Bloodspot 17 alpha-hydroxyprogesterone radioimmunoassay for diagnosis of congenital adrenal hyperplasia and home monitoring of corticosteroid replacement therapy.

A convenient and inexpensive radioimmunoassay for bloodspot 17 alpha-hydroxyprogesterone (17-OHP) has been evaluated in the screening of newborn infants for congenital adrenal hyperplasia (CAH) and for home monitoring of CAH patients on steroid replacement therapy. In the screening study, analysis of 491 bloodspots taken for routine screening programmes for phenylketonuria and hypothyroidism established the upper limit of normal for infants aged 5-10 days as 64 nmol 17-OHP/l blood (99.9 centile). Home monitoring of patients by examination of fingerprick bloodspot 17-OHP profiles taken by parents over Saturday and Sunday on consecutive weekends showed that changes in control occurred as a result of transition from inpatient to outpatient treatment or following adjustment of steroid replacement regimens. The method was found to be valuable in the diagnosis and management of children with CAH.