Renin and electrolytes indicate the mineralocorticoid activity of fludrocortisone: a 6 year study in primary adrenal insufficiency

Dual-release hydrocortisone treatment improves serum and peripheral blood mononuclear cell inflammatory and immune profiles in patients with autoimmune primary adrenal insufficiency

Objective

The primary outcome was the evaluation of the T-cell phenotype in autoimmune primary adrenal insufficiency (PAI). Secondary outcomes included the evaluation of the CD4+CD25+Foxp3+ Treg population and the gene expression levels of IL-6, IL-17A, cyclooxygenase (COX)-2, heat shock proteins (HSP)-70, indoleamine-2,3-dioxygenase (IDO), programmed death-ligand 1 (PD-L1), inducible nitric oxide synthase (iNOS), and thioredoxin (TXN)-1.

Methods

We prospectively included 15 patients with PAI on conventional glucocorticoid (GC) replacement therapy, 15 switched to dual-release hydrocortisone (DR-HC), and 20 healthy controls. Serum inflammatory parameters and peripheral blood mononuclear cells (PBMCs) were evaluated at baseline and after 12 months of treatment.

Result

At baseline, significantly higher CD4+ and CD8+ (both p < 0.001) T-cell percentages, a lower CD4+/CD8+ ratio (p < 0.05), and higher CD25+ and CD4+/CD25+ T cells (both p < 0.001) were observed in PAI compared to controls. After 12 months of DR-HC treatment, we found significantly lower IL-6 (p = 0.019), IL-17A (p = 0.046), COX-2 (p < 0.001), HSP-70 (p = 0.006), and TXN-1 (p = 0.008) and higher PD-L1 (p < 0.001) and IDO (p < 0.001) mRNA values compared to baseline. After 12 months of DR-HC treatment, a significant increase in CD4+ T cells (p = 0.012), PD-L1 (p = 0.003), and IDO (p < 0.001) and a decrease in CD8+ T cells (p < 0.001), IL-6 (p = 0.003), IL-17A (p = 0.0014), COX-2 (p < 0.001), HSP-70 (p = 0.005), and TXN-1 (p = 0.0008), as well as a significantly higher conversion in the CD4+/CD8+ ratio (p = 0.033), were observed compared to conventional GCs.

Conclusions

The switch from conventional GCs to DR-HC treatment altered the T lymphocyte phenotype and CD4+/CD8+ ratio in a Treg-independent manner, inducing significant improvements in the immune and inflammatory profile in PAI.

Mineralocorticoid replacement therapy in salt-wasting congenital adrenal hyperplasia

Patients with salt-wasting congenital adrenal hyperplasia (SW-CAH) usually show pronounced impairment of aldosterone secretion and, therefore, also require mineralocorticoid replacement. While a lot of research and discussion focusses on the glucocorticoid therapy in SW-CAH to replace the missing cortisol and to control adrenal androgen excess, very little research is dealing with mineralocorticoid replacement. However, recent data demonstrated an increased cardiovascular risk in adult CAH patients urging to reflect also on the current mineralocorticoid replacement therapy. In this review, we explain the role and function of the mineralocorticoid receptor, its ligands and inhibitors and its relevance for the therapy of patients with SW-CAH. We performed an extensive literature search and present data on mineralocorticoid therapy in SW-CAH patients as well as clinical advice how to monitor and optimise mineralocorticoid replacement 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.

Long-term health consequences of congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency accounts for 95% of all CAH cases and is one of the most common inborn metabolic conditions. The introduction of life-saving glucocorticoid replacement therapy 70 years ago has changed the perception of CAH from a paediatric disorder into a lifelong, chronic condition affecting patients of all age groups. Alongside health problems that can develop during the time of paediatric care, there is an emerging body of evidence suggesting an increased risk of developing co-morbidities during adult life in patients with CAH. The mechanisms that drive the negative long-term outcomes associated with CAH are complex and involve supraphysiological replacement therapies (glucocorticoids and mineralocorticoids), excess adrenal androgens both in the intrauterine and postnatal life, elevated steroid precursors and adrenocorticotropic hormone levels. Alongside a review of mortality outcome, we discuss issues that need to be addressed when caring for the CAH patient including female and male fertility, cardio-metabolic morbidity, bone health and other important long-term outcomes of CAH.

Plasma Renin: A Useful Marker for Mineralocorticoid Adjustment in Patients With Primary Adrenal Insufficiency

Context

Renin is a marker of blood volume. There is no consensus on the validity of plasma renin measurement for adjusting mineralocorticoid (MC) substitution in patients with primary adrenal insufficiency (PAI).

Objective

This work aimed to investigate if plasma renin could be used to adjust MC substitution in patients with PAI.

Methods

A total of 150 patients with at least one measurement of plasma renin followed for PAI at 2 tertiary expert centers between 2008 and 2022 were retrospectively included. As supraphysiological hydrocortisone might have additional MC activity, we integrated the individual hydrocortisone dose to obtain the MC equivalent dose (Eq-MC). Renin less than 20 mIU/L was considered oversubstituted, renin between 20 and 60 mIU/L as correctly substituted, and renin over 60 mIU/L as undersubstituted.

Results

The mean dose of fludrocortisone was 82.3 ± 46 μg/day. Plasma renin was abnormal in 56.7% of cases (7 patients oversubstituted and 78 patients undersubstituted). Abnormalities in electrolyte levels were observed in only 12.7% of patients. Plasma renin correlated negatively with sodium (P < .01) and systolic blood pressure (P = .026), and positively with potassium (P < .01). Doses changes in Eq-MC had a statistically significant effect on renin levels (P = .0037), with an increase of MC dose correlating with a decrease in renin level and vice versa; no correlation was observed using electrolytes or blood pressure.

Conclusion

Plasma renin correlates with electrolytes and blood pressure. While dose changes significantly alter renin levels, electrolytes and blood pressure do not, suggesting that renin may provide more information about MC replacement therapy than electrolytes and blood pressure.

Performance of renin assays in selecting fludrocortisone dose in children with adrenal disorders

Children with salt-wasting adrenal insufficiency are managed with glucocorticoid and mineralocorticoid replacement. Measurement of renin activity or concentration alongside blood electrolyte levels is used to monitor the adequacy of mineralocorticoid replacement. Our unit changed from using renin activity to renin concentration and carried out a service review to assess whether this influenced decision-making for fludrocortisone dosing. In total, 50 measurements of plasma renin activity and 50 of renin concentration were analysed on separate cohorts before and after the assay change, with values standardised to multiples of the upper limit of normal (MoU) to allow comparison between assays. We were more likely to increase the fludrocortisone dose for a raised renin concentration than a raised renin activity. The renin concentration MoU was more strongly related to plasma sodium (negatively) and 17α-hydroxyprogesterone (17α-OHP) (positively) than the renin activity MoU. Using a MoU cut-off of 1.5, a decision to increase the dose of fludrocortisone was more likely to be made when using the renin concentration assay compared with the activity assay. Using a cut-off of 40 nmol/L for 17α-OHP, a decision not to change the fludrocortisone dose when 17α-OHP was <40 was more likely when using the renin concentration assay. For both assays, a plasma sodium <140 mmol/L was more likely to lead to a fludrocortisone dose increase, and most likely for the renin concentration assay. Overall, the decision to adjust fludrocortisone dose in this cohort of children with adrenal insufficiency was better supported by the biochemical parameters when based on renin concentration results and clinical status.

Novel agents to treat adrenal insufficiency: findings of preclinical and early clinical trials

INTRODUCTION

Adrenal insufficiency currently affects over 300/million population, with higher morbidity and mortality compared to the general population. Current glucocorticoid replacement therapy is limited by a lack of reliable biomarkers to guide dosing, inter-patient variation in metabolism and narrow therapeutic window. Increased morbidity and mortality may relate to unappreciated under- or over-exposure to glucocorticoids and impaired cortisol circadian rhythm. New agents are required to emulate physiological cortisol secretion and individualize glucocorticoid dosing.

AREAS COVERED

History of glucocorticoid therapy, current limitations, and novel chronotherapeutic glucocorticoid delivery mechanisms. Literature search incorporated searches of PubMed and Embase utilizing terms such as adrenal insufficiency, Chronocort, Plenadren, continuous subcutaneous hydrocortisone infusion (CHSI), and glucocorticoid receptor modulator.

EXPERT OPINION

Glucocorticoid chronotherapy is necessary to optimize glucocorticoid exposure and minimize complications. Current oral chronotherapeutics provide improved dosing functionality, but are modifiable only in specific increments and cannot accommodate ultradian cortisol variation. Current data show improvement in quality of life but not morbidity or mortality outcomes. CHSI has significant potential for individualized glucocorticoid dosing, but would require a suitable biomarker of glucocorticoid adequacy to be implementable. Avenues for future research include determining a glucocorticoid sufficiency biomarker, development of interstitial or systemic cortisol monitoring, or development of glucocorticoid receptor modulators.

On Primary Adrenal Insufficiency with Normal Concentrations of Cortisol - Early Manifestation of Addison's Disease

Primary adrenal insufficiency (AI) is an endocrine disorder in which hormones of the adrenal cortex are produced to an insufficient extent. Since receptors for adrenal steroids have a wide distribution, initial symptoms may be nonspecific. In particular, the lack of glucocorticoids can quickly lead to a life-threatening adrenal crisis. Therefore, current guidelines suggest applying a low threshold for testing and to rule out AI not before serum cortisol concentrations are higher than 500 nmol/l (18 μg/dl). To ease the diagnostic, determination of morning cortisol concentrations is increasingly used for making a diagnosis whereby values of>350 nmol/l are considered to safely rule out Addison's disease. Also, elevated corticotropin concentrations (>300 pg/ml) are indicative of primary AI when cortisol levels are below 140 nmol/l (5 μg/dl). However, approximately 10 percent of our patients with the final diagnosis of primary adrenal insufficiency would clearly have been missed for they presented with normal cortisol concentrations. Here, we present five such cases to support the view that normal to high basal concentrations of cortisol in the presence of clearly elevated corticotropin are indicative of primary adrenal insufficiency when the case history is suggestive of Addison's disease. In all cases, treatment with hydrocortisone had been started, after which the symptoms improved. Moreover, autoantibodies to the adrenal cortex had been present and all patients underwent a structured national education program to ensure that self-monitored dose adjustments could be made as needed.

Assessing treatment adherence is crucial to determine adequacy of mineralocorticoid therapy

Background

There is no consensus strategy for mineralocorticoid (MC) therapy titration in patients with primary adrenal insufficiency (PAI). We aim to measure serum fludrocortisone (sFC) and urine fludrocortisone (uFC) levels and to determine their utility, alongside clinical/biochemical variables and treatment adherence to guide MC replacement dose titration.

Methods

Multi-centre, observational, cross-sectional study on 41 patients with PAI on MC replacement therapy. sFC and uFC levels (measured by liquid chromatography-tandem mass spectrometry), plasma renin concentration (PRC), electrolytes (Na+, K+), mean arterial blood pressure (MAP), total daily glucocorticoid (dGC) and MC (dMC) dose, and assessment of treatment adherence were incorporated into statistical models.

Results

We observed a close relationship between sFC and uFC (r = 0.434, P = 0.005) and between sFC and the time from the last fludrocortisone dose (r = -0.355, P = 0.023). Total dMC dose was related to dGC dose (r = 0.556, P < 0.001), K+ (r = -0.388, P = 0.013) as well as sFC (r = 0.356, P = 0.022) and uFC (r = 0.531, P < 0.001). PRC was related to Na+ (r = 0.517, P < 0.001) and MAP (r = -0.427, P = 0.006), but not to MC dose, sFC or uFC. Regression analyses did not support a role for sFC, uFC or PRC measurements and confirmed K+ (B = -44.593, P = 0.005) as the most important variable to guide dMC titration. Of the patients, 32% were non-adherent with replacement therapy. When adherence was inserted into the regression model, it was the only factor affecting dMC.

Conclusions

sFC and uFC levels are not helpful in guiding dMC titration. Treatment adherence impacts on clinical variables used to assess MC replacement and should be included as part of routine care in patients with PAI.

Addison's Disease: Diagnosis and Management Strategies

We aim to overview Addison's disease (AD) with regard to current diagnosis and management. This is a narrative review of full-length articles published in English between January 2022 and December 2022 (including online ahead of print versions) in PubMed-indexed journals. We included original studies in living humans regardless of the level of statistical significance starting from the key search terms "Addison's disease" or "primary adrenal insufficiency" in title or abstract. We excluded articles with secondary adrenal insufficiency. Briefly, 199 and 355 papers, respectively were identified; we manually checked each of them, excluded the duplicates, and then selected 129 based on their clinical relevance in order to address our 1-year analysis. We organized the data in different subsections covering all published aspects on the subject of AD. To our knowledge, this is the largest AD retrospective from 2022 on published data. A massive role of genetic diagnosis especially in pediatric cases is highlighted; the importance of both pediatric and adult awareness remains since unusual presentations continue to be described. COVID-19 infection is a strong player amid this third year of pandemic although we still not do have large cohorts in this particular matter as seen, for instance, in thyroid anomalies. In our opinion, the most important topic for research is immune checkpoint inhibitors, which cause a large panel of endocrine side effects, AD being one of them.