Dynamic change of neutrophil to lymphocyte ratio and hemorrhagic transformation after thrombolysis in stroke

BACKGROUND: The neutrophil to lymphocyte ratio (NLR) has been shown to predict short- and long-term outcomes in ischemic stroke patients. We sought to explore the temporal profile of the plasma NLR in stroke patients treated with intravenous thrombolysis (IVT) and its relationship with intracranial bleeding complications after thrombolysis. METHODS: A total of 189 ischemic stroke patients were prospectively enrolled. Blood samples for leukocyte, neutrophil, and lymphocyte counts were obtained at admission and at 3-6, 12-18, and 36-48 h after IVT. Head CT was performed on admission and repeated after 36-48 h, and a CT scan was done immediately in case of clinical worsening. Hemorrhagic events were categorized as symptomatic intracranial hemorrhage (sICH) and parenchymal hematomas (PH) according to previously published criteria. RESULTS: An increasing trend in the NLR was observed after stroke, and the NLR was higher in patients who developed PH or sICH at 3-6, 12-18, and 36-48 h after IVT (P < 0.01) than in those without PH or sICH. The optimal cutoff value for the serum NLR as an indicator for auxiliary diagnosis of PH and sICH was 10.59 at 12-18 h. Furthermore, the NLR obtained at 12-18-h post-treatment was independently associated with PH (adjusted odds ratio OR 1.14) and sICH (adjusted OR 1.14). In addition, patients with a NLR ≥10.59 had an 8.50-fold greater risk for PH (95 % confidence interval CI 2.69-26.89) and a 7.93-fold greater risk for sICH (95 % CI 2.25-27.99) than patients with a NLR <10.59. CONCLUSIONS: NLR is a dynamic variable, and its variation is associated with HT after thrombolysis in stroke patients.