A Rational Approach to JAK2 Mutation Testing in Patients with Elevated Hemoglobin: Results from the JAK2 Prediction Cohort (JAKPOT) Study
- 30 November 2022
- journal article
- research article
- Published by Springer Science and Business Media LLC in Journal of General Internal Medicine
- Vol. 38 (8), 1828-1833
- https://doi.org/10.1007/s11606-022-07963-x
Abstract
Background Erythrocytosis, most often measured as an increase in hemoglobin and/or hematocrit, is a common reason for referral to internal medicine and hematology clinics and a rational approach is required to effectively identify patients with polycythemia vera while avoiding over-investigation. Aim We aimed to develop and validate a simple rule to predict JAK2 mutation positivity based on complete blood count parameters to aid in the diagnostic approach to patients referred for elevated hemoglobin. Setting Internal medicine and hematology clinics at an academic tertiary referral center. Participants The JAK2 Prediction Cohort (JAKPOT), a large retrospective cohort (n = 901) of patients evaluated by internal medicine and hematology specialists for elevated hemoglobin. Design JAK2 mutation analysis was performed in all patients and clinical and laboratory variables were collected. Patients were randomly divided into derivation and validation cohorts. A prediction rule was developed using data from the derivation cohort and tested in the validation cohort. Key Results The JAKPOT prediction rule included three variables: (i) red blood cell count >6.45×1012/L, (ii) platelets >350×109/L, and (iii) neutrophils >6.2×109/L; absence of all criteria was effective at ruling out JAK2-positivity with sensitivities 94.7% and 100%, and negative predictive values of 98.8% and 100% in the derivation and validation cohorts, respectively, with an overall low false negative rate of 0.4%. The rule was validated for three different methods of JAK2 testing. Applying this rule to our entire cohort would have resulted in over 50% fewer tests. Conclusion In patients with elevated hemoglobin, the use of a simple prediction rule helps to accurately identify patients with a low likelihood of having a JAK2 mutation, potentially limiting costly over-investigation in this common referral population.Keywords
This publication has 16 references indexed in Scilit:
- Investigation and management of erythrocytosisCMAJ : Canadian Medical Association Journal, 2020
- Time for revival of the red blood cell count and red cell mass in the differential diagnosis between essential thrombocythemia and polycythemia vera?Haematologica, 2019
- How I treat polycythemia veraBlood, 2019
- JAK2-tree: a simple CBC-based decision rule to guide appropriate JAK2 V617F mutation testingJournal of Clinical Pathology, 2018
- Frequency of polycythemia in individuals with normal complete blood cell counts according to the new 2016 WHO classification of myeloid neoplasmsInternational Journal of Laboratory Hematology, 2017
- The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemiaBlood, 2016
- Masked polycythemia Vera (mPV): Results of an international studyAmerican Journal of Hematology, 2013
- Vascular and Neoplastic Risk in a Large Cohort of Patients With Polycythemia VeraJournal of Clinical Oncology, 2005
- Evaluation of D-Dimer in the Diagnosis of Suspected Deep-Vein ThrombosisThe New England Journal of Medicine, 2003
- Excluding Pulmonary Embolism at the Bedside without Diagnostic Imaging: Management of Patients with Suspected Pulmonary Embolism Presenting to the Emergency Department by Using a Simple Clinical Model and d-dimerAnnals of Internal Medicine, 2001