Evaluation of an automated chemiluminescent immunoassay for salivary cortisol measurement. Utility in the diagnosis of Cushing's syndrome

REPETTO, ESTEBAN M.; GONZALEZ, DIEGO; JACOBSEN, DARIO; SMITHUIS, FERNANDO; JAMARDO, JUAN; CANO, MARIEL; ARANDA, CLAUDIO; ONETO, ADRIANA; BERG, GABRIELA; FABRE, BIBIANA

CLINICAL CHEMISTRY AND LABORATORY MEDICINE

WALTER DE GRUYTER & CO

Año: 2017 vol. 55 p. 65 - 68

1434-6621

The aim of the current study was to validate an automated chemiluminescent immunoassay for cortisol quantification in saliva and to determine the cut-off level for Cushing´s Syndrome diagnosis in an adult population. The salivary cortisol levels from healthy individuals and patients previously diagnosed with Cushing´s Syndrome were measured with Siemens Immulite 2000 ® automatic chemiluminescent enzyme-immunoassay analyser with a brief modification. The limit of quantification was 3,4 nmol/L. The assay also demonstrated a high level of accuracy, as determined by linearity under dilution and recovery tests. Using this methodology, levels higher than 5.7 nmol/L is indicative of Cushing´s Syndrome with a diagnostic sensitivity and specificity of 90,5% and 97.4% respectively. The assay validated in the present study could be used in the clinical laboratories for the evaluation of cortisol levels in patients in which Cushing´s Syndrome is suspected.