Venous Blood Cell Ratios as Predictors of Reperfusion Outcomes in Ischemic Stroke: A Systematic Review and Meta-analysis
Year: 2026
Type: review
Study designs: Systematic Review, Meta-Analysis
Abstract: Inflammation plays a critical role in the pathophysiology of acute ischemic stroke (AIS). Ratios derived from routine blood counts, especially the neutrophil-to-lymphocyte ratio (NLR), have been proposed as prognostic biomarkers, but their value in patients receiving reperfusion therapies—intravenous thrombolysis (IVT) or mechanical thrombectomy (MT)—remains uncertain. We systematically searched PubMed, Cochrane Library, Web of Science, and Scopus on November 30, 2024, following PRISMA guidelines. Eligible studies included patients with AIS treated with IVT or MT that reported associations between pre-treatment blood cell ratios and outcomes measured by the modified Rankin Scale (mRS). Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models. Fifty-seven studies with 17,394 patients were included. NLR was the predominantly studied biomarker. In the MT subgroup, elevated NLR predicted poor 3-month outcome (OR 1.09, 95% CI 1.04–1.15) and higher mortality (OR 1.05, 95% CI 1.01–1.08). In IVT-treated patients, higher NLR also predicted poor outcome (OR 1.11, 95% CI 1.01–1.21) with lower heterogeneity across studies. Other ratios showed variable associations: lymphocyte-to-monocyte ratio (LMR) appeared protective, while platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-neutrophil ratio (PNR) showed inconsistent or null results. Data regarding hemorrhagic transformation were heterogeneous and unsuitable for meta-analysis. Elevated pre-treatment NLR consistently predicted poor outcome and mortality after reperfusion therapy for AIS, supporting its role as a simple biomarker for early risk stratification. Future large, prospective multicenter studies with standardized methods are needed to confirm the clinical utility of these inflammatory ratios in stroke management. Stroke is a leading cause of death and long-term disability. Two treatments, intravenous thrombolysis and mechanical thrombectomy, are used to reopen blocked brain arteries. Even when these treatments are given promptly, a large number of patients still do not recover well or die. Doctors therefore need simple and reliable tools to identify patients at high risk of a bad outcome early in the hospital stay. Blood tests taken at the time of hospital admission may give useful clues. In particular, the balance between different types of white blood cells reflects how active the immune system is. In this study, we systematically reviewed and combined results from previously published research to determine whether simple blood cell ratios—such as the neutrophil-to-lymphocyte ratio (NLR)—measured before treatment can help predict how patients will recover after these therapies. We found that a higher NLR measured on admission was consistently linked with a greater chance of disability or death after treatment. This pattern was seen in patients treated with both thrombolysis and thrombectomy. Other blood cell ratios showed weaker or inconsistent results. Because NLR comes from a routine blood count, it is cheap, fast, and available in all hospitals. Our findings suggest that NLR could be used alongside clinical judgment and brain imaging to help identify stroke patients at higher risk of poor outcomes early on. Future large studies are needed to confirm these results and to test whether combining NLR with other clinical or imaging markers improves prediction further.
Source: Neurology and Therapy
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $7,400
Award: G1696362519
OpenAlex ID: W7123781651