Multicentre Evaluation of an Enzyme-Immunoassay for Cortisol Determination

Abstract

The present paper describes a multicentre evaluation of a one step enzyme-immunoassay for the determination of cortisol in serum or plasma. Data from the investigation were analysed in terms of imprecision, detection limit, and correlation with other test methods.Within-run and between-run imprecisions (coefficient of variation) of Enzymun-Test® Cortisol were less than 8% and 12%, respectively. The detection limit was 30 nmol/1 (11 g/l). With the exception of prednisolone, only low interference was found with other endogenous steroids. A good correlation between Enzymun-Test® Cortisol and HPLC, LIA, FPIA and RIA was registered, although the latter two methods showed a scattering of regression lines from the different evaluators.The results show that Enzymun-Test® Cortisol can be recommended as an alternative for the measurement of cortisol. As the method is calibrated against isotope dilution-mass spectrometry, results obtained with Enzymun-Test® Cortisol are in agreement with the reference method.

Development and validation of a fast and sensitive bioanalytical method for the quantitative determination of glucocorticoids—Quantitative measurement of dexamethasone in rabbit ocular matrices by liquid chromatography tandem mass spectrometry

“…Various analytical methods have been reported in literature to estimate GC concentrations in biological samples. These include high performance liquid chromatography (HPLC) [11, 12] gas chromatography [13, 14], radioimmunoassay (RIA) [15] and capillary separations coupled with various detectors [16, 17]. HPLC technique utilizing ultra-violet (UV) detection suffers from disadvantages such longer retention time, tedious extraction procedure and inadequate limit of quantitation (LOQ) [18].…”

“…Though fluorescence and gas chromatography are highly sensitive they require derivatization steps which are time consuming [12]. RIA usually suffers from cross-reactivity and hence resulting in lack of adequate selectivity for GC [15, 20]. …”

Development of a sensitive and selective method for the quantitative analysis of cortisol, cortisone, prednisolone and prednisone in human plasma

“…Radioimmunoassay methods are usually impacted by crossreactivity, thus lacking adequate selectivity between cortisol and prednisolone [21,22]. GC-MS and fluorescence methods employ derivatization steps which are time consuming [13,15,23].…”

Use of corticosteroid therapy in patients with sepsis and septic shock: An evidence-based review

“…Second, a consensus concerning reference values for baseline and stimulated cortisol concentrations is missing (see above). Proposed cut-off points may depend on different methods used to measure cortisol, with variations when compared with high performance liquid chromatography as the reference method (64). In addition, free cortisol or an increase in free cortisol in response to ACTH could increase accuracy of adrenocortical function tests (53).…”