Steroid profiling in congenital adrenal hyperplasia: comparing immunoassays and LC-MS/MS accuracy
Shahla Taba-Tabai1, Elif Ozsu2, Sirmen Kizilcan Cetin2
1Department of Pediatrics, Ankara University Faculty of Medicine, Ankara, Türkiye.
Objectives:
Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder caused by defects in enzymes responsible for cortisol synthesis in the adrenal cortex. Accurate steroid hormone measurement is essential for diagnosis and monitoring, but not all metabolites can be reliably quantified by ELISA. Immunoassays and liquid chromatography-tandem mass spectrometry (LC-MS/MS) are commonly used for steroid profiling. This study aimed to compare steroid hormone levels measured by immunoassay and LC-MS/MS and to evaluate their correlation with clinical control in CAH patients.
Methods:
Forty-nine genetically confirmed CAH patients followed at the Pediatric Endocrinology Department were retrospectively reviewed. Demographics, clinical findings, simultaneous steroid hormone measurements by immunoassay and LC-MS/MS, follow-up data, and treatment-related complications were analyzed. Correlations between hormone levels and clinical control were assessed.
Results:
Patients' ages ranged from 0.48 to 21.43 years (mean 10.53 ± 5.90); 31 were girls and 18 boys. Most patients (91.9 %, n=45) had 21-hydroxylase deficiency. Seventy-eight paired steroid measurements were evaluated. No significant differences were observed between LC-MS/MS and immunoassay for 17-hydroxyprogesterone, DHEA-S, cortisol, testosterone, or estradiol; all metabolites were significantly correlated. The smallest inter-method difference was observed for DHEA-S, and the largest for 17-hydroxyprogesterone. Among patient groups classified as clinically well- vs. poorly controlled, only androstenedione differed significantly, serving as the most sensitive marker of inadequate glucocorticoid therapy (p=0.032).
Conclusions:
Steroid hormone measurements by immunoassay and LC-MS/MS were generally consistent in CAH patients. No method showed clear superiority for routine follow-up. Androstenedione emerged as a sensitive marker of clinical control, highlighting its potential utility for optimizing treatment.
