SALIVARY 17α-HYDROXYPROGESTERONE IN CONGENITAL ADRENAL HYPERPLASIA

A specific radioimmunoassay having the sensitivity (4 pg/tube) and precision required for the routine determinations of 17α-hydroxyprogesterone concentrations in mixed whole saliva, parotid fluid and plasma has been developed. The correlation between 17α-hydroxyprogesterone concentrations in matched samples of saliva and parotid fluid was excellent (r = 0.98): therefore saliva, being easier to collect, was used exclusively in later studies. The median 17α-hydroxyprogesterone concentration in mixed whole saliva collected from thirty-two healthy children was 390 pmol/litre ranging from 90–1520 pmol/litre. In a group (n=14) of treated CAH patients having a C21 hydroxylase deficiency, 17α-hydroxyprogesterone showed a 20 fold greater variation, ranging from 67 pmol/litre in patients receiving excessive glucocorticoid dosage to 26300 pmol/litre in inadequately treated patients. A close correlation (r = 0.91) in 17α-hydroxyprogesterone levels was observed in matched samples of saliva and plasma collected between 09.00 and 10.00 h from these patients. Concentrations of 17α-hydroxyprogesterone in saliva therefore could well replace those in plasma for monitoring treatment of these patients. Matched samples of mixed whole saliva, parotid fluid and plasma were also collected from one inadequately treated female patient at frequent intervals over a 24 h period. Two other patients, one male and one female, collected matched samples at 30 min intervals for 4 h following Synacthen stimulation. The pattern of 17α-hydroxyprogesterone in these samples suggests that salivary steroid concentrations are of potential value in assessing endocrine function in conditions such as CAH, where frequent sampling over prolonged periods is required.