Yanovski J A, Cutler G B, Doppman J L, Miller D L, Chrousos G P, Oldfield E H, Nieman L K
Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892.
J Clin Endocrinol Metab. 1993 Aug;77(2):503-9. doi: 10.1210/jcem.77.2.8393887.
To determine whether petrosal sinus sampling is useful to distinguish patients with mild or intermittent Cushing's disease from normal subjects and individuals with pseudo-Cushing states, we performed bilateral inferior petrosal sinus sampling for ACTH before and after the administration of CRH in 7 eucortisolemic volunteers, 8 hypercortisolemic patients with pseudo-Cushing states, and 40 patients with ACTH-dependent Cushing's disease whose urinary free cortisol excretion was within the range found in patients with, pseudo-Cushing states (< 1000 nmol/day; < 360 micrograms/day). The ACTH level, the ratio of the inferior petrosal sinus ACTH to the peripheral venous ACTH concentration (the IPS:P ratio), and the greater ratio of right to left or left to right petrosal sinuses (the R:L ratio) were compared in patients with and without Cushing's disease. Maximal petrosal ACTH values were significantly elevated in patients with Cushing's disease compared to patients with pseudo-Cushing states before CRH administration (P < 0.001), but not after CRH. Maximal petrosal plasma ACTH values after the administration of CRH as high as 808 pmol/L (3670 pg/mL) and 469 pmol/L (2130 pg/mL) were found in patients with pseudo-Cushing states and in normal volunteers, respectively, whereas maximal petrosal ACTH levels as low as 10 pmol/L (46 pg/mL) were observed in patients with surgically proven Cushing's disease. Maximal and minimal IPS:P ratios were significantly greater in patients with Cushing's disease than in subjects without Cushing's disease before, but not after, CRH treatment. R:L ratios did not differ among groups either before or after CRH. All of the subjects without Cushing's disease showed large R:L gradients, consistent with the notion of one dominant petrosal sinus containing a greater percentage of pituitary effluent. The ACTH concentrations, IPS:P ratios, and R:L ratios exhibited great overlap between those with and without Cushing's disease, which resulted in a diagnostic accuracy of 81% at best for the diagnosis of Cushing's disease. We conclude that petrosal sinus sampling is of limited usefulness in distinguishing either normal individuals or patients with pseudo-Cushing states from those with mild Cushing's disease. This limited usefulness must be recognized when interpreting the results of petrosal sinus sampling in patients with mild or intermittent hypercortisolism who may have a pseudo-Cushing state. Because of these limitations, petrosal sinus sampling should be reserved for patients with clear clinical and biochemical evidence of Cushing's syndrome.
为了确定岩下窦采血是否有助于区分轻度或间歇性库欣病患者与正常受试者及假性库欣状态个体，我们对7名皮质醇正常的志愿者、8名患有假性库欣状态的皮质醇增多症患者以及40名促肾上腺皮质激素（ACTH）依赖性库欣病患者进行了双侧岩下窦ACTH采血，这些库欣病患者的尿游离皮质醇排泄量处于假性库欣状态患者（<1000 nmol/天；<360μg/天）的范围内。比较了有或没有库欣病的患者的ACTH水平、岩下窦ACTH与外周静脉ACTH浓度的比值（IPS:P比值）以及右侧与左侧或左侧与右侧岩下窦的更大比值（R:L比值）。与假性库欣状态患者相比（P<0.001），库欣病患者在注射促肾上腺皮质激素释放激素（CRH）前岩下窦ACTH的最大值显著升高，但注射CRH后则无显著差异。在假性库欣状态患者和正常志愿者中，注射CRH后岩下窦血浆ACTH的最大值分别高达808 pmol/L（3670 pg/mL）和469 pmol/L（2130 pg/mL），而在经手术证实的库欣病患者中观察到岩下窦ACTH水平低至10 pmol/L（46 pg/mL）。在CRH治疗前，库欣病患者的最大和最小IPS:P比值显著高于无库欣病的受试者，但治疗后则无显著差异。CRH治疗前后各组的R:L比值均无差异。所有无库欣病的受试者均显示出较大的R:L梯度，这与一个主要的岩下窦含有更大比例垂体流出物的概念一致。有或没有库欣病的患者之间的ACTH浓度、IPS:P比值和R:L比值存在很大重叠，这导致诊断库欣病的最佳诊断准确率为81%。我们得出结论，岩下窦采血在区分正常个体或假性库欣状态患者与轻度库欣病患者方面的作用有限。在解释可能患有假性库欣状态的轻度或间歇性皮质醇增多症患者的岩下窦采血结果时，必须认识到这种有限的作用。由于这些局限性，岩下窦采血应仅用于有明确临床和生化证据的库欣综合征患者。
