Division of Hematology, Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
Division of Hematology, Department of Medicine, London Health Sciences Centre, London, Ontario, Canada.
J Gen Intern Med. 2023 Jun;38(8):1828-1833. doi: 10.1007/s11606-022-07963-x. Epub 2022 Nov 30.
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.
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.
Internal medicine and hematology clinics at an academic tertiary referral center.
The JAK2 Prediction Cohort (JAKPOT), a large retrospective cohort (n = 901) of patients evaluated by internal medicine and hematology specialists for elevated hemoglobin.
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.
The JAKPOT prediction rule included three variables: (i) red blood cell count >6.45×10/L, (ii) platelets >350×10/L, and (iii) neutrophils >6.2×10/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.
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.
红细胞增多症，通常表现为血红蛋白和/或红细胞压积升高，是内科和血液科就诊的常见原因，需要采取合理的方法来有效识别真性红细胞增多症患者，同时避免过度检查。
我们旨在开发和验证一种基于全血细胞计数参数的简单规则，以预测 JAK2 突变阳性，辅助血红蛋白升高患者的诊断方法。
在学术性三级转诊中心的内科和血液科诊所。
JAK2 预测队列（JAKPOT），这是一个由内科和血液科专家评估血红蛋白升高的大型回顾性队列（n=901）。
对所有患者进行 JAK2 突变分析，并收集临床和实验室变量。患者被随机分为推导队列和验证队列。使用推导队列的数据开发预测规则，并在验证队列中进行测试。
JAKPOT 预测规则包括三个变量：（i）红细胞计数>6.45×10/L，（ii）血小板>350×10/L，（iii）中性粒细胞>6.2×10/L；三个标准均不满足时，在推导和验证队列中，对 JAK2 阳性的排除敏感性分别为 94.7%和 100%，阴性预测值分别为 98.8%和 100%，总体假阴性率为 0.4%。该规则在三种不同的 JAK2 检测方法中得到验证。在我们的整个队列中应用该规则将导致检测数量减少 50%以上。
在血红蛋白升高的患者中，使用简单的预测规则有助于准确识别 JAK2 突变可能性较低的患者，可能会限制这种常见转诊人群的过度昂贵检查。
