The complete blood count (CBC) is an important screening tool for healthy adults and a common test at periodic exams. However, results are usually interpreted relative to one-size-fits-all reference intervals^1,2, undermining the precision medicine goal to tailor care for patients on the basis of their unique characteristics^3,4. Here we study thousands of diverse patients at an academic medical centre and show that routine CBC indices fluctuate around stable values or setpoints⁵, and setpoints are patient-specific, with the typical healthy adult’s nine CBC setpoints distinguishable as a group from those of 98% of other healthy adults, and setpoint differences persist for at least 20 years. Haematological setpoints reflect a deep physiologic phenotype enabling investigation of acquired and genetic determinants of haematological regulation and its variation among healthy adults. Setpoints in apparently healthy adults were associated with significant variation in clinical risk: absolute risk of some common diseases and morbidities varied by more than 2% (heart attack and stroke, diabetes, kidney disease, osteoporosis), and absolute risk of all-cause 10 year mortality varied by more than 5%. Setpoints also define patient-specific reference intervals and personalize the interpretation of subsequent test results. In retrospective analysis, setpoints improved sensitivity and specificity for evaluation of some common conditions including diabetes, kidney disease, thyroid dysfunction, iron deficiency and myeloproliferative neoplasms. This study shows CBC setpoints are sufficiently stable and patient-specific to help realize the promise of precision medicine for healthy adults.

全血细胞计数 （CBC） 是健康成年人的重要筛查工具，也是定期检查的常见测试。然而，结果通常是相对于一刀切的参考区间^1,2 进行解释的，这破坏了根据患者的独特特征为患者量身定制护理的精准医学目标^3,4。在这里，我们研究了学术医疗中心的数千名不同患者，结果表明常规 CBC 指数在稳定值或设定点⁵ 附近波动，并且设定点是特定于患者的，典型健康成年人的 9 个 CBC 设定点作为一个组与其他 98% 的健康成年人的设定点区分开来，并且设定点差异持续至少 20 年。血液学设定点反映了深层生理表型，能够研究血液学调节的获得性和遗传决定因素及其在健康成人中的变异。表面健康的成年人的设定点与临床风险的显着差异相关：一些常见疾病和发病率的绝对风险变化超过 2%（心脏病发作和中风、糖尿病、肾病、骨质疏松症），全因 10 年死亡率的绝对风险变化超过 5%。设定值还定义了患者特定的参考区间，并个性化了对后续测试结果的解释。在回顾性分析中，设定点提高了评估一些常见病症的敏感性和特异性，包括糖尿病、肾病、甲状腺功能障碍、缺铁和骨髓增生性肿瘤。这项研究表明，CBC 设定值足够稳定且具有患者特异性，有助于实现对健康成人的精准医疗的承诺。