A retrospective study on weaning glucocorticoids and recovery of the hypothalamic-pituitary-adrenal axis

CONTEXT

Glucocorticoids suppress the hypothalamic-pituitary-adrenal (HPA) axis resulting in tertiary adrenal insufficiency (AI). When weaning patients off glucocorticoids there is no consensus on whether to maintain patients on prednisolone or convert to hydrocortisone.

OBJECTIVE

Investigate HPA axis recovery in patients on long-term prednisolone and assess outcome after hydrocortisone conversion.

DESIGN

Retrospective cohort study.

SETTING

Outpatient endocrine steroid clinic.

PATIENTS

Patients on long-term prednisolone referred for HPA axis testing between 2015-2022.

MAIN OUTCOMES MEASURED

1) HPA axis recovery rate in patients on prednisolone demonstrated by normal ACTH stimulation test (AST).2) HPA axis recovery rate sub-analysis of dose-matched patients with confirmed tertiary AI on prednisolone or hydrocortisone.

RESULTS

206 patients on prednisolone were tested for tertiary AI. Of these 176 remained on prednisolone while 30 were converted to hydrocortisone. The overall HPA axis recovery rate for patients on prednisolone after interval testing was 137/206 (66.5%). HPA axis recovery rate in dose-matched prednisolone and hydrocortisone conversion groups was 7/10 (70%) and 2/13 (15%) (p=0.008), respectively. There was no difference in mean (SD) age (67.1(12.2) v 63.4(11.1) years; p=0.464) and baseline cortisol (5.3(4.2) v 4.6(3.1)µg/dL; p=0.648) and median [IQR] glucocorticoids duration (1213[1114] v 2316[4808] days; p=0.693) and baseline ACTH (20.5[29.0] v 16.3[14.8]ng/L; p=0.905) between dose-matched prednisolone and hydrocortisone groups. Follow-up duration in prednisolone group was significantly lower (median [IQR] 348[975] v 667[884] days; p=0.012).

CONCLUSIONS

Patients with glucocorticoid induced AI maintained on once-daily prednisolone can recover HPA axis function when weaning. There is no apparent advantage to recover HPA axis function in converting to multiple dosing hydrocortisone.

Real world evidence supports waking salivary cortisone as a screening test for adrenal insufficiency

OBJECTIVE

Worldwide, adults and children are at risk of adrenal insufficiency largely due to infectious diseases and adrenal suppression from use of anti-inflammatory glucocorticoids. Home waking salivary cortisone is an accurate screening test for adrenal insufficiency, it has potential to reduce costs, and patients prefer it to the adrenocorticotropin (ACTH) (synacthen) stimulation test. We carried out a service evaluation of home waking salivary cortisone in clinical care to identify implementation barriers.

DESIGN, PATIENTS AND MEASUREMENTS

Service evaluation in a centre where 212 patients referred for adrenal insufficiency had a waking salivary cortisone. Problems encountered during testing were recorded and patient feedback, via focus groups, collected.

RESULTS

From all patients providing a waking salivary cortisone 55% had a normal test, 23% adrenal suppression, and 22% an equivocal result requiring a clinical centre ACTH stimulation test. The median (interquartile range [IQR]) for the time of the saliva sample was 07:40 (07:00-08:40). The median (IQR) days between collection and (i) delivery to local laboratory was 1 (0.25-2) day; (ii) reporting by local laboratory was 13 (11-18) days. Patients considered the test is "easy to do" and preferred it to the inpatient ACTH stimulation test. The principal challenge to clinical implementation was results reporting to clinicians due to delays at the local laboratory.

CONCLUSIONS

This service evaluation provides real-world evidence that home waking salivary cortisone is an effective, practical screening test for adrenal insufficiency. It identified key barriers to testing implementation that need to be addressed when introducing the test to a health service.

Analysis of Genetic Variation in the Bovine SLC11A1 Gene, Its Influence on the Expression of NRAMP1 and Potential Association With Resistance to Bovine Tuberculosis

Bovine tuberculosis (bTB), caused by Mycobacterium bovis, is a chronic zoonotic disease where host genetics is thought to contribute to susceptibility or resistance. One of the genes implicated is the SLC11A1 gene, that encodes for the natural resistance-associated macrophage protein 1 (NRAMP1). The aim of this study was to identify SLC11A1 polymorphisms and to investigate any resulting functional differences in NRAMP1 expression that might be correlated with resistance/susceptibility to M. bovis infection. Sequencing of the SLC11A1 gene in cDNA isolated from Brown Swiss, Holstein Friesian, and Sahiwal cattle identified five single nucleotide polymorphisms (SNPs) in the coding region, but only one of these (SNP4, c.1066C>G, rs109453173) was present in all three cattle breeds and therefore warranted further investigation. Additionally, variations of 10, 11, and 12 GT repeats were identified in a microsatellite (MS1) in the SLC11A1 3′UTR. Measurement of NRAMP1 expression in bovine macrophages by ELISA showed no differences between cells generated from the different breeds. Furthermore, variations in the length of the MS1 microsatellite did not impact on NRAMP1 protein expression as analyzed by luciferase reporter assay. However, further analysis of the ELISA data identified that the presence of the alternative G allele at SNP4 was associated with increased expression of NRAMP1 in bovine macrophages. Since NRAMP1 has been shown to influence the survival of intracellular pathogens such as M. bovis through the sequestering of iron, it is possible that cattle expressing the alternative G allele might have an increased resistance to bTB through increased NRAMP1 expression in their macrophages.

Non classic presentations of a genetic mutation typically associated with transient neonatal diabetes

SUMMARY

This case report describes a family pedigree of a mother and her children with an E227K mutation in the KCNJ11 gene. People with this particular gene mutation typically present with transient neonatal diabetes; with more than half the cohort relapsing into permanent diabetes in adolescence or early adulthood. However, the mother developed diabetes as an adolescent and thus was initially diagnosed as having Type 1 Diabetes. All her children have inherited the same genetic mutation but with differing presentations. Her second, third and fourth child presented with transient neonatal diabetes which remitted at varying times. Her first child is 16 years old but had not developed diabetes at the time of writing. The KCNJ11 gene codes for the KIR6.2 subunit of the KATP channels of the pancreatic beta cells. Mutations in this gene limit insulin release from beta cells despite high blood glucose concentrations. Most people with diabetes caused by this genetic mutation can be successfully managed with glibenclamide. Learning of the genetic mutation changed the therapeutic approach to the mother's diabetes and enabled rapid diagnosis for her children. Through this family, we identified that an identical genetic mutation does not necessarily lead to the same diabetic phenotype. We recommend clinicians to consider screening for this gene in their patients whom MODY is suspected; especially in those presenting before the age of 25 who remain C-peptide positive.

LEARNING POINTS

KATP channel closure in pancreatic beta cells is a critical step in stimulating insulin release. Mutations in the KIR6.2 subunit can result in the KATP channels remaining open, limiting insulin release. People with KCNJ11 mutations may not present with neonatal diabetes as the age of presentation of diabetes can be highly variable. Most affected individuals can be treated successfully with glibenclamide, which closes the KATP channels via an independent mechanism. All first degree relatives of the index case should be offered genetic testing, including asymptomatic individuals. Offspring of affected individuals should be monitored for neonatal diabetes from birth. Affected individuals will require long-term follow-up as there is a high risk of recurrence in later life.

Update on adrenal steroid hormone biosynthesis and clinical implications

Steroid biosynthesis is a complex process in which cholesterol is converted to steroid hormones with the involvement of multiple enzymes and cofactors. Inborn conditions affecting adrenal steroidogenesis are relatively common in paediatric practice and have serious implications on patient mortality and morbidity. This paper provides an overview of novel insights into human adrenal steroid biosynthesis. Inborn errors of steroidogenesis associated with congenital adrenal hyperplasia are discussed, with a particular focus on the pathophysiology and clinical features of 21-hydroxylase deficiency. The final section of the review presents more recent findings and clinical implications of adrenal-specific androgen biosynthesis.

How do paediatricians use and monitor antithyroid drugs in the UK? A clinician survey

OBJECTIVE

We aimed to document current practice in the medical management of paediatric hyperthyroidism in the UK and compare to international recommendations.

DESIGN

A 27-question online survey distributed via an electronic newsletter in August 2018.

PARTICIPANTS

Responses from 48 members (11%) of the British Society for Paediatric Endocrinology and Diabetes.

MEASUREMENTS

Information about antithyroid drug (ATD) preference, treatment duration, monitoring of full blood count (FBC), management of neutropaenia, agranulocytosis screening and patient education.

RESULTS

Carbimazole is favoured by 98% of respondents and a "dose titration" regimen preferred over "block and replace" (65% vs 29%). TRAbs (thyroid-stimulating hormone receptor antibodies) are used for diagnostic purposes by 85% and by 33% to look for evidence of disease remission. The majority (81%) treat for a minimum of 2 years before considering a trial off ATD. All respondents reported that they "always/usually" warn their patients about the risk of agranulocytosis before starting ATD, but written information is "rarely/never" provided by 63%. Sore throat (98%) and fever (92%) are the most commonly cited symptoms used to alert a patient to possible agranulocytosis. FBC is measured prior to treatment by 65% and measured periodically during treatment by 70%.

CONCLUSIONS

The management of paediatric hyperthyroidism with ATDs in the UK is not consistent with all international recommendations because a block and replace ATD regimen remains widely used. TRAbs are utilized at presentation, but underused for detecting disease remission. National consensus guidelines and written patient information may refine the management of paediatric patients on ATDs.

Integrating teaching into everyday clinical practice

The teaching and training of doctors-in-training in paediatrics has become increasingly challenging in recent times. All too often there is a perception that training must come second to service provision. In this article, the case of a child with community-acquired pneumonia is considered and used to illustrate how a culture of teaching can be embedded in everyday clinical practice.

Consensus and experience trump leadership, suppressing individual personality during social foraging

Whether individual behavior in social settings correlates with behavior when individuals are alone is a fundamental question in collective behavior. However, evidence for whether behavior correlates across asocial and social settings is mixed, and no study has linked observed trends with underlying mechanisms. Consistent differences between individuals in boldness, which describes willingness to accept reward over risk, are likely to be under strong selection pressure. By testing three-spined sticklebacks (Gasterosteus aculeatus) in a risky foraging task alone and repeatedly in shoals, we demonstrate that the expression of boldness in groups is context-specific. Whereas personality is repeatable in a low-risk behavior (leaving a refuge), the collectively made consensus decision to then cross the arena outweighs leadership by bolder individuals, explaining the suppression of personality in this context. However, despite this social coordination, bolder individuals were still more likely to feed. Habituation and satiation over repeated trials degrade the effect of personality on leaving the refuge and also whether crossing the arena is a collective decision. The suppression of personality in groups suggests that individual risk-taking tendency may rarely represent actual risk in social settings, with implications for the evolution and ecology of personality variation.

Electrically stimulated resistance training in SCI individuals increases muscle fatigue resistance but not femoral artery size or blood flow

STUDY DESIGN

Longitudinal.

OBJECTIVES

The purpose of this study was to evaluate the effect of lower extremity resistance training on quadriceps fatigability, femoral artery diameter, and femoral artery blood flow.

SETTING

Academic Institution.

METHODS

Five male chronic spinal cord injury (SCI) individuals (American Spinal Injury Association (ASIA): A complete; C5-T10; 36+/-5 years old) completed 18 weeks of home-based neuromuscular electrical stimulation (NMES) resistance training. Subjects trained the quadriceps muscle group twice a week with four sets of 10 dynamic knee extensions against resistance while in a seated position. All measurements were made before training and after 8, 12, and 18 weeks of training. Ultrasound was used to measure femoral artery diameter and blood flow. Blood flow was measured before and after 5 and 10 min of distal cuff occlusion, and during a 4-min isometric electrical stimulation fatigue protocol.

RESULTS

Training resulted in significant increases in weight lifted and muscle mass, as well as a 60% reduction in muscle fatigue (P = 0.001). However, femoral arterial diameter did not increase. The range was 0.44+/-0.03 to 0.46+/-0.05 cm over the four time points (P = 0.70). Resting, reactive hyperemic, and exercise blood flow did not appear to change with training.

CONCLUSION

NMES resistance training improved muscle size and fatigue despite an absence of response in the supplying vasculature. These results suggest that the decreases in arterial caliber and blood flow seen with SCI are not tightly linked to muscle mass and fatigue resistance. In addition, muscle fatigue in SCI patients can be improved without increases in arterial diameter or blood flow capacity.

In vivo anti-HIV activity of (+)-calanolide A in the hollow fiber mouse model

In vivo anti-HIV efficacy of (+)-calanolide A has been evaluated in a hollow fiber mouse model. It was demonstrated that the compound was capable of suppressing virus replication in two distinct and separate physiologic compartments (i.p. and s.c.) following oral or parenteral administration on a once- or twice-daily treatment schedule. A synergistic effect was observed for the combination of (+)-calanolide A and AZT.

The role of family status and ethnic group on body image and eating behavior

OBJECTIVE

To examine the role of ethnic group and family status on body dissatisfaction and eating behavior.

METHOD

One hundred women (Asian mothers and daughters, n = 50; white mothers and daughters, n = 50) completed a questionnaire about their perceived ethnic identity (acculturation), body image, and eating behavior.

RESULTS

The results showed no matching between mothers and daughters and no effect of acculturation on body image and eating behavior. However, mothers reported greater body dissatisfaction and white subjects reported higher levels of restrained eating. In addition, the results showed a significant Ethnic Group x Family Status interaction for both body image and eating behavior irrespective of body mass index (BMI). Accordingly, white daughters were found to be the most dissatisfied with their bodies and most concerned with the calorie content of their food, followed by the Asian mothers. White mothers were found to be the most satisfied with their body and Asian daughters were the least concerned with calories.

DISCUSSION

The results are discussed in terms of the changing nature of media images in both Asian and white cultures and the impact of the transition between these two cultures.

Efficacy, pharmacokinetics, and in vivo antiviral activity of UC781, a highly potent, orally bioavailable nonnucleoside reverse transcriptase inhibitor of HIV type 1

A series of compounds related to oxathiin carboxanilide has been identified as nonnucleoside reverse transcriptase inhibitors (NNRTIs) of HIV-1, and structure-activity relationships have been described (Buckheit RW, et al.: Antimicrob Agents Chemother 1995;39:2718-2727). Three new analogs (UC040, UC82, and UC781) inhibited laboratory and clinical isolates of HIV-1, including isolates representative of the various clades of HIV-1 found worldwide, in both established and fresh human cells. Virus isolates with the amino acid changes L100I, K103N, V106I, and Y181C in the reverse transcriptase were partially resistant to these compounds. However, UC781 inhibited these virus isolates at low nontoxic concentrations, presenting a broad in vitro therapeutic index. As with other NNRTIs, each of the compounds synergistically interacted with AZT to inhibit HIV-1 replication. UC781 possesses a favorable pharmacokinetic profile in mice with a high level of oral bioavailability. Plasma concentrations reached maximum levels within 2 to 4 hr of oral administration and remained in excess of those required for in vitro anti-HIV activity for at least 24 hr after a single oral dose. When evaluated in a murine hollow fiber implant model of HIV infection, UC781 dosed orally or parenterally was able to suppress HIV replication completely in this model system, providing evidence of the in vivo efficacy of the compound.

In vivo drug screening applications of HIV-infected cells cultivated within hollow fibers in two physiologic compartments of mice

Previous studies demonstrated that human cell lines can be cultivated in hollow fibers in the subcutaneous and intraperitoneal compartments of mice. We have extended the range of cell lines to include cells infected with the human immunodeficiency virus (HIV). Furthermore, these HIV-infected cells have been shown to replicate in the hollow fibers located in both physiologic compartments (intraperitoneal and subcutaneous) of SCID mice. Treatment of the host mice with antiviral agents can suppress virus replication in these hollow fiber cultures. The potential use of this system for early in vivo screening of anti-HIV compounds is discussed.