The Influence of Prior Hyperthyroidism on Euthyroid Graves’ Ophthalmopathy

Background. To investigate the influence of previous exposure to elevated thyroid hormones in euthyroid Graves’ ophthalmopathy. Design. Retrospective, observational case series in university setting Median follow-up of 1 year with ranges of 0,8–7,6 years. Study performance of 10 years. Participants. We reviewed the clinical records of 731 Graves’ ophthalmopathy patients. There were 88 (12%) patients with onset of Graves’ ophthalmopathy during euthyroidism: 37 (5%) patients had ophthalmopathy without known history of thyroid dysfunction (group A) and 51 patients (6%) had onset of ophthalmopathy 6 months or more euthyroid after completion of antithyroid therapy (group B). Main Outcome Measures. Graves’ ophthalmopathy was graded using the EUGOGO severity criteria. Unilaterality was investigated. TSH receptor antibody and thyroid peroxidase antibody were measured as markers of Graves’ disease. Results. Group A had more often a normal ocular motility (46%) and less proptosis (14±4 mm) compared to group B (22%, 16±4 mm) (P=0.032 and 0.028, resp.). TSH receptor antibody was more frequently elevated in group B (94%) than in group A (17%) (P<0.001). Conclusion. Patients with euthyroid Graves’ ophthalmopathy present more often with ocular muscle restriction and proptosis when previously exposed to elevated thyroid hormones

2019 European Thyroid Association Guidelines on the Management of Thyroid Dysfunction following Immune Reconstitution Therapy.

Thyroid dysfunction (TD) frequently occurs as an autoimmune complication of immune reconstitution therapy (IRT), especially in individuals with multiple sclerosis treated with alemtuzumab, a pan-lymphocyte depleting drug with subsequent recovery of immune cell numbers. Less frequently, TD is triggered by highly active antiretroviral therapy (HAART) in patients infected with human immunodeficiency virus (HIV), or patients undergoing bone-marrow/hematopoietic-stem-cell transplantation (BMT/HSCT). In both alemtuzumab-induced TD and HIV/HAART patients, the commonest disorder is Graves' disease (GD), followed by hypothyroidism and thyroiditis; Graves' orbitopathy is observed in some GD patients. On the contrary, GD is rare post-BMT/HSCT, where hypothyroidism predominates probably as a consequence of the associated radiation damage. In alemtuzumab-induced TD, the autoantibodies against the thyrotropin receptor (TRAb) play a major role, and 2 main aspects distinguish this condition from the spontaneous form: (1) up to 20% of GD cases exhibit a fluctuating course, with alternating phases of hyper- and hypothyroidism, due to the coexistence of TRAb with stimulating and blocking function; (2) TRAb are also positive in about 70% of hypothyroid patients, with blocking TRAb responsible for nearly half of the cases. The present guidelines will provide up-to-date recommendations and suggestions dedicated to all phases of IRT-induced TD: (1) screening before IRT (recommendations 1-3); (2) monitoring during/after IRT (recommendations 4-7); (3) management of TD post-IRT (recommendations 8-17). The clinical management of IRT-induced TD, and in particular GD, can be challenging. In these guidelines, we propose a summary algorithm which has particular utility for nonspecialist physicians and which is tailored toward management of alemtuzumab-induced TD. However, we recommend prompt referral to specialist endocrinology services following diagnosis of any IRT-induced TD diagnosis, and in particular for pregnant women and those considering pregnancy

Sex hormone-binding globulin regulation of androgen bioactivity in vivo : validation of the free hormone hypothesis

Sex hormone-binding globulin (SHBG) is the high-affinity binding protein for androgens and estrogens. According to the free hormone hypothesis, SHBG modulates the bioactivity of sex steroids by limiting their diffusion into target tissues. Still, the in vivo physiological role of circulating SHBG remains unclear, especially since mice and rats lack circulating SHBG post-natally. To test the free hormone hypothesis in vivo, we examined total and free sex steroid concentrations and bioactivity on target organs in mice expressing a human SHBG transgene. SHBG increased total androgen and estrogen concentrations via hypothalamic-pituitary feedback regulation and prolonged ligand half-life. Despite markedly raised total sex steroid concentrations, free testosterone was unaffected while sex steroid bioactivity on male and female reproductive organs was attenuated. This occurred via a liganddependent, genotype-independent mechanism according to in vitro seminal vesicle organ cultures. These results provide compelling support for the determination of free or bioavailable sex steroid concentrations in medicine, and clarify important comparative differences between translational mouse models and human endocrinology

Androgen action on renal calcium and phosphate handling: Effects of bisphosphonate treatment and low calcium diet

Renal calcium and phosphate handling is an important contributor to mineral homeostasis and bone health and the androgen receptor (AR) is highly expressed in the kidney. We investigated the short term effects of androgen deprivation on renal calcium and phosphate reabsorption, independent of their effects on bone. Two weeks following orchidectomy (ORX) of adult mice, bone loss occurred along with hypercalciuria, which was similarly prevented by testosterone and dihydrotestosterone supplementation. Treatment with bisphosphonates prior to ORX also inhibited hypercalciuria, indicating that the calcium flux originated from the bone. Renal calcium and phosphate transporter expression was increased post-ORX, independent of bisphosphonates. Furthermore, androgen deprivation appeared to stimulate local synthesis of 1,25(OH)2D3. When bisphosphonate-treated mice were fed a low calcium diet, bone resorption was no longer blocked and secondary hyperparathyroidism developed, which was more pronounced in ORX mice than sham-operated mice. In conclusion, this study shows that androgen deprivation increased renal calcium and phosphate transporter expression, independent of bone, and underlines the importance of adequate intestinal calcium supply in circumstances of androgen deprivation and bisphosphonate treatment.status: publishe

2019 European thyroid association guidelines on the management of thyroid dysfunction following immune reconstitution therapy

Thyroid dysfunction (TD) frequently occurs as an autoimmune complication of immune reconstitution therapy (IRT), especially in individuals with multiple sclerosis treated with alemtuzumab, a pan-lymphocyte depleting drug with subsequent recovery of immune cell numbers. Less frequently, TD is triggered by highly active antiretroviral therapy (HAART) in patients infected with human immunodeficiency virus (HIV), or patients undergoing bone-marrow/hematopoietic-stem-cell transplantation (BMT/HSCT). In both alemtuzumab-induced TD and HIV/HAART patients, the commonest disorder is Graves’ disease (GD), followed by hypothyroidism and thyroiditis; Graves’ orbitopathy is observed in some GD patients. On the contrary, GD is rare post-BMT/HSCT, where hypothyroidism predominates probably as a consequence of the associated radiation damage. In alemtuzumab-induced TD, the autoantibodies against the thyrotropin receptor (TRAb) play a major role, and 2 main aspects distinguish this condition from the spontaneous form: (1) up to 20% of GD cases exhibit a fluctuating course, with alternating phases of hyper- and hypothyroidism, due to the coexistence of TRAb with stimulating and blocking function; (2) TRAb are also positive in about 70% of hypothyroid patients, with blocking TRAb responsible for nearly half of the cases. The present guidelines will provide up-to-date recommendations and suggestions dedicated to all phases of IRT-induced TD: (1) screening before IRT (recommendations 1–3); (2) monitoring during/after IRT (recommendations 4–7); (3) management of TD post-IRT (recommendations 8–17). The clinical management of IRT-induced TD, and in particular GD, can be challenging. In these guidelines, we propose a summary algorithm which has particular utility for nonspecialist physicians and which is tailored toward management of alemtuzumab-induced TD. However, we recommend prompt referral to specialist endocrinology services following diagnosis of any IRT-induced TD diagnosis, and in particular for pregnant women and those considering pregnancy

Early effects of androgen deprivation on bone and mineral homeostasis in adult men: a prospective cohort study

Objective: Long-term androgen deprivation therapy (ADT) negatively influences bone. The short term effects on bone and mineral homeostasis are less known. Therefore, we aimed to investigate the early effects of ADT on calcium/phosphate homeostasis and bone turnover. Design: Prospective cohort study Methods: Eugonadal adult male sex offenders, who were referred for ADT to the endocrine outpatient clinic, received cyproterone acetate. Changes in blood markers of calcium/phosphate homeostasis and bone turnover between baseline and first follow-up visit were studied. Results: Of 26 screened patients, 17 were included. The median age was 44 (range 20-75) years. The median time interval between baseline and first follow-up was 13 (6-27) weeks. Compared to baseline, an 81% decrease was observed for median total testosterone (to 3.4 nmol/L (0.4-12.2); P<0.0001) and free testosterone (to 0.06 nmol/L (0.01-0.18); P<0.0001). Median total estradiol decreased 71% (to 17.6 pmol/L (4.7-35.6); P<0.0001). Increased serum calcium (P<0.0001) and phosphate (P=0.0016) was observed, paralleled by decreased PTH (P=0.0156) and 1,25 dihydroxyvitamin D3 (P=0.0134). The stable calcium isotope ratio (δ44/42Ca) decreased (P=0.0458), indicating net calcium loss from bone. Bone-specific alkaline phosphatase and osteocalcin decreased (P<0.0001 and P=0.0056, respectively), periostin tended to decrease (P=0.0500) whereas sclerostin increased (P<0.0001), indicating suppressed bone formation. Serum bone resorption markers (TRAcP5b, CTX) were unaltered. Conclusions: In adult men, calcium release from the skeleton occurs early following sex steroid deprivation, reflecting early bone resorption. The increase of sclerostin and reduction of bone formation markers, without changes in resorption markers, suggests a dominant negative effect on bone formation in the acute phase

Genome-wide DNA methylation analysis of pseudohypoparathyroidism patients with GNAS imprinting defects

Background: Pseudohypoparathyroidism (PHP) is caused by (epi) genetic defects in the imprinted GNAS cluster. Current classification of PHP patients is hampered by clinical and molecular diagnostic overlaps. The European Consortium for the study of PHP designed a genome-wide methylation study to improve molecular diagnosis. Methods: The Human Methylation 450K BeadChip was used to analyze genome-wide methylation in 24 PHP patients with parathyroid hormone resistance and 20 age- and gender-matched controls. Patients were previously diagnosed with GNAS-specific differentially methylated regions (DMRs) and include 6 patients with known STX16 deletion (PHP Delta stx16) and 18 without deletion (PHPneg). Results: The array demonstrated that PHP patients do not show DNA methylation differences at the whole-genome level. Unsupervised clustering of GNAS-specific DMRs divides PHP Delta stx16 versus PHPneg patients. Interestingly, in contrast to the notion that all PHP patients share methylation defects in the A/B DMR while only PHP Delta stx16 patients have normal NESP, GNAS-AS1 and XL methylation, we found a novel DMR (named GNAS-AS2) in the GNAS-AS1 region that is significantly different in both PHP Delta stx16 and PHPneg, as validated by Sequenom EpiTYPER in a larger PHP cohort. The analysis of 58 DMRs revealed that 8/18 PHPneg and 1/6 PHP Delta stx16 patients have multi-locus methylation defects. Validation was performed for FANCC and SVOPL DMRs. Conclusions: This is the first genome-wide methylation study for PHP patients that confirmed that GNAS is the most significant DMR, and the presence of STX16 deletion divides PHP patients in two groups. Moreover, a novel GNAS-AS2 DMR affects all PHP patients, and PHP patients seem sensitive to multi-locus methylation defects

Standardization of free thyroxine measurements allows the adoption of a more uniform reference interval

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Use of thyroid hormones in hypothyroid and euthyroid patients: a THESIS* survey of Belgian specialists *THESIS: treatment of hypothyroidism in Europe by specialists: an international survey.

[en] BACKGROUND: Hypothyroidism is a topic that continues to provoke debate and controversy with regards to specific indications, type of thyroid hormone substitution and efficacy. We investigated the use of thyroid hormones in clinical practice in Belgium, a country where currently only levothyroxine (LT4) tablet formulations are available. METHOD: Members of the Belgian Endocrine Society were invited to respond to an online questionnaire. Results were compared with those from other THESIS surveys. RESULTS: Eighty (50%) of the invited 160 individuals, completed the questionnaire. LT4 was the first treatment of choice for all respondents. As secondary choice, some also prescribed liothyronine (LT3) and LT4 + LT3 combinations (2 and 7 respondents, respectively). Besides hypothyroidism, 34 and 50% of respondents used thyroid hormones for infertile euthyroid TPOAb positive women and the treatment of a growing non-toxic goiter, respectively. Had alternative formulations of LT4 to tablets been available (soft gel or liquid L-T4), 2 out of 80 (2.5%) participants would consider them for patients achieving biochemical euthyroidism but remaining symptomatic. This proportion was higher in case of unexplained poor biochemical control of hypothyroidism (13.5%) and in patients with celiac disease or malabsorption or interfering drugs (10%). In symptomatic euthyroid patients, 20% of respondents would try combined LT4 + LT3 treatment. Psychosocial factors were highlighted as the main contributors to persistent symptoms. CONCLUSIONS: LT4 tablets is the preferred treatment for hypothyroidism in Belgium. A minority of the respondents would try combined LT4 + LT3 in symptomatic but biochemically euthyroid patients. Thyroid hormones are prescribed for euthyroid infertile women with thyroid autoimmunity and patients with non-toxic goiter, a tendency noted in other European countries, despite current evidence of lack of benefit