The Predictive Value of Neutrophil-Lymphocyte Ratio in Patients with Polycythemia Vera at the Time of Initial Diagnosis for Thrombotic Events

Abstract

Objective. To investigate and discuss the predictive value of the neutrophil-to-lymphocyte ratio (NLR) in patients with polycythemia vera (PV) at the time of initial diagnosis, as well as its clinical significance in predicting the occurrence of thrombotic events and the progression of future thrombotic events during follow-ups, with the goal of providing a reference for the early identification of high-risk PV patients and the early intervention necessary to improve the prognosis of PV patients. Method. A total of 170 patients diagnosed with PV for the first time were enrolled in this study. The risk factors affecting the occurrence and development of thrombotic events in these patients were statistically analyzed. Results. NLR ( $P=0.030$ ), WBC count ( $P=0.045$ ), and history of previous thrombosis ( $P<0.001$ ) were independent risk factors for thrombotic events at the time of initial diagnosis. $\text{Age}\ge 60\text{years}$ ( $P=0.004$ ), NLR ( $P=0.025$ ), history of previous thrombosis ( $P<0.001$ ), and fibrinogen ( $P=0.042$ ) were independent risk factors for the progression of future thrombotic events during follow-ups. The receiver operating characteristic curve (ROC curves) showed that NLR was more effective in predicting the progression of future thrombotic events than $\text{age}\ge 60$ years, history of previous thrombosis, and fibrinogen. Kaplan-Meier survival analysis showed progression-free survival time of thrombotic events in the high NLR value group ( $\text{NLR}\ge 4.713$ ) (median survival time 22.033 months, 95% CI: 4.226-35.840), which was significantly lower compared to the low NLR value group ( $\text{NLR}<4.713$ ) (median overall survival time 66.000 months, 95% CI: 50.670-81.330); the observed difference was statistically significant ( $P<0.001$ ). The 60-month progression-free survival in the low NLR value group was 58.8%, while it was 32.8% in the high NLR value group. Conclusion. Peripheral blood NLR levels in patients with PV resulted as an independent risk factor for the occurrence of thrombotic events at the time of initial diagnosis and for the progression of future thrombotic events during follow-ups. Peripheral blood NLR levels at the time of initial diagnosis and treatment had better diagnostic and predictive value for the progression of future thrombotic events in patients with PV than $\text{age}\ge 60$ years, history of previous thrombosis, and fibrinogen.