Serum Cortisol Assay Performance Following the 1 mg Overnight Dexamethasone Suppression Test

Autor: Jonathan Shaun Atkins, James M Hawley, Laura J Owen, Jonathan Christopher Clayton, Jonathan Scargill, Brian G Keevil
Rok vydání: 2023
Předmět:
Zdroj: Annals of Clinical Biochemistry: International Journal of Laboratory Medicine. :000456322311795
ISSN: 1758-1001
0004-5632
DOI: 10.1177/00045632231179560
Popis: Background: The 1 mg overnight dexamethasone suppression test (ONDST) is recommended for the differential diagnosis of Cushing’s syndrome and the investigation of adrenal incidentalomas. Despite documented variation in serum cortisol immunoassay performance, little has been published regarding its effect on the ONDST. Aims: Assess the performance of three immunoassay platforms (Roche Elecsys II, Abbott Alinity & Siemens Centaur) when compared to a liquid chromatography tandem mass spectrometry (LC-MS/MS) method. Methods: Samples (n=77) sent to the laboratory as part of an ONDST were retrieved prior to disposal, anonymised, and analysed on all platforms. Samples with factors impacting immunoassay analysis quality were excluded. Results were statistically compared to an LC-MS/MS method that previously demonstrated excellent comparability to a candidate reference method. Results: The Roche gen II showed a mean bias of -2.4 nmol/L and a Passing-Bablok fit of y = -0.9 + 0.97x. This was not affected by sex. The Abbott showed a mean bias -18.8 nmol/L, and a fit of y = -11.3 + 0.88x. This bias was -20.7 nmol/L in females vs -17.2 nmol/L in males. The Siemens had a mean bias of 2.3 nmol/L and a fit of y = 1.4 + 1.07x. This bias was 5.7 nmol/L in males vs -1.0 nmol/L in females. Conclusions: Clinicians should be aware of the method-dependent variation that exists within serum cortisol analysis during the ONDSTs. Roche and Siemens aligned more closely with LC-MS/MS while the Abbot may cause a reduction in ONDST sensitivity. This data supports assay-specific cut-offs for the ONDST.
Databáze: OpenAIRE
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