title: Parallel diurnal fluctuation of testosterone, androstenedione, dehydroepiandrosterone and 17OHprogesterone as assessed in serum and saliva: validation of a novel liquid chromatography-tandem mass spectrometry method for salivary steroid profiling.
abstract: BACKGROUND
  Salivary androgen testing represents a valuable source of biological information. However, the proper measurement of such low levels is challenging for direct immunoassays, lacking adequate accuracy. In the last few years, many conflicting findings reporting low correlation with the serum counterparts have hampered the clinical application of salivary androgen testing. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) makes it possible to overcome previous analytical limits, providing new insights in endocrinology practice.
  
  
  METHODS
  Salivary testosterone (T), androstenedione (A), dehydroepiandrosterone (DHEA) and 17OHprogesterone (17OHP) were extracted from 500µL of saliva, separated in 9.5 min LC-gradient and detected by positive electrospray ionization - multiple reaction monitoring. The diurnal variation of salivary and serum androgens was described by a four paired collection protocol (8 am, 12 am, 4 pm and 8 pm) in 19 healthy subjects.
  
  
  RESULTS
  The assay allowed the quantitation of T, A, DHEA and 17OHP down to 3.40, 6.81, 271.0 and 23.7 pmol/L, respectively, with accuracy between 83.0 and 106.1% for all analytes. A parallel diurnal rhythm in saliva and serum was observed for all androgens, with values decreasing from the morning to the evening time points. Salivary androgen levels revealed a high linear correlation with serum counterparts in both sexes (T: R>0.85; A: R>0.90; DHEA: R>0.73 and 17OHP: R>0.89; p<0.0001 for all).
  
  
  CONCLUSIONS
  Our LC-MS/MS method allowed a sensitive evaluation of androgen salivary levels and represents an optimal technique to explore the relevance of a comprehensive androgen profile as measured in saliva for the study of androgen secretion modulation and activity in physiologic and pathologic states.
authors.affiliation: .
authors.forename: Marco
authors.identifier: http://orcid.org/0000-0001-6748-3041
authors.initials: M
authors.lastname: Mezzullo
authors.affiliation: .
authors.forename: Alessia
authors.initials: A
authors.lastname: Fazzini
authors.affiliation: .
authors.forename: Alessandra
authors.initials: A
authors.lastname: Gambineri
authors.affiliation: .
authors.forename: Guido
authors.initials: G
authors.lastname: Di Dalmazi
authors.affiliation: .
authors.forename: Roberta
authors.initials: R
authors.lastname: Mazza
authors.affiliation: .
authors.forename: Carla
authors.initials: C
authors.lastname: Pelusi
authors.affiliation: .
authors.forename: Valentina
authors.initials: V
authors.lastname: Vicennati
authors.affiliation: .
authors.forename: Renato
authors.initials: R
authors.lastname: Pasquali
authors.affiliation: .
authors.forename: Uberto
authors.initials: U
authors.lastname: Pagotto
authors.affiliation: .
authors.forename: Flaminia
authors.identifier: http://orcid.org/0000-0003-2601-2694
authors.initials: F
authors.lastname: Fanelli
mesh_terms: D019326:17-alpha-Hydroxyprogesterone / Q000097:blood*; D000328:Adult; D000368:Aged; D000735:Androstenedione / Q000097:blood*; D001774:Blood Chemical Analysis / Q000592:standards; D002853:Chromatography, Liquid / Q000592:standards; D002940:Circadian Rhythm; D003687:Dehydroepiandrosterone / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000592:standards*; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone; D000735:Androstenedione; D003687:Dehydroepiandrosterone; D019326:17-alpha-Hydroxyprogesterone
keywords: 17OHProgesterone; androstenedione; dehydroepiandrosterone (DHEA); liquid chromatography-tandem mass spectrometry; saliva; testosterone