论著外周DDAVP兴奋试验在促肾上腺皮质激素依赖性库欣综合征鉴别诊断中的价值

目的 评价外周1-脱氨-8-精氨酸血管加压素(DDAVP)兴奋试验，在促肾上腺皮质激素(ACTH)依赖性库欣综合征鉴别诊断中的价值。方法 回顾性分析2012年1月至2013年6月在北京协和医院诊断明确的ACTH依赖性库欣综合征患者的临床资料，包括外周DDAVP兴奋试验、岩下窦静脉取血、鞍区MRI和手术病理的结果，评价外周DDAVP兴奋试验对诊断垂体ACTH腺瘤的敏感度和特异度。另收集10例文献报告的异位ACTH肿瘤患者资料，纳入统计分析。通过比较岩下窦静脉取血和外周DDAVP兴奋试验结果的差异，分析外周DDAVP兴奋试验中ACTH不升高的原因和此项检查的局限性。结果 (1)共纳入41例ACTH依赖性库欣综合征患者，其中28例为垂体ACTH腺瘤(简称库欣病)，13例为异位分泌ACTH肿瘤。(2)如以ACTH升高到基础值1.5倍作为阳性反应标准，82%(23/28)库欣病和38%(5/13)的异位ACTH肿瘤患者可达到此反应。如以ACTH升高到基础值3倍为反应标准，50%(14/28)的库欣病患者达此标准，而异位ACTH肿瘤为0(0/13)。(3)有12例库欣病患者同时进行岩下窦静脉取血。其中7例外周DDAVP试验中ACTH水平未达到基础值的3倍，但岩下窦ACTH水平在DDAVP刺激后明显升高。结论 外周DDAVP兴奋试验有助于ACTH依赖性库欣综合征的鉴别诊断。ACTH升高幅度越大，越支持库欣病的诊断。如ACTH升高到基础值3倍以上，可确诊为库欣病。

Desmopressin stimulation test for the differential diagnosis of ACTH dependent Cushing syndrome.

Abstract：Objective To clarify the values of DDAVP stimulation test in the differential diagnosis of ACTH dependent Cushing syndrome.Methods To calculate the sensitivity and specificity of DDAVP stimulation test for the diagnosis of Cushing’s disease by retrospectively reviewing the clinical results from 41 patients with Cushing syndrome.The clinical data includes high dosage dexamethasone depression test，DDAVP stimulation test，inferior petrosal sinus sampling (IPSS) and sellar MR images.Ten patients with ectopic ACTH syndrome，from the other studies，were recruited for data analysis.The exploration for false-negative results was conducted by comparing the different levels of ACTH between IPSS and DDAVP stimulation test.Results (1) Totally 28 patients with Cushing’s disease and 13 patients with ectopic ACTH syndrome were recorded.(2) The ratio of ACTH max/ACTH basal was taken as a marker for ACTH increment.Taken the ratio of 1.5 as a cut point，the sensitive and specific rate of Cushing’s disease was 82% and 62% respectively.Taken the ratio of 3 as a cut point，the sensitive and specific rate of Cushing’s disease was 50% and 100%，respectively.(3) Twelve patients performed IPSS.At the baseline，the ratio (ACTH inferior petrosal sinus /ACTH peripheral) was 17.3±5.4 and the central level of ACTH significantly increased after DDAVP injection.Conclusion The peripheral level of ACTH would increase in 80% patients with Cushing’s disease after DDAVP injection.A greater increment in ACTH indicates a greater chance for Cushing’s disease and an increment in ACTH above three folds of the baseline makes the diagnosis more definitive.