Searchable abstracts of presentations at key conferences in endocrinology
Endocrine Abstracts (2012) 29 P66

ICEECE2012 Poster Presentations Adrenal cortex (113 abstracts)

Comparison of salivary cortysol by chemiluminensce and mass spectometry in hypercortilosism

G. Marcelli , C. Concettoni , V. Scocco , M. Brugia , G. Tirabassi , L. Trementino , M. Boscaro & G. Arnaldi


Ospedali Riuniti, Ancona, Italy.


BACKGROUND: The determination of Night Salivary Cortisol (NSC) is a useful survey in the screening for hypercortilosism. Study data about its usefulness, even when different methods of dosage are used, are anyway scarce.

OBJECTIVE: To compare the diagnostic performance in the NSC dosage of the chemiluminescence method (CLIA) and of mass spectrometry (LC-MS/MS).

METHODS: Saliva samples were taken at 11:00 pm in 36 healthy volunteers and in 10 patients with Cushing’s syndrome at the diagnosis. Each subject provided 2 saliva samples which were used for the NCS dosage by CLIA and with LC-MS/MS.

RESULTS: The controls had NSC values in LC-MS/MS (0.89l±0.37 ng/ml; range 0.10–1.89) significantly lower than the Cushing ones (3.18l±1.86 ng/ml; range 0.98–6.19); the same using CLIA: the NCS in the controls (0.40±0.22 mcg/dl; range 0.18–1.05) was significantly lower than the Cushing ones (1.43±0.66 mcg/dl; range 0.02–2.29). The diagnostic performance in LC-MS/MS [AUC 0.94 (0.86–1.02] was a bit higher than that of the CLIA [AUC 0.89 (0.71–1.07)]. The cutoff able to guarantee the highest sensitivity and specificity was calculated through the ROC curve, and it was to 1.2 ng/ml in LC-MS and 0.58 mcg/dl in CLIA. In LC-MS/MS a 90% sensitivity and a 88% specificity were obtained; for CLIA, a 90% sensitivity and a 84.8% specificity; if the cut off provided from the lab was used (0.2 mcg/dl), an unacceptably low performance was obtained. The values in CLIA related significantly to those in LCMS/MS (r 0.9).

CONCLUSIONS: This is the first study which compares a CLIA method with a method such as LC-MS/MS. Our data demonstrate that the cutoffs are highly influenced by the method being used. The analyzed methods can have a similar performance, provided the cutoffs are redefined in the single labs.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.

Volume 29

15th International & 14th European Congress of Endocrinology

European Society of Endocrinology 

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