Hyperparathyroid and hypoparathyroid disorders

Increased Risk of Chronic Kidney Disease After Total Thyroidectomy: A Nationwide Matched Cohort Study

BACKGROUND

Development of hypoparathyroidism (hypoPT) after total thyroidectomy (TT) may increase the risk of kidney-related morbidity. We aimed to examine the risk of hypoPT and chronic kidney disease (CKD) in patients undergoing TT in Denmark over a 20-year period.

MATERIALS AND METHODS

Using population-based registries, we identified all Danish individuals with TT between January 1998 and December 2017. We included a matched comparison cohort by randomly selecting 10 citizens for each patient by sex and birth year. We calculated the cumulative incidence and hazard ratio (HR) of CKD by Cox regression in patients with TT compared with the comparison cohort. Further, CKD risks were stratified by indications for TT and comorbidity groups according to the Charlson Comorbidity Index.

RESULTS

We included 2421 patients with TT; 21.5% had hypoPT. After 10 years, the risk of developing CKD for hypoPT patients was 13.5% [95% confidence interval (CI): 9.8-17.7], 11.6% (95% CI: 9.7-13.7) for patients without hypoPT, and 5.8% (95% CI: 5.3-6.2) for the comparison cohort. When compared with the matched comparison cohort, the adjusted HR for CKD in hypoPT patients was 3.23 (95% CI: 2.37-4.41) and 2.27 (95% CI: 1.87-2.75) for patients without hypoPT. For patients without previous comorbidities, the adjusted HR of CKD was higher than in patients with several comorbidities.

CONCLUSION

HypoPT was a frequent complication after TT and was associated with an increased risk of CKD. We also found an increased risk of CKD in patients with a normal parathyroid function after TT, which needs to be further evaluated.

Exploring a Rare Association: Systematic Review of Hypercalcemia in Nontuberculous Mycobacterial Infections

Hypercalcemia represents a rare complication of nontuberculous Mycobacterium (NTM) infections, particularly in individuals with human immunodeficiency virus (HIV) positivity. This systematic review examines NTM infections associated with hypercalcemia, including the presentation of a novel and illustrative case of Mycobacterium simiae. A meticulous literature search identified 24 cases relevant to this phenomenon (11 HIV-positive and 13 non-HIV), which were included in the analysis. Key clinical and laboratory findings reveal significant contrasts between HIV-positive and non-HIV patients. In the HIV-positive cohort, hypercalcemia is commonly developed after the initiation of highly active antiretroviral therapy (HAART) or treatment for NTM infections despite severe underlying immunosuppression. Conversely, in the non-HIV group, a spectrum of immunosuppressive conditions, including chronic renal failure and prolonged use of immunosuppressive drugs, was implicated in the pathogenesis of NTM infections with hypercalcemia. Two distinct mechanistic pathways likely underlie this association. In HIV-positive patients, immune restoration following HAART appears to drive granuloma formation and excessive 1,25-dihydroxyvitamin D production. In non-HIV individuals, prolonged immune suppression may facilitate macrophage activation associated with NTM infections, thereby contributing to hypercalcemia. Treatment strategies varied and included bisphosphonates, corticosteroids, and hemodialysis. Notably, bisphosphonates emerged as a safe and effective option in most cases. Antibiotic therapy was deemed unnecessary when hypercalcemia was the sole symptom of NTM infection. This review underscores the importance of recognizing hypercalcemia as a potential complication of NTM infections and tailoring management strategies to the patient's underlying immunological status.

Diagnostic Approach to the Patient with Altered Mental Status

Acute encephalopathy is a common presenting symptom in the emergency room and complicates many hospital and intensive care unit admissions. The evaluation of patients with encephalopathy poses several challenges: limited history and examination due to the patient's mental status, broad differential diagnosis of systemic and neurologic etiologies, low yield of neurodiagnostic testing due to the high base rate of systemic causes, and the importance of identifying less common neurologic causes of encephalopathy that can be life-threatening if not identified and treated. This article discusses the differential diagnosis of acute encephalopathy, presents an approach to the history and examination in a patient with encephalopathy, reviews the literature on the yield of neurodiagnostic testing in this population, and provides a diagnostic framework for the evaluation of patients with altered mental status.

Evaluation of the Protective Effects of Lugol's Solution in Rats Poisoned with Aluminum Phosphide (Rice Tablets)

Aluminum phosphide (AlP) is the main component of rice tablets (a pesticide), which produces phosphine gas (PH3) when exposed to stomach acid. The most important symptoms of PH3 toxicity include, lethargy, tachycardia, hypotension, and cardiac shock. It was shown that Iodine can chemically react with PH3, and the purpose of this study is to investigate the protective effects of Lugol solution in poisoning with rice tablets. Five doses (12, 15, 21, 23, and 25 mg/kg) of AlP were selected, for calculating its lethal dose (LD50). Then, the rats were divided into 4 groups: AlP, Lugol, AlP + Lugol, and Almond oil (as a control). After 4 h, the blood pressure and electrocardiogram (ECG) were recorded, and blood samples were obtained for biochemical tests, then liver, lung, kidney, heart, and brain tissues were removed for histopathological examination. The results of the blood pressure showed no significant changes (P > 0.05). In ECG, the PR interval showed a significant decrease in the AlP + Lugol group (P < 0.05). In biochemical tests, LDH, Ca2+, Creatinine, ALP, Mg2+, and K+ represented significant decreases in AlP + Lugol compared to the AlP group (P < 0.05). Also, the administration of Lugol's solution to AlP-poisoned rats resulted in a significant decrease in malondialdehyde levels and a significant increase in catalase activity (P < 0.05). Histopathological evaluation indicates that Lugol improves changes in the lungs, kidneys, brain, and heart. Our results showed that the Lugol solution could reduce tissue damage and oxidative stress in AlP-poisoned rats. We assume that the positive effects of Lugol on pulmonary and cardiac tissues are due to its ability to react directly with PH3.

Calcium Disorders

This article provides a comprehensive overview of calcium physiology, clinical presentation with physical examination findings, laboratory assessment, differential diagnosis, and management of hypocalcemia and hypercalcemia for the primary care provider.

Acute pancreatitis and refractory hypercalcemia in the third trimester caused by parathyroid carcinoma

BACKGROUND

Hypercalcemia can be a rare contributor to acute pancreatitis (AP) in pregnancy. This is primarily due to primary hyperparathyroidism (PHPT), resulting from parathyroid carcinoma. We exhibited a case report to analyze the diagnosis and treatment during the onset of hypercalcemia-induced AP.

CASE PRESENTATION

A 32-year-old primigravida presented with acute pancreatitis near full-term gestation. Following a cesarean delivery, there was a reduction in serum amylase and peripancreatic exudate, but her serum calcium concentrations persistently elevated over 4.0 mmol/L. Interventions to lower the hypercalcemia were only temporarily effective, until a high serum parathyroid hormone (PTH) concentration of 1404 pg/mL was detected. Ultrasound revealed a 31 mm × 24 mm hypoechoic oval nodule in the left lower lobe of the thyroid gland. She underwent a parathyroidectomy, resulting in a dramatic decrease in serum PTH level, from preoperative levels of 2051 pg/mL to 299 pg/mL just 20 minutes after removal. Similarly, her serum calcium declined from 3.82 mmol/L to 1.73 mmol/L within 24 hours postoperatively. The final histopathology suggested parathyroid carcinoma.

CONCLUSION

When refractory hypercalcemia is present, serum PTH levels should be measured to determine PHPT. Parathyroidectomy is the optimal strategy for alleviating hypercalcemia and clarifying the underlying pathology.

Four-dimensional computed tomography as first-line imaging in primary hyperparathyroidism, a retrospective comparison to conventional imaging in a predominantly single adenoma population

BACKGROUND

To determine the use of four-dimensional CT as first-line imaging compared to the traditional combination of ultrasound and [99mTc]Tc-Sestamibi SPECT.

MATERIALS AND METHODS

Retrospective review of preoperative imaging in patients with primary hyperparathyroidism, who underwent parathyroidectomy between 2012 and 2021. In one group, the combination ultrasound and [99mTc]Tc-Sestamibi SPECT was used as first-line imaging (n = 54), in the other group four-dimensional CT was the first-line imaging modality (n = 51). Sensitivity and positive predictive value were calculated on patient, lateralisation and localisation level. The need for additional imaging was also assessed for both groups.

RESULTS

Four-dimensional CT had a significantly higher sensitivity compared to the combination of ultrasound/[99mTc]Tc-Sestamibi SPECT on patient and localisation level (70.6% vs. 51.9%, p = 0.049 and 60.8% vs. 35.2%, p = 0.009 respectively). Sensitivity for lateralisation also appeared higher, but did not reach significance (62.7% vs. 44.4%, p = 0.060). Positive predictive value was not significantly higher for four-dimensional CT compared to ultrasound and [99mTc]Tc-Sestamibi SPECT (88.9% vs. 85.7% for lateralisation and 86.1% vs. 67.9% for localisation respectively). Additional imaging was required in 14 patients with four-dimensional CT as first-line imaging (27.4%) consisting of 2 ultrasound/[99mTc]Tc-Sestamibi SPECT and 13 [18F]fluorocholine PET/CT, compared to 24 patients with ultrasound/[99mTc]Tc-Sestamibi SPECT as first-line imaging (44.4%), requiring 22 four-dimensional CT and 9 [18F]fluorocholine PET/CT.

CONCLUSIONS

Four-dimensional CT as the sole first-line parathyroid imaging modality had higher sensitivity than the combination of ultrasound and [99mTc]Tc-Sestamibi SPECT, therefore requiring fewer additional procedures. Although the most costly, [18F]fluorocholine PET/CT was the most effective technique to localise parathyroid adenoma in case all other imaging was negative.

Hypoparathyroidism and mortality after total thyroidectomy: A nationwide matched cohort study

OBJECTIVE

Total thyroidectomy (TT) carries a risk of hypoparathyroidism (hypoPT). Recently, hypoPT has been associated with higher overall mortality rates. We aimed to evaluate the frequency of hypoPT and mortality in patients undergoing TT in Denmark covering 20 years.

DESIGN

Retrospective Cohort study.

PATIENTS AND MEASUREMENTS

Using population-based registries, we identified all Danish individuals who had undergone TT between January 1998 and December 2017. We included a comparison cohort by randomly selecting 10 citizens for each patient, matched on sex and birth year. HypoPT was defined as treatment with active vitamin D after 12 months postoperatively. We used cumulative incidence to calculate risks and Cox regression to compare the rate of mortality between patients and the comparison cohort. We evaluated patients in different comorbidity groups using the Charlson Comorbidity Index and by different indications for surgery.

RESULTS

7912 patients underwent TT in the period. The prevalence of hypoPT in the study period was 16.6%, 12 months postoperatively. After adjusting for potential confounders the risk of death due to any causes (hazard ratio; 95% confidence intervals) following TT was significantly increased (1.34; 1.15-1.56) for patients who developed hypoPT. However, subgroup analysis revealed mortality was only increased in malignancy cases (2.48; 1.99-3.10) whereas mortality was not increased when surgery was due to benign indications such as goitre (0.88; 0.68-1.15) or thyrotoxicosis (0.86; 0.57-1.28).

CONCLUSIONS

The use of active vitamin D for hypoPT was prevalent one year after TT. Patients with hypoPT did not have an increased risk of mortality following TT unless the indication was due to malignancy.

Assessment of quality of life in patients with permanent hypoparathyroidism receiving conventional treatment

Introduction

Patients with permanent hypoparathyroidism suffer from multiple complaints and are exposed to long-term complications that might compromise their well-being. The aim of this study was to assess the quality of life (QoL) in patients with permanent hypoparathyroidism receiving conventional therapy and to determine the associated factors.

Methods

This was a cross-sectional matched case-control study including 53 patients with permanent hypoparathyroidism and 53 matched controls. Biochemical blood parameters (calcium, phosphate, albumin, magnesium, 25-hydroxy-vitamin D, creatinine, TSH, and PTH) and 24-hours calciuria were measured in patients with hypoparathyroidism. QoL was assessed in all participants using the Short Form 36 Health Survey (SF-36).

Results

The study included 53 patients (41 women and 12 men) with hypoparathyroidism receiving conventional therapy.Their mean age was 52.8 ± 16.5 years. In comparison with controls, patients with hypoparathyroidism had significantly lower scores in all eight domains of SF-36 (p < 10- 3). Patients with poor socioeconomic conditions had lower SF-36 scores than those with good conditions.The etiology of hypoparathyroidism, the disease duration, the control of the disease, and the body mass index did not significantly interfere with SF-36 scores. SF-36 total score was negatively correlated with age (r=-0.619, p < 10- 3) and symptoms of hypocalcemia (r=-0.284, p = 0.039), and positively correlated with creatinine clearance (r = 0.559, p < 10- 3), magnesium level (r = 0.345, p = 0.011), and 25 hydroxy-vitamin D level (r = 320, p = 0.021). No significant correlations were found between SF-36 scores and other biological parameters such as calcemia, phosphatemia, phosphocalcic product, PTH, TSH, and calciuria.

Conclusion

Patients with permanent hypoparathyroidism had impairment in their QoL. Age, socioeconomic conditions, renal function, magnesium level, and 25 hydroxy-vitamin D level may interfere in the decline of the QoL of these patients.

Primary Hyperparathyroidism in Older Adults: A Narrative Review of the Most Recent Literature on Epidemiology, Diagnosis and Management

BACKGROUND

Primary hyperparathyroidism (PHPT) is a common endocrine disorder among older adults. The aim of this review is to shed light on PHPT, particularly in this age group, in terms of prevalence, clinical manifestations, medical and surgical management, and post-operative complications.

METHODS

Eligible studies were those considering PHPT exclusively in the older population (main databases: PubMed, Medline, Google Scholar and the University Online database). Articles published in the last 10 years (2013-2023) were considered. Eligibility criteria followed the SPIDER (sample, phenomenon of interest, design, evaluation, research type) tool. The methodological quality of the studies was assessed using the Joanna Briggs Institute critical appraisal tool. A total of 29 studies (mainly observational) matched the inclusion criteria.

RESULTS

The prevalence of PHPT is approximately 1 per 100 in the elderly, and it is more common in females. The clinical presentation varies by age and can include osteoporosis, fractures, and neuropsychiatric symptoms. Conservative management can be an option whenever surgery is not indicated or feasible. However, parathyroidectomy (PTX) remains a safe and effective modality in aging populations with improvement to symptoms, bone mineral density, fracture risk, frailty, quality of life, and metabolic derangements. Complication rates are similar in elderly people compared to younger ones, except for mildly longer length of hospital stay and reoperation for those with higher frailty.

CONCLUSION

PHPT is a common yet overlooked and underdiagnosed condition among the older population. The safety and efficacy of PTX in the older population on different levels is now well demonstrated in the literature.

Robot-Assisted Parathyroidectomy Using Indocyanine Green (ICG) Fluorescence in Primary Hyperparathyroidism

Background and Objectives: Surgical treatment for primary hyperparathyroidism (PHPT) has evolved from bilateral exploration through a long transcervical incision to focused parathyroidectomy with a minimal incision above the pathologic gland. Recently, endoscopic or robot-assisted parathyroid surgery without direct neck incision has been introduced. The aim of this study was to investigate the effectiveness of indocyanine green (ICG) fluorescence as a new method for the visual identification of abnormal hyperfunctioning parathyroid glands in robot-assisted parathyroidectomy using FireflyTM technology. We also aimed to conduct a comparative analysis between robot-assisted parathyroidectomy and conventional focused parathyroidectomy in order to identify clinical differences between the two surgical approaches. Materials and Methods: A total of 37 patients with PHPT underwent parathyroidectomy at a single university hospital between September 2018 and December 2022. Thirty-one patients underwent open focused parathyroidectomy (open group), and six patients underwent robot-assisted parathyroidectomy (robot group). Pre-operative localization via parathyroid SPECT-CT and an intraoperative parathyroid hormone (IOPTH) assay were used to successfully remove the pathologic parathyroid in both groups. ICG was administered only in the robot group. Results: Pathologic parathyroid showed a persistent fluorescence pattern under near-infrared vision. After the removal of the fluorescent parathyroid gland, IOPTH was normalized in all six patients in the robot group. However, the open group showed shorter hospital stays (1.8 ± 1.2 vs. 3.0 ± 0.0 days, p < 0.001) and shorter operation times (91.1 ± 69.1 vs. 152.5 ± 23.6 min, p = 0.001) than the robot group. After 6 months of surgery, PTH, calcium, and ionized calcium levels were all normalized without significant differences between the groups. Conclusions: Robot-assisted parathyroidectomy using ICG is helpful for the visual identification of the pathologic parathyroid gland. The advantage of robot parathyroidectomy is a better cosmetic outcome. However, it still does not show better clinical outcomes than conventional open focused parathyroidectomy.

Postoperative hypoparathyroidism after thyroid operation and exploration of permanent hypoparathyroidism evaluation

Background

To investigate the risk factors for hypoparathyroidism, discuss the prevention of postoperative hypoparathyroidism, and explore permanent postoperative hypoparathyroidism evaluation (PPHE).

Methods

A total of 2,903 patients with thyroid nodules were treated between October 2012 and August 2015. Serum calcium and intact parathyroid hormone (iPTH) levels were measured at 1 day, 1 month, and 6 months postoperatively. The incidence and management of hypoparathyroidism were analyzed. The PPHE was established based on the risk factors and clinical practice.

Results

A total of 637 (21.94%) patients developed hypoparathyroidism, and 92.15% of them had malignant nodules. The incidence rates of transient and permanent hypoparathyroidism were 11.47% and 10.47%, respectively. The iPTH level was lower in patients with malignant nodules who underwent total thyroidectomy (TT) and central-compartment neck dissection (CND). These factors were independently associated with the recovery rate of parathyroid function. The formula for PPHE is as follows: {iPTH} + {sCa} + {surgical procedure} + {reoperation} + {pathologic type}. A scoring system was developed, and we scored low, middle, and high risk of permanent postoperative hypoparathyroidism as 4-6, 7-9, and 10-13, respectively. The differences in the recovery rates of parathyroid function in several risk groups were statistically significant (p < 0.001).

Conclusion

Simultaneous TT and CND is a risk factor for hypoparathyroidism. The reoperation is not associated with hypoparathyroidism. Identification of parathyroid glands in situ and preservation of their vascular pedicles are key factors in managing hypoparathyroidism. PPHE can forecast the risk of permanent postoperative hypoparathyroidism well.

Bioactive, full-length parathyroid hormone delivered using an adeno-associated viral vector

Delivering the parathyroid hormone (PTH) gene has been attempted preclinically in a handful of studies, but delivering full-length PTH (1-84) using adeno-associated viral (AAV) vectors has not. Given the difficulty in achieving therapeutic levels of secreted proteins using gene therapy, this study seeks to determine the feasibility of doing so with PTH. An AAV vector was used to deliver human PTH driven by a strong promoter. We demonstrate the ability to secrete full-length PTH from various cell types in vitro. PTH secretion from hepatocytes was measured over time and a fluorescent marker was used to compare the secretion rate of PTH in various cell types. Potency was measured by the ability of PTH to act on the PTH receptors of osteosarcoma cells and induced proliferation. PTH showed potency in vitro by inducing proliferation in two osteosarcoma cell lines. In vivo, AAV was administered systemically in immunocompromised mice which received xenografts of osteosarcoma cells. Animals that received the highest dose of AAV-PTH had higher liver and plasma concentrations of PTH. All dosing groups achieved measurable plasma concentrations of human PTH that were above the normal range. The high-dose group also had significantly larger tumors compared to control groups on the final day of the study. The tumors also showed dose-dependent differences in morphology. When looking at endocrine signaling and endogenous bone turnover, we observed a significant difference in tibial growth plate width in animals that received the high-dose AAV as well as dose-dependent changes in blood biomarkers related to PTH. This proof-of-concept study shows promise for further exploration of an AAV gene therapy to deliver full-length PTH for hypoparathyroidism. Additional investigation will determine efficacy in a disease model, but data shown establish bioactivity in well-established models of osteosarcoma.

[Hypercalcemia - Diagnosis and Management]

Hypercalcemia - Diagnosis and Management Abstract. The diagnostic workup of hypercalcemia requires a thorough patient history, a focused clinical examination as well as a step-by-step laboratory diagnostic approach. In order to detect the exact aetiology of hypercalcemia an accurate measurement of serum calcium in correlation with the parathyroid hormone level is therefore essential. Primary hyperparathyroidism and malignancy-related hypercalcemia are responsible for about 90% of all hypercalcemia cases. Therefore, these two pathologies should always be considered in the diagnostic approach. The therapeutic procedure is based on the aetiology and severity of the hypercalcemia.

Parathyroid Cell Differentiation from Progenitor Cells and Stem Cells: Development, Molecular Mechanism, Function, and Tissue Engineering

Parathyroid glands are endocrine organs which are located posterior to thyroid glands and control secretion of parathyroid hormone (PTH) in order to regulate blood calcium level. PTH maintains calcium homeostasis by acting on the bone, kidney, and small intestine. PTH deficiency leads to chronic hypocalcemia, organ calcinosis, kidney and heart failure, painful muscle spasms, neuromuscular problems, and memory problems. Since parathyroid cells have inadequate proliferation potential in culture conditions, their utilization as a cellular therapy option is very limited. Although studies conducted so far include parathyroid cell differentiation from various cell types, problems related to successful cellular differentiation and transplantation still remain. Recently, parathyroid tissue engineering has attracted attention as a potential treatment for the parathyroid-related diseases caused by hypoparathyroidism. Although major progression is made in the construction of tissue engineering protocols using parathyroid cells and biomaterials, PTH secretion to mimic its spontaneous harmony in the body is a challenge. This chapter comprehensively defines the derivation of parathyroid cells from various cell sources including pluripotent stem cells, molecular mechanisms, and tissue engineering applications.

Assessment of calcium and vitamin D medications adherence in patients with hypoparathyroidism after thyroidectomy

In this study, we found that patients with hypoparathyroidism had a problem with calcium medication compliance, and this problem increased with the duration of the disease. We also showed that patients are concerned about the possible side effects of drugs.

INTRODUCTION

In this study, we aimed to evaluate adherence to active vitamin D and calcium replacement in patients with post-surgical hypoparathyroidism.

METHODS

To elucidate the medication adherence, we performed a questionnaire survey using the six-item "Medication adherence questionnaire"(MAQ). The first, second, and sixth questions reflect the motivation status of the patients whereas the third, fourth, and fifth questions reflect the knowledge about the medication that is received. The responses are scored and patients are classified regarding their motivation to and knowledge about the particular drug.

RESULTS

Totally, 64 patients (male: 12/female: 52; mean age 48.6±11.6 years) who had post-operative hypoparathyroidism were included in our study. Median disease durance was 60 months (min-max: 12-295 months). We found that motivation score of calcium usage was significantly lower compared to vitamin D usage (p<0.001). The calcium motivation score was reversely correlated with disease duration (r= -0.256 and p=0.046). The most common worry about calcium usage was nephrotoxicity, and the most common worries about calcitriol treatment were kidney damage and polyuria. One-third of the patients were taking oral calcium and calcitriol less than the recommended dose.

CONCLUSION

One-third of patients lack motivation to use calcium whereas half of the patients experiences anxiety about drug-related side effects. This is a preliminary study showing that vital calcium and active vitamin D intake may be interrupted due to side effect anxiety.

Effect of Citrate-Acidified Dialysate on Intact Parathyroid Hormone in Prevalent Hemodialysis Patients: A Matched Retrospective Cohort Study

Background

It has been proposed that substituting citrate-acidified dialysate (CAD) solutions for acetate-acidified dialysate (AAD) could improve hemodynamics and dialysis tolerance and reduce the requirement for systemic anticoagulation. Citrate chelates ionized calcium, but long-term effects of CAD use during maintenance hemodialysis have not been well studied. While many studies of the effects of CAD on serum calcium and intact parathyroid hormone (iPTH) have been short-term or have been limited by sample size, we aimed to determine if there are any long-term (i.e., 6-month) changes from pre-dialysis iPTH levels when patients are switched from AAD to CAD.

Methods

This retrospective cohort study compared various clinical parameters, including pre-dialysis iPTH and serum calcium as well as single pool Kt/V, from eligible patients who received in-center hemodialysis thrice-weekly in geographically matched CAD (n=3) or AAD clinics (n=12). CAD clinics were defined as clinics converting from AAD to CAD if >85% of the patients were prescribed CAD after implementation of CAD within the clinic.

Results

Pre-dialysis iPTH was not significantly different from baseline to 6-month follow-up within either CAD or AAD clinics. Moreover, the mean change from baseline to month 6 in iPTH between patients (n=142) in CAD clinics (−17 pg/mL) and patients (n=671) in AAD clinics (13 pg/mL) was similar (p = 0.24). Likewise, the differences in the mean change in serum calcium concentrations and dialysis adequacy (single pool Kt/V) were not significant between CAD and AAD clinics. For subgroups of patients who were never prescribed cinacalcet or calcium-based phosphate binders, there were no significantly different categorical shifts in iPTH between CAD and AAD clinics.

Conclusion

Similar trends in single pool Kt/V, iPTH, and serum calcium levels were observed in clinics that switched from AAD to CAD versus the geographically matched AAD clinics. These results support CAD as a potential alternative to AAD in hemodialysis.

Bee venom acupuncture therapy ameliorates neuroinflammatory alterations in a pilocarpine-induced epilepticus model

Bee venom (BV) is applied in different traditional medicinal therapies and is used worldwide to prevent and treat many acute and chronic diseases. Epilepsy has various neurological effects, e.g., epileptogenic insults; thus, it is considered a life-threatening condition. Seizures and their effects add to the burden of epilepsy because they can have health effects including residual disability and even premature mortality. The use of antiinflammatory drugs to treat epilepsy is controversial; therefore, the alternative nonchemical apitherapy benefits of BV were evaluated in the present study by assessing neuroinflammatory changes in a pilocarpine-induced epilepticus model. Levels of electrolytes, neurotransmitters, and mRNA expression for some gate channels were determined. Moreover, ELISA assays were conducted to detect pro- and anti-inflammatory cytokines, whereas RT-PCR was performed to assess mRNA expression of Foxp3 and CTLA-4. BV ameliorated the interruption in electrolytes and ions through voltage- and ligand-gated ion channels, and it limited neuronal excitability via rapid repolarization of action potentials. In addition, BV inhibited the high expression of proinflammatory cytokines. Acupuncture with BV was effective in preventing some of the deleterious consequences of epileptogenesis associated with high levels of glutamate and DOPA in the hippocampus. BV ameliorates changes in the expression of voltage-gated channels, rebalances blood electrolytes and neurotransmitters, and modulates the levels of pro- and anti-inflammatory cytokines. Thus, BV could reduce the progression of epileptogenesis as a cotherapy with other antiepileptic drugs.

Changes in treatment needs for chronic postoperative hypoparathyroidism during initiation of conventional treatment compared to stable phase of treatment

INTRODUCTION

In our clinical experience, need for doses of active vitamin D and calcium supplements changes during the period following a diagnosis of postsurgical hypoparathyroidism (HypoPT), but only sparse data are available. In the present study, we aimed to investigate the magnitude of changes in need for activated vitamin D (alfacalcidol) and calcium supplements during initiation of therapy as well as time to be expected until a stable phase was achieved. Furthermore, we determined the frequency of (unexpected) episodes of hypo- and hypercalcaemia after reaching a steady state for alfacalcidol and calcium.

METHODS

Retrospective study of twenty-four patients with chronic postsurgical HypoPT (>6 months) diagnosed from 2016 to 2018. Data were extracted from medical records on doses of alfacalcidol and calcium as well as ionized plasma calcium levels (P-Ca2+) from time of diagnosis and until 86 weeks after surgery.

RESULTS

Patients were treated with alfacalcidol and calcium in order to maintain a stable concentration of P-Ca2+. Our data demonstrated a great variation in treatment needs until 11 weeks after surgery, where the mean doses of alfacalcidol stabilize, while calcium doses stabilized a bit earlier. After the stable phase had emerged, 21 out of 24 patients continued to have one or more episodes of spontaneous hypo- or hypercalcaemia.

CONCLUSIONS

Patients with chronic HypoPT attain a steady state for alfacalcidol 11 weeks after the diagnosis. Continuous monitoring of P-Ca2+ is of continued importance after reaching steady state due to a high frequency of spontaneous hypo- or hypercalcaemia.

An Institutional experience with primary hyperparathyroidism in the elderly over two decades

BACKGROUND

Parathyroidectomy is the only curative treatment for primary hyperparathyroidism (pHPT) and is associated with low morbidity. This study examined the severity of disease and outcomes of parathyroidectomy based on patient age at a high-volume institution.

METHODS

This is a retrospective review of sporadic pHPT patients who underwent initial parathyroidectomy. To study disease severity over time, patients were divided into timeframes: 1999-2007, 2007-2012, and 2013-2018. Elderly was defined as age ≥75 years.

RESULTS

Over time, the elderly had progressively lower preoperative calcium (11.0, 10.7, 10.7; p = 0.05) and PTH (150.4, 111.9, 107.9; p < 0.001) levels. By age, there was no difference in preoperative calcium (10.8, 10.9; p = 0.91) or in rates of recurrent laryngeal nerve injury, hypoparathyroidism, or persistent/recurrent pHPT.

CONCLUSIONS

Over the 3 time periods of the study, elderly patients had progressively lower calcium and PTH levels. There was no difference in endocrine-specific complications between the age groups, suggesting that parathyroidectomy in the elderly is safe and therefore, age-associated morbidity should not preclude parathyroidectomy.

Misleading localization by 18F-fluorocholine PET/CT in familial hypocalciuric hypercalcemia type-3: a case report

BACKGROUND

Familial hypocalciuric hypercalcemia (FHH) is a heterogeneous autosomal-dominant disorder of calcium hemostasis that may be difficult to distinguish clinically from mild primary hyperparathyroidism. Loss-of-function mutations mainly involving Arg15 residue of the adaptor-related protein complex 2, sigma subunit 1 (AP2S1) cause a rarer, more recently recognized form of FHH, FFH type-3. Recently, ¹⁸F-fluorocholine positron emission tomography/computed tomography (FCH-PET/CT) showed superior sensitivity to conventional imaging in localizing parathyroid adenomas. We report a new FFH type-3 patient who underwent unnecessary parathyroidectomy in association with misleading FCH-PET/CT imaging.

CASE PRESENTATION

A 29-year old woman was initially evaluated for parathyroid hormone (PTH)-dependent hypercalcemia in 2013. Medical history was positive only for chronic constipation and malaise with no personal or family history of hypercalcemia, kidney stones, or neck surgery. Over seven years, serum calcium level was 2.51-2.89 mmol/L with concomitant PTH level of 58.7-94.8 mmol/L. Serum phosphate levels were in the low/low normal range. Serum creatinine and magnesium levels were normal. 25-hydroxy vitamin D level was 13 nmol/L. 24-hour urine calcium level was 1.92 mmol/day but increased to 6.99 mmol/day after treatment with cholecalciferol 1000 IU daily. Bone mineral density and renal ultrasound were normal. Parathyroid ultrasound showed two hypoechoic nodules inferior to the left and right thyroid lobes; however, ^99mtechnitium-sestamibi scans (2013, 2016, 2018) were negative. FCH-PET/CT (2019) showed focal uptake co-localizing with the nodule inferior to the left thyroid lobe. The patient underwent left inferior parathyroidectomy and pathology was consistent with parathyroid hyperplasia. However, postoperatively, serum calcium and PTH levels remained elevated and FCH-PET/CT and ultrasound showed persistence of the uptake/nodule. Whole exome sequencing showed Arg15Cys mutation in the AP2S1 gene characteristic of FHH type-3.

CONCLUSIONS

In this new case of FHH type-3, FCH-PET/CT failed to localize to the hyperplastic parathyroid glands and localized instead to apparently a lymph node. This, together with increased urinary calcium after vitamin D supplementation, led to unnecessary parathyroidectomy. Given the increasingly lower cost of genetic testing and the cost of follow up and unnecessary surgery, it may prudent to include genetic testing for FHH early on in patients with mild PTH-dependent hypercalcemia.

Parathyroid adenoma combined with a rib tumor as the primary disease: A case report

BACKGROUND

Parathyroid adenoma is a benign parathyroid tumor, with serum parathyroid hormone and calcium ion concentrations as the typical basis for diagnosis. Its clinical manifestations are complex and changeable; thus it is easily missed or misdiagnosed. Approximately 85% of patients with parathyroid adenoma develop primary hyperparathyroidism, and abnormalities in bones, kidneys and other organs can occur. Brown tumors are rare.

CASE SUMMARY

We report a rare case of fibrocystic osteitis associated with a parathyroid adenoma, which was discovered by chance due to a rib tumor. Abnormally elevated serum parathyroid hormone and calcium ion were found before surgery. We suspected primary hyperparathyroidism, and color Doppler ultrasound suggested the presence of a thyroid mass. With informed consent by the patient and her family, we first removed the rib tumor, and one week later, resection of the parathyroid adenoma and thyroid mass was performed on both sides, and the patient recovered well after surgery.

CONCLUSION

In the case of parathyroid adenoma combined with brown tumor, the bone cyst will gradually decrease in size with time without treatment. If not, surgery should be performed as soon as possible.

The role of selective venous sampling in patients with non-localized primary hyperparathyroidism

Objectives

The aim of this observational clinical study was to evaluate the success of angiographic selective venous sampling (ASVS) in locating parathyroid adenoma in patients with primary hyperparathyroidism (PHPT), in whom the other imaging modalities have failed, and and to evaluate its possible contribution to the applicability of minimal invasive surgery.

Material and Methods

Fifty-five patients who were admitted to our hospital's General Surgery department between January 2012 and January 2015 for PHPT in whom ultrasound and sestamibi scintigraphy have failed to localize the diseased gland were included to the study. Patients were divided into two groups: those who underwent ASVS and those who did not. The outcomes of patients were reviewed retrospectively.

Results

Among 55 patients, 20 underwent ASVS. ASVS successfully lateralized the diseased gland in 17 (85%) patients, and minimally invasive parathyroidectomy could be performed in 14 (70%) patients. The cut-off value of parathormon gradient was considered 10% for lateralization and the accuracy of ASVS in lateralization was 94.1%. In 11 (59%) patients, the superior-inferior discrimination could be achieved in addition to lateralization.

Conclusion

ASVS has a high sensitivity in locating the diseased gland in patients with PHPT in whom ultrasound and sestamibi scan have failed, and thereby, rendering the performance of minimally invasive surgery possible. Further studies may reveal the role of ASVS in providing useful information about not only lateralization but also the superior-inferior discrimination.

Five-year Estimated Glomerular Filtration Rate in Patients With Hypoparathyroidism Treated With and Without rhPTH(1-84)

CONTEXT

Chronic hypoparathyroidism (HypoPT) is conventionally managed with oral calcium and active vitamin D. Recombinant human parathyroid hormone (1-84) (rhPTH[1-84]) is a therapy targeting the pathophysiology of HypoPT by replacing parathyroid hormone.

OBJECTIVE

To compare changes in the estimated glomerular filtration rate (eGFR) in patients with chronic HypoPT receiving or not receiving rhPTH(1-84) during a 5-year period.

DESIGN/SETTING

A retrospective analysis of patients with chronic HypoPT treated with or without rhPTH(1-84).

PATIENTS

Sixty-nine patients with chronic HypoPT from 4 open-label, long-term trials (NCT00732615, NCT01268098, NCT01297309, and NCT02910466) composed the rhPTH(1-84) cohort and 53 patients with chronic HypoPT not receiving rhPTH(1-84) from the Geisinger Healthcare Database (01/2004-06/2016) composed the historical control cohort.

INTERVENTIONS

The rhPTH(1-84) cohort (N = 69) received rhPTH(1-84) therapy; the historical control cohort (N = 53) did not receive rhPTH(1-84).

MAIN OUTCOME MEASURES

Changes in eGFR from baseline during a 5-year follow-up were examined in multivariate regression analyses.

RESULTS

At baseline, demographic characteristics and eGFR were similar between cohorts, though the proportions with diabetes and cardiac disorders were lower in the rhPTH(1-84) cohort. At the end of follow-up, mean eGFR increased by 2.8 mL/min/1.73 m2 in the rhPTH(1-84) cohort, while mean eGFR fell by 8.0 mL/min/1.73 m2 in the control cohort. In the adjusted model, the difference in the annual eGFR change between the rhPTH(1-84) cohort and the control cohort was 1.7 mL/min/1.73 m2 per year (P = 0.009).

CONCLUSIONS

Estimated glomerular filtration rate was preserved for over 5 years among patients with chronic HypoPT receiving rhPTH(1-84) treatment, contrasting with an eGFR decline among those not receiving rhPTH(1-84).

Physical Activity-Dependent Regulation of Parathyroid Hormone and Calcium-Phosphorous Metabolism

Exercise perturbs homeostasis, alters the levels of circulating mediators and hormones, and increases the demand by skeletal muscles and other vital organs for energy substrates. Exercise also affects bone and mineral metabolism, particularly calcium and phosphate, both of which are essential for muscle contraction, neuromuscular signaling, biosynthesis of adenosine triphosphate (ATP), and other energy substrates. Parathyroid hormone (PTH) is involved in the regulation of calcium and phosphate homeostasis. Understanding the effects of exercise on PTH secretion is fundamental for appreciating how the body adapts to exercise. Altered PTH metabolism underlies hyperparathyroidism and hypoparathyroidism, the complications of which affect the organs involved in calcium and phosphorous metabolism (bone and kidney) and other body systems as well. Exercise affects PTH expression and secretion by altering the circulating levels of calcium and phosphate. In turn, PTH responds directly to exercise and exercise-induced myokines. Here, we review the main concepts of the regulation of PTH expression and secretion under physiological conditions, in acute and chronic exercise, and in relation to PTH-related disorders.

Recent advances in understanding and managing hypoparathyroidism

Hypoparathyroidism is a rare endocrine disorder which leads to hypocalcemia, hypercalciuria, and hyperphosphatemia. Complications include nephrocalcinosis with renal dysfunction, reduced quality of life, and abnormal skeletal properties. Conventional therapy with calcium and vitamin D analogs addresses hypocalcemia but has important limitations. Parathyroid hormone (PTH) therapy is a fundamental advance, although the effects of PTH on long-term complications require additional testing. Continuous PTH therapy is likely to be particularly advantageous for addressing renal, quality of life, and skeletal complications. Overall, much progress has been made, yet more information is needed to improve our understanding and management of hypoparathyroidism.

Calcification of Cardiac Valves in Metabolic Bone Disease: An Updated Review of Clinical Studies

Epidemiological and clinical data have suggested the existence of a relationship between cardiovascular diseases and metabolic bone disease. Several studies have demonstrated that heart valve calcification presents substantial similarities with that of bone. Literature data indicate that there are many active processes which promote osteogenesis and loss of mineralization inhibitors that lead to the deposition of extracellular matrix and proteins of bone tissue in cardiac valves. This review aimed to synthesize the available data in order to allow a better understanding of the relationship between osteoporosis or other metabolic bone diseases, such as primary hyperparathyroidism, and valvular calcification in humans. Electronic databases of Pubmed-Medline, Cochrane Library, and SCOPUS from inception to March 31, 2019 were searched. The full set of the articles potentially eligible were carefully assessed and reviewed. Finally, 23 studies were eligible and included in the systematic review. The majority of studies reported that osteoporosis and/or osteopenia were independent risk factors for valvular calcifications, even after adjusting for common cardiovascular risk factors. This suggests that this relationship is not only due to the presence of common cardiovascular risk factors but rather to underlying biological factors that connect them. Instead, regarding the association between primary hyperparathyroidism and valve calcification, conflicting data were found in the literature. To sum up, most of the literature data confirm that cardiac valve calcification processes are strongly influenced by alterations in bone metabolism. In particular, the patients with osteoporosis or primary hyperparathyroidism have an acceleration in the process of valvular calcification. Additional studies are needed to specifically address the mechanisms by which metabolic bone diseases could influence cardiac valve calcification.

A registry for patients with chronic hypoparathyroidism in Russian adults

Hypoparathyroidism and pseudohypoparathyroidism are rare endocrine disorders, characterized by low serum calcium due to inappropriate parathyroid hormone (PTH) levels or resistance to its action. There is little epidemiological information regarding chronic hypoparathyroidism in Russia. This study aims to build a registry database of Russian patients with chronic hypoparathyroidism who were referred for hospital treatment in order to conduct initial analysis of clinical presentations and hospital management. The Italian registry model was taken to be able to integrate our data in the future. Two hundred patients with hypoparathyroidism (n = 194) and pseudohypoparathyroidism (n = 6) were enrolled over 2 years (2017-2019). The most frequent cause of hypoparathyroidism was neck surgery (82.5%, mostly females), followed by idiopathic hypoparathyroidism (10%), syndromic forms of genetic hypoparathyroidism (4.5%) and forms of defective PTH action (3%). Calcium supplements and alfacalcidol were prescribed in most cases. However, a minority of patients (n = 6) needed to receive teriparatide as the only way to maintain calcium levels and to prevent symptoms of hypocalcemia. Consequently, substitution treatment with parathyroid hormone should be available in certain cases of hypoparathyroidism. This database will be useful to estimate the potential requirement for recombinant PTH in Russia and standards for clinical and therapeutic approaches.

18F-Fluorocholine PET and Multiphase CT Integrated in Dual Modality PET/4D-CT for Preoperative Evaluation of Primary Hyperparathyroidism

The present retrospective study evaluates the diagnostic value of integrated ¹⁸F-Fluorocholine positron emission tomography/four-dimensional contrast-enhanced computed tomography (¹⁸F-FCH PET/4D-CT) as second-line imaging in preoperative work-up of primary hyperparathyroidism (pHPT), and compares ¹⁸F-FCH PET with 4D-CT. Patients with pHPT and negative/discordant first-line imaging addressed for integrated ¹⁸F-FCH PET/4D-CT were retrospectively selected. Sensitivity and detection rate (DR%) of ¹⁸F-FCH PET/CT, 4D-CT, and PET/4D-CT were calculated according to the per patient and per lesion analyses, and afterwards compared. Histology associated with a decrease more than 50% of perioperative parathyroid hormone (PTH) blood level was used as a gold standard. Persistent high serum PTH and calcium levels during a 6-month follow-up was considered as presence of pHPT in both operated and non-operated patients. 50 patients (55 glands) were included. 44/50 patients (88%) were surgically treated. On a per patient analysis, sensitivity was 93%, 80%, and 95%, and DR% was 82%, 68%, and 84%, respectively for PET/CT, 4D-CT, and PET/4D-CT. PET/CT was more sensitive than 4D-CT (p = 0.046). PET/4D-CT performed better than 4D-CT (p = 0.013) but was equivalent to PET/CT alone. On a per gland analysis, sensitivity PET/CT, 4D-CT, and PET/4D-CT was 88%, 66%, and 92%, and DR% was 79%, 57%, and 83%, respectively. PET/CT and PET/4D-CT were more sensitive than 4D-CT alone (p = 0.01, p < 0.001, respectively). However, PET/CT and PET/4D-CT performed similarly. In conclusion, ¹⁸F-FCH PET provides better identification of hyperfunctioning parathyroids than 4D-CT and the combination of both did not significantly improve diagnostic sensitivity. Further investigations involving larger populations are necessary to define the role of ¹⁸F-FCH PET/4D-CT as a “one-stop shop” second-line imaging in preoperative work-up of pHPT, especially considering the additional patient radiation exposure due to multi-phase CT.

Case Report: Familial Hypocalciuric Hypercalcaemia and Hashimoto's Thyroiditis

Introduction: Hypercalcaemia can be caused by many disorders. Primary hyperparathyroidism is the leading cause with parathyroidectomy being the definitive management. Familial hypocalciuric hypercalcaemia is a rarer cause in which resection of the parathyroid tissue does not result in normalized serum calcium.

Case presentation: We report the unusual case of a 53-year-old lady who presented with hypercalcaemia and elevated parathyroid hormone with a presumed diagnosis of primary hyperparathyroidism. She remained hypercalcaemic after parathyroidectomy and was later diagnosed with familial hypocalciuric hypercalcaemia. During the first operation, a lymph node was also removed, and the histopathology report suggested a metastasis of follicular variant papillary thyroid carcinoma (FVPTC). After multi-disciplinary team (MDT) discussion, the patient underwent a second exploration where total thyroidectomy and removal of the other parathyroid glands were performed. Hypercalcaemia completely resolved on surgical resection of the thyroid and parathyroid tissue, however histopathology revealed normal parathyroid glands and florid Hashimoto's thyroiditis. The initial diagnosis of FVPTC in the lymph node was revisited and the final histopathology report suggested an accessory thyroid nodule with florid Hashimoto's thyroiditis mimicking a lymph node.

Conclusion: Our case demonstrates the diagnostic dilemma in hypercalcaemia that may lead a patient to undergo unnecessary invasive procedures; the misdiagnosis of FVPTC after the first operation resulted in a second more extensive procedure. Patients with no clear surgical target and urine CCCR in the gray/non-diagnostic area should be routinely offered genetic testing despite negative family history.

Interaction between serum FGF-23 and PTH in renal phosphate excretion, a case-control study in hypoparathyroid patients

BACKGROUND

phosphate homeostasis is mediated through complex counter regulatory feed-back balance between parathyroid hormone, FGF-23 and 1,25(OH)2D. Both parathyroid hormone and FGF-23 regulate proximal tubular phosphate excretion through signaling on sodium- phosphate cotransporters II_a and II_c. However, the interaction between these hormones on phosphate excretion is not clearly understood. We performed the present study to evaluate whether the existence of sufficient parathyroid hormone is necessary for full phosphaturic function of FGF-23 or not.

METHODS

In this case-control study, 19 patients with hypoparathyroidism and their age- and gender-matched normal population were enrolled. Serum calcium, phosphate, alkaline phosphatase,parathyroid hormone, FGF-23, 25(OH)D, 1,25(OH)2D and Fractional excretion of phosphorous were assessed and compared between the two groups, using SPSS software.

RESULTS

The mean serum calcium and parathyroid hormone level was significantly lower in hypoparathyroid patients in comparison with the control group (P < 0.001 and P < 0.001, respectively). We found high serum level of phosphate and FGF-23 in hypoparathyroid patients compared to the control group (P < 0.001 and P < 0.001, respectively). However, there was no significant difference in Fractional excretion of phosphorous or 1,25OH2D level between the two groups. There was a positive correlation between serum FGF-23 and Fractional excretion of phosphorous just in the normal individuals (P < 0.001, r = 0.79).

CONCLUSIONS

Although the FGF-23 is a main regulator of urinary phosphate excretion but the existence of sufficient parathyroid hormone is necessary for the full phosphaturic effect of FGF-23.

Primary hyperparathyroidism presenting as severe hypercalcemia with acute pancreatitis in pregnancy

Primary hyperparathyroidism presenting first time with severe hypercalcemia is rare in pregnancy. We report a case of primary hyperparathyroidism due to a cystic parathyroid adenoma presenting as severe hypercalcemia with acute pancreatitis in second trimester of pregnancy. Acute pancreatitis was managed by conservative treatment. Hypercalcemia failed to respond to medical management and ultimately responded to ultrasound-guided ethanol ablation of parathyroid adenoma. The delivery was uneventful and patient continues to remain normocalcemic during follow up. As such, ethanol ablation of parathyroid adenoma may be considered during pregnancy in case of failure of response to medical management and when surgical removal of parathyroid adenoma is not safe.

Facial twitching: calcium or concussion conundrum? Hypocalcaemia in a young American football player masking an internal carotid artery dissection

A 30-year-old male American football player presented to the acute medical unit with left-hand and hemifacial spasms. History and examination revealed hemifacial spasms in keeping with seizure-like activity possibly due to symptomatic hypocalcaemia. Subsequent investigations revealed an adjusted calcium of 1.87 mmol/L and, hence, he was managed with intravenous calcium replacement. He presented two further times in a 1-month period, with subjective limb weakness, despite normal adjusted calcium. During his third admission, he developed slurred speech and a marked facial droop, with absence of power in the right upper limb. Imaging revealed acute and old infarctions in the left middle cerebral artery territory and appearances consistent with left internal carotid artery dissection. This presentation of arterial stroke is atypical but with potentially grave consequences if missed. There is limited literature on the presentation of hemifacial spasm, and its association with ischaemic or haemorrhagic stroke represents a key learning point.

A rare case of hypercalcemic encephalopathy from ectopic secretion of parathyroid hormone

Altered mental status can be the initial presenting symptom of an ectopic hyperparathyroidism from severe hypercalcemia. A high index of suspicion for paraneoplastic hypercalcemia and a systematic approach to diagnosis should be considered.

Genetic Screening in a Large Chinese Cohort of Childhood Onset Hypoparathyroidism by Next-Generation Sequencing Combined with TBX1-MLPA

At least 15 candidate genes have been implicated in hypoparathyroidism (HP). However, comprehensive screening of causative genes for HP is lacking. Here, we investigated the genotype spectrum in a large group of Chinese patients with childhood onset HP. A total of 173 patients with childhood onset HP were analyzed using targeted next-generation sequencing (NGS), including 15 candidate genes combined with multiplex ligation-dependent probe amplification (MLPA) of the TBX1 gene. Twenty-seven pathogenic or likely pathogenic mutations in five genes (TBX1, AIRE, GATA3, FAM111A, and CASR) including 13 novel variants in 23 patients, and 12 variants of uncertain clinical significance in five genes (GATA3, CASR, FAM111A, GCM2, and PTH) in 11 patients, were identified by NGS. Additionally, an entire gene deletion of TBX1 in 25 patients was found by TBX1-MLPA. Combined with clinical data, 26 (15.0%) cases of DiGeorge syndrome (OMIM #188400), nine (5.2%) autoimmune polyglandular syndrome type 1 (OMIM #240300), eight (4.6%) autosomal dominant hypocalcemia type 1 (OMIM #601198), four (2.3%) hypoparathyroidism-deafness-renal dysplasia syndrome (OMIM #146255), and one (0.6%) Kenny-Caffey syndrome type 2 (OMIM #127000) were verified. Among them, 16 of 26 (61.5%) DiGeorge syndrome cases were undiagnosed due to the lack of obvious clinical clues before genetic testing. The onset age of patients with mutations (median [interquartile range], 2.8 [0.1, 9.6] years) was significantly earlier than those without mutations (13.0 [8.8, 15.0] years) (p < 0.001). Family history, early onset age, especially prior to 5 years old, and extraparathyroid manifestations were clues for hereditary HP. The combined targeted NGS and TBX-1 MLPA were conveniently and effectively used for comprehensive genetic screening in this large Chinese cohort of childhood onset HP patients. Genetic defects were identified in 27.7% of early-onset HP patients, including four kinds of syndromic HP and one isolated HP. A total of 13 novel mutations were detected, which expands the mutation spectrum of hypoparathyroidism. © 2019 American Society for Bone and Mineral Research.

Clinical burden and healthcare resource utilization among patients with chronic hypoparathyroidism, overall and by adequately vs not adequately controlled disease: a multi-country chart review

Aims: To assess the real-world clinical burden and healthcare resource utilization (HRU) among patients with chronic hypoparathyroidism, overall and by adequately controlled (AC) vs not adequately controlled (NAC) disease, informed by guideline-recommended clinical management targets, including biochemistry and symptoms. Materials and methods: In this retrospective online chart review, endocrinologists in the US, Canada, the UK, France, Germany, Italy, and Spain were randomly selected to review the medical charts of adult patients with chronic hypoparathyroidism receiving calcium and activated vitamin D. Patients' demographics, disease characteristics, symptoms, comorbidities, and hypoparathyroidism-related HRU during the 1 year before the review date were assessed. Clinical burden and HRU were compared between patients with NAC and AC hypoparathyroidism. Results: Of 614 patients with hypoparathyroidism (AC, N = 442; NAC, N = 172), the mean age was 43.6 years, and the majority were female (61.6%), Caucasian (78.8%), and had post-surgical hypoparathyroidism (74.4%). Mean duration of hypoparathyroidism was 46.0 months. Hypoparathyroidism-related symptoms and comorbidities were reported in 59.4% and 46.7% of patients, respectively; 90.7% of patients had ≥1 hypoparathyroidism-related HRU event. More patients with NAC (57.6%) vs AC (42.5%) hypoparathyroidism experienced ≥1 comorbidity including calcium/phosphate imbalances, and brain, cardiovascular, metabolic, and renal disorders (all p < 0.01). More patients with NAC vs AC hypoparathyroidism incurred ≥1 hypoparathyroidism-related hospitalization (27.9% vs 16.3%) and emergency room visits (47.7% vs 38.5%), and patients with NAC vs AC hypoparathyroidism had a higher number of outpatient visits (3.6 vs 2.6; all p < 0.05), in the 1-year observation period. Limitations and conclusions: Limitations of this online chart review include possible under-estimation of disease burden, limited sample size, and the inability to rule out selection bias. Findings indicate that patients with chronic hypoparathyroidism experience substantial symptomatic and comorbid burdens resulting in frequent HRU, suggesting an unmet need, particularly in NAC disease.

Efficacy of Scintigraphy, Ultrasound and Both Scintigraphy and Ultrasonography in Preoperative Detection and Localization of Primary Hyperparathyroidism

Objective: The aim of our study was to evaluate the efficacy of preoperative dual-phase 99mTc-methoxyisobutylnitrile (MIBI) parathyroid scintigraphy (PS), and ultrasound (US) in primary hyperparathyroidism (pHPT) diagnosis and compare the results with the surgical findings.

Methods: Forty-five patients were enrolled in this study. Preoperative serum parathyroid hormone (PTH) levels, calcium (Ca), phosphate (P), and alkaline phosphatase (AP) levels were measured. All parathyroid patients were evaluated by ultrasonography, dual phase 99mTc-MIBI. Surgical findings were used as a reference standard.

Results: Of the 45 patients included in this study, 30 were females (66.7%) with an age range between 30 years and 70 years (mean age 41± 13). The sensitivity and specificity of 99mTc-MIBI scintigraphy was 97.4% and 71.4%, respectively, while the sensitivity of ultrasound was 94.4% and specificity 44.4%. The sensitivity, specificity, and accuracy of combined scintigraphy and ultrasound was higher-97.4%, 83.3%, and 95.6%, respectively.

Conclusions: The combination of MIBI and US appears promising for localizing parathyroid pathology in patients with primary hyperparathyroidism. The concordance rate is high together with a lower chance of missing concomitant thyroid pathology, which might alter the surgical approach.

Brown tumor of the thoracic spine presenting with paraplegia in a patient with peritoneal dialysis

Secondary and tertiary hyperparathyroidism is an important problem of chronic kidney disease. Brown tumor is a benign, unusual, reactive lesion as a result of disturbed bone remodeling, from long-standing increase in parathyroid hormone level. Brown tumors may cause morbidity due to pressure symptoms on neural structures and spontaneous bone fractures. Herein, we presented a peritoneal dialysis patient with tertiary hyperparathyroidism under calcand calcitriol treatment for 4 years due to refusing of the parathyroidectomy operation. She admitted to hospital for sudden onset back pain with difficulty in gait and walking, and imaging studies showed an expansile mass lesion in the thoracic spine. She was operated for mass and diagnosed with brown tumor. After operation, she lost the ability of walking than become paraplegic and she underwent rehabilitation program. Preventive measures including calcitriol and cinacalcet may cause a modest decrease in parathyroid hormone levels but it should be remembered for the development of bone complications such as brown tumor formation in patients with moderate elevated PTH levels, especially those with tertiary hyperparathyroidism. Parathyroidectomy should be performed without delay in these cases.

Parathyroid Tissue Cryopreservation: Does the Storage Time Affect Viability and Functionality?

Parathyroidectomy is a standard practice to treat recurrent or persistent hyperparathyroidism. However, this can lead to the onset of hypoparathyroidism, treatable with the autotransplantation of parathyroid tissue (PT). Tissue can be transplanted immediately after parathyroidectomy or cryopreserved and transplanted only in case of necessity. Since 2011, the Cord Blood Bank and Cardiovascular Tissue Bank of Emilia-Romagna has been storing PT for potential autologous transplantation. To date, there are highly variable data about the viability and function of PT after thawing. However, it is not clear if the PT quality is affected by different cryopreservation protocols and/or by the storage time. The aim of this study was to assess the ex vivo function and viability of the PTs of ten patients stored in the Bank. Tissue morphology was evaluated before and after cryopreservation through histological investigations. PT function was analyzed by assessing the ability of cryopreserved PT to synthesize and secrete parathyroid hormone (PTH) in response to different calcium concentrations. Moreover, viability and function were also investigated on tissue-isolated cells in culture. These data show that tested tissues appear to be viable and able to produce PTH even after 5 years of storage, and the histological architecture is well preserved.

Characterization of a novel CDC73 gene mutation in a hyperparathyrodism-jaw tumor patient affected by parathyroid carcinoma in the absence of somatic loss of heterozygosity

Hyperparathyrodism-jaw tumor (HPT-JT) syndrome is an autosomal dominant disorder. Loss of function of the cell division cycle protein 73 homolog (CDC73) gene is responsible for the syndrome. This gene encodes an ubiquitously expressed 531 amino acid protein, parafibromin, that acts as a tumor suppressor. Loss of heterozygosity (LOH) of the CDC73 locus in many HPT-JT associated parathyroid tumors from patients with germline mutation is in accordance with Knudson's "two-hit" model for hereditary cancer. A 41-year-old man with mandible ossifying fibroma suffered from severe hypercalcemia due to parathyroid carcinoma (PC). Genetic analysis was performed to evaluate germinal and somatic CDC73 gene mutation as well as real-time qRT-PCR to quantify CDC73 mRNA, miR-155 and miR-664 expression levels. Immunohistochemistry and Western blotting (WB) assay were carried out to evaluate parafibromin protein expression. A novel heterozygous nonsense mutation, c.191-192 delT, was identified in the CDC73 gene. No CDC73 LOH was found in PC tissue, nor any differences in expression levels for CDC73 gene, miR-155 and miR-664 between PC and parathyroid adenoma control tissues. On the contrary, both immunohistochemistry and WB assay showed an approximate 90% reduction of parafibromin protein expression in PC. In conclusion, this study describes a novel germinal mutation, c.191-192 delT, in the CDC73 gene. Despite normal CDC73 gene expression, we found a significant decrease in parafibromin. We hypothesize that a gene silencing mechanism, possibly induced by microRNA, could play a role in determining somatic post-transcriptional inactivation of the wild type CDC73 allele.

Bioinformatics analysis of various signal peptides for periplasmic expression of parathyroid hormone in E.coli

Hypoparathyroidism is a rare endocrine disease which is characterized by the deficiency of serum calcium levels. RhPTH is prescribed as a therapy for the management of refractory hypoparathyroidism. The aim of this study is to investigate 32 signal peptides of gram-negative bacterial origin and evaluate their potential for efficient secretion of recombinant human PTH (1-84)In E.coli to obtain higher expression of recombinant PTH in bacterial systems by using this fusion partner. SignalP and ProtParam servers were employed to predict the presence and location of signal peptide cleavage sites in protein sequence and computation of various physical and chemical parameters of protein respectively. Also, SOLpro server was applied for prediction of the protein solubility. Then ProtComp and SecretomeP online servers were employed to determine protein location. The evaluations showed that theoretically two signal peptides Lipopolysaccharide export system protein LptA (lptA) and Periplasmic pH-dependent serine endoprotease DegQ (degQ) are the most appropriate signal peptides examined. Due to the lack of post-translational modification in PTH, its periplasmic expression has preferences. Based on the results of this study, using bioinformatics and reliable servers signal peptides with appropriate secretory potential can be obtained which lead to the highest expression level.

Non-surgical management of primary hyperparathyroidism

The purpose of this chapter is to discuss the options available for patients with primary hyperparathyrodism (PHPT) not undergoing parathyroidectomy (PTx). Adequate hydration should be recommended in all patients. Calcium intake should not be restricted and vitamin D deficiency should be corrected aiming at a serum concentration of 25OHD of >20 ng/mL or even higher (>30 ng/mL according to some opinion leaders). Pharmacologic therapy is not an alternative to PTx and could be considered in patients who meet the surgical criteria but unwilling to undergo PTx, as well as in patients with an increased risk of surgery or failed surgery. Targeted therapy includes antiresorptive drugs for skeletal protection and cinacalcet for lowering serum calcium. Combined therapy can be an option when appropriate. Pregnant women should be treated conservatively (hydration) and surgery, if needed, performed in the second trimester of pregnancy. Severe hypercalcemia is a life-threatening condition and requires immediate intensive treatment.

HypoparaNet: A Database of Chronic Hypoparathyroidism Based on Expert Medical-Surgical Centers in Italy

Hypoparathyroidism is a rare disease characterized by low serum calcium levels and absent or deficient parathyroid hormone level. Regarding the epidemiology of chronic hypoparathyroidism, there are limited data in Italy and worldwide. Therefore, the purpose of this study was to build a unique database of patients with chronic hypoparathyroidism, derived from the databases of 16 referral centers for endocrinological diseases, affiliated with the Italian Society of Endocrinology, and four centers for endocrine surgery with expertise in hypoparathyroidism, to conduct an epidemiological analysis of chronic hypoparathyroidism in Italy. The study was approved by the Institutional Review Board. A total of 537 patients with chronic hypoparathyroidism were identified. The leading etiology was represented by postsurgical hypoparathyroidism (67.6%), followed by idiopathic hypoparathyroidism (14.6%), syndromic forms of genetic hypoparathyroidism (11%), forms of defective PTH action (5.2%), non-syndromic forms of genetic hypoparathyroidism (0.9%), and, finally, other forms of acquired hypoparathyroidism, due to infiltrative diseases, copper or iron overload, or ionizing radiation exposure (0.7%). This study represents one of the first large-scale epidemiological assessments of chronic hypoparathyroidism based on data collected at medical and/or surgical centers with expertise in hypoparathyroidism in Italy. Although the study presents some limitations, it introduces the possibility of a large-scale national survey, with the final aim of defining not only the prevalence of chronic hypoparathyroidism in Italy, but also standards for clinical and therapeutic approaches.

Dental Findings in Patients With Non-surgical Hypoparathyroidism and Pseudohypoparathyroidism: A Systematic Review

Background: Dental aberrations have been mentioned in relation to non-surgical hypoparathyroidism (Ns-HypoPT) and pseudohypoparathyroidism (PHP). However, a systematic review of dental characteristics have not been performed. The present systematic review describes the dental findings in patients with Ns-HypoPT and PHP.

Methods: Studies on Ns-HypoPT and PHP reporting dental features were eligible. A systematic literature search was conducted using four bibliographic databases (Web of Science, Scopus, Pubmed, and Embase) and was limited to studies written in English. Reviews, meta-analyses and letters were excluded. Both the research and reporting of results were based on PRISMA (preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines.

Results: Of 88 studies included, nine were cross-sectional, one was a prospective cohort study, 26 were case series, and 52 were case reports. The most frequently reported findings in patients with Ns-HypoPT were enamel opacities, enamel hypoplasia, hypodontia, and eruption disturbances. In patients with PHP, enamel hypoplasia, eruption disturbance, and deviation of the root morphology were the most frequently reported findings.

Conclusion: An association between enamel hypoplasia and Ns-HypoPT and PHP is likely. The results should, however, be interpreted cautiously due to the limited number of high-quality studies. The present review confirms the need of further well-designed studies, such as large-scale studies, e.g., multicenter studies, to conclude on the reported associations between Ns-HypoPT/PHP and enamel hypoplasia.