Dried Blood Spot Multiplexed Steroid Profiling Using Liquid Chromatography Tandem Mass Spectrometry in Korean Neonates.

BACKGROUND

Screening for congenital adrenal hyperplasia (CAH) using immunoassays for 17α-hydroxyprogesterone generates many false-positive results. We developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for simultaneous quantification of nine steroid hormones in dried blood spot (DBS) samples, and established reference intervals for these hormones.

METHODS

We examined our method for linearity, precision, accuracy, extraction recovery, and matrix effects and determined the reference intervals of cortisol, 17α-hydroxyproges-terone, 11-deoxycortisol, 21-deoxycortisol, androstenedione, corticosterone, 11-deoxycorticosterone, testosterone, and progesterone in 1,146 DBS samples (from 272 preterm and 874 full-term neonates). Immunoassay and LC-MS/MS methods were compared for 17α-hydroxyprogesterone. Fourteen additional samples were tested to validate the clinical applicability of the LC-MS/MS method.

RESULTS

The linearity range was 2.8-828.0 nmol/L for cortisol and 0.9-40.0 nmol/L for the other steroids (R²>0.99). Intra-day and inter-day precision CVs were 2.52-12.26% and 3.53-17.12%, respectively. Accuracy was 80.81-99.94%, and extraction recovery and matrix effects were 88.0-125.4% and 61.7-74.2%, respectively. There was a negative bias, with higher values measured by immunoassay compared with LC-MS/MS (=0.8104, <0.0001). The LC-MS/MS method was successfully applied to the analysis of nine steroids in DBS for screening and diagnosis of CAH using the 14 additional samples.

CONCLUSIONS

Our method enables highly sensitive and specific assessment of nine steroids from DBS and is a promising tool for clinical analysis of CAH.