Comparison of multiple steroid concentrations in serum and dried blood spots throughout the day of patients with congenital adrenal hyperplasia

Abstract

Background/aim: periodic measurement of plasma concentrations of cortisol precursors on a clinic visit may be of limited value in patients with congenital adrenal hyperplasia because it does not reflect a patient's circadian patterns of adrenal steroid secretion. Steroid profiling in dried blood spots (DBS) may allow for more frequent and sensitive monitoring.

Methods: we compared the agreement between 17α-hydroxyprogesterone (17-OHP) and androstenedione (D4A) levels determined from DBS samples and concurrently collected serum samples. Blood was drawn from 9 congenital adrenal hyperplasia patients every 4 h over a 24-hour period. Serum and DBS steroid levels were measured by liquid chromatography tandem mass spectrometry.

Results: DBS determinations of 17-OHP overestimated corresponding serum levels (mean difference 1.67 ng/ml), and underestimated D4A serum levels (mean difference 0.84 ng/ml). However, the DBS assay yielded excellent agreement (97%) with serum 17-OHP, but did considerably poorer for D4A (31%).

Conclusions: our results indicate an excellent agreement between DBS and serum 17-OHP measurements to identify the peaks and troughs associated with an individual's circadian pattern. Larger-scale studies are required to evaluate the utility of DBS for home monitoring and to determine if more frequent monitoring leads to improved clinical outcomes.

Fig. 1

Serum and DBS measurements of 17-OHP over a 24-hour period in patient 3 (a) and 6 (b). Black arrows indicate the time the patient took hydrocortisone. Both patients took fludrocortisone with morning hydrocortisone dose (approximately 8 a.m.). FP = Filter paper.

Fig. 2

Serum and DBS measurements of D4A over a 24-hour period in patient 3 (a) and 6 (b).