Relationship between Peripheral Blood Inflammatory Factors and Prognosis of Subarachnoid Hemorrhage: A Meta-Analysis

Abstract

Background: Subarachnoid hemorrhage (SAH) is a severe cerebrovascular event with high mortality and disability rate. Neuroinflammation is involved in the brain injury after SAH, but the exact association between SAH progression and peripheral blood inflammatory factors is unknown. Therefore, to determine the relationship between inflammatory factors and the prognosis of SAH, we performed a meta-analysis. Method: A systematic literature review was conducted in PubMed, EMBASE, and Cochrane Library. Studies comparing the relationship between inflammatory factors (C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor (TNF-α) and prognosis of SAH were included in the study. A random-effects meta-analysis was conducted based on mRS, GOS, and the occurrence of CVS, DCI, and DINDs. Sensitivity analysis was performed using the leave-one-out method. The New-castle–Ottawa Scale (NOS) for case-control studies was used to assess the quality of included studies. And for continuous variables, we calculated the mean difference (MD) with a 95% confidence interval (CI). Results: 1469 patients from 18 case-control studies met the inclusion criteria. The results found that patients in the good outcome group had significantly lower CRP levels than those in the poor outcome group (SMD: -1.15, 95% CI: -1.64– -0.66, p < 0.00001, I2 = 87%), and peripheral IL-6 levels were significantly lower in SAH patients with the good functional outcome than those with the poor functional outcome (SMD: -0.99, 95% CI: -1.48– -0.51, p < 0.0001, I2 = 88%). As for IL-10 (SMD: -0.28, 95% CI: -0.97– 0.42, p =0.43, I2 = 88%) and TNF-α (SMD: -0.40, 95% CI: -0.98– 0.19, p =0.18, I2 = 79%), due to the small number of studies, heterogeneity, and uncontrollable factors, robust conclusions cannot be drawn. Conclusion: SAH patients with good prognoses have significantly lower peripheral CRP and IL-6 levels. In addition, due to the small number of studies, heterogeneity, and uncontrollable factors, robust conclusions cannot be drawn for IL-10 and TNF-α. More high-quality studies are needed in the future to provide more specific recommendations for the clinical practice of inflammatory factors.

A prognostic model incorporating the albumin-corrected anion gap in patients with aneurysmal subarachnoid hemorrhage

“…Finally, high serum AG levels have been found to be related to a high level of inflammatory biomarkers, including white blood cells and C-reactive protein (29). The inflammatory response after aSAH plays an important role in the pathophysiological process of brain injury and extracranial organ dysfunction (30)(31)(32)(33).…”

Potential application of peripheral blood biomarkers in intracranial aneurysms

“…Values of cytokines in evaluating prognosis for aneurysmal SAH (aSAH) have sparked considerable attention. Elevated peripheral C-reactive protein (CRP) and IL-6 levels existed in aSAH patients with poor prognoses ( 37 ). According to Schranz et al ( 38 ), tumor necrosis factor superfamily 14 and oncostatin-M serum levels were higher in aSAH patients within 24 h after symptoms onset than healthy controls.…”

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

“…Although the underlying mechanism of cerebral vasospasm is still not fully explored, there is growing evidence that neuroinflammation has a significant role [4][5][6]. Among widely available laboratory markers, leukocyte count, neutrophil-to-lymphocyte ratio, and C-reactive protein levels showed correlations with variable complications and poor functional outcomes [6][7][8][9][10][11][12].…”