Suggested Cutoff Point for Testosterone by Liquid Chromatography with Tandem Mass Spectrometry (LC-MS/MS) after Stimulation with Recombinant Human Chorionic Gonadotropin

The human chorionic gonadotropin (hCG) stimulation test that evaluates gonadal steroidogenesis is crucial in the assessment of patients with 46,XY disorders of sex development (DSD). This study aimed to determine a testosterone (T) cutoff level that indicates an adequate testicular function using LC-MS/MS after stimulation with recombinant human chorionic gonadotropin (rhCG) in a single dose. Nineteen prepubertal children with 46,XY DSD and normal T secretion were evaluated. T and dihydrotestosterone (DHT) levels were measured by liquid chromatography technique with tandem mass spectrometry (LC-MS/MS) before and 7 days after rhCG application at 250 µg. We suggest 0.89 ng/mL as the cutoff point for T after rhCG stimulation analyzed by LC-MS/MS.

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Human chorionic gonadotropin stimulation gives evidence of differences in testicular steroidogenesis in Klinefelter syndrome, as assessed by liquid chromatography–tandem mass spectrometry

Acta Endocrinologica ◽

10.1530/eje-15-1224 ◽

2016 ◽

Vol 174 (6) ◽

pp. 801-811 ◽

Cited By ~ 18

Author(s):

S Belli ◽

D Santi ◽

E Leoni ◽

E Dall’Olio ◽

F Fanelli ◽

...

Keyword(s):

Mass Spectrometry ◽

Liquid Chromatography ◽

Tandem Mass Spectrometry ◽

Chorionic Gonadotropin ◽

Human Chorionic Gonadotropin ◽

Klinefelter Syndrome ◽

Tandem Mass ◽

Chromatography Tandem Mass Spectrometry ◽

Liquid Chromatography Tandem Mass ◽

Testicular Steroidogenesis

Background Men with Klinefelter syndrome (KS) show hypergonadotropic hypogonadism, but the pathogenesis of hypotestosteronemia remains unclear. Testicular steroidogenesis in KS men was evaluated over three decades ago after human chorionic gonadotropin (hCG) stimulation, but inconclusive results were obtained. Intriguingly, some recent studies show increased intratesticular testosterone concentrations in men with KS. Objective To analyze serum steroid profile, as a proxy of testicular steroidogenesis, after hCG stimulation in KS compared with control men. Design A prospective, longitudinal, case–control, clinical trial. Methods Thirteen KS patients (36±9 years) not receiving testosterone (TS) replacement therapy and 12 eugonadic controls (32±8 years) were enrolled. Serum steroids were measured by liquid chromatography–tandem mass spectrometry (LC–MS/MS) at baseline and for five consecutive days after intramuscular injection of 5000IU hCG. Results Progesterone (P), 17-hydroxyprogesterone (17OHP), TS, and estradiol (E2) showed a significant increase (P<0.001) after hCG stimulation in both groups. On the contrary, androstenedione (AS) and dehydroepiandrosterone did not increase after hCG stimulation. The 17OHP/P ratio increased in both groups (P<0.001), the TS/AS ratio (17β-hydroxysteroid dehydrogenase type 3 (17βHSD3) activity) did not increase after hCG in any group, and the E2/TS ratio (aromatase activity) increased significantly in both groups (P=0.009 in KS and P<0.001 in controls). Luteinizing hormone decreased after hCG in both groups (P=0.014 in KS and P<0.001 in controls), whereas follicle-stimulating hormone decreased only in control men (P<0.001). Conclusion This study demonstrates for the first time using LC–MS/MS that Leydig cells of KS men are able to respond to hCG stimulation and that the first steps of steroidogenesis are fully functional. However, the TS production in KS men is impaired, possibly related to reduced hydroxysteroid deydrogenase activity due to an unfavorable intratesticular metabolic state.

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