Predictive accuracy of the low erythropoietin level for the diagnosis of polycythemia vera
Lupak O, Han X, Xie P, Mahmood S, Mohammed H, and Donthireddy V. Predictive accuracy of the low erythropoietin level for the diagnosis of polycythemia vera. J Clin Oncol 2019; 37.
J Clin Oncol
Background: A low erythropoietin (EPO) level is a minor diagnostic criterion for Polycythemia Vera (PV) based on the updated 2016 World Health Organization (WHO) diagnostic criteria for myeloproliferative neoplasms. The diagnostic value of EPO has been debated due to the increasing availability of advanced molecular testing. We hypothesized that EPO level below the normal range may not provide additional diagnostic information if JAK2 mutation status is positive. Methods: In this retrospective review we used Logistic regression to build a predictive model for the diagnosis of PV based on EPO value and JAK2V617F mutation status. 415 patient records were reviewed. 162 were used in the final statistical analysis. The area under the receiver operating characteristic curve (AUC) was calculated to evaluate the predictive accuracy. All statistical analysis was performed with R version 3.5.1. A p-value less than 0.05 was considered statistically significant. Results: EPO level below the normal range as a standalone diagnostic modality is significantly associated with PV (odds ratio (OR) 0.857; p-value < 0.001). When JAK2V617F mutation status is included in the prediction model, the association of the low erythropoietin level is not statistically significant (OR 0.962 and p-value 0.269). Positive JAK2V617F demonstrates a strong predictive value for PV (OR 670.5, p-value 0.006) either alone or in combination with other variables. Moreover, 34.2% of patients with the diagnosis of PV had EPO level within the normal range, which reflects it's physiological variability. Conclusions: Results show that erythropoietin level below the normal range does not bring additional diagnostic value when JAK2V617F mutation status is positive. Additionally, erythropoietin level has a negative correlation with increased BMI and smoking status, making it not a reliable diagnostic marker.