基于地塞米松抑制试验的原发性色素性结节样肾上腺皮质病鉴别诊断切点探讨

Diagnostic cut-off point of dexamethasone suppression test for the diagnosis of primary pigmented nodular adrenocortical disease

目的通过比较原发性色素性结节样肾上腺皮质病(PPNAD)、原发性双侧肾上腺大结节增生(PBMAH)和肾上腺皮质腺瘤(ADA)三种疾病的地塞米松抑制试验后尿游离皮质醇变化比值,探讨PPNAD患者的鉴别诊断切点。方法收集2008年1月-2020年12月于解放军总医院第一医学中心住院病理明确诊断为PPNAD(7例)、PBMAH(31例)及ADA(130例)患者的临床资料进行回顾性分析。通过受试者工作特征(ROC)曲线,以患者小剂量地塞米松抑制试验(LDDST)和大剂量地塞米松抑制试验(HDDST)抑制后24 h尿游离皮质醇(24 h UFC)与抑制前(基线)24 h UFC比值(post UFC/pre UFC)为检测变量,以是否为PPNAD为状态变量,寻找鉴别诊断PPNAD的最佳切点。结果PPNAD、PBMAH及ADA三组患者基线及LDDST、HDDST后血皮质醇(F)水平均明显升高,组间差异无统计学意义(P>0.05);三组患者促肾上腺皮质激素(ACTH)水平均受抑制,且PBMAH组基线及HDDST后ACTH水平最高,ADA组ACTH水平最低(P<0.05);三组患者基线24 h UFC均明显升高,差异无统计学意义(P>0.05)。与PBMAH、ADA组比较,PPNAD组患者LDDST post UFC/pre UFC[1.88(1.39,2.59)]明显高于PBMAH组[1.13(0.82,1.37),P=0.001]及ADA组[1.11(0.70,1.49),P=0.003],且HDDST抑制后的post UFC/pre UFC[2.31(1.23,3.08)]亦高于PBMAH组[1.22(0.94,1.63),P=0.004]及ADA组[1.39(1.08,1.53),P=0.008]。与PBMAH、ADA组比较,PPNAD组患者LDDST中post UFC/pre UFC诊断切点为1.385,敏感度为85.7%,特异度为71.5%;HDDST中post UFC/pre UFC诊断切点为2.290,敏感度为57.1%,特异度为95.0%。结论地塞米松抑制试验post UFC/pre UFC切点对PPNAD患者鉴别诊断具有重要临床价值;当LDDST中post UFC/pre UFC为1.385以上,HDDST中post UFC/pre UFC为2.290以上可能诊断为PPNAD。

Objective By comparison of the urinary free cortisol(UFC)levels in post-to prior-dexamethasone suppression test(post UFC/pre UFC)with primary pigmented nodular adrenocortical disease(PPNAD),primary bilateral macronodular adrenal hyperplasia(PBMAH)and adrenocortical adenoma(ADA),to explore the optimal differential diagnostic cut-off point of PPNAD from PBMAH and ADA.Methods The clinical data were collected and retrospectively analyzed of in patients admitted from January 2008 to December 2020 with finally diagnosed as PPNAD(n=7),PBMAH(n=31)and ADA(n=130)in the First Medical Center of Chinese PLA General Hospital.Based on the receiver operating characteristic(ROC)curve,the value of post UFC/pre UFC in low-dose dexamethasone suppression test(LDDST)and high-dose dexamethasone suppression test(HDDST)was used as the detection variable,and the diagnosis of PPNAD was used as the status variable to search the best cut-off point for the differential diagnosis of PPNAD.Results The serum cortisol(F)levels of all the 3 groups of patients(PPNAD,PBMAH and ADA)increased significantly in the baseline,LDDST and HDDST,and no statistical difference existed among them(P>0.05).The adrenocorticotropic hormone(ACTH)levels in all the 3 groups of patients were inhibited,and ACTH levels in PBMAH group were the highest at the baseline and after HDDST,and the ACTH levels of ADA group were the lowest among the three groups(P<0.05).The baseline 24 h UFC levels elevated obviously with no statistical difference(P>0.05)among the three groups.For patients in PPNAD group,the LDDST post UFC/pre UFC[1.88(1.39,2.59)]was obviously higher than that in PBMAH group[1.13(0.82,1.37),P=0.001]and ADA group[1.11(0.70,1.49),P=0.003];and the HDDST post UFC/pre UFC in PPNAD group[2.31(1.23,3.08)]was still higher than that in PBMAH group[1.22(0.94,1.63),P=0.004]and ADA group[1.39(1.08,1.53),P=0.008].Compared with PBMAH group and ADA group,the diagnostic cut-off point for PPNAD group after LDDST post UFC/pre UFC was 1.385,with 85.7%sensitivity and 71.5%specificity;and after HDDST post UFC/pre UFC was 2.290,with 57.1%sensitivity and 95.0%specificity.Conclusion The cut-off points of post UFC/pre UFC in DST had a clear advantage in distinguishing PPNAD from PBMAH and ADA.The diagnosis of PPNAD may be considered once the value of post UFC/pre UFC after LDDST is greater than 1.385,or after HDDST is above 2.290.