Endocrine Abstracts

Introduction: Aldosterone synthase participates in the key reactions of aldosterone synthesis – 11-hydroxylation, 18-hydroxylation and, finally, 18-oxidation. In recent works devoted to evaluating the effectiveness of hybrid steroids in the differential diagnosis of subtypes of primary aldosteronism (PA), it is worth emphasizing the experience of using high-performance liquid chromatography – tandem mass spectrometry (HPLC-MS/MS), which allows detecting even very low concentrations in peripheral plasma (the lower limit for 18-oxocortisol is 0.25 ng/dl).

Objective: To evaluate differences in the synthesis of steroid end products by HPLC-MS/MS at PA.

Material and methods: Retrospective evaluation of blood serum samples from 136 patients with a verified diagnosis of primary aldosteronism. In accordance with standard protocols, the parameters of steroidogenesis were evaluated – aldosterone, 18-oxocortisol, 18-hydroxycortisol, 18-hydroxycorticosterone, 20b-dihydrocortisone, cortisone, cortisol, testosterone, 21-deoxycortisol, corticosterone, 11-deoxycortisol, androstenedione, 11-deoxycorticosterone, DHEA, 17-OH progesterone, 17-OH pregnenolone, progesterone, pregnenolone, androstenedione, adrenosterone, 11-hydroxyandrostendione by HPLC–MS/MS.

Results: As part of the study, in 136 patients with aldosterone-producing adenoma (APA) (n=56), idiopathic hyperaldosteronism (IHA) (n=24) and 56 with hormonally inactive tumors (HIT), a study of steroidogenesis was conducted, including the determination of the end products of steroid synthesis – 18-hydroxycortisol, 18-oxocortisol by HPLC–MS/MS. Thus in patients with APA, the levels of 18-oxocortisol, 18-hydroxycortisol, 18-hydroxycorticosterone, pregnenolone, determined by HPLC–MS/MS, were statistically significantly increased compared to the study of those in patients with hormonally inactive tumors (18-Oxocortisol Me(PA) 0.75 [0.13; 1.98] ng/dl, Me(HIT) 0.1 [0.06; 0.14] ng/dl, P< 0.05; 18-Hydroxycortisol Me(PA) 5 [2.52; 10.95] ng/dl, Me(HIT) 2.4 [2; 3.44] ng/dl, P< 0.05; 18-Hydroxycorticosterone Me(PA) 3.48 [1.97; 7.02] ng/dl, Me(HIT) 1.76 [1.25; 2.52] ng/dl, P< 0.05; Pregnenolone Me(PA) 2.22 [1.4; 3.07] ng/dl, Me(HIT) 1.38 [0.98; 2.19] ng/dl, P< 0.05).

Conclusions: Thus, the expediency of determining 18-oxocortisol and 18-hydroxycortisol by HPLC–MS/MS in the differential diagnosis of various forms of PA has been proved.