Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston.
Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston.
Clin Infect Dis. 2020 Mar 3;70(6):1215-1221. doi: 10.1093/cid/ciz346.
Anaplasmosis presents with fever, headache, and laboratory abnormalities including leukopenia and thrombocytopenia. Polymerase chain reaction (PCR) is the preferred diagnostic but is overutilized. We determined if routine laboratory tests could exclude anaplasmosis, improving PCR utilization.
Anaplasma PCR results from a 3-year period, with associated complete blood count (CBC) and liver function test results, were retrospectively reviewed. PCR rejection criteria, based on white blood cell (WBC) and platelet (PLT) counts, were developed and prospectively applied in a mock stewardship program. If rejection criteria were met, a committee mock-refused PCR unless the patient was clinically unstable or immunocompromised.
WBC and PLT counts were the most actionable routine tests for excluding anaplasmosis. Retrospective review demonstrated that rejection criteria of WBC ≥11 000 cells/µL or PLT ≥300 000 cells/µL would have led to PCR refusal in 428 of 1685 true-negative cases (25%) and 3 of 66 true-positive cases (5%) involving clinically unstable or immunocompromised patients. In the prospective phase, 155 of 663 PCR requests (23%) met rejection criteria and were reviewed by committee, which endorsed refusal in 110 of 155 cases (71%) and approval in 45 (29%), based on clinical criteria. PCR was negative in all 45 committee-approved cases. Only 1 of 110 mock-refused requests yielded a positive PCR result; this patient was already receiving doxycycline at the time of testing.
A CBC-based stewardship algorithm would reduce unnecessary Anaplasma PCR testing, without missing active cases. Although the prospectively evaluated screening approach involved medical record review, this was unnecessary to prevent errors and could be replaced by a rejection comment specifying clinical situations that might warrant overriding the algorithm.
无形体病的表现为发热、头痛和实验室异常，包括白细胞减少和血小板减少。聚合酶链反应（PCR）是首选的诊断方法，但过度使用。我们确定常规实验室检查是否可以排除无形体病，从而提高 PCR 的利用率。
回顾性分析了 3 年期间的无形体 PCR 结果，以及相关的全血细胞计数（CBC）和肝功能检查结果。根据白细胞（WBC）和血小板（PLT）计数制定了 PCR 排除标准，并在模拟管理计划中进行了前瞻性应用。如果符合排除标准，委员会将模拟拒绝 PCR，除非患者临床不稳定或免疫功能低下。
WBC 和 PLT 计数是排除无形体病最具操作性的常规检查。回顾性研究表明，WBC≥11000 个/μL 或 PLT≥300000 个/μL 的排除标准将导致在 1685 例真阴性病例（25%）中的 428 例和 66 例真阳性病例（5%）中的 3 例中拒绝 PCR，这些病例涉及临床不稳定或免疫功能低下的患者。在前瞻性阶段，663 例 PCR 请求中有 155 例（23%）符合排除标准，并由委员会进行了审查，根据临床标准，委员会批准了其中 110 例（71%），拒绝了 45 例（29%）。所有 45 例委员会批准的病例的 PCR 结果均为阴性。在 110 例模拟拒绝请求中，只有 1 例结果为阳性 PCR 结果；该患者在检测时已接受多西环素治疗。
基于 CBC 的管理算法可减少不必要的无形体 PCR 检测，而不会遗漏活动病例。尽管前瞻性评估的筛选方法涉及病历审查，但这对于防止错误是不必要的，并且可以用指定可能需要超越算法的临床情况的拒绝注释来代替。
