Determination of Urinary 17α-Hydroxyprogesterone Excretion Using ELISA

Abstract

The utility of urinary 17 alpha-hydroxyprogesterone (U-17-OHP) in the diagnosis and management of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) was evaluated in 16 patients with 21-OHD. The normal values for U-17-OHP in relation to age and other physiological conditions were investigated in 96 normal subjects and 7 low birth weight infants. Levels of U-17-OHP, serum 17-OHP (S-17-OHP) and urinary free cortisol (U-FC) were simultaneously determined using enzyme-linked immunosolvent assay (ELISA) combined with fractionation by high performance liquid chromatography (HPLC). Pregnanetriol (PT) levels in the same urine specimens were determined using glass capillary gas chromatography (GC). The results were as follows: 1) Normal subjects and low birth weight infants. A significant correlation between U-17-OHP excretions corrected for body surface area (BSA) in 2-h urine specimens and S-17-OHP concentrations at the midpoint of the urine sampling period was observed in normal subjects (r = 0.768, p less than 0.01). Circadian U-17-OHP excretion in 6 adult males was synchronous with that of U-FC. Age-related changes in actual U-17-OHP excretions (Mean +/- SD ng/day) were as follows: neonates: 31.9 +/- 10.3, children aged 2 to 4 years old: 29.1 +/- 14.5, 5 to 8 years old: 68.6 +/- 29.9, 9 to 11 years old: 151.3 +/- 50.0, 12 to 15 years old: 222.7 +/- 82.0, adult males: 400.1 +/- 62.5, adult females (luteal phase): 339.1 +/- 109.7, and adult females (follicular phase): 185.6 +/- 72.3, respectively. Correlation between U-17-OHP and PT excretions in 24-h urine specimens from normal subjects greater than 2 years of age was highly significant (r = 0.871, p less than 0.01). Although U-17-OHP values were measurable in neonates, those of PT were not detectable by GC in the same specimens because of low conversion of 17-OHP to PT. 2) Cases of 21-OHD. In 4 cases of 21-OHD diagnosed in the neonatal period (aged 11 to 15 days, all were of the salt-losing type), the U-17-OHP concentration in a single urine specimen was significantly higher than that of age-matched controls, whereas the PT concentration in one case was low and therefore had no diagnostic value. In 12 patients with 21-OHD receiving suppressive therapy, correlation between S-17-OHP concentrations and 24-h U-17-OHP excretions corrected for BSA was significant (r = 0.847, p less than 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)