Nouvel Migueline, Rabilloud Muriel, Raverot Véronique, Subtil Fabien, Vouillarmet Julien, Thivolet Charles, Jouanneau Emmanuel, Borson-Chazot Françoise, Pugeat Michel, Raverot Gérald
Fédération d'endocrinologie, groupement hospitalier Est, Hospices Civils de Lyon, 69500 Bron, France.
Service de biostatistique, Hospices Civils de Lyon, 69003 Lyon, France; Université de Lyon, 69000 Lyon, France; Université Lyon 1, 69100 Villeurbanne, France; CNRS, UMR5558, laboratoire de biométrie et biologie évolutive, équipe biotatistique-santé, 69100 Villeurbanne, France.
Ann Endocrinol (Paris). 2016 Feb;77(1):30-6. doi: 10.1016/j.ando.2015.11.001. Epub 2015 Dec 3.
Discriminating Cushing disease (CD) from pseudo-Cushing syndrome (PCS) is a challenging task that may be overcome with the 4-mg intravenous (IV) dexamethasone suppression test (DST).
Assess the performance of the 4-mg IV DST in the differential diagnosis between CD and PCS in well-characterized patients.
Retrospective comparative study of subjects seen in a tertiary care unit (November 2008 to July 2011).
Thirty-six patients with PCS and 32 patients with CD underwent 4-mg IV dexamethasone infusions from 11 am to 3 pm. Areas Under ROC Curves (AUCs) were estimated and compared for ACTH and cortisol measured at 4 pm the same day (day 1) and 8 am the next day (day 2). The ROC curve of the marker with the highest AUC was used to determine the threshold with the highest specificity for 100% sensitivity.
The AUC of ACTH at 8 am on day 2 was estimated at 98.4% (95% CI: [92.1-100]), which is significantly greater than that of ACTH at 4 pm on day 1 (P=0.04) and that of cortisol at 8 am on day 2 (P=0.05). For ACTH at 8 am on day 2, the threshold with the highest specificity for 100% sensitivity was estimated at 14.8 ng/L. At this threshold, the sensitivity was estimated at 100% [89-100] and the specificity at 83.3% [67-94].
The 4-mg IV DST is an easy and accurate tool in distinguishing CD from PCS. It deserves thus a better place in establishing the diagnosis of CD.
鉴别库欣病（CD）与假性库欣综合征（PCS）是一项具有挑战性的任务，而4毫克静脉注射（IV）地塞米松抑制试验（DST）或许可以解决这一问题。
评估4毫克IV DST在特征明确的患者中对CD和PCS进行鉴别诊断的性能。
对一家三级医疗机构（2008年11月至2011年7月）的受试者进行回顾性比较研究。
36例PCS患者和32例CD患者于上午11点至下午3点接受4毫克IV地塞米松输注。对同日下午4点（第1天）和次日上午8点（第2天）测量的促肾上腺皮质激素（ACTH）和皮质醇进行ROC曲线下面积（AUC）估计和比较。使用AUC最高的标志物的ROC曲线来确定具有100%敏感性的最高特异性阈值。
第2天上午8点ACTH的AUC估计为98.4%（95%置信区间：[92.1 - 100]），显著高于第1天下午4点ACTH的AUC（P = 0.04）以及第2天上午8点皮质醇的AUC（P = 0.05）。对于第2天上午8点的ACTH，具有100%敏感性的最高特异性阈值估计为14.8纳克/升。在此阈值下，敏感性估计为100% [89 - 100]，特异性为83.3% [67 - 94]。
4毫克IV DST是区分CD与PCS的简便且准确的工具。因此，它在CD的诊断确立中应占有更重要的地位。
