A possible defect in the inter-conversion between cortisone and cortisol in prepubertal patients with congenital adrenal hyperplasia receiving cortisone acetate therapy

Biomarkers in congenital adrenal hyperplasia

Monitoring of hormone replacement therapy represents a major challenge in the management of congenital adrenal hyperplasia (CAH). In the absence of clear guidance and standardised monitoring strategies, there is no consensus among clinicians regarding the relevance of various biochemical markers used in practice, leading to wide variability in their application and interpretation. In this review, we summarise the published evidence on biochemical monitoring of CAH. We discuss temporal variations of the most commonly measured biomarkers throughout the day, the interrelationship between different biomarkers, as well as their relationship with different glucocorticoid and mineralocorticoid treatment regimens and clinical outcomes. Our review highlights significant heterogeneity across studies in both aims and methodology. However, we identified key messages for the management of patients with CAH. The approach to hormone replacement therapy should be individualised, based on the individual hormonal profile throughout the day in relation to medication. There are limitations to using 17-hydroxyprogesterone, androstenedione and testosterone, and the role of additional biomarkers such 11-oxygenated androgens which are more disease specific should be further established. Noninvasive monitoring via salivary and urinary steroid measurements is becoming increasingly available and should be considered, especially in the management of children with CAH. Additionally, this review indicates the need for large scale longitudinal studies analysing the interrelation between different monitoring strategies used in clinical practice and health outcomes in children and adults with CAH.

One-year clinical evaluation of single morning dose prednisolone therapy for 21-hydroxylase deficiency

Replacement schedules with hydrocortisone (HC) to treat 21OHD are generally unsatisfactory and partially successful regarding growth. Noncompliance is common since its short half-life requires TID administration. Even multiple daily HC doses do not reproduce cortisol chronobiology and may disturb hypothalamic-mediated rhythms. Because synthetic glucocorticoids could improve clinical control, we evaluated the possible benefits of a one-year treatment period with a single morning oral dose of prednisolone (PD) phosphate in 44 patients with 21OHD randomized to two sex and age-matched groups: one (n=23) receiving PD (2.4-3.5 mg/m2 BSA) and the other (n=21) TID HC (10-15 mg/m2 BSA). After one year, bone maturation ratio was kept stable in the PD group (from 1.20 to 1.14), whereas a slight increase was seen in the HC group (from 1.21 to 1.29). Growth velocity (SDS) was preserved in the PD group (from 1.2 to 1.2 in all; 0.79 to 1.13 in pre-pubertals), whereas a slight increase occurred in the pre-pubertal HC-treated patients (from 1.1 to 1.9); height SDS for BA increased significantly in the PD group. Thus, patients with 21OHD treated for one year with a single morning dose of PD appear to achieve a better clinical and hormonal control than those on TID HC, permitting a reduction of the replacement dose. The current PD schedule used by our group (1.5-3 mg/m2 BSA/day) suggests a higher HC:PD bioequivalence ratio of 6-8:1.

Poor response to substitution therapy with cortisone acetate in patients with congenital adrenal hyperplasia

Although cortisone acetate is approved worldwide as corticosteroid substitution therapy in congenital adrenal hyperplasia (21-hydroxylase deficiency), its effectiveness is uncertain since its biologic activity depends on activation by 11β-hydroxysteroid dehydrogenase (11β-HSD). We sought to compare the effect of cortisone acetate with that of hydrocortisone. In 10 patients with congenital adrenal hyperplasia, cortisone acetate was replaced with hydrocortisone in substitution therapy. During this change, blood concentrations of 17-hydroxy-progesterone, adrenocorticotropin (ACTH), and requirements for each drug were monitored. Concentrations of 17-hydroxyprogesterone decreased (mean 10.1 vs. 48.6 ng/ml), as did those of ACTH. Cortisone acetate dose requirements averaged 33.9 mg/m², while hydrocortisone dose requirements averaged only 20.3 mg/m². In one of the patients resistant to cortisone acetate therapy, DNA sequences in the coding regions and promoter of the 11β-HSD gene were analyzed, detecting no genetic abnormalities. Cortisone acetate is inferior to hydrocortisone as substitution therapy in patients with congenital adrenal hyperplasia.

Isozymes of 11 beta-hydroxysteroid dehydrogenase: which enzyme endows mineralocorticoid specificity?

Intracellular enzymes which interconvert circulating hormones between active and inactive forms aid in regulating the biological activity of the ligand in a cell-specific manner. This is particularly important in mineralocorticoid target tissues where glucocorticoids and mineralocorticoids have equivalent affinity for the mineralocorticoid receptor. Inactivation of glucocorticoids at the 11-hydroxyl position by the action of 11 beta-hydroxysteroid dehydrogenase (11 beta-OHSD) permits the occupation of the mineralocorticoid receptor by aldosterone in the presence of much higher levels of circulating cortisol. The suppression of dehydrogenase activity allows glucocorticoids to activate the mineralocorticoid receptor, leading to classical mineralocorticoid type effects such as sodium retention and potassium excretion. A number of 11 beta-OHSDs are currently candidate protectors of the mineralocorticoid receptor. This review examines the attributes of these 11 beta-hydroxysteroid dehydrogenase isozymes and suggests reasons why a high affinity, NAD-dependent enzyme appears to be the most likely candidate to endow specificity on the mineralocorticoid receptor.