Abstract
Objective: Platelets and neutrophils play pivotal roles in the pathogenesis of atherosclerosis, thrombosis, and acute ischemic stroke. Circulating leukocyte–platelet aggregates in peripheral blood have been proposed as potential biomarkers of platelet activation. The platelet-to-leukocyte ratio (PLR) may reflect stroke severity and prognosis in patients undergoing intravenous (IV) recombinant tissue plasminogen activator (rtPA) therapy. This study aimed to investigate the relationship between PLR, treatment response, and prognosis in patients with acute ischemic stroke (AIS) treated with IV rtPA.
Methods: Sixty patients diagnosed with AIS and treated with IV rtPA were included. PLR values were calculated from peripheral blood samples obtained before and 24 hours after treatment. Treatment efficacy was evaluated by comparing National Institutes of Health Stroke Scale (NIHSS) scores at baseline and 24 hours post-thrombolysis. A favorable treatment response was defined as a ≥4-point reduction in NIHSS score or a 24-hour NIHSS ≤1. Prognosis was assessed at the 90-day follow-up using the modified Rankin Scale (mRS), with a good prognosis defined as mRS ≤3.
Results: NIHSS scores significantly decreased 24 hours after rtPA administration (p < 0.001). PLR values also showed a significant reduction following treatment (p = 0.002). However, the magnitude of PLR reduction was not significantly associated with treatment response (p = 0.08). Receiver operating characteristic (ROC) analysis for PLR as a prognostic marker yielded an area under the curve (AUC) of 0.51 (95% CI, 0.36–0.66; p = 0.89), indicating no significant predictive value for 90-day outcomes.
Conclusion: Although PLR was not significantly associated with treatment response or prognosis in this study, it may still represent an early and potentially useful biomarker in AIS patients receiving IV rtPA therapy. Larger, prospective, randomized controlled trials are warranted to clarify the prognostic value of PLR in this patient population.

Key words: Ischemic stroke, Platelet-to-leukocyte ratio, Thrombolytic therapy, Treatment outcome