Loggini A, Hornik J, Henson J, Wesler J, Hornik A. Association between neutrophil-to-lymphocyte ratio and hematoma expansion in spontaneous intracerebral hemorrhage: A systematic review and meta-analysis. World J Crit Care Med 2025; 14(2): 99445 [DOI: 10.5492/wjccm.v14.i2.99445]
Corresponding Author of This Article
Andrea Loggini, MD, Doctor, Brain and Spine Institute, Southern Illinois Healthcare, 405 W Jackson Street, Carbondale, IL 62901, United States. andrea.loggini@sih.net
Research Domain of This Article
Critical Care Medicine
Article-Type of This Article
Meta-Analysis
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
World J Crit Care Med. Jun 9, 2025; 14(2): 99445 Published online Jun 9, 2025. doi: 10.5492/wjccm.v14.i2.99445
Association between neutrophil-to-lymphocyte ratio and hematoma expansion in spontaneous intracerebral hemorrhage: A systematic review and meta-analysis
Andrea Loggini, Jonatan Hornik, Jessie Henson, Julie Wesler, Alejandro Hornik
Andrea Loggini, Jonatan Hornik, Jessie Henson, Julie Wesler, Alejandro Hornik, Brain and Spine Institute, Southern Illinois Healthcare, Carbondale, IL 62901, United States
Andrea Loggini, Jonatan Hornik, Alejandro Hornik, Southern Illinois University School of Medicine, Carbondale, IL 62901, United States
Author contributions: Loggini A was responsible for study concept, study design, data abstraction, data analysis, and drafting the manuscript; Hornik J was responsible for study design, data abstraction, data analysis, and drafting the manuscript; Henson J and Wesler J were responsible for data abstraction and data analysis; Hornik A was responsible for critical revision and approval of the final version of the manuscript; all of the authors read and approved the final version of the manuscript to be published.
Conflict-of-interest statement: None of the authors has any conflict of interest or financial disclosures to declare.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Andrea Loggini, MD, Doctor, Brain and Spine Institute, Southern Illinois Healthcare, 405 W Jackson Street, Carbondale, IL 62901, United States. andrea.loggini@sih.net
Received: July 22, 2024 Revised: December 2, 2024 Accepted: December 16, 2024 Published online: June 9, 2025 Processing time: 219 Days and 12.1 Hours
Abstract
BACKGROUND
Hematoma expansion (HE) typically portends a poor prognosis in spontaneous intracerebral hemorrhage (ICH). Several radiographic and laboratory values have been proposed as predictive markers of HE.
AIM
To perform a systematic review and meta-analysis on the association of neutrophil-to-lymphocyte ratio (NLR) and HE in ICH. A secondary outcome examined was the association of NLR and perihematomal (PHE) growth.
METHODS
Three databases were searched (PubMed, EMBASE, and Cochrane) for studies evaluating the effect of NLR on HE and PHE growth. The inverse variance method was applied to estimate an overall effect for each specific outcome by combining weighted averages of the individual studies’ estimates of the logarithm odds ratio (OR). Given heterogeneity of the studies, a random effect was applied. Risk of bias was analyzed using the Newcastle-Ottawa Scale. The study was conducted following the Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. The protocol was registered in PROSPERO (No. CRD42024549924).
RESULTS
Eleven retrospective cohort studies involving 2953 patients were included in the meta-analysis. Among those, HE was investigated in eight studies, whereas PHE growth was evaluated in three. Blood sample was obtained on admission in ten studies, and at 24 hours in one study. There was no consensus on cut-off value among the studies. NLR was found to be significantly associated with higher odds of HE (OR = 1.09, 95%CI: 1.04-1.15, I2 = 86%, P < 0.01), and PHE growth (OR = 1.28, 95%CI: 1.19-1.38, I2 = 0%, P < 0.01). Qualitative analysis of each outcome revealed overall moderate risk of bias mainly due to lack of control for systemic confounders.
CONCLUSION
The available literature suggests that a possible association may exist between NLR on admission and HE, and PHE growth. Future studies controlled for systemic confounders should be designed to consolidate this finding. If confirmed, NLR could be added as a readily available and inexpensive biomarker to identify a subgroup of patients at higher risk of developing HE.
Core Tip: In this work, we provide an updated and concise quantitative synthesis of the literature addressing the association between neutrophil-to-lymphocyte ratio and hematoma expansion (HE) in intracerebral hemorrhage. We found an independent association between neutrophil-to-lymphocyte ratio (NLR) on admission and HE, and perihematomal growth. Our findings support the idea that NLR could be added as a readily available and inexpensive biomarker to identify a subgroup of patients at higher risk of developing HE.
