Analysis of 21‐deoxycortisol, a marker of congenital adrenal hyperplasia, in blood by atmospheric pressure chemical ionization and electrospray ionization using multiple reaction monitoring

Abstract

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder mainly caused by 21-hydroxylase deficit (21-OHD). Deletions or mutations of the CYP21 gene induce the impairment of glucocorticoid and mineralcorticoid synthesis. 17-Hydroxyprogesterone (17-OHP) is the hormonal marker in patients, but not in the heterozygous subjects. Excess 17-OHP is hydroxylated into 21-deoxycortisol (21-DF), and therefore 21-DF can be used as a specific marker for diagnosis of heterozygous individuals. We report an analytical method for analysis of 21-DF in blood samples using electrospray (ESI) and atmospheric pressure chemical ionization (APCI), showing that ESI is very sensitive for the analysis of this marker molecule. The multiple reaction monitoring (MRM) approach was used to increase the specificity and the sensitivity of the method.

Concurrent Confirmation and Differential Diagnosis of Congenital Adrenal Hyperplasia from Dried Blood Spots: Application of a Second-Tier LC-MS/MS Assay in a Cross-Border Cooperation for Newborn Screening

“…Previously, the analysis of 21-Deox and 11-Deox and the differential diagnosis of CAH have almost exclusively been performed using serum samples [9,10,11,12] or urine [13,14,15]. However, the DBS, not serum or urine, is the standard sample type in newborn screening, due to its advantages, including the ease of sample collection, transportation, storage and stability [23].…”

“…This requires separation of the isobaric analytes 21-deoxycortisol (21-Deox) and 11-deoxycortisol (11-Deox), specific to these two forms of CAH [1,2,3]. Most previous assays for 21-Deox and 11-Deox did not allow an analysis of DBSs [9,10,11,12,13,14,15], and those which did achieved acceptable but not baseline resolution of these isobaric compounds [16,17]. …”

Surface‐activated chemical ionization ion trap mass spectrometry in the analysis of 21‐deoxycortisol in blood

“…22 Thus, under these conditions, both the linearity range and the limit of quantitation (LOQ) of the technique could be significantly different. The data reported here suggest that the fast LC/SACI-MRM method employed for the analysis of 21-DF has performance similar to the LC/ ESI-MRM method previously developed 17 in terms of LOD but higher performance in terms of linearity range when aqueous solutions of pure standard are analyzed. Furthermore, it Scheme 1.…”

“…For these reasons, it could be used in conjunction with the LC/ESI-MRM approach 17 for the detection of heterozygous individuals.…”

“…New methods for the measurement of 21-DF in plasma have recently been described. [14][15][16][17] In particular, a highly sensitive method based on electrospray ionization (ESI) coupled to an ion trap mass analyzer with multiple reaction monitoring (MRM) 17 has been developed; this method has a low limit of detection (LOD) and good linearity range, and can be used for the quantitative analysis of 21-DF. Recently, a new high sensitivity ionization technique named surfaceactivated chemical ionization (SACI) has been described.…”