Salivary 17-OH-Progesterone , 96 Wells
An enzyme immunoassay for the quantitative in vitro diagnostic measurement of active free 17-hydroxyprogesterone in saliva.
The steroid 17-α-Hydroxyprogesterone (17-α-OHP) is produced by both the adrenal cortex and gonads. Even though 17-α-OHP has relatively little progestational activity, it is of intense clinical interest because it is the immediate precursor to 11-desoxycortisol (Cpd-S). Because Cpd-S is produced by 21-hydroxylation of 17-α-OHP, measurement of 17α-OHP is a useful indirect indicator of 21-hydroxylase activity. In congenital 21-hydroxylase deficiency, the most common variety
of Congenital Adrenal Hyperplasia (CAH), 17-α-OHP is secreted in abundant excess. It is moderately elevated in the 11-β-hydroxylase deficiency as well. Measurement of 17-α-OHP is therefore valuable in the initial diagnosis of CAH.
Adult non-pregnant women:
In adult non-pregnant women in the childbearing age group, 17-α-OHP concentrations vary over the menstrual cycle with luteal phase concentrations being higher than follicular phase concentrations. This is because 17-α-OHP is secreted parallel with progesterone from maturing follicles or from the corpus luteum. There is also a diurnal variation of 17-α-OHP concentrations.
This rhythm is parallel with adrenal cortisol secretion such that maximum 17-α-OHP concentrations are measured in samples obtained in the morning.
Congenital adrenal hyperplasia:
The principal application of the 17-α-OHP is in the diagnosis of CAH in newborns with ambiguous genitalia and in virilized adolescent girls. Since 17-α-OHP is the immediate precursor to 11-desoxycortisol, basal 17-α-OHP concentrations are sharply elevated in patients with 21-hydroxylase deficiency and to a lesser degree in patients with 11-hydroxylase deficiency.
Because 17-α-OHP concentrations are so markedly elevated in newborns and adolescent girls afflicted with CAH, a single basal measurement is all that is normally required to make the diagnosis.
Late onset adrenal hyperplasia:
More recently, 17-α-OHP concentrations have been utilized in the evaluation of androgenized women where late onset 21-hydroxylase is suspected. This condition is clinically very subtle and since the presentation is the same as classical polycystic ovarian disease, basal plasma 17-α-OHP concentrations, unlike classical congenital adrenal hyperplasia, are normal. The diagnosis is made by administration of an ACTH stimulation test.