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Open access

Susanne Thiele, Ralf Werner, Annika Stubbe, Olaf Hiort, and Wolfgang Hoeppner

Background:

Hypophosphataemic rickets (HR) comprise a clinically and genetically heterogeneous group of conditions, defined by renal-tubular phosphate wasting and consecutive loss of bone mineralisation. X-linked hypophosphataemia (XLH) is the most common form, caused by inactivating dominant mutations in PHEX, a gene encompassing 22 exons located at Xp22.1. XLH is treatable by anti-Fibroblast Growth Factor 23 antibody, while for other forms of HR such as therapy may not be indicated. Therefore, a genetic differentiation of HR is recommended.

Objective:

To develop and validate a next-generation sequencing panel for HR with special focus on PHEX.

Design and methods:

We designed an AmpliSeq gene panel for the IonTorrent PGM next-generation platform for PHEX and ten other HR-related genes. For validation of PHEX sequencing 50 DNA-samples from XLH-patients, in whom 42 different mutations in PHEX and 1 structural variation have been proven before, were blinded, anonymised and investigated with the NGS panel. In addition, we analyzed one known homozygous DMP1 mutation and two samples of HR-patients, where no pathogenic PHEX mutation had been detected by conventional sequencing.

Results:

The panel detected all 42 pathogenic missense/nonsense/splice-site/indel PHEX-mutations and in one the known homozygous DMP1 mutation. In the remaining two patients, we revealed a somatic mosaicism of a PHEX mutation in one; as well as two variations in DMP1 and a very rare compound heterozygous variation in ENPP1 in the second patient.

Conclusions:

This developed NGS panel is a reliable tool with high sensitivity and specificity for the diagnosis of XLH and related forms of HR.

Open access

John-Paul Fuller-Jackson, Aimee L Dordevic, Iain J Clarke, and Belinda A Henry

Objective:

Retrospective studies suggest that women have more active brown adipose tissue (BAT) than men, but little is known of the effect of fluctuating sex steroids across the menstrual cycle on thermogenesis in women.

Design:

To characterise the effects of sex and sex steroids on BAT activity we recruited healthy weight men (n = 14) and women at two stages of the menstrual cycle (luteal, n = 9; follicular, n = 11).

Methods:

Infrared thermography measured supraclavicular temperature to index BAT thermogenesis in response to both cold (immersion of one hand in water at 15°C) and meal (Ensure, 10 kcal/kg body weight) stimuli.

Results:

Adaptive BAT temperature responses were greater (P < 0.05) in women than men, irrespective of stage of menstrual cycle. Whereas during cold exposure, the increase in BAT temperature was abrogated (P < 0.05) in women during follicular phase compared to men and women during luteal phase. Plasma concentrations of progesterone, 17β-estradiol, testosterone and cortisol were measured. Regression analyses demonstrated that baseline BAT temperature was positively correlated (P < 0.05) with progesterone levels, but was inversely associated (P < 0.05) with cortisol concentration. Both cold- and meal-induced changes in BAT temperature mildly correlated (P = 0.07; P < 0.05) with 17β-estradiol levels, but not with testosterone concentrations.

Conclusions:

Baseline supraclavicular temperature is elevated in women during the luteal phase of the menstrual cycle, which correlated with elevated progesterone concentrations. Women exhibited greater thermogenic responses than men, irrespective of the state of the menstrual cycle, which was associated with plasma levels of 17β-estradiol. We conclude that sex steroids may regulate BAT thermogenesis in healthy adults.

Open access

Claire L Wood, Michael Cole, Malcolm Donaldson, David P Dunger, Ruth Wood, Niamh Morrison, John Ns Matthews, Simon Hs Pearce, and Timothy D Cheetham

Objective

First line treatment of thyrotoxicosis in young people is thionamide antithyroid drug (ATD) in a blocking dose with levothyroxine replacement (block and replace, BR) or in a smaller dose tailored to render the patient euthyroid (dose titration, DT). Our objective was to determine which regimen provides more stable biochemical control.

Design

A multi-centre phase III, open-label randomised trial comparing BR with DT in patients aged 2-16 years with newly diagnosed thyrotoxicosis at 15 UK centres.

Methods

Patients were randomised shortly after diagnosis and treated for 3 years. The primary outcome was the percentage of serum thyroid stimulating hormone (TSH) levels in the reference range between 6 months and 3 years. Secondary outcomes included the proportion of Free thyroxine (FT4) levels in the reference range, adverse event frequency and 4y outcome (remission/relapse).

Results

Eighty-two patients were randomised, with details on clinical course in 81 (62 Female); 40 were allocated to BR (41 DT). Three withdrew with one ineligible. The mean percentage of serum TSH within reference range was 60·2% in BR and 63·8% in DT patients; adjusted difference 4·3%, 95% CI (-7·8 to 16·4);p=0.48. Proportions for FT4 were 79·2% in BR and 85·7% in DT patients; adjusted difference 6·8%, (-0·2 to 15·6);p=0·13. Three patients developed neutropenia – all on BR. 6 BR and 10 DT patients were in remission at 4y.

Conclusion

This randomised trial has shown no evidence to suggest that BR, when managing the young patient with thyrotoxicosis, is associated with improved biochemical stability when compared to DT.

Open access

Emily Cottrell, Claudia P Cabrera, Miho Ishida, Sumana Chatterjee, James Greening, Neil Wright, Artur Bossowski, Leo Dunkel, Asma Deeb, Iman Al Basiri, Stephen J Rose, Avril Mason, Susan Bint, Joo Wook Ahn, Vivian Hwa, Louise A Metherell, Gudrun Moore, and Helen L Storr

Objective: Copy number variation (CNV) has been associated with idiopathic short stature, small for gestational age and Silver-Russell syndrome (SRS). It has not been extensively investigated in growth hormone insensitivity (GHI; short stature, IGF-1 deficiency and normal/high GH) or previously in IGF-1 insensitivity (short stature, high/normal GH and IGF-1).

Design and Methods: Array Comparative Genomic Hybridisation was performed with ~60,000 probe oligonucleotide array in GHI (n=53) and IGF-1 insensitivity (n=10) subjects. Published literature, mouse models, DECIPHER CNV tracks, growth associated GWAS loci and pathway enrichment analyses were used to identify key biological pathways/novel candidate growth genes within the CNV regions.

Results: Both cohorts were enriched for class 3-5 CNVs (7/53 (13%) GHI and 3/10 (30%) IGF-1 insensitivity patients). Interestingly, 6/10 (60%) CNV subjects had diagnostic/associated clinical features of SRS. 5/10 subjects (50%) had CNVs previously reported in suspected SRS: 1q21 (n=2), 12q14 (n=1) deletions and Xp22 (n=1), Xq26 (n=1) duplications. A novel 15q11 deletion, previously associated with growth failure but not SRS/GHI was identified. Bioinformatic analysis identified 45 novel candidate growth genes, 15 being associated with growth in GWAS. The WNT canonical pathway was enriched in the GHI cohort and CLOCK was identified as an upstream regulator in the IGF-1 insensitivity cohorts.

Conclusions: Our cohort was enriched for low frequency CNVs. Our study emphasises the importance of CNV testing in GHI and IGF-1 insensitivity patients, particularly GHI subjects with SRS features. Functional experimental evidence is now required to validate the novel candidate growth genes, interactions and biological pathways identified.

Open access

Friso de Vries, Mees Bruin, Angelica Cersosimo, Charlotte N van Beuzekom, S Faisal Ahmed, Robin P Peeters, Nienke R Biermasz, Olaf Hiort, and Alberto M Pereira

Objective

Given that volumes of patients and interventions are important criteria to qualify as a reference centre (RC) for the European Reference Network on Rare Endocrine Conditions (Endo-ERN), the present study aimed to evaluate the data that were reported in the original application against subsequent assessments of activity and review the criteria that may define RCs using two main thematic groups (MTGs): Pituitary and Thyroid, as examples.

Methods

Review of content in application forms and continuous monitoring data and of a survey distributed to RCs. A list of ‘key procedures’ for the assessment of performance of RCs was composed with the help of the Pituitary and Thyroid MTG chairs.

Results

In the original application, the number of undefined procedures ranged from 20 to 5500/year (Pituitary) and from 10 to 2700/year (phyroid) between applicants. In the survey, the number of key procedures per centre ranged from 18 to 150/year (Pituitary) and from 20 to 1376/year (Thyroid). The median numbers of new patients reported in the continuous monitoring program were comparable with the application and survey; however, some centres reported large variations.

Conclusions

Monitoring of clinical activity in an ERN requires clear definitions that are optimally aligned with clinical practice, diagnosis registration, and hospital IT systems. This is a particular challenge in the rare disease field where the centre may also provide expert input in collaboration with local hospitals. Application of uniform definitions, in addition to condition-specific clinical benchmarks, which can include patient-reported- as well as clinician-reported outcome measures, is urgently needed to allow benchmarking of care across Endo-ERN.

Open access

Serena Khoo, Greta Lyons, Anne McGowan, Mark Gurnell, Susan Oddy, W Edward Visser, Sjoerd van den Berg, David Halsall, Kevin Taylor, Krishna Chatterjee, and Carla Moran

Objective

Familial dysalbuminaemic hyperthyroxinaemia (FDH), most commonly due to an Arginine to Histidine mutation at residue 218 (R218H) in the albumin gene, causes artefactual elevation of free thyroid hormones in euthyroid individuals. We have evaluated the susceptibility of most current free thyroid hormone immunoassay methods used in the United Kingdom, Europe and Far East to interference by R218H FDH.

Methods

Different, one- and two-step immunoassay methods were tested, measuring free T4 (FT4) and free T3 (FT3) in 37 individuals with genetically proven R218H FDH.

Results

With the exception of Ortho VITROS, FT4 measurements were raised in all assays, with greatest to lowest susceptibility to interference being Beckman ACCESS > Roche ELECSYS > FUJIREBIO Lumipulse > Siemens CENTAUR > Abbott ARCHITECT > Perkin-Elmer DELFIA. Five different assays recorded high FT3 levels, with the Siemens CENTAUR method measuring high FT3 values in up to 30% of cases. However, depending on the assay method, FT4 measurements were unexpectedly normal in some, genetically confirmed, affected relatives of index FDH cases.

Conclusions

All FT4 immunoassays evaluated are prone to interference by R218H FDH, with their varying susceptibility not being related to assay architecture but likely due to differing assay conditions or buffer composition. Added susceptibility of many FT3 assays to measurement interference, resulting in high FT4 and FT3 with non-suppressed TSH levels, raises the possibility of R218H FDH being misdiagnosed as resistance to thyroid hormone beta or TSH-secreting pituitary tumour, potentially leading to unnecessary investigation and inappropriate treatment.

Open access

Annamaria Colao, Marcello D Bronstein, Thierry Brue, Laura De Marinis, Maria Fleseriu, Mirtha Guitelman, Gerald Raverot, Ilan Shimon, Jürgen Fleck, Pritam Gupta, Alberto M Pedroncelli, and Mônica R Gadelha

Objective

In the Phase III PAOLA study (clinicaltrials.gov: NCT01137682), enrolled patients had uncontrolled acromegaly despite ≥6 months of octreotide/lanreotide treatment before study start. More patients achieved biochemical control with long-acting pasireotide versus continued treatment with octreotide/lanreotide (active control) at month 6. The current work assessed the extent of comorbidities at baseline and outcomes during a long-term extension.

Design/methods

Patients receiving pasireotide 40 or 60 mg at core study end could continue on the same dose in an extension phase if biochemically controlled or receive pasireotide 60 mg if uncontrolled. Uncontrolled patients on active control were switched to pasireotide 40 mg, with the dose increased at week 16 of the extension if still uncontrolled (crossover group). Efficacy and safety are reported to 304 weeks (~5.8 years) for patients randomized to pasireotide (core + extension), and 268 weeks for patients in the crossover group (extension only).

Results

Almost half (49.5%; 98/198) of patients had ≥3 comorbidities at core baseline. During the extension, 173 patients received pasireotide. Pasireotide effectively and consistently reduced GH and IGF-I levels for up to 5.8 years’ treatment; 37.0% of patients achieved GH <1.0 µg/L and normal IGF-I at some point during the core or extension. Improvements were observed in key symptoms. The long-term safety profile was similar to that in the core study; 23/173 patients discontinued treatment because of adverse events.

Conclusions

In this patient population with a high burden of comorbid illness, pasireotide was well tolerated and efficacious, providing prolonged maintenance of biochemical control and improving symptoms.

Open access

Jakob Skov, Daniel Eriksson, Ralf Kuja-Halkola, Jonas Höijer, Soffia Gudbjörnsdottir, Ann-Marie Svensson, Patrik K E Magnusson, Jonas F Ludvigsson, Olle Kämpe, and Sophie Bensing

Objective

Co-aggregation of autoimmune diseases is common, suggesting partly shared etiologies. Genetic factors are believed to be important, but objective measures of environmental vs heritable influences on co-aggregation are absent. With a novel approach to twin studies, we aimed at estimating heritability and genetic overlap in seven organ-specific autoimmune diseases.

Design

Prospective twin cohort study.

Methods

We used a cohort of 110 814 twins to examine co-aggregation and heritability of Hashimoto’s thyroiditis, atrophic gastritis, celiac disease, Graves’ disease, type 1 diabetes, vitiligo and Addison’s disease. Hazard ratios (HR) were calculated for twins developing the same or different disease as compared to their co-twin. The differences between monozygotic and dizygotic twin pairs were used to estimate the genetic influence on co-aggregation. Heritability for individual disorders was calculated using structural equational modeling adjusting for censoring and truncation of data.

Results

Co-aggregation was more pronounced in monozygotic twins (median HR: 3.2, range: 2.2–9.2) than in dizygotic twins (median HR: 2.4, range: 1.1–10.0). Heritability was moderate for atrophic gastritis (0.38, 95% CI: 0.23–0.53) but high for all other diseases, ranging from 0.60 (95% CI: 0.49–0.71) for Graves’ disease to 0.97 (95% CI: 0.91–1.00) for Addison’s disease.

Conclusions

Overall, co-aggregation was more pronounced in monozygotic than in dizygotic twins, suggesting that disease overlap is largely attributable to genetic factors. Co-aggregation was common, and twins faced up to a ten-fold risk of developing diseases not present in their co-twin. Our results validate and refine previous heritability estimates based on smaller twin cohorts.

Open access

A Veltroni, E Cosaro, F Spada, N Fazio, A Faggiano, A Colao, S Pusceddu, M C Zatelli, D Campana, A Piovesan, A Pia, E M Grossrubatscher, A Filice, A Bianchi, P Razzore, M Toaiari, S Cingarlini, L Landoni, R Micciolo, and M V Davì

Introduction

Management of malignant insulinomas is challenging due to the need to control both hypoglycaemic syndrome and tumor growth. Literature data is limited to small series.

Aim of the study

To analyze clinico-pathological characteristics, treatments and prognosis of patients with malignant insulinoma.

Materials and methods

Multicenter retrospective study on 31 patients (male: 61.3%) diagnosed between 1988 and 2017.

Results

The mean age at diagnosis was 48 years. The mean NET diameter was 41 ± 31 mm, and 70.8% of NETs were G2. Metastases were widespread in 38.7%, hepatic in 41.9% and only lymph nodal in 19.4%. In 16.1% of the cases, the hypoglycaemic syndrome occurred after 46 ± 35 months from the diagnosis of originally non-functioning NET, whereas in 83.9% of the cases it led to the diagnosis of NET, of which 42.3% with a mean diagnostic delay of 32.7 ± 39.8 months. Surgical treatment was performed in 67.7% of the cases. The 5-year survival rate was 62%. Overall survival was significantly higher in patients with Ki-67 ≤10% (P = 0.03), insulin level <60 µU/mL (P = 0.015) and in patients who underwent surgery (P = 0.006). Peptide Receptor Radionuclide Therapy (PRRT) was performed in 45.1%, with syndrome control in 93% of patients.

Conclusions

Our study includes the largest series of patients with malignant insulinoma reported to date. The hypoglycaemic syndrome may occur after years in initially non-functioning NETs or be misunderstood with delayed diagnosis of NETs. Surgical treatment and Ki67 ≤10% are prognostic factors associated with better survival. PPRT proved to be effective in the control of hypoglycaemia in majority of cases.

Open access

Andreas Stomby, Julia Otten, Mats Ryberg, Ruth Andrew, Brian R Walker, and Tommy Olsson

Context

Altered tissue-specific glucocorticoid metabolism has been described in uncomplicated obesity and type 2 diabetes. We hypothesized that weight loss induced by diet and exercise, which has previously been shown to reverse abnormal cortisol metabolism in uncomplicated obesity, also normalizes cortisol metabolism in patients with type 2 diabetes.

Objective

Test the effects of a diet intervention with added exercise on glucocorticoid metabolism.

Design

Two groups followed a Paleolithic diet (PD) for 12 weeks with added 180 min of structured aerobic and resistance exercise per week in one randomized group (PDEX).

Setting

Umeå University Hospital.

Participants

Men and women with type 2 diabetes treated with lifestyle modification ± metformin were included. Twenty-eight participants (PD, n = 15; PDEX, n = 13) completed measurements of glucocorticoid metabolism.

Main outcome measures

Changes in glucocorticoid metabolite levels in 24-h urine samples, expression of HSD11B1 mRNA in s.c. adipose tissue and conversion of orally administered cortisone to cortisol measured in plasma. Body composition and insulin sensitivity were measured using a hyperinsulinemic-euglycemic clamp, and liver fat was measured by magnetic resonance spectroscopy.

Results

Both groups lost weight and improved insulin sensitivity. Conversion of orally taken cortisone to plasma cortisol and the ratio of 5α-THF + 5β-THF/THE in urine increased in both groups.

Conclusions

These interventions caused weight loss and improved insulin sensitivity with concomitant increases in the conversion of cortisone to cortisol, which is an estimate of hepatic HSD11B1 activity. This suggests that dysregulation of liver glucocorticoid metabolism in these patients is a consequence rather than a cause of metabolic dysfunction.