쿠싱증후군 진단에 사용되는 screening and confirmation tests에는 다음 3가지 검사(세실 20판, Williams 13판, 2008 Endocrine Society Clinical Practice guideline)가 있습니다.
해리슨 20판에서는 midnight plasma cortisol이 salivary cortisol과 같이 언급되어 있습니다.
이 3가지 검사는 쿠싱증후군의 screening test이고 LDDST가 confirmation test라고 언급되어 있는 책이 있으나 ,이 검사들 중에 2가지 이상에서 양성이면 쿠싱증후군을 진단할 수 있고 감별 진단을 위한 검사는 그 이후에 시행합니다.
쿠싱증후군 진단 Goldman-Cecil Medicine, 26th edtition
Exogenous administration of glucocorticoid should be excluded before screening for endogenous Cushing syndrome. In the absence of pseudo-Cushing states (see later), at least two different screening test results should be abnormal to establish the diagnosis. Tests for the differential diagnosis of Cushing syndrome should not be used to make the diagnosis. Figure 214-4 is the Endocrine Society's recommended algorithm for testing of patients suspected of having Cushing syndrome.
FIGURE 214-4
Algorithm for testing of patients suspected of having Cushing syndrome (CS).
All statements are recommendations except for those prefaced by “suggest.” Diagnostic criteria that suggest Cushing syndrome are urine free cortisol (UFC) greater than the normal range for the assay, serum cortisol greater than 1.8 µg/dL (50 nmol/liter) after 1 mg dexamethasone (1-mg DST), and late-night salivary cortisol greater than 145 ng/dL (4 nmol/liter). Dex-CRH = dexamethasone–corticotropin-releasing hormone test; DST = dexamethasone suppression test.
(Reprinted with permission from Nieman LK, Biller BM, Findling JW, et al. The diagnosis of Cushing syndrome: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2008;93:1526-1540.)
쿠싱증후군 진단 Harrison's internal medicine, 20th edition
Management of the patient with suspected Cushing’s syndrome. ACTH, adrenocorticotropic hormone; CRH, corticotropin-releasing hormone; CT, computed tomography; DEX, dexamethasone; MRI, magnetic resonance imaging.
A diagnosis of Cushing’s can be considered as established if the results of several tests are consistently suggestive of Cushing’s. These tests may include increased 24-h urinary free cortisol excretion in three separate collections, failure to appropriately suppress morning cortisol after overnight exposure to dexamethasone, and evidence of loss of diurnal cortisol secretion with high levels at midnight, the time of the physiologically lowest secretion (Fig. 379-10). Factors potentially affecting the outcome of these diagnostic tests have to be excluded such as incomplete 24-h urine collection or rapid inactivation of dexamethasone due to concurrent intake of CYP3A4-inducing drugs (e.g., antiepileptics, rifampicin). Concurrent intake of oral contraceptives that raise CBG and thus total cortisol can cause failure to suppress after dexamethasone. If in doubt, testing should be repeated after 4–6 weeks off estrogens. Patients with pseudo-Cushing states, i.e., alcohol-related, and those with cyclic Cushing’s may require further testing to safely confirm or exclude the diagnosis of Cushing’s. In addition, the biochemical assays employed can affect the test results, with specificity representing a common problem with antibody-based assays for the measurement of urinary free cortisol. These assays have been greatly improved by the introduction of highly specific tandem mass spectrometry.
REF. Harrison's internal medicine, 20th edition
Goldman-Cecil Medicine, 26th edition
