Danet-Lamasou Marie, Asselineau Julien, Perez Paul, Vivot Alexandre, Nunes Marie-Laure, Loiseau Hugues, San-Galli François, Cherifi-Gatta Blandine, Corcuff Jean-Benoît, Tabarin Antoine
Departement d'Endocrinologie et Maladies Metaboliques, CHU de Bordeaux, Hopital du Haut Leveque, Pessac, France.
Clin Endocrinol (Oxf). 2015 Feb;82(2):260-6. doi: 10.1111/cen.12534. Epub 2014 Jul 25.
The performance of late-night salivary cortisol (LNSC) to accurately screen for postoperative recurrence of Cushing's disease (CD) at an early stage is unknown. The aim of this study was to compare the accuracy of multiple sampling strategies to suggest the optimal number of LNSC samples needed for diagnosing post-surgical recurrences of CD at an early stage.
Retrospective analysis in a single centre.
Thirty-six patients in surgical remission of CD had successive measurements of LNSC, defined as 'sequences', using a locally modified RIA assay as part of long-term follow-up (69·2 ± 10·6 months). Patients underwent an extensive biochemical evaluation within 3 months before or after a sequence of saliva sampling and were classified as being in remission or in early-stage recurrence. The accuracy of three diagnostic strategies combining two, three or four LNSC results from a sequence was estimated using areas under the ROC curves (AUC), sensitivity, specificity and predictive values.
Forty-four sequences of LNSC measurements were available. Fifty-two percent of sequences were performed during early-stage recurrence. The intrasequence variability of LNSC was higher during recurrence than during remission (medians of SDs: 2·1 vs 0·5 nm; P < 0·0001). AUCs from ROC curves ranged from 0·93 to 0·96 depending on the strategy. For 90% sensitivities, the best specificities (92·9% and 90·9%) were achieved by strategies taking into account three or four measurements summarized either by their mean or their maximum value.
Increase in LNSC concentration is an early abnormality during post-surgical recurrence of CD. However, due to a major within-patient variability of LNSC from 1 day to another, a screening strategy using three or four samples collected on successive days may be recommended to detect early-stage recurrence of CD with a high accuracy.
深夜唾液皮质醇（LNSC）在早期准确筛查库欣病（CD）术后复发的表现尚不清楚。本研究的目的是比较多种采样策略的准确性，以确定早期诊断CD术后复发所需的最佳LNSC样本数量。
单中心回顾性分析。
36例处于手术缓解期的CD患者连续测量LNSC，定义为“序列”，使用局部改良的放射免疫分析方法作为长期随访（69.2±10.6个月）的一部分。患者在一系列唾液采样前或后3个月内接受了广泛的生化评估，并被分类为缓解期或早期复发。使用ROC曲线下面积（AUC）、敏感性、特异性和预测值估计了三种诊断策略的准确性，这三种策略结合了序列中两个、三个或四个LNSC结果。
获得了44个LNSC测量序列。52%的序列是在早期复发期间进行的。复发期间LNSC的序列内变异性高于缓解期（标准差中位数：2.1 vs 0.5 nmol/L；P<0.0001）。根据策略不同，ROC曲线的AUC范围为0.93至0.96。对于90%的敏感性，通过考虑三个或四个测量值（以其平均值或最大值汇总）的策略可实现最佳特异性（92.9%和90.9%）。
LNSC浓度升高是CD术后复发的早期异常。然而，由于LNSC在患者体内一天到另一天的变异性很大，建议采用连续几天采集三个或四个样本的筛查策略，以高精度检测CD的早期复发。
