Neutrophil to Lymphocyte Ratio and Serum Biomarkers : A Potential Tool for Prediction of Clinically Relevant Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage

The association between systemic immune-inflammation index and the short-term functional outcome of patients with aneurysmal subarachnoid hemorrhage: a meta-analysis

Systemic immune-inflammation index (SII), calculated as platelet count × neutrophil count/lymphocyte count, is a novel biomarker reflecting immune and inflammatory responses. Its prognostic value in patients with subarachnoid hemorrhage (SAH) remains unclear. This meta-analysis aimed to evaluate the association between SII at admission and the short-term functional outcomes of patients with SAH. A systematic search of PubMed, Embase, Web of Science, China National Knowledge Infrastructure, and Wanfang databases identified cohort studies reporting the relationship between SII levels and functional outcomes in SAH. Poor functional outcomes were defined as modified Rankin Scale > 2 or Glasgow Outcome Scale < 4. Heterogeneity was assessed using I² statistic, and data synthesis was performed using a random-effects model by incorporating the influence of heterogeneity. RevMan 5.1 and Stata 17.0 were used for the analyses. Ten cohort studies involving 2,228 patients were included. Meta-analysis revealed that a high SII at admission significantly increased the risk of poor functional outcomes (OR: 3.08, 95% CI: 2.07-4.59, p < 0.001) with moderate heterogeneity (I² = 61%). Subgroup analysis showed a stronger association in studies with SII cutoffs ≥ 1400 compared to < 1400 (p for subgroup difference < 0.001). Meta-regression identified the cutoff value for SII as a significant modifier (p = 0.03) for the association between SII and poor functional outcome. Sensitivity analyses by excluding one dataset at a time showed similar results (p all < 0.05). In conclusion, elevated SII at admission is associated with an increased risk of poor short-term functional outcomes in SAH. These findings highlight SII as a potential prognostic biomarker for early risk stratification in SAH patients.

Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage: The Role of the Complement and Innate Immune System

Specific inflammatory pathways are important in the development of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage. Understanding the specific pathways of inflammation may be critical for finding new treatments. Evidence is accumulating that innate inflammatory cells and proteins play a more important role than cells of the adaptive inflammatory system. In this work, we review the evidence from clinical and preclinical data regarding which cells of the immune system play a role in DCI with particular emphasis on the bone-marrow-derived cells monocytes and neutrophils and the brain parenchymal microglia. In addition, we will review the evidence that complement proteins, a non-cellular part of the innate immune system, play a role in the development of DCI.

Dynamic changes of systemic inflammation response index and systemic immune-inflammation index are associated with delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

OBJECTIVES

Delayed cerebral ischemia (DCI) is a factor contributing to poor outcome of aneurysmal subarachnoid hemorrhage (aSAH). Serial inflammatory response is known to affect the occurrence of DCI. The aim of this study was to evaluate associations of dynamic changes of various inflammatory markers with occurrence of DCI after aSAH.

METHODS

A total of 279 patients with interventional treatment for aSAH were enrolled, and dichotomized according to the occurrence of DCI. Various inflammatory markers, including systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), and their dynamic changes were analyzed at four different time points. Receiver operating characteristic (ROC) curve analysis with area under the curve (AUC) and univariate, multivariate Cox regression analyses with hazard ratio (HR) and 95 % confidence interval (CI) were performed to identify predictors for DCI.

RESULTS

Differences of SII and SIRI values between DCI (+) and DCI (-) group were significantly higher at 5-7 days than at other time points (P < 0.001 and P < 0.001, respectively). SII and SIRI had higher predicting values for DCI occurrence than other inflammatory markers (AUC: 0.862, 95 % CI: 0.786-0.928; P < 0.001 and AUC: 0.851, 95 % CI: 0.769-0.913; P < 0.001, respectively). SII at 5-7 days (HR: 1.74, 95 % CI: 1.38-3.22, P = 0.020) and SIRI at 5-7 days (HR: 1.62, 95 % CI: 1.28-2.84, P = 0.035) were associated with occurrence of DCI.

CONCLUSIONS

Dynamic changes of SII and SII might be predictors of DCI occurrence in patients with aSAH.

Advances in biomarkers for vasospasm - Towards a future blood-based diagnostic test

Objective

Cerebral vasospasm and the resultant delayed cerebral infarction is a significant source of mortality following aneurysmal SAH. Vasospasm is currently detected using invasive or expensive imaging at regular intervals in patients following SAH, thus posing a risk of complications following the procedure and financial burden on these patients. Currently, there is no blood-based test to detect vasospasm.

Methods

PubMed, Web of Science, and Embase databases were systematically searched to retrieve studies related to cerebral vasospasm, aneurysm rupture, and biomarkers. The study search dated from 1997 to 2022. Data from eligible studies was extracted and then summarized.

Results

Out of the 632 citations screened, only 217 abstracts were selected for further review. Out of those, only 59 full text articles met eligibility and another 13 were excluded.

Conclusions

We summarize the current literature on the mechanism of cerebral vasospasm and delayed cerebral ischemia, specifically studies relating to inflammation, and provide a rationale and commentary on a hypothetical future bloodbased test to detect vasospasm. Efforts should be focused on clinical-translational approaches to create such a test to improve treatment timing and prediction of vasospasm to reduce the incidence of delayed cerebral infarction.

Correlation of Inflammatory Parameters with the Development of Cerebral Vasospasm, Takotsubo Cardiomyopathy, and Functional Outcome after Spontaneous Subarachnoid Hemorrhage

Background: The present work aimed to determine whether a relationship exists between inflammatory parameters and the development of vasospasm (VS) and Takotsubo cardiomyopathy (TTC), as well as clinical outcome, in patients suffering from spontaneous subarachnoid hemorrhage (SAH). Methods: In this study, the authors processed the prospectively collected laboratory and clinical data of spontaneous SAH patients admitted to the neurointensive care unit between March 2015 and October 2023. The highest values of neutrophils (NEUpeak), monocytes (MONOpeak), neutrophil-to-lymphocyte ratio (NLRpeak), and CRP (CRPpeak) during the initial 7 days were correlated with the occurrence of VS and TTC, and with the outcome measures at day 30 after onset. Results: Data were collected from 175 SAH patients. Based on ROC analysis, for the development of VS, MONOpeak was the most accurate indicator (AUC: 0.619, optimal cut-off: 1.45 G/L). TTC with severe left ventricular dysfunction (ejection fraction < 40%) was indicated most sensitively by NEUpeak (ROC: 0.763, optimal cut-off: 12.34 G/L). Both for GOS and Barthel Index at day 30, CRPpeak was the best predictor for the outcome (GOS: ROC: 0.846, optimal cut-off: 78.33 mg/L and Barthel Index: ROC: 0.819, optimal cut-off: 78.33 mg/L). Conclusions: Laboratory parameters referring to inflammation during the initial 7 days after SAH correlate with the development of VS and TTC, and thus may predict functional outcome.