Lymphocyte-to-Monocyte Ratio: A Novel Predictor of the Prognosis of Acute Ischemic Stroke

Abstract

Background: Lymphocyte-to-monocyte ratio (LMR) is associated with diverse malignancies and cardiovascular diseases. However, it has not yet been identified whether LMR is correlated with stroke severity and prognosis. We aimed to explore the relationship between LMR and stroke severity, prognosis, and the predictive value of LMR on a 3-month functional outcome in patients with acute ischemic stroke (AIS).

Materials and methods: A total of 512 patients were enrolled in this study. Baseline demographic and clinical data of all patients were collected. Based on the LMR value on admission (>4.83, 2.97-4.83, <2.97), patients were divided into 3 groups. Moderate to severe stroke was defined as a National Institutes of Health Stroke Scale score of 6 or higher. Poor outcome was defined as a modified Rankin Scale score of 3 or higher. We used the Spearman rank correlation to evaluate the relationship between LMR and stroke severity. Binary logistic regression analysis was used to assess risk factors of stroke severity and prognosis. The receiver operating characteristic (ROC) curve was used to estimate the predictive value of LMR on prognosis.

Results: LMR was inversely correlated with stroke severity (r = -.014, P = .019). Moreover, LMR was an independent protective factor of stroke severity (odds ratio [OR] .891, 95% confidence interval [CI] .815-.973, P = .010) and prognosis (OR .507, 95% CI .437-.590, P < .001). ROC indicated that an LMR lower than 2.99 predicted a poor outcome, with a sensitivity of 69.3% and a specificity of 86.6%.

Conclusion: A lower LMR on admission was independently associated with severe stroke and 3-month poor outcome in patients with AIS.

Keywords: Lymphocyte-to-monocyte ratio; acute ischemic stroke; prognosis; stroke severity.