTI) is not clear.

Aim: To investigate the usefulness of NLR obtained within 24 h after AIS for predicting PSP and UTI in the first week.

Methods: Clinical and laboratory data were retrieved from the University Hospital Brussels stroke database/electronic record system. Patients were divided into those who developed PSP or UTI within the first week after stroke onset and those who didn't. Receiver operating characteristics (ROC) curves and logistic regression analysis were used to identify independent predictors.

Results: Five hundred and fourteen patients were included, of which 15.4% (n = 79) developed PSP and 22% (n = 115) UTI. In univariate analysis, NLR was significantly higher in patients who developed PSP (4.1 vs. 2.8, p < 0.001) but not in those who developed UTI (3.3 vs. 2.9, p = 0.074). Multiple logistic regression analysis for PSP showed that NLR, male gender, dysphagia, and stroke severity measured by the National Institutes of Health Stroke Scale (NIHSS), were independent predictors of PSP. For NLR alone, the area under the curve (AUC) in the ROC curve was 0.66 (95% CI = 0.59–0.73). When combining NLR ≥ 4.7 with age >75 years, male gender, NIHSS > 7, and dysphagia, the AUC increased to 0.84 (95% CI = 0.79–0.89).

Conclusion: The NLR within 24 h after AIS appears to have no predictive value for post-stroke UTI, and is only a weak predictor for identifying patients at high risk for PSP. Its predictive value for PSP appears to be much stronger when incorporated in a prediction model including age, gender, NIHSS score, and dysphagia.