Androgens by immunoassay and mass spectrometry in children with 46,XY disorder of sex development

in Endocrine Connections
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  • 1 L de Oliveira, Pediatrics, Federal University of Uberlandia, Uberlandia, Brazil
  • 2 C Longui, Pediatrics , Irmandade da Santa Casa de Misericórdia de São Paulo, São Paulo, Brazil
  • 3 G Guaragna-Filho, Pediatrics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
  • 4 J Costa, School of Pharmaceutical Sciences, State University of Campinas, Campinas, Brazil
  • 5 R Lanaro, Poison Control center, State University of Campinas, Campinas, Brazil
  • 6 D Silva, Laboratory of Physiology, State University of Campinas, Campinas, Brazil
  • 7 M Chiamolera, Laboratory, Fleury Group, Sao Paulo, Brazil
  • 8 M de Mello, Center for Molecular Biology and Genetic Engineering, State University of Campinas, Campinas, 13083-875, Brazil
  • 9 A Morcillo, Pediatrics, State University of Campinas, Campinas, Brazil
  • 10 A Maciel-Guerra, Medical Genetics, State University of Campinas, Campinas, 13083-887, Brazil
  • 11 G Guerra Júnior, Pediatrics, State University of Campinas, Campinas, 13083-887, Brazil

Correspondence: Gil Guerra Júnior, Email: gilguer@unicamp.br

Objective: Steroid measurement is a challenge in pediatric endocrinology. Currently, liquid chromatography with tandem mass spectrometry (LC-MS/MS) is considered a gold standard for this purpose. The aim of this study was to compare both LC-MS/MS and immunoassay (IA) for androgens before and after human recombinant chorionic gonadotropin (r-hCG) stimulus in children with 46,XY Disorders of Sex Development (DSD).

Methods: Nineteen patients with 46,XY DSD were evaluated; all of them were prepubertal and non gonadectomized. Testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA) and androstenedione were measured by IA and LC-MS/MS before and 7 days after rhCG injection. The correlation between IA and LC-MS/MS was analysed by the intraclass correlation coefficient (ICC) and Spearman's rank correlation coefficient (SCC). For concordance analysis the Passing and Bablok (PB) regression and the Bland and Altman (BA) method were used.

Results: Testosterone showed excellent correlation (ICC = 0.960 and SCC = 0.964); DHT showed insignificant and moderate correlations as indicated by ICC (0.222) and SCC (0.631), respectively; DHEA showed moderate correlation (ICC = 0.585 and SCC = 0.716); and androstenedione had poor and moderate correlations in ICC (0.363) and SCC (0.735), respectively. Using the PB method, all hormones showed a linear correlation, but proportional and systematic concordance errors were detected for androstenedione, systematic errors for testosterone and no errors for DHEA and DHT. By the BA method, there was a trend of IA to overestimate testosterone and androstenedione and underestimate DHEA and DHT when compared to LC-MS/MS.

Conclusion: Traditional IA should be replaced by LC-MS/MS for the androgens measurement in prepubertal children whenever is possible.

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