Establishment of reference intervals for serum concentrations of androstanediol glucuronide by a newly developed LC-MS/MS method.

BACKGROUND: Androstanediol glucuronide is linked to a range of disorders of peripheral androgen formation and action, such as in hirsutism and acne. Nowadays its accurate quantification is still challenging and there are just a few LC-MS/MS methods available. Besides, their reference intervals for normal European populations by LC-MS/MS, including prepubertal and pubertal children, have not been reported yet. METHODS: Validation of the proposed new methodology was performed at 3 levels in triplicate during 3 different days. Calibration curve concentration ranged from 0.1 to 25microg/L. For method comparison between ELISA and the newly developed LC-MS/MS method, 43 patient samples were tested. A reference interval study was performed with 264 healthy Belgian individuals (108 male and 156 female). RESULTS: Validation of the proposed LC-MS/MS method was satisfactorily achieved, with mean imprecision values lower than 7.4%, mean recoveries within 99-108% and a limit of quantification of 0.059microg/L. Compared to LC-MS/MS, ELISA showed a positive bias in serum samples, providing results 43% higher for the same sample. As a consequence, new reference intervals based on age and gender have been calculated. CONCLUSION: An easy, fast and straightforward LC-MS/MS method for the determination of androstanediol glucuronide has been developed and fully validated. Besides, reference interval for normal European populations, including prepubertal and pubertal children has been established for the first time.