Failure of cortisone acetate treatment in congenital adrenal hyperplasia because of defective 11beta-hydroxysteroid dehydrogenase reductase activity

Towards the tailoring of glucocorticoid replacement in adrenal insufficiency: the Italian Society of Endocrinology Expert Opinion

CONTEXT

Glucocorticoid (GC) replacement therapy in patients with adrenal insufficiency (AI) is life saving. After over 50 years of conventional GC treatment, novel formulations are now entering routine clinical practice.

METHODS

Given the spectrum of medications currently available and new insights into the understanding of AI, the authors reviewed relevant medical literature with emphasis on original studies, prospective observational data and randomized controlled trials performed in the past 35 years. The Expert Opinion of a panel of selected endocrinologists was sought to answer specific clinical questions. The objective was to provide an evidence-supported guide, for the use of GC in various settings from university hospitals to outpatient clinics, that offers specific advice tailored to the individual patient.

RESULTS

The Panel reviewed available GC replacement therapies, comprising short-acting, intermediate and long-acting oral formulations, subcutaneous formulations and the novel modified-release hydrocortisone. Advantages and disadvantages of these formulations were reviewed.

CONCLUSIONS

In the Panel's opinion, achieving the optimal GC timing and dosing is needed to improve the outcome of AI. No-single formulation offers the best option for every patients. Recent data suggest that more emphasis should be given to the timing of intake. Tailoring of GS should be attempted in all patients-by experts-on a case-by-case basis. The Panel identified specific subgroups of AI patients that could be help by this process. Long-term studies are needed to confirm the short-term benefits associated with the modified-release GCs. The impact of GC tailoring has yet to be proven in terms of hospitalization rate, morbidity and mortality.

Clinical perspectives in congenital adrenal hyperplasia due to 11β-hydroxylase deficiency

Congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency is a rare autosomal recessive genetic disorder. It is caused by reduced or absent activity of 11β-hydroxylase (CYP11B1) enzyme and the resultant defects in adrenal steroidogenesis. The most common clinical features of 11 beta-hydroxylase deficiency are ambiguous genitalia, accelerated skeletal maturation and resultant short stature, peripheral precocious puberty and hyporeninemic hypokalemic hypertension. The biochemical diagnosis is based on raised serum 11-deoxycortisol and 11-deoxycorticosterone levels together with increased adrenal androgens. More than 100 mutations in CYP11B1 gene have been reported to date. The level of in-vivo activity of CYP11B1 relates to the degree of severity of 11 beta-hydroxylase deficiency. Clinical management of 11 beta-hydroxylase deficiency can pose a challenge to maintain adequate glucocorticoid dosing to suppress adrenal androgen excess while avoiding glucocorticoid-induced side effects. The long-term outcomes of clinical and surgical management are not well studied. This review article aims to collate the current available data about 11 beta-hydroxylase deficiency and its management.

Nonclassic congenital adrenal hyperplasia due to 21-hydroxylase deficiency: clinical presentation, diagnosis, treatment, and outcome

Nonclassic congenital adrenal hyperplasia (NCAH) is one of the most frequent autosomal recessive disorders in man with a prevalence ranging from 0.1 % in Caucasians up to a few percent in certain ethnic groups. Most cases are never diagnosed due to very mild symptoms, misdiagnosing as polycystic ovary syndrome, or ignorance. In contrast to classic CAH, patients with NCAH present with mild partial cortisol insufficiency and hyperandrogenism and will survive without any treatment. Undiagnosed NCAH may result in infertility, miscarriages, oligomenorrhea, hirsutism, acne, premature pubarche, testicular adrenal rest tumors, adrenal tumors, and voice problems among other symptoms. A baseline measurement of 17-hydroxyprogesterone can be used for diagnosis, but the ACTH stimulation test with measurement of 17-hydroxyprogesterone is regarded as the golden standard. The diagnosis can be verified by CYP21A2 mutation analysis. Treatment is symptomatic and usually with glucocorticoids alone. The lowest possible glucocorticoid dose should be used. Long-term treatment with glucocorticoids will improve the symptoms but will also result in iatrogenic cortisol insufficiency and may also lead to long-term complications such as obesity, insulin resistance, hypertension, osteoporosis, and fractures. Although the complications seen in NCAH patients have been assumed to be related to the glucocorticoid treatment, some may, in fact, be associated with prolonged hyperandrogenism. Different risk factors and negative consequences should be monitored regularly in an attempt to improve the clinical outcome. More research is needed in this relatively common disorder.

Dual-release Hydrocortisone in Addison's Disease - A Review of the Literature

In patients with adrenal insufficiency, glucocorticoids (GCs) are insufficiently secreted and GC replacement is essential for health and, indeed, life. Despite GC-replacement therapy, patients with adrenal insufficiency have a greater cardiovascular risk than the general population, and suffer from impaired health-related quality of life. Although the aim of the replacement GC therapy is to reproduce as much as possible the physiological pattern of cortisol secretion by the normal adrenal gland, the pharmacokinetics of available oral immediate-release hydrocortisone or cortisone make it impossible to fully mimic the cortisol rhythm. Therefore, there is an unmet clinical need for the development of novel pharmaceutical preparations of hydrocortisone, in order to guarantee a more physiological serum cortisol concentration time-profile, and to improve the long-term outcome in patients under GC substitution therapy.

Therapy of endocrine disease: Perspectives on the management of adrenal insufficiency: clinical insights from across Europe

BACKGROUND

Conventional glucocorticoid (GC) replacement for patients with adrenal insufficiency (AI) is inadequate. Patients with AI continue to have increased mortality and morbidity and compromised quality of life despite treatment and monitoring.

OBJECTIVES

i) To review current management of AI and the unmet medical need based on literature and treatment experience and ii) to offer practical advice for managing AI in specific clinical situations.

METHODS

The review considers the most urgent questions endocrinologists face in managing AI and presents generalised patient cases with suggested strategies for treatment.

RESULTS

Optimisation and individualisation of GC replacement remain a challenge because available therapies do not mimic physiological cortisol patterns. While increased mortality and morbidity appear related to inadequate GC replacement, there are no objective measures to guide dose selection and optimisation. Physicians must rely on experience to recognise the clinical signs, which are not unique to AI, of inadequate treatment. The increased demand for corticosteroids during periods of stress can result in a life-threatening adrenal crisis (AC) in a patient with AI. Education is paramount for patients and their caregivers to anticipate, recognise and provide proper early treatment to prevent or reduce the occurrence of ACs.

CONCLUSIONS

This review highlights and offers suggestions to address the challenges endocrinologists encounter in treating patients with AI. New preparations are being developed to better mimic normal physiological cortisol levels with convenient, once-daily dosing which may improve treatment outcomes.

Novel H6PDH mutations in two girls with premature adrenarche: 'apparent' and 'true' CRD can be differentiated by urinary steroid profiling

CONTEXT

Inactivating mutations in the enzyme hexose-6-phosphate dehydrogenase (H6PDH, encoded by H6PD) cause apparent cortisone reductase deficiency (ACRD). H6PDH generates cofactor NADPH for 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1, encoded by HSD11B1) oxo-reductase activity, converting cortisone to cortisol. Inactivating mutations in HSD11B1 cause true cortisone reductase deficiency (CRD). Both ACRD and CRD present with hypothalamic-pituitary-adrenal (HPA) axis activation and adrenal hyperandrogenism.

OBJECTIVE

To describe the clinical, biochemical and molecular characteristics of two additional female children with ACRD and to illustrate the diagnostic value of urinary steroid profiling in identifying and differentiating a total of six ACRD and four CRD cases.

DESIGN

Clinical, biochemical and genetic assessment of two female patients presenting during childhood. In addition, results of urinary steroid profiling in a total of ten ACRD/CRD patients were compared to identify distinguishing characteristics.

RESULTS

Case 1 was compound heterozygous for R109AfsX3 and a novel P146L missense mutation in H6PD. Case 2 was compound heterozygous for novel nonsense mutations Q325X and Y446X in H6PD. Mutant expression studies confirmed loss of H6PDH activity in both cases. Urinary steroid metabolite profiling by gas chromatography/mass spectrometry suggested ACRD in both cases. In addition, we were able to establish a steroid metabolite signature differentiating ACRD and CRD, providing a basis for genetic diagnosis and future individualised management.

CONCLUSIONS

Steroid profile analysis of a 24-h urine collection provides a diagnostic method for discriminating between ACRD and CRD. This will provide a useful tool in stratifying unresolved adrenal hyperandrogenism in children with premature adrenarche and adult females with polycystic ovary syndrome (PCOS).

Synovial DKK1 expression is regulated by local glucocorticoid metabolism in inflammatory arthritis

INTRODUCTION

Inflammatory arthritis is associated with increased bone resorption and suppressed bone formation. The Wnt antagonist dickkopf-1 (DKK1) is secreted by synovial fibroblasts in response to inflammation and this protein has been proposed to be a master regulator of bone remodelling in inflammatory arthritis. Local glucocorticoid production is also significantly increased during joint inflammation. Therefore, we investigated how locally derived glucocorticoids and inflammatory cytokines regulate DKK1 synthesis in synovial fibroblasts during inflammatory arthritis.

METHODS

We examined expression and regulation of DKK1 in primary cultures of human synovial fibroblasts isolated from patients with inflammatory arthritis. The effect of TNFα, IL-1β and glucocorticoids on DKK1 mRNA and protein expression was examined by real-time PCR and ELISA. The ability of inflammatory cytokine-induced expression of the glucocorticoid-activating enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) to sensitise fibroblasts to endogenous glucocorticoids was explored. Global expression of Wnt signalling and target genes in response to TNFα and glucocorticoids was assessed using a custom array.

RESULTS

DKK1 expression in human synovial fibroblasts was directly regulated by glucocorticoids but not proinflammatory cytokines. Glucocorticoids, but not TNFα, regulated expression of multiple Wnt agonists and antagonists in favour of inhibition of Wnt signalling. However, TNFα and IL-1β indirectly stimulated DKK1 production through increased expression of 11β-HSD1.

CONCLUSIONS

These results demonstrate that in rheumatoid arthritis synovial fibroblasts, DKK1 expression is directly regulated by glucocorticoids rather than TNFα. Consequently, the links between synovial inflammation, altered Wnt signalling and bone remodelling are not direct but are dependent on local activation of endogenous glucocorticoids.

Clinical outcomes in the management of congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a group of disorders affecting adrenal steroid synthesis. The most common form, 21-hydroxylase deficiency, leads to decreased production of cortisol and aldosterone with increased androgen secretion. In classic CAH glucocorticoid treatment can be life-saving, and provides symptom control, but must be given in an unphysiological manner with the risk of negative long-term outcomes. A late diagnosis or a severe phenotype or genotype has also a negative impact. These factors can result in impaired quality of life (QoL), increased cardiometabolic risk, short stature, osteoporosis and fractures, benign tumors, decreased fertility, and vocal problems. The prognosis has improved during the last decades, thanks to better clinical management and nowadays the most affected patients seem to have a good QoL. Very few patients above the age of 60 years have, however, been studied. Classifying patients according to genotype may give additional useful clinical information. The introduction of neonatal CAH screening may enhance long-term results. Monitoring of different risk factors and negative consequences should be done regularly in an attempt to improve clinical outcomes further.

Cortisone-reductase deficiency associated with heterozygous mutations in 11beta-hydroxysteroid dehydrogenase type 1

In peripheral target tissues, levels of active glucocorticoid hormones are controlled by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), a dimeric enzyme that catalyzes the reduction of cortisone to cortisol within the endoplasmic reticulum. Loss of this activity results in a disorder termed cortisone reductase deficiency (CRD), typified by increased cortisol clearance and androgen excess. To date, only mutations in H6PD, which encodes an enzyme supplying cofactor for the reaction, have been identified as the cause of disease. Here we examined the HSD11B1 gene in two cases presenting with biochemical features indicative of a milder form of CRD in whom the H6PD gene was normal. Novel heterozygous mutations (R137C or K187N) were found in the coding sequence of HSD11B1. The R137C mutation disrupts salt bridges at the subunit interface of the 11β-HSD1 dimer, whereas K187N affects a key active site residue. On expression of the mutants in bacterial and mammalian cells, activity was either abolished (K187N) or greatly reduced (R137C). Expression of either mutant in a bacterial system greatly reduced the yield of soluble protein, suggesting that both mutations interfere with subunit folding or dimer assembly. Simultaneous expression of mutant and WT 11β-HSD1 in bacterial or mammalian cells, to simulate the heterozygous condition, indicated a marked suppressive effect of the mutants on both the yield and activity of 11β-HSD1 dimers. Thus, these heterozygous mutations in the HSD11B1 gene have a dominant negative effect on the formation of functional dimers and explain the genetic cause of CRD in these patients.

Pharmacogenetics of glucocorticoid replacement could optimize the treatment of congenital adrenal hyperplasia due to 21-hydroxylase deficiency

INTRODUCTION

21-hydroxylase deficiency is an autosomal recessive disorder that causes glucocorticoid deficiency and increased androgen production. Treatment is based on glucocorticoid replacement; however, interindividual variability in the glucocorticoid dose required to achieve adequate hormonal control has been observed.

OBJECTIVE

The present study aimed to evaluate the association between polymorphic variants involved inglucocorticoid action and/or metabolism and the mean daily glucocorticoid dose in 21-hydroxylase deficiency patients.

METHODS

We evaluated 53 patients with classical forms of 21-hydroxylase deficiency who were receiving cortisone acetate. All patients were between four and six years of age and had normal androgen levels.

RESULTS

The P450 oxidoreductase A503V, HSD11B1 rs12086634, and CYP3A7*1C variants were found in 19%, 11.3% and 3.8% of the patients, respectively. The mean ± SD glucocorticoid dose in patients with the CYP3A7*1C and wild-type alleles was 13.9 ± 0.8 and 19.5 ± 3.2 mg/m²/d, respectively. We did not identify an association between the P450 oxidoreductase or HSD11B1 allelic variants and the mean glucocorticoid dose.

CONCLUSION

Patients carrying the CYP3A7*1C variant required a significantly lower mean glucocorticoid dose. Indeed, the CYP3A7*1C allele accounted for 20% of the variability in the cortisone acetate dose. The analysis of genes involved in glucocorticoid metabolism may be useful in the optimization of treatment of 21-hydroxylase deficiency.

Local and systemic glucocorticoid metabolism in inflammatory arthritis

BACKGROUND

Isolated, primary synovial fibroblasts generate active glucocorticoids through expression of 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). This enzyme produces cortisol from inactive cortisone (and prednisolone from prednisone).

OBJECTIVE

To determine how intact synovial tissue metabolises glucocorticoids and to identify the local and systemic consequences of this activity by examination of glucocorticoid metabolism in patients with rheumatoid arthritis (RA).

METHODS

Synovial tissue was taken from patients with RA during joint replacement surgery. Glucocorticoid metabolism in explants was assessed by thin-layer chromatography and specific enzyme inhibitors. RT-PCR and immunohistochemistry were used to determine expression and distribution of 11beta-HSD enzymes. Systemic glucocorticoid metabolism was examined in patients with RA using gas chromatography/mass spectrometry.

RESULTS

Synovial tissue synthesised cortisol from cortisone, confirming functional 11beta-HSD1 expression. In patients with RA, enzyme activity correlated with donor erythrocyte sedimentation rate (ESR). Synovial tissues could also convert cortisol back to cortisone. Inhibitor studies and immunohistochemistry suggested this was owing to 11beta-HSD2 expression in synovial macrophages, whereas 11beta-HSD1 expression occurred primarily in fibroblasts. Synovial fluids exhibited lower cortisone levels than matched serum samples, indicating net local steroid activation. Urinary analyses indicated high 11beta-HSD1 activity in untreated patients with RA compared with controls and a significant correlation between total body 11beta-HSD1 activity and ESR.

CONCLUSIONS

Synovial tissue metabolises glucocorticoids, the predominant effect being glucocorticoid activation, and this increases with inflammation. Endogenous glucocorticoid production in the joint is likely to have an impact on local inflammation and bone integrity.

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.