EVALUATION OF AN AUTOMATED CHEMILUMINESCENT IMMUNOASSAY FOR SALIVARY CORTISOL MEASUREMENT. UTILITY IN THE DIAGNOSIS OF CUSHING?S SYNDROME

REPETTO EM; GONZALEZ D; JACOBSEN, D; SMITHUIS F; JAMARDO, J; CANO, M; ARANDA C; ONETO A; BERG, G; FABRE B

CLINICAL CHEMISTRY AND LABORATORY MEDICINE

WALTER DE GRUYTER & CO

Lugar: Berlin; Año: 2017

1434-6621

Saliva is a biological fluid easy to obtain with non-invasive procedures in a stress-free way compared to the collection of serum for the determination of hormone levels. It has been suggested that measurement of salivary cortisol levels is more appropriate for the clinical assessment of adrenocortical function. In fact, determination of late-night salivary cortisol concentration is recommended for the screening of patients with suspected Cushing´s Syndrome (CS). Automated systems have a rapid turn-around time on a large number of samples and have demonstrated high analytical accuracy. Given that salivary cortisol levels are a valuable indicator of the activity of the hypothalamic-pituitary-adrenocortical axis [3], its determination by automated systems may allow a broader use of this diagnostic tool.The aim of this study was to validate an automated chemiluminescent immunoassay (CLIA), Siemens Immulite 2000® analyser (Gwynedd, United Kingdom), for the measurement of salivary cortisol and to compare it with the electrochemiluminiscent immunoassay (ECLIA), Roche Cobas e-411 (Mannheim, Germany), which has been validated by the manufacturer for the measurement of salivary cortisol. In order to validate the assay we evaluated limit of blank (LOB), limit of detection (LOD) and limit of quantification (LOQ), precision, linearity, recovery and we performed the method comparison. We have also determined the cut-off level for salivary cortisol by CLIA in CS diagnosis in an adult population