LC-MS/MS techniques for the analysis of steroid panel in human cerebrospinal fluid

The metabolic processes within the brain are reflected in the cerebrospinal fluid (CSF). It is in close contact with the nervous system, which is both target and source of multiple steroids. The aim of our study was to develop and validate robust, sensitive LC-MS/MS methods with and without derivatization step for the analysis of unconjugated steroids from all major steroid classes in CSF. The validation of the method without derivatization was performed for ten C19- steroids (dehydroepiandrosterone (DHEA), 7α-hydroxyDHEA, 7β-hydroxyDHEA, 7-ketoDHEA, testosterone, epitestosterone, dihydrotestosterone, 11-hydroxytestosterone, 11-ketotestosterone and androstenedione), ten C21- steroids (cortisol, 11-deoxycortisol, 21-deoxycortisol, cortisone, corticosterone, 11-deoxycorticosterone, pregnenolone, progesterone, 17-hydroxyprogesterone, aldosterone) and three C18- steroids (estrone, estradiol, estriol). The method with derivatization is validated for determination of eleven C19- steroids (testosterone, 11-ketodihydrotestosterone, 11-hydroxytestosterone, DHEA, 7α-hydroxyDHEA, 7β-hydroxyDHEA, 7-ketoDHEA, androstenedione, androsterone, epiandrosterone, 7β-hydroxyepiandrosterone) and six C21- steroids (cortisol, cortisone, corticosterone, pregnenolone, 17-hydroxypregnenolone, progesterone) in CSF. The method without derivatization is applicable for the determination of the majority of steroids in CSF, except for pregnenolone, 17-hydroxypregnenolone and DHEA, for which the derivatization method provides better sensitivity. When analyzing CSF samples of normal pressure hydrocephalus (NPH) patients, 11-ketodihydrotestosterone, epitestosterone, androsterone, epiandrosterone, 7β-hydroxyepiandrosterone, 7-ketoDHEA and 21-deoxycortisol were found to be below the LLOQ, suggesting that their presence is very limited. 17-hydroxypregnenolone, and 11-deoxycortisol were quantified for the first time, their CSF levels in NPH subjects are presented. We also observed significantly increased CSF levels of testosterone and 17-hydroxyprogesterone in men compared to women, both with NPH.