关键词: 垂体ACTH分泌过多；库欣病；库欣综合征；脱氨基精氨酸血管升压素；去氨加压素；外周去氨加压素兴奋试验；地塞米松；大剂量地塞米松抑制试验；诊断, 鉴别

Abstract: Background　The clinical manifestations of Cushing's syndrome are complex.It is difficult to determine whether Cushing's syndrome is induced by Cushing's disease or ectopic ACTH syndrome.Although bilateral inferior petrosal sinus sampling，a recognized gold standard，can be used to differentiate the two，it can not be implemented in most hospitals.High-dose dexamethasone suppression test（HDDST）is commonly used to diagnose Cushing's disease，but its sensitivity is not satisfactory.Desmopressin has been reported to have the effect similar to corticotropin-releasing hormone，promoting the ACTH-producing pituitary tumor to secrete ACTH.Objective　To explore the diagnostic value of desmopressin stimulation test versus HDDST in Cushing's disease.Methods　72 patients with a clear diagnosis of ACTH-dependent Cushing's syndrome were retrospectively recruited from Chinese PLA General Hospital during January 1st，2015 to August 30th，2018.General data，results of desmopressin stimulation test and HDDST were collected.The sensitivity and specificity of desmopressin stimulation test and HDDST in the diagnosis of Cushing's disease were evaluated.Results　Of the 72 cases，64 were found with Cushing's disease，and 8 with ectopic ACTH syndrome.All of them underwent desmopressin stimulation test except 9 cases of Cushing's disease being excluded.51 had positive test results and other 12 showed negative test results.The desmopressin stimulation test showed a sensitivity of 92.7% and a specificity of 100.0% in diagnosing Cushing's disease.43 had positive results and other 29 had negative results in HDDST.The HDDST demonstrated a sensitivity of 67.2% and a specificity of 100.0% in diagnosing Cushing's disease.38 cases of Cushing's disease had positive results and 9 cases of ectopic ACTH syndrome（8 with ectopic ACTH syndrome）had negative results in both the tests.16 cases had positive results in desmopressin stimulation test but showed negative results in HDDST，and 0 showed negative results in desmopressin stimulation test but showed positive results in HDDST.Among the 55 cases of Cushing's disease undergoing both tests，38 showed positive response and 1 showed negative response to both tests，16 showed positive response to desmopressin stimulation test but showed negative response to HDDST，and 0 showed negative response to desmopressin stimulation test but showed positive response to HDDST.Conclusion　Desmopressin stimulation test has a high diagnostic value for Cushing's disease.It may be used for those with suspected Cushing's disease but show negative response to HDDST，by which the possibility of missed diagnosis of Cushing's disease may be significantly reduced.