Measurement of salivary cortisol with liquid chromatography-tandem mass spectrometry in patients undergoing dynamic endocrine testing

摘要: OBJECTIVE: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) eliminates cross-reactivity, which is a major limitation of immunoassays used for the measurement salivary cortisol (SalC). We aimed to evaluate potential SalC measured by LC-MS/MS in patients undergoing assessment HPA axis. DESIGN AND PATIENTS: Cross-sectional study 78 admitted routine testing specialized endocrine unit. MEASUREMENTS: Matched serum and saliva samples were collected from 68 who had short synacthen test (SST, 250 mcg im) 10 an insulin tolerance (ITT, 0.15 U/kg iv). Serum (SerC) was with automated immunoassay LC-MS/MS. Adequate SerC responses >500 nmol/l. RESULTS: In all adequate responses, relative increase significantly higher than that [6.4(0.3-26.1) vs. 1.0(0.3-4.9), P < 0.0001)]. The SerC-SalC relationship better explained exponential rather linear model (R(2)=0.83 R(2)=0.65, both 0.0001). Based on 59 SST, response defined as 8.3 Seven following SST three ITT showed inadequate SalC, but two CBG deficiency low normal SalC. CONCLUSIONS: have shown excellent diagnostic sensitivity specificity axis superiority over when levels are altered. between supports concept binding capacity saturation.