Improved Performance of Newborn Screening for Congenital Adrenal Hyperplasia Using 21-deoxycortisol Measurement

Area of Science:

• Endocrinology
• Biochemistry
• Neonatal Medicine

Background:

• Newborn screening for 21-hydroxylase deficiency congenital adrenal hyperplasia (CAH) often yields high false-positive rates.
• Second-tier testing using liquid chromatography-mass spectrometry can enhance the specificity of CAH screening.

Purpose of the Study:

• To evaluate multiple screening algorithms for optimizing the detection of salt-wasting CAH (SW-CAH).
• To improve the accuracy and efficiency of newborn screening for CAH.

Main Methods:

• Analysis of 1710 immunoassay-positive samples using a second-tier steroid profile.
• Application of principal components analysis to identify potential steroid biomarker combinations.
• Utilizing Monte Carlo simulation to assess algorithm performance and cutoffs.

Main Results:

• An optimal 3-component algorithm identified all 8 SW-CAH cases with 100% sensitivity and 70% positive predictive value.
• The algorithm correctly identified 13 of 13 historical SW-CAH cases and 6 of 6 SV-CAH cases.
• Low 21-deoxycortisol levels effectively filtered out other forms of CAH.

Conclusions:

• A 3-component algorithm incorporating 21-deoxycortisol significantly enhances newborn screening for SW-CAH.
• This approach reduces the burden on patients and the healthcare system by improving diagnostic accuracy.
• The algorithm is optimized for high sensitivity and positive predictive value for life-threatening SW-CAH.