ESPE Abstracts

Background: Congenital adrenal hyperplasia (CAH) is an autosomal recessive inherited disorder resulting from a genetic defect in one of the enzymes involved in the synthesis of cortisol from cholesterol in the adrenal cortex. Although steroid hormone levels are used in the diagnosis and monitoring of CAH, not all steroid hormone levels can be measured by ELISA. Steroid hormone levels are measured using immunoassay and liquid chromatography-mass spectrometry (LC-MS). This study aim ed to evaluate the steroid hormone levels used in the follow-up of CAH patients at the Pediatric Endocrinology Department, by comparing immunoassay and LC-MS methods, and to investigate the correlation between these methods and the relationship between steroid hormone levels and clinical control.

Methods: Fourty-nine patients diagnosed with CAH and followed up and treated at the Pediatric Endocrinology were reviewed. Demographic information, auxology data, clinical findings, simultaneous immunoassay and LC-MS results of steroid hormones, follow-up, and complications during treatment were evaluated for each patient. The correlation between steroid hormone levels measured by both methods and clinical control was analyzed.

Results: The age of the patients was between 0.48 and 21.43 years, with a mean age of 10.53±5.90 years. Among the patients (31 girls and 18 boys), 51.0% of the cases were prepubertal and 49% were in the pubertal period. In 45 patients (91.9%), was diagnosed with 21-hydroxylase deficiency. A total of 78 sample results from CAH patients were evaluated. There was no significant difference between the LC-MS and immunoassay values for 17-OHP, DHEA-S, cortisol, testosterone, and estradiol. All steroid hormone results measured by both methods were statistically correlated. The smallest difference between immunoassay and LC-MS values was for DHEA-S, and the largest difference was for 17-OHP. Among the patient groups classified as clinically well-controlled and poorly controlled, a statistically significant difference was found only for androstenedione among the laboratory parameters.

Conclusion: In the laboratory follow-up of CAH patients, we compared the steroid hormone results measured by immunoassay and LC-MS methods. All metabolites measured by both methods were found to be consistent with each other. Our study concluded that neither immunoassay nor LC-MS method had a significant superiority over the other in the follow-up of CAH patients. A statistically significant difference was found only for androstenedione among the laboratory parameters in patient groups classified as clinically well-controlled and poorly controlled.