Urinary 17α‐hydroxyprogesterone in management of 21 ‐hydroxylase deficiency

Objectives: The study was designed to assess the reliability of measurement of 24-hour urinary 17α-hydroxyprogesterone (17-OHP) by radio-immunoassay (RIA) as an alternative biochemical assessment for monitoring the treatment of congenital adrenal hyperplasia (CAH) due to 21 -hydroxylase deficiency (21 -OHD) and to assess the need for sample purification by column chromatography to improve assay specificity. Methodology: Morning serum 17-OHP was measured using RIA and 24-hour urinary pregnanetriol using gas chromatography. Twenty-four-hour urinary 17-OHP was measured in samples from 17 prepubertal patients with CAH due to 21 -OHD, and 20 normal prepubertal children as controls. In 24 urine samples, RIA of 17-OHP was performed with and without column chromatography. Results: There was a good correlation between 24-hour urinary 17-OHP and 24-hour urinary pregnanetriol (r = 0.962, P<0.01) and between 24-hour urinary 17-OHP and morning serum 17-OHP (r= 0.955, P<0.01). There was no significant difference in the RIA of the urine samples with and without purification by column chromatography. Conclusions: The measurement of 24-hour urinary 17-OHP is a reliable alternative for the biochemical monitoring of 21-OHD, and RIA specificity is unaffected by omission of column chromatography.