Morning salivary 17-hydroxyprogesterone is a useful screening test for nonclassical 21-hydroxylase deficiency

A screening test for nonclassical 21-hydroxylase deficiency (NC 21-OHD) has been established based on early morning salivary 17-hydroxyprogesterone (17-OHP) measurements. Saliva and serum samples were collected simultaneously between 0700 and 1100 h from 57 normal subjects (37 women and 20 men) and from 15 untreated patients (6 women and 9 men) with NC 21-OHD. The salivary (mean ± SD, 524 ± 508 pg/mL) and serum (10, 548 ± 5, 998 pg/mL) 17-OHP concentrations in all 15 patients were unequivocally higher than the levels in normal subjects (saliva, 51 ± 24 pg/mL; serum, 1, 564 ± 787 pg/mL). Salivary 17-OHP levels in patients with NC 21-OHD were significantly higher at 0700-0900 h (828 ± 653 pg/mL) than at 0900-1100 h (314 ± 227 pg/mL), while no such change was found in normal subjects. The salivary 17-OHP concentration was 1.3-6.9% of its serum concentration, and there was an excellent correlation (r = 0.93) between salivary and serum concentration in both normal subjects and patients with NC 21-OHD. In conclusion, early morning salivary 17-OHP measurement is an excellent screening test for the diagnosis of NC 21-OHD, since it accurately reflects serum 17-OHP levels, and sample collection is easy and noninvasive. We propose that salivary 17-OHP determination be used in population screening programs for NC 21-OHD to establish the true frequency of this disease.