Prognostic Role of the Platelet-Lymphocyte Ratio in Acute Ischemic Stroke Patients Undergoing Reperfusion Therapy: A Meta-Analysis

BACKGROUND: Both inflammation and thrombotic/hemostatic mechanisms may play a role in acute ischemic stroke (AIS) pathogenesis, and a biomarker, such as the platelet-to-lymphocyte ratio (PLR), considering both mechanisms may be of clinical utility. OBJECTIVES: This meta-analysis sought to examine the effect of PLR on functional outcomes, early neurological changes, bleeding complications, mortality, and adverse outcomes in AIS patients treated with reperfusion therapy (RT). DESIGN: Systematic Review and Meta-Analysis DATA SOURCES AND METHODS: Individual studies were retrieved from the PubMed/Medline, EMBASE and Cochrane databases. References thereof were also consulted. Data were extracted using a standardised data sheet, and systematic reviews and meta-analyses on the association of admission (pre-RT) or delayed (post-RT) PLR with defined clinical and safety outcomes were conducted. In the case of multiple delayed PLR timepoints, the timepoint closest to 24 hours was selected. RESULTS: Eighteen studies (n=4878) were identified for the systematic review, of which 14 (n=4413) were included in the meta-analyses. PLR collected at admission was significantly negatively associated with 90-day good functional outcomes (SMD=−.32; 95% CI = −.58 to −.05; P=.020; z=−2.328), as was PLR collected at delayed timepoints (SMD=−.43; 95% CI = −.54 to −.32; P<.0001; z=−7.454). PLR at delayed timepoints was also significantly negatively associated with ENI (SMD=−.18; 95% CI = −.29 to −.08; P=.001. Conversely, the study suggested that a higher PLR at delayed timepoints may be associated with radiological bleeding and mortality. The results varied based on the type of RT administered. CONCLUSIONS: A higher PLR is associated with worse outcomes after stroke in terms of morbidity, mortality, and safety outcomes after stroke.