A Study about the Relationship between Thrombotic Events and Peripheral Neutrophil-to-Lymphocyte Ratio in Patients with Newly Diagnosed Essential Thrombocythemia

To explore the role of neutrophil-to-lymphocyte ratio (NLR) in patients with newly diagnosed essential thrombocythemia (ET) and the relationship with thrombotic events.150 ET patients with ET from January 2013 to December 2017 were retrospectively enrolled in this study to investigate the risk factors of thrombosis and analyse the role of NLR in thrombotic events. The following parameters were evaluated: age, sex, blood routine examination, JAK2V617F mutation, cardiovascular risk factors, history of previous thrombosis, thrombosis during follow-up, examination and biopsy of bone marrow.Age(P=0.001) and JAK2 V617F mutation(P=0.003) were independent risk factors for thrombotic events at diagnosis after Logistic multivariate analysis. WBC count (P=0.047), NLR (P<0.001), age (P=0.037) and thrombosis at diagnosis (P=0.036) were independent risk factors for future thrombotic events and NLR was better for prediction of future thrombotic events than other risk factors in ROC curve. The thrombosis-free survival of thrombotic events in patients with higher NLR(median survival 22.3 months, 95% CI:17.8-26.8) was significantly shorter than that of patients with lower NLR(median survival 55.5 months, 95% CI:53.4-57.5) in Kaplan-Meier analysis (P<0.001). After 60 months of follow-up, patients with lower NLR had a thrombosis-free survival of 97.4%, while patients with higher NLR had a thrombosis-free survival of 46.7%. NLR at diagnosis was a better predictive parameter for future thrombotic events than other clinical parameters in ET patients, but was not associated with thrombosis at diagnosis.