Departement of General Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
J Investig Med High Impact Case Rep. 2022 Jan-Dec;10:23247096221103368. doi: 10.1177/23247096221103368.
A 35-year-old woman with unintentional weight gain, hyperpigmentation of bilateral palms, and general fatigue was initially suspected of Cushing's syndrome or adrenal insufficiency based on the isolated elevation of the plasma adrenocorticotropic hormone (ACTH) level (113.0 pg/mL) in the Siemens ACTH Immulite assay (ACTH [Immulite]). However, both of the diagnoses were excluded by screening tests including the overnight dexamethasone suppression test, the 24-hour urinary free cortisol excretion, and the ACTH stimulation test in spite of the consistent elevation of the plasma ACTH levels. We speculated that the existence of the immunoassay interference may be the underlying cause because the plasma ACTH level analyzed by the CIS Bio International ELSA-ACTH immunoassay (ELSA-ACTH) was within the normal range. After reviewing our case and several reported cases of falsely elevated plasma ACTH levels, we conclude that when discrepancy between clinical symptoms and laboratory measurements exists, medical practitioners ought to rely on formal diagnostic criteria rather than misleading laboratory results to avoid misdiagnosis or even unnecessary invasive testing and procedures. In addition, current methods for investigation and elimination of immunoassay interferences should be applied with caution due to variable efficacy and inevitable deviations.
一位 35 岁女性，出现不明原因体重增加、双侧手掌色素沉着和全身乏力，最初根据西门子 ACTH Immulite 检测（ACTH[Immulite]）中血浆促肾上腺皮质激素（ACTH）水平（113.0 pg/mL）孤立升高，怀疑为库欣综合征或肾上腺功能不全。然而，尽管血浆 ACTH 水平持续升高，但通过筛查试验，包括 overnight dexamethasone suppression test、24 小时尿游离皮质醇排泄和 ACTH 刺激试验，排除了这两种诊断。我们推测免疫测定干扰的存在可能是根本原因，因为 CIS Bio International ELISA-ACTH 免疫测定（ELSA-ACTH）分析的血浆 ACTH 水平在正常范围内。在回顾我们的病例和几例报告的假性升高血浆 ACTH 水平的病例后，我们得出结论，当临床症状和实验室检测结果存在差异时，临床医生应该依靠正式的诊断标准，而不是误导性的实验室结果，以避免误诊甚至不必要的有创性检查和程序。此外，由于疗效的可变性和不可避免的偏差，应谨慎应用当前用于调查和消除免疫测定干扰的方法。
