Secondary and tertiary hyperparathyroidism

Pseudotumoral calcinosis of the elbow with ulnar and radial nerve deficits

We report here a rare case of an acute peripheral nerve compression by pseudotumoral calcinosis (PCT) at the right elbow in a patient with severe tertiary hyperaparathyroidism. This complication required urgent multidisciplinary management. Surgical decompression by PCT resection enabled rapid motor and sensory recovery.

Pharmaceutical Management of Secondary Hyperparathyroidism and the Role of Surgery: A 5-Year Retrospective Study

Background and Objectives: Secondary hyperparathyroidism (SHPT) poses a common condition among patients with chronic kidney disease (CKD) due to the chronic stimulation of the parathyroid glands as a result of persistently low calcium levels. As a first option for medical treatment, vitamin D receptor analogs (VDRAs) and calcimimetic agents are generally used. Apart from cinacalcet, which is orally taken, in recent years, another calcimimetic agent, etelcalcetide, is being administered intravenously during dialysis. Materials and Methods: In a 5-year retrospective study between 2018 and 2023, 52 patients undergoing dialysis were studied. The aim of this study is to highlight the possible effects and/or benefits that intravenously administered calcimimetic agents have on CKD patients. A total of 34 patients (65.4%) received cinacalcet and etelcalcetide while parathormone (PTH) and calcium serum levels were monitored on a monthly basis. Results: A total of 29 out of 33 patients (87.9%) that received treatment with etelcalcetide showed a significant decrease in PTH levels, which rose up to 57% compared to the initial values. None of the included patients needed to undergo parathyroidectomy (PTx) due to either extremely high and persistent PTH levels or severe side effects of the medications. It is generally strongly advised that parathyroidectomies should be performed by an expert surgical team. In recent years, a significant decrease in parathyroidectomies has been recorded globally, a fact that is mainly linked to the constantly wider use of new calcimimetic agents. This decrease in parathyroidectomies has resulted in an important decrease in complications occurring in cervical surgeries (e.g., perioperative hemorrhage and nerve damage). Conslusions: Despite the fact that these surgical complications cannot be easily compared to the pharmaceutical side effects, the recorded decrease in parathyroidectomies is considered to be notable, especially in cases of relapse where a difficult reoperation would be considered based on previously published guidelines.

Small vs. Large Library Docking for Positive Allosteric Modulators of the Calcium Sensing Receptor

Drugs acting as positive allosteric modulators (PAMs) to enhance the activation of the calcium sensing receptor (CaSR) and to suppress parathyroid hormone (PTH) secretion can treat hyperparathyroidism but suffer from side effects including hypocalcemia and arrhythmias. Seeking new CaSR modulators, we docked libraries of 2.7 million and 1.2 billion molecules against transforming pockets in the active-state receptor dimer structure. Consistent with simulations suggesting that docking improves with library size, billion-molecule docking found new PAMs with a hit rate that was 2.7-fold higher than the million-molecule library and with hits up to 37-fold more potent. Structure-based optimization of ligands from both campaigns led to nanomolar leads, one of which was advanced to animal testing. This PAM displays 100-fold the potency of the standard of care, cinacalcet, in ex vivo organ assays, and reduces serum PTH levels in mice by up to 80% without the hypocalcemia typical of CaSR drugs. Cryo-EM structures with the new PAMs show that they induce residue rearrangements in the binding pockets and promote CaSR dimer conformations that are closer to the G-protein coupled state compared to established drugs. These findings highlight the promise of large library docking for therapeutic leads, especially when combined with experimental structure determination and mechanism.

Serendipitous Diagnosis of Tertiary Hyperparathyroidism in a Case Purportedly thought to have Skeletal Metastases

Tertiary hyperparathyroidism (THPT) is characterized by over secretion of parathyroid hormone caused by long-standing secondary hyperparathyroidism. THPT can affect the bones as well as cause extraskeletal calcifications. The bony lesions often mimic multiple skeletal metastases or multiple myeloma. We report a case of a 48-year-old man with chronic kidney disease on dialysis, who presented with chief complaints of low back ache and swelling over the left clavicle. In view of clinical suspicion of malignancy with bony metastases, he underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography and was subsequently found to have parathyroid adenomas, which were confirmed on 99mTc-methoxy-isobutyl-isonitrile scintigraphy.

[The role of calcium sensitive and vitamin D receptors in the pathogenesis of sporadic multiple parathyroid gland disease]

BACKGROUND

Sporadic multiple parathyroid gland disease is ¼ cases of primary hyperparathyroidism (PHPT). However, a single tactic for diagnosing and operating volume in patients with this variant of PHPT has not yet been developed. One of the possible directions in the search for pathogenetically substantiated methods of diagnosis and treatment is the study of the molecular genetic features of the disease and associated clinical and laboratory factors.

AIM

To study the features of the expression of calcium sensitive (CaSR) and vitamin D (VDR) receptors on the surface of parathyroid cells in primary hyperparathyroidism with solitary and multiple lesions of the parathyroid glands, as well as its changes under the influence of a decrease in the filtration function of the kidneys.

MATERIALS AND METHODS

In a single center observational prospective study with retrospective data collection, there were patients who during 2019-2021. operated on for PHPT, secondary hyperparathyroidism (SHPT) and all cases of tertiary hyperparathyroidism (THPT) operated during 2014-2021. The expression of CaSR, VDR and its relationship with the main laboratory parameters, the clinical variant of hyperparathyroidism, and the morphological substrate were studied.

RESULTS

The study included 69 patients: 19 with multiple and 25 with solitary PTG near PHPT, 15 with SHPT, 10 with THPT. A statistically significant decrease in the frequency of detection of normal expression of CaSR and VDR receptors occurs in any morphological variant of hyperparathyroidism and is observed in 93-60% of drugs. A decrease in the normal expression of CaSR in hyperplasia is detected statistically significantly less frequently than in adenoma (p≤0.01). The median expression intensity in adenoma was 2.5 (2:3), in hyperplasia 3.5 (3-4) (p≤0.01). The difference in the molecular mechanisms of the development of hyperparathyroidism with a predominance of a morphological substrate in the form of adenoma (PHPT with solitary adenoma) or hyperplasia (SHPT and PHPT with multiple PTG lesions) is realized in the frequency of maintaining normal CaSR expression in the PTG tissue. These mechanisms are implemented at the local level, their variability does not change under the influence of RRT. A common molecular genetic mechanism for the development of hyperparathyroidism with a predominance of a morphological substrate in the form of adenoma or hyperplasia has been found to reduce the frequency of maintaining normal VDR expression in PTG (up to 7-13%), p<0.01. This mechanism is implemented at the local level, its variability changes under the influence of RRT, reaching statistically significant differences in patients with THPT.

CONCLUSION

The study demonstrates the features of changes in the expression of CaSR and VDR in PHPT with multiple lesions of the parathyroid glands. The relationship between the expression of these receptors and the clinical variant of hyperparathyroidism, the morphological substrate, the main laboratory parameters, and renal function was shown.

The Dark Side of Ultrasound Imaging in Parathyroid Disease

The diagnosis of parathyroid diseases by imaging still has some intrinsic technical limitations due to the differential diagnosis of different structures of the neck that mimic the parathyroid glands. In this view, ultrasound (US) is an established, low-cost, and non-invasive imaging technique that still represents the first-line approach for evaluating patients with parathyroid disease. The objective of this article is to provide a comprehensive review of the applications of USs in clinical practice, discussing the histopathological and US characteristics of the parathyroid glands in normal and pathological conditions, the advantages of preoperative imaging, and novel updates on the most useful and currently available multiparameter US techniques.

Parathyroid diseases and metabolic syndrome

PURPOSE

Parathyroid diseases are related to parathyroid hormone (PTH) dysregulation by parathyroid cells or alteration of PTH function. They include hyperparathyroidism (PTH excess), hypoparathyroidism (PTH deficiency) and pseudohypoparathyroidism (PTH resistance). Little is known about correlation between parathyroid diseases and metabolic syndrome (MetS).

METHODS

An electronic-based search using PubMed was performed until October 2022 and articles were selected based on relevance of title, abstract, English language and publication in peer-reviewed journals.

RESULTS

Possible association between PTH alterations and the diverse manifestation of MetS have been proposed and it could be supposed that MetS may negatively influence parathyroid diseases. Available data show significant association for hyperparathyroidism and pseudohypoparathyroidism.

CONCLUSIONS

This review highlights the possible implications between MetS and parathyroid diseases. Given the increasing MetS global prevalence and the higher parathyroid diseases awareness and diagnosis, it may be interesting to further explore the possible role of alterations in parathyroid homeostasis in the development of MetS components with dedicated prospective studies.

A rare case of "Brown tumor" of the axis with parathyroid adenoma and tertiary hyperparathyroidism

"Brown tumors (BTs)" of the spine are benign rare lesions, seen in about 5%-13% of all patients with chronic hyperparathyroidism (HPT). They are not true neoplasms and are also known as osteitis fibrosa cystica or occasionally osteoclastoma. Radiological presentations are often misleading and may mimic other common lesions such as metastasis. A strong clinical suspicion is therefore necessary, especially in the background of chronic kidney disease with HPT and parathyroid adenoma. Surgical spinal fixation in case of instability due to pathological fracture may be required along with excision of the parathyroid adenoma being the treatment of choice, that maybe usually curative and carries a good prognosis. We would like to report one such rare case of BT involving the axis, or C2 vertebra, presenting with neck pain and weakness that was treated surgically. Only a few cases of spinal BTs have been reported so far in the literature. Involvement of cervical vertebrae and in particular C2 is rarer still with the one in this report only being the fourth such case.

Determinants of Secondary Hyperparathyroidism 1 Year After One-Anastomosis Gastric Bypass or Sleeve Gastrectomy

PURPOSE

Bariatric surgery alters the anatomic and physiological structure of the gastrointestinal tract, predisposing patients to the malabsorption of nutrients. The purpose of this study was to determine the prevalence and determinants of secondary hyperparathyroidism (SHPT) in the patients undergoing either one-anastomosis gastric bypass (OAGB) or sleeve gastrectomy (SG).

MATERIALS AND METHODS

A total of 517 patients (without SHPT at the baseline) who had undergone OAGB or SG were prospectively assessed 1 year after the surgery. Anthropometric parameters, calcium, intact parathyroid hormone (iPTH), and 25(OH)D levels were compared according to the surgery type before and 1 year after surgery. Multiple logistic regression models were used to evaluate possible SHPT predictors after bariatric surgery.

RESULTS

The overall prevalence of SHPT was 12.6% after surgery, significantly different between the OAGB and SG groups (17.1 vs. 9.9%, respectively). The serum levels of albumin-corrected calcium and 25(OH)D were not significantly different between the two groups. The patients undergoing OAGB had significantly higher serum levels of ALP (198.2 vs. 156.6) compared to the subjects undergoing SG. Higher iPTH levels preoperatively, lower 1-year excess weight loss%, and OAGB surgery seemed to be independent predictors for SHPT 1 year after surgery.

CONCLUSION

Morbidly-obese patients undergoing OAGB had a higher risk of SHPT than their counterparts undergoing SG, whereas 25(OH)D deficiency and calcium levels did not differ between the two groups. The OAGB procedure, preoperative iPTH levels, and 1-year weight loss were predictors of postoperative SHPT development.

Cholecalciferol supplementation effectively improved tertiary hyperparathyroidism, FGF23 resistance and lowered coronary calcification score: a prospective study

INTRODUCTION

Tertiary hyperparathyroidism (THPT) and vitamin D deficiency are commonly seen in kidney transplant recipients, which may result in persistently elevated fibroblast growth factor 23 (FGF23) level after transplantation and decreased graft survival. The aim of this study is to evaluate the effect of vitamin D supplementation on THPT, FGF23-alpha Klotho (KLA) axis and cardiovascular complications after transplantation.

MATERIALS AND METHODS

Two hundred nine kidney transplant recipients were included and further divided into treated and untreated groups depending on whether they received vitamin D supplementation. We tracked the state of THPT, bone metabolism and FGF23-KLA axis within 12 months posttransplant and explored the predictors and risk factors for intact FGF23 levels, KLA levels, THPT and cardiovascular complications in recipients.

RESULTS

Vitamin D supplementation significantly improved FGF23 resistance, THPT and high bone turnover status, preserved better graft function and prevented coronary calcification in the treated group compared to the untreated group at month 12. The absence of vitamin D supplementation was an independent risk factor for THPT and a predictor for intact FGF23 and KLA levels at month 12. Age and vitamin D deficiency were independent risk factors for coronary calcification in recipients at month 12.

CONCLUSION

Vitamin D supplementation effectively improved THPT, FGF23 resistance and bone metabolism, preserved graft function and prevented coronary calcification after transplantation.

Calcium Challenge to Confirm Secondary Hyperparathyroidism due to Decreased Calcium Intake

OBJECTIVE

Secondary hyperparathyroidism commonly occurs in the setting of mid-to low-normal serum calcium levels, often in the setting of chronic kidney disease, phosphate loading, vitamin D deficiency, or insufficient calcium intake or absorption. We are reporting nine patients who had adequate kidney function [eGFR (estimated glomerular filtration rate) >60 mL/min/1.73 m²] and normal 25-hydroxy vitamin D level (≥30 ng/dL) whose secondary hyperparathyroidism resolved after starting adequate oral calcium intake.

METHODS

Our retrospective case series included eight women and a man, aged (mean ± standard deviation) 69.0 ± 12.2 years. Initial intact parathyroid hormone (iPTH) level was 80.6 ± 13.4 pg/mL (reference range [ref]: 10-65 pg/mL), corrected serum calcium 9.2 ± 0.2 mg/dL (ref: 8.5-10.5 mg/dL), serum phosphate 3.6 ± 0.4 mg/dL (ref: 2.5-4.9 mg/dL), 25-hydroxy vitamin D 42.2 ± 10.5 mg/dL (ref: 20-50 ng/mL), and eGFR 72.6 ± 14.4 ml/min/1.73 m². Patients were treated clinically with oral calcium 600 mg twice daily.

RESULTS

iPTH was retested after a mean duration of 17.6 ± 12.7 days of calcium supplementation, decreased to 51.0 ± 10.6 pg/mL, with all patients achieving iPTH in the normal range with normocalcemia, consistent with the hyperparathyroidism being due to insufficient calcium intake or absorption. All patients were normocalcemic after supplementation.

CONCLUSION

Secondary hyperparathyroidism can result from insufficient oral calcium intake. Calcium challenge is an efficacious cost-effective tool in confirming and treating secondary hyperparathyroidism in the setting of normal vitamin D stores and kidney function.

Ultrasound-guided thermal ablation for hyperparathyroidism: current status and prospects

BACKGROUND

Hyperparathyroidism (HPT) is classified into primary HPT (PHPT), secondary HPT (SHPT), tertiary HPT (THPT), and pseudohyperparathyroidism. Parathyroid surgery is generally reserved for patients with symptomatic PHPT and asymptomatic patients who meet the surgical guideline criteria. However, the risk of complications and mortality after parathyroid gland surgery increases with increasing patient age.

AIM

This study aimed to review existing research on laser ablation, radiofrequency ablation, microwave ablation, and high-intensity focused ultrasound in the treatment of HPT and analyze its application prospects.

CONCLUSIONS

Thermal ablation is a good alternative treatment for patients with parathyroid hyperplasia who do not meet the criteria or decline surgery. Being a type of minimally invasive treatment, ultrasound-guided thermal ablation has the advantages of easy operation, rapid recovery, and reusability and is used widely.

Incidence of and risk factors for post-parathyroidectomy hungry bone syndrome in patients with secondary hyperparathyroidism

Background

Hungry bone syndrome (HBS) following parathyroidectomy is associated with severe hypocalcemia and increased morbidity. This study aims to determine the incidence and risk factors of post-parathyroidectomy HBS in dialysis patients with secondary hyperparathyroidism (SHPT).

Methods

A retrospective cohort study was conducted, and medical records of patients with SHPT requiring parathyroidectomy between January 2014 and January 2020 were reviewed. HBS was defined as the requirement of intravenous calcium administration due to hypocalcemia-related symptoms and/or reductions in serum calcium concentration (<8.4 mg/dL) within 72 h after parathyroidectomy.

Results

A total of 130 dialysis patients were enrolled. The majority of patients (85.4%) received hemodialysis and the remaining patients (14.6%) received peritoneal dialysis. Ectopic parathyroid glands were identified in 6.6% of patients by preoperative parathyroid scintigraphy. Diffuse parathyroid hyperplasia was the most common histopathological characteristic of SHPT (90.8%). HBS occurred in 82.3% of patients following parathyroidectomy. Preoperative serum intact parathyroid hormone (iPTH) concentration was significantly correlated with serum calcium (r = −0.48, p < 0.01) and alkaline phosphatase (ALP) concentration (r = 0.71, p < 0.01). Patients with HBS had significantly longer hospital stays than patients without (8 versus 3 days, p < 0.01). Based on multiple logistic regression analysis, young age (≤45 years), high preoperative serum ALP (>420 IU/L) and iPTH (>1,000 pg/mL), and absence of preoperative hypercalcemia (>10.2 mg/dL) were significantly associated with HBS.

Conclusions

Post-parathyroidectomy HBS is common in dialysis patients with SHPT. Young age, high preoperative serum ALP and iPTH, and low preoperative serum calcium concentrations were important risk factors for HBS.

Central odontogenic fibroma in association with brown tumor of hyperparathyroidism in a patient with neurofibromatosis type 1

We present a patient with bone abnormalities and a myriad of lesions secondary to his redeveloping renal failure and neurofibromatosis type 1 (NF1). A 21-year-old male renal transplant recipient with NF1 presented with painless masses and large, irregular radiolucent lesions in the maxilla and mandible. After histologic examination, the lesion was diagnosed as a central odontogenic fibroma (COdF) in association with a central giant cell lesion, most consistent with brown tumor of hyperparathyroidism. The bone changes were interpreted to be highly suggestive of renal osteodystrophy. Around 30 cases of hybrid central giant cell granuloma-like lesion in association with central odontogenic fibroma have been reported. This, to our knowledge, is the first reported case of brown tumor in association with COdF. Our case provides further evidence of the giant cell component as the initiating entity in these hybrid lesions.

The Role of Diet in Bone and Mineral Metabolism and Secondary Hyperparathyroidism

Bone disorders are a common complication of chronic kidney disease (CKD), obesity and gut malabsorption. Secondary hyperparathyroidism (SHPT) is defined as an appropriate increase in parathyroid hormone (PTH) secretion, driven by either reduced serum calcium or increased phosphate concentrations, due to an underlying condition. The available evidence on the effects of dietary advice on secondary hyperparathyroidism confirms the benefit of a diet characterized by decreased phosphate intake, avoiding low calcium and vitamin D consumption (recommended intakes 1000-1200 mg/day and 400-800 UI/day, respectively). In addition, low protein intake in CKD patients is associated with a better control of SHPT risk factors, although its strength in avoiding hyperphosphatemia and the resulting outcomes are debated, mostly for dialyzed patients. Ultimately, a consensus on the effect of dietary acid loads in the prevention of SHPT is still lacking. In conclusion, a reasonable approach for reducing the risk for secondary hyperparathyroidism is to individualize dietary manipulation based on existing risk factors and concomitant medical conditions. More studies are needed to evaluate long-term outcomes of a balanced diet on the management and prevention of secondary hyperparathyroidism in at-risk patients at.

[Adenoma of the parathyroid gland in a young woman with chronic kidney disease: primary or tertiary hyperparathyroidism?]

Clinical observation of a young woman with chronic kidney disease IV stage and hyperparathyroidism is presented. Ultrasound and99mTc-sestamibi scintigraphy of the anterior surface of the neck visualized a tumor of the left upper parathyroid gland. In a histological examination of distant education was diagnosed a solid parathyroid adenoma. The difficulty of differential diagnosis between primary and secondary/tertiary hyperparathyroidism in chronic kidney disease is discussed.

Parathyroid Hormone and Bone Mineral Density: A Mendelian Randomization Study

PURPOSE

Accumulating evidence implicates parathyroid hormone (PTH) in the development of osteoporosis. However, the causal effect of PTH on bone mineral density (BMD) remains unclear. Thus, this study is aimed at exploring the association between the concentrations of serum PTH and BMD.

METHODS

The instrumental variables for PTH were selected from a large-scale genome-wide association study (GWAS; n = 29 155). Outcomes included BMD of the forearm (FA; n = 8143), femoral neck (FN; n = 33 297), lumbar spine (LS; n = 32 735), heel (HL; n = 394 929), and risk of fractures in these bones (n = 361 194). Furthermore, the BMD of 5 different age groups: 15 years or younger (n = 11 807), 15-30 (n = 4180), 30-45 (n = 10 062), 45-60 (n = 18 805), and 60 years or older (n = 22 504) were extracted from a GWAS meta-analysis study. The analyses were performed using the 2-sample Mendelian randomization method.

RESULTS

Mendelian randomization analysis revealed that the level of serum PTH was inversely associated with BMD of FA (95% CI: -0.763 to -0.016), FN (95% CI: -0.669 to -0.304), and LS (95% CI: -0.667 to -0.243). A causal relationship between serum PTH levels and BMD was observed in individuals aged 30-45 (95% CI: -0.888 to -0.166), 45-60 (95% CI: -0.758 to -0.232), and over 60 years (95% CI: -0.649 to -0.163).

MAIN CONCLUSIONS

This study demonstrated that the concentrations of serum PTH is inversely associated with BMD of several bones. Further analysis revealed site- and age-specific correlations between serum PTH levels and BMD, which implies that the levels of serum PTH contribute to the development of osteoporosis.

18F-Fluorocholine PET/CT, Tc-99m-MIBI and TC-99m-MDP SPECT/CT in Tertiary Hyperparathyroidism with Renal Osteodystrophy

Tertiary hyperparathyroidism (HPT) is a metabolic disorder characterized by the semi-autonomous hypersecretion of parathyroid hormone (PTH), leading to hypercalcemia. It can be the end result of persistent secondary hyperparathyroidism and is most commonly observed in patients with long-standing chronic kidney disease (CKD) and often after renal transplantation. Untreated HPT can lead to progressive bone disease, fibrocystic osteitis, and soft-tissue calcifications, along with other severe complications. In the 2009 Kidney Disease Improving Global Outcomes (KDIGO) guidelines, CKD-Mineral and Bone Disorder (CKD-MBD) is used to describe the broader clinical syndrome encompassing mineral, bone, and calcific cardiovascular abnormalities that develop as a complication of CKD. We report a 62-year-old female with a severe HPT evolved from advanced chronic kidney disease (stage 5D, KDIGO). Patient was evaluated with multimodality nuclear medicine functional imaging to assess hyperfunctioning parathyroid glands and bone lesions. Tc-99m-methoxyisobutylisonitrile (MIBI) dual-phase scintigraphy, Tc-99m-methylenediphosphonate (MDP) bone scan and ¹⁸F-Fluorocholine positron emission tomography/computed tomography (¹⁸F-FCH PET/CT) were performed before surgery.

Calcium-mediated parathyroid hormone suppression test in uraemic secondary hyperparathyroidism

AIM

The present study aimed to investigate the value of calcium-mediated parathyroid hormone (PTH) suppression test in evaluating the autonomic secretory function of parathyroid, and the management of uraemic secondary hyperparathyroidism (SHPT).

METHODS

Calcium-mediated PTH suppression test was performed in dialysis with SHPT, who were candidates for parathyroidectomy from June 2017 to December 2019 in our hospital. The PTH inhibition rate (PTH-IR) was calculated, and the correlation between PTH-IR and clinical indicators was explored.

RESULTS

Fifty-one subjects were included. PTH-IR was negatively correlated with baseline PTH (r = -0.35, P = .012), it was also correlated with dialysis years, coronary artery calcification score (CACS) and parathyroid mass (r = -0.397, P = .004; r = -0.327, P = .028; r = -0.363, P = .015), which were not found for baseline PTH. Forty-four patients underwent surgical treatment. According to the histological results, 26 patients presented with parathyroid non-nodular hyperplasia, and 18 patients presented with parathyroid nodular hyperplasia. The mass of parathyroid of patients with nodular hyperplasia was higher than that of patients with non-nodular hyperplasia (ρ = 0.01). The difference of the PTH-IR was not found between the two groups (ρ = 0.296). During the test, the highest serum calcium was 2.9 ± 0.4 mmol/L, which dropped to normal at the end of the test.

CONCLUSION

Parathyroid hormone inhibition rate might be a useful indicator in evaluating the autonomic secretory function of parathyroid and the progression of SHPT on top of intact PTH. Calcium-mediated PTH suppression test was safe in uraemic SHPT patients, but need to monitor for transient hypercalcaemia.

Combined versus subtraction-only technique in parathyroid scintigraphy: effect on scan interpretation

INTRODUCTION

Parathyroidectomy is the choice of treatment for patients with primary and tertiary hyperparathyroidism. Scintigraphic, preoperative localization of hyperfunctioning parathyroid tissue depends on either a delayed washout technique, a subtraction technique, or a combination of the two. The rationale for adopting a combination approach is its presumed superior sensitivity, but there is limited evidence to support this strategy at the cost of patient inconvenience and impact on departmental workflows.

OBJECTIVE

To determine whether a combined technique detects any additional lesions during scan interpretation compared to using subtraction-only technique in patients undergoing parathyroid scintigraphy before surgery.

METHODS

A retrospective analysis was performed of parathyroid scans at Tygerberg Hospital between January 2012 and April 2018. Scans were reinterpreted by consensus by three readers, blinded to the original interpretation. A McNemar discordant pairs analysis was then performed.

RESULTS

A total of 97 participant scans were reviewed (female: 71; mean age: 50.8 years). The number of patients with primary, secondary, and tertiary hyperparathyroidism were 63, 21, and 13, respectively. A total of 192 lesions were identified in this study. While both combined and subtraction-only approaches identified hyperfunctioning parathyroid lesions, only four lesions were identified using the combined technique that were missed by the subtraction technique. This result was not statistically significant (P = 0.125).

CONCLUSION

Based on our findings, the combined parathyroid scintigraphic technique does not improve lesion detection and may be dispensed with. Doing so will enhance patient convenience and comfort and improve departmental workflows without compromising lesion detection.

A Dairy Product to Reconstitute Enriched with Bioactive Nutrients Stops Bone Loss in High-Risk Menopausal Women without Pharmacological Treatment

Osteoporosis is a multifactorial disease characterized by the loss of bone mass and deterioration of the internal structure of the bone, increasing the risk of fractures, and is becoming an economic and social problem. The main treatment is pharmacological, however, the population demands other therapies, such as foods with nutrients beneficial to bone health. Seventy-eight healthy menopausal women at risk of osteoporosis or untreated osteopenia were recruited for a randomized, parallel, double-blind clinical trial with two intervention groups: one group consumed a serving a day of the experimental enriched product (experimental group (EG)) and the other group (control group (CG)) consumed the same product without enrichment. The main objective was to compare the effect of consuming a dairy preparation to reconstitute, similar to yogurt when prepared, enriched in calcium, vitamin D, vitamin K, vitamin C, zinc, magnesium, L-leucine and probiotic (Lactobacillus plantarum 3547) on bone metabolism markers for 24 weeks. The EG showed a significantly increased bone mass compared to the CG (0.01 ± 0.03 vs. −0.01 ± 0.03 kg; p < 0.05). In addition, the EG maintained their bone mineral density (BMD) compared to the CG, whose BMD significantly decreased at the end of the study. For biochemical markers, the EG significantly increased the serum levels of the N-terminal propeptide of type I collagen (P1NP) bone formation marker (13.19 ± 25.17 vs. −4.21 ± 15.62 ng/mL; p < 0.05), and decreased the carbo-terminal telopeptide of type I collagen (CTx) bone resorption marker compared to the CG (−0.05 ± 0.19 vs. 0.04 ± 0.14 ng/mL; p < 0.05). On the other hand, the EG exhibited a significantly decreased systolic and diastolic blood pressure compared to the start of the study. Finally, the EG significantly increased their dietary calcium and vitamin D intake compared to the CG. In conclusion, the regular consumption of a dairy product to reconstitute enriched with bioactive nutrients improves bone health markers in menopausal women at risk of osteoporosis without pharmacological treatment.

Safety and effectiveness of reoperation for persistent or recurrent drug refractory secondary hyperparathyroidism

Background

Drug-refractory secondary hyperparathyroidism (SHPT) is the most common complication in patients with chronic renal failure (CRF). Although surgery is the most effective and safe method for drug-refractory SHPT, the condition may persist or recur after the primary surgery, and reoperation is often required in these patients. The purpose of our current study was to evaluate the safety and effectiveness of reoperation for drug-refractory SHPT.

Methods

The clinical data of 15 patients requiring reoperation after a surgery for drug-refractory SHPT in our hospital from 2010 to 2019 were retrospectively analyzed. Changes in biochemical markers including intact parathyroid hormone (iPTH), blood calcium (Ca), blood phosphorus (P), alkaline phosphatase (ALP), and blood calcium phosphorus product (Ca*P) were compared before and after the surgery, and the effectiveness and complications of the reoperation were summarized.

Results

The reoperation was successful in all the 15 patients after a single attempt. Routine pathological examinations identified a total of 25 parathyroid glands, of which 10 were in the neck in situ, 5 were ectopic in the neck, and 10 were in the forearm. The ectopic parathyroid glands were located inside the thyroid gland (n=1), anterior superior mediastinum (n=1), or thymus (n=3). Surgical treatment significantly improved clinical symptoms such as skin pruritus and bone pain. Blood iPTH, Ca, P, ALP, and Ca*P were significantly reduced (P<0.05 or P<0.01) after surgery. Hypothyroidism occurred in 1 patient; 4 patients undergoing orthotopic neck surgery developed transient hoarseness, which were alleviated within 6 months; no severe complications such as bleeding or death were noted. No recurrence occurred during the 6-month follow-up.

Conclusions

Reoperation is safe and effective for drug-refractory SHPT. Preoperative imaging should be performed to achieve accurate positioning, and the recurrent laryngeal nerve should be closely monitored during surgery. The purpose of the reoperation is to remove all possible parathyroid tissues to avoid recurrence.

Behavior of Calcium, Phosphorus, and Parathormone Before Transplantation and in Months 1, 3, 6, 9, and 12 After Transplantation

BACKGROUND

Bone mineral disease after transplantation persists and is an issue that must be addressed owing to the cardiovascular impact it presents. The objective of this study is to present the behavior of calcium, phosphorus, and parathormone (PTH) before renal transplantation (RT) and throughout the 12 months after transplant surgery.

METHODS

A longitudinal observational study of RT patients was performed from 2013 to 2017 in 2 renal transplant units in Mexico. In total, 1009 records of patients with RT were analyzed. Calcium, phosphorus, and PTH levels were studied before transplantation and for 12 months after. Central tendency and dispersion were measured, the difference of means was established with chi square or student t tests, and the significant value of P was set at <.05. We also used the SPSS statistical package, version 25.

RESULTS

Phosphorus had a median pre-RT of 5.73, which decreased to 2.8 in the first month post-transplant and then increased to 3.41 at 12 months post-RT. The median PTH, on the other hand, started at 420.60 and decreased to 67.45. Calcium began at 9.04 and hit a plateau of 9.58 during month 12 after the surgical event.

CONCLUSIONS

Of the 3 biochemical parameters evaluated, phosphorus was the one that most corrected itself after transplantation. Despite a tendency toward hypophosphatemia in the first month after transplantation, it began to normalize from month 6 on. Meanwhile, calcium was the biochemical value that changed the least after transplantation.

Association between renal function and bone mineral density in healthy postmenopausal Chinese women

BACKGROUND

The relationship between renal function and bone mineral density (BMD) is controversial. The aim of this study was to determine the relationship of renal function with BMD and osteoporosis risk in healthy postmenopausal Chinese women.

METHODS

A cross-sectional study was conducted in 776 healthy postmenopausal Chinese women. Dual-energy X-ray absorptiometry was used to measure BMDs. Clinical, demographic, and biochemical data were obtained at the time of image acquisition. Estimated glomerular filtration rate (eGFR) was calculated using a Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

RESULTS

Women with eGFR levels of at least 90 ml/min/1.73m² had a lower prevalence of osteoporosis compared with women with decreased eGFR levels (60 ml/min/1.73 m² ≤ eGFR < 90.0 ml/min/1.73 m²). BMDs at femoral neck and total hip were significantly lower in the lower eGFR class than the higher class (0.717 ± 0.106 vs 0.744 ± 0.125 g/cm², P < 0.01; 0.796 ± 0.116 vs 0.823 ± 0.129 g/cm², P < 0.01, respectively). eGFR was positively correlated with BMDs at femoral neck and total hip in unadjusted analysis (P < 0.05). After controlling for age, menopausal duration and body mass index (BMI), decreased eGFR was not associated with osteoporosis risk.

CONCLUSIONS

After adjustments for age, menopausal duration and BMI, the decline in renal function was not independently associated with osteoporosis risk in healthy postmenopausal Chinese women.

Efficacy analysis of medical and surgical treatments in chronic kidney disease patients with secondary hyperparathyroidism

PURPOSE

To investigate the effects of surgical and medical treatments on chronic kidney disease (CKD) patients with secondary hyperparathyroidism (SHPT).

MATERIALS AND METHODS

A total of 198 CKD patients with SHPT were identified at Tongji Hospital from January 2013 to June 2017.

RESULTS

Surgical group (53 patients) received maintenance dialysis for 78.0 ± 4.9 months, while medical group (84 patients) for 62.0 ± 6.4 months. The serum intact parathyroid hormone (iPTH) in surgical group reduced apparently compared with medical group (P = 0.015) and maintained satisfied result during three years of follow-up (67.4 ± 7.4 pg/ml). The recurrence rate in surgical group was 7.5% and in medical group was 15.5% (P = 0.024). Beyond that, 5 (5.9%) patients suffered persistent hyperparathyroidism in medical group.

CONCLUSION

Although the progress of medical treatment is changing rapidly, surgical treatment is still an effective way to control serum iPTH and calcium chronically for SHPT patients. Complex SHPT patients can also receive satisfied effect by surgical treatment, without apparently increasing the risk of complications.

International and Racial Differences in Mineral and Bone Disorder Markers and Treatments Over the First 5 Years of Hemodialysis in the Dialysis Outcomes and Practice Patterns Study

RATIONALE & OBJECTIVE

Normalization of parathyroid hormone (PTH), serum calcium, and phosphorus levels may prevent coronary and bone disease in hemodialysis (HD) patients. We describe the trajectory of these mineral bone disorder parameters and treatments during the first 5 years of HD by international region and race.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

33,517 US black/African American, US non-black/African American, European, and Japanese HD patients from the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 4 to 5 (2009-2015).

PREDICTOR

Time since HD initiation.

OUTCOMES

Monthly cross-sections of mineral bone disorder parameters (PTH, serum calcium, and phosphorus) and medications (cinacalcet, active vitamin D, and phosphate binders).

RESULTS

Mean PTH levels declined precipitously during the first 4 months of HD in all 4 groups, then steadily increased during the next 4.5 years in the United States/Europe but not in Japan. 3 years after HD initiation (month 36), mean PTH level was highest in US black/African Americans (496 pg/mL), despite greater prescription of cinacalcet (23%) and active vitamin D (85%), and lowest in Japan (151 pg/mL). Mean serum calcium and phosphorus levels increased during the first 4 months of HD. By month 36, the mean calcium level was lower in Japan (8.8 mg/dL) than United States/Europe (9.0-9.1 mg/dL), while the mean phosphorus level was lower in Europe (4.8 mg/dL) than United States/Japan (5.1-5.3 mg/dL).

LIMITATIONS

Lack of data for medication dosages; most patients were not followed from HD onset.

CONCLUSIONS

Large differences exist in the levels, trajectories, and therapies for PTH, calcium, and phosphorus by country and race in the first 5 years of HD. Higher PTH levels were observed in the United States, especially among black/African American patients, despite greater use of cinacalcet and active vitamin D than in Japan or Europe. Potential contributors to differences in PTH levels should be explored to study their impact on PTH management strategies and consequent bone and cardiovascular complications.

The effect of parathyroidectomy on patients' symptoms in tertiary hyperparathyroidism

BACKGROUND

The efficacy of parathyroidectomy for primary and secondary hyperparathyroidism is well-established but evidence in tertiary hyperparathyroidism is lacking. We examined parathyroidectomy's effect in tertiary hyperparathyroidism.

METHODS

Patients with tertiary hyperparathyroidism who underwent parathyroidectomy were followed up for 12 months. A modification of the 13-item parathyroid symptoms list developed by Pasieka was administered at 0, 1, 3, 6, and 12 months post-surgery. We also examined if preoperative factors would predict symptom improvement post-surgery.

RESULTS

Ninety-one patients were included. Survey response rates at 1, 3, 6, and 12 months post-surgery were 97.8%, 90.1%, 82.4%, and 80.2%, respectively. Mean preoperative Pasieka parathyroid score (PSS) was 6.3 ± 2.7. At first month, PSS decreased to 2.9 ± 2.0 (P < .001) and was sustained at 3, 6, and 12 months (2.7 ± 2.1, P < .001, 2.3 ± 1.6, P < .001 and 3.4 ± 2.5, P < .001). The degree of PSS reduction at 1-month post-parathyroidectomy correlated strongly with preoperative symptom severity (Pearson's coefficient: 0.690, P < .001).

CONCLUSIONS

Parathyroid symptoms unequivocally improve post-parathyroidectomy. The greatest degree of improvement was observed in early postoperative period up to 6 months.

Clinical Value of Tc99m-MIBI SPECT/CT Versus 4D-CT or US in Management of Patients With Hyperparathyroidism

Localization of parathyroid adenomas for treatment of primary hyperparathyroidism can be challenging. This retrospective study compared single-photon emission computed tomography/computed tomography (SPECT/CT), 4D-CT, and US studies in detection of adenomas prior to surgery. A retrospective chart review was performed on all consecutive patients with parathyroid adenoma presenting to an urban tertiary care medical center. A total of 58 patients (45 female, 13 male) underwent surgery for parathyroid adenoma. Patients aged 28 to 80 years (mean: 58.8) with parathyroid hormone levels ranging from 42 to 424 pg/mL (mean: 168). All patients underwent preoperative SPECT/CT with 20 mCi technetium-99m MIBI (^99mTc-MIBI). Fifty-three patients had additional US imaging and 14 patients had 4D-CT scans. Additionally, 34 patients had injection of 20 mCi ^99mTc-MIBI on the day of surgery. Pathological correlation was performed. Comparing SPECT/CT versus 4D-CT resulted in sensitivity (77% vs 80%), specificity (71% vs 75%), and accuracy (77% vs 79%). Ultrasound was less sensitive with similar specificity (44%, 86%, respectively). Combination of SPECT/CT and 4D-CT increased sensitivity to 88%, specificity to 100%, and accuracy to 89%. Combining SPECT/CT with US resulted in sensitivity of 85%, specificity of 83%, and accuracy of 85%. Intraoperative localization substantially improved in patients who received preoperative injections. The SPECT/CT remains the best imaging modality for preoperative localization of parathyroid adenomas with high sensitivity. Combining SPECT/CT with US resulted in increased sensitivity and accuracy. For suspicion of ectopic cases or suspicion of unidentifiable adenoma with negative scintigraphy, addition of 4D-CT is recommended. Intraoperative localization and adjunctive imaging may improve surgical management of patients with hyperparathyroidism.

Chronic kidney disease associated with decreased bone mineral density, uric acid and metabolic syndrome

OBJECTIVE

The relationship between decreased bone mineral density (BMD) and chronic kidney disease (CKD) is controversial. The associations among metabolic syndrome (MetS), serum uric acid and CKD are also unclear. We aimed to investigate the relationship between decreased BMD, MetS, serum uric acid and CKD in a general population.

METHODS

A total of 802 subjects who visited a medical center in Southern Taiwan and underwent a BMD measured by dual-energy X-ray absorptiometry (DEXA) during a health examination were enrolled in this retrospective cross-sectional study. Either osteopenia or osteoporosis was defined as decreased BMD. CKD was defined as the estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73m2. Simple and multivariate logistic regression analyses were used to investigate the association between variables, decreased BMD and CKD.

RESULTS

Of the 802 subjects with a mean age of 54.4±10.2 years, the prevalence of decreased BMD was 62.9%, and CKD was 3.7%. Simple logistic analysis showed that sex (OR 3.50, 95% CI 1.21-10.12, p = 0.021), age (OR 1.14, 95% CI 1.07-1.21, p<0.001), BMI (OR 1.11, 95% CI 1.01-1.22, p = 0.028), waist circumference (OR 1.06, 95% CI 1.02-1.10, p = 0.002), SBP (OR 1.03, 95% CI 1.01-1.04, p = 0.003), DBP (OR 1.03, 95% CI 1.00-1.06, p = 0.030), HDL-C (OR 0.97, 95% CI 0.94-1.00, p = 0.026), uric acid (OR 1.84, 95% CI 1.49-2.27, p<0.001), metabolic syndrome (OR 2.68, 95% CI 1.29-5.67, p = 0.009), and decreased BMD (OR 3.998, 95% CI 1.38-11.57, p = 0.011) were significantly associated with CKD. Multivariate analysis showed that age (OR 1.05, 95% CI 1.03-1.07, p<0.001), decreased BMD (OR 0.64, 95% CI 0.45-0.91, p = 0.013), and uric acid (OR 1.40, 95% CI 1.24-1.59, p<0.001) were significantly independently associated with CKD.

CONCLUSIONS

Decreased BMD, uric acid and MetS were significantly associated with CKD.. Further large and prospective cohort studies are necessary to investigate whether management of osteoporosis, hyperuricemia, or MetS might prevent the progression of CKD.

Review on the Utility of Trabecular Bone Score, a Surrogate of Bone Micro-architecture, in the Chronic Kidney Disease Spectrum and in Kidney Transplant Recipients

Chronic kidney disease (CKD) is defined as abnormalities of kidney structure or function, present for >3 months, with implications for, among others, bone health. Advanced stages of CKD have an increased risk of fragility fractures. Trabecular bone score (TBS) is a relatively new gray-level textural parameter, which provides information on bone microarchitecture and has been shown to be a good predictor of fragility fractures independently of bone density and clinical risk factors. We aimed to review the scientific literature on TBS and its utility along the CKD spectrum and in kidney transplant recipients. In total, eight articles had investigated this topic: one article in patients with reduced kidney function, two in patients on hemodialysis, and five in kidney transplant recipients. In general, all the studies had shown an association between lower values of TBS and reduced kidney function; or lower TBS values among the hemodialysis or kidney transplant patients compared to healthy controls. Moreover, TBS was shown to be a good and independent predictor of fragility fractures in patients with CKD or who underwent kidney transplantation. TBS postulates itself as a valuable marker to be used in clinical practice as an assessor of bone microarchitecture and fracture risk predictor in these specific populations. However, evidence is to some extent limited and larger follow-up case-control studies would help to further investigate the TBS utility in the management of bone health damage and increased fracture risk in patients with CKD or kidney transplant.

Association between the age-related decline in renal function and lumbar spine bone mineral density in healthy Chinese postmenopausal women

OBJECTIVES

The relationship between the decline of renal function and bone mineral density (BMD) in healthy populations is not well-researched. The aim of this study was to investigate the association between the age-related decline in renal function and lumbar spine BMD (LBMD) in a community-based cross-sectional study of 390 healthy postmenopausal women (mean age 62.97 ± 8.79 years) from Shenyang, China.

METHODS

Dual-energy x-ray absorptiometry was used to measure LBMD. Estimated glomerular filtration rate (eGFR) was calculated using a modified Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation for Asians and the CKD-EPI serum creatinine-cystatin c equation. Pearson's correlation analysis and binary logistic regression were used to evaluate associations.

RESULTS

The eGFR-ASIA and eGFR-Scys were positively correlated with LBMD (r = 0.120 and r = 0.108, respectively). After adjustments for numerous potential confounders, the odds ratio for participants with LBMD decline in eGFR-ASIA quartile 3 group and 4 group were 2.45 (95% confidence interval [CI] 1.12-5.38, P < 0.05) and 3.89 (95% CI 1.55-9.76, P < 0.01), respectively, with P = 0.003 for the trend in eGFR-ASIA compared with the lowest quartile 1 group of eGFR-ASIA, where the odds ratio of eGFR-Scys for the quartile of 3 and 4 groups were 2.47 (95% CI 1.09-5.62, P < 0.05) and 2.63 (95% CI 1.10-6.29, P < 0.05), respectively, with P = 0.016 for the trend in eGFR-Scys compared with the lowest quartile 1 group of eGFR-Scys.

CONCLUSIONS

The renal function decline was independently associated with decreased LBMD, and it was possible that the age-related decline in kidney function was an independent risk factor for decreased LBMD in healthy Chinese postmenopausal women.

Risk Factors for Elevated Preoperative Alkaline Phosphatase in Patients with Refractory Secondary Hyperparathyroidism

Elevated preoperative levels of alkaline phosphatase (ALP) in patients with refractory secondary hyperparathyroidism are correlated with postoperative hypocalcemia and mortality. The aim of this study was to identify the predictors of preoperative ALP in patients with secondary hyperparathyroidism. From April 2012 to December 2015, 220 patients with refractory secondary hyperparathyroidism undergoing total parathyroidectomy without autotransplantation were reviewed. A total of 164 patients presented with elevated preoperative ALP. Univariate analysis showed that patients with elevated ALP were significantly younger. The elevated ALP group had significantly higher levels of preoperative parathyroid hormone (PTH), lower preoperative serum calcium, higher preoperative phosphorus, lower postoperative hypocalcemia, and a longer hospital stay. Logistic regression analysis showed that elevated preoperative PTH was a significant independent risk factor for elevated preoperative ALP (P = 0.000), and its value of 1624 pg/mL was the optimal cutoff point. Factors predictive of elevated preoperative ALP in patients with secondary hyperparathyroidism include preoperative PTH. Earlier surgery, aggressive calcium supplementation, and more careful or aggressive postoperative care for high-risk patients are needed.

Sudden onset of parathyroid hormone-independent severe hypercalcemia from reversal of tumoral calcinosis in a dialysis patient

Background

Tumoral calcinosis is a rare manifestation of extraskeletal calcification, featuring large calcified cystic masses in the periarticular regions of large joints. In chronic kidney disease (CKD), this disorder is thought to evolve through a chronically elevated calcium-phosphorus solubility product leading to calcium precipitation in soft tissue. Treating tumoral calcinosis in these patients involves interventions to lower the calcium-phosphorus product such as reduction in vitamin D therapy and intensive hemodialysis regimens.

Case Presentation

We report the case of a 54-year old woman with polycystic kidney disease on peritoneal dialysis with widespread tumoral calcinosis in the context of hypercalcemic tertiary hyperparathyroidism who had been on long-term alfacalcidol therapy. After withdrawal of the vitamin D analogue and initiation of daily hemodialysis, there was rapid dissolution of her tumoral calcium deposits with the abrupt onset of parathyroid hormone (PTH)-independent transient hypercalcemia that resolved once the soft tissue deposits disappeared.

Conclusions

Resorption of soft tissue calcific deposits may result in transient parathyroid hormone (PTH)-independent hypercalcemia. In CKD patients, this hypercalcemia causes a decrease in the PTH level, distinguishing it from tertiary hyperparathyroidism, though PTH may not be totally suppressed, the way it is seen in PTH-independent hypercalcemia in non-CKD patients.

Expanding the net: The re-evaluation of the multidimensional nomogram calculating the upper limit of normal PTH (maxPTH) in the setting of secondary hyperparathyroidism and the development of the MultIdimensional Predictive hyperparaTHyroid model (Mi-PTH)

BACKGROUND

The multidimensional nomogram calculating the upper limit of normal PTH (maxPTH) model identifies a personalized upper limit of normal parathyroid hormone (PTH) and successfully predicts classical primary hyperparathyroidism (PHP). We aimed to assess whether maxPTH can distinguish normocalcemic PHP (NCPHP) from secondary hyperparathyroidism (SHP), including subjects who underwent bariatric surgery (BrS).

METHODS

A total of 172 subjects with 359 complete datasets of serum calcium (Ca), 25-OH vitamin D, and intact PTH from Oregon were analyzed: 123 subjects (212 datasets) with PHP and 47 (143) with SHP, including 28 (100) with previous BrS. An improved prediction model, MultIdimensional evaluation for Primary hyperparaTHyroidism (Mi-PTH), was created with the same variables as maxPTH by the use of a combined cohort (995 subjects) including participants from previous studies.

RESULTS

In the Oregon cohort, maxPTH's sensitivity was 100% for classical PHP and 89% for NCPHP, but only 50% for normohormonal PHP (NHPHP) and 40% specific for SHP. In comparison, although sensitivity for NCPHP was similar (89%), Mi-PTH vastly improved SHP specificity (85%). In the combined cohort, Mi-PTH had better sensitivity of 98.5% (vs 95%) and specificity 97% (vs 85%).

CONCLUSION

MaxPTH was sensitive in detecting PHP; however, there was low specificity for SHP, especially in patients who underwent BrS. The creation of Mi-PTH provided improved performance measures but requires further prospective evaluation.

Surgical management of secondary hyperparathyroidism in chronic kidney disease--a consensus report of the European Society of Endocrine Surgeons

BACKGROUND

Despite advances in the medical management of secondary hyperparathyroidism due to chronic renal failure and dialysis (renal hyperparathyroidism), parathyroid surgery remains an important treatment option in the spectrum of the disease. Patients with severe and complicated renal hyperparathyroidism (HPT), refractory or intolerant to medical therapy and patients with specific requirements in prospect of or excluded from renal transplantation may require parathyroidectomy for renal hyperparathyroidism.

METHODS

Present standard and actual controversial issues regarding surgical treatment of patients with hyperparathyroidism due to chronic renal failure were identified, and pertinent literature was searched and reviewed. Whenever applicable, evaluation of the level of evidence concerning diagnosis and management of renal hyperparathyroidism according to standard criteria and recommendation grading were employed. Results were discussed at the 6th Workshop of the European Society of Endocrine Surgeons entitled Hyperparathyroidism due to multiple gland disease: An evidence-based perspective.

RESULTS

Presently, literature reveals scant data, especially, no prospective randomized studies to provide sufficient levels of evidence to substantiate recommendations for surgery in renal hyperparathyroidism. Appropriate surgical management of renal hyperparathyroidism involves standard bilateral exploration with bilateral cervical thymectomy and a spectrum of four standardized types of parathyroid resection that reveal comparable outcome results with regard to levels of evidence and recommendation. Specific patient requirements may favour one over the other procedure according to individualized demands.

CONCLUSIONS

Surgery for patients with renal hyperparathyroidism in the era of calcimimetics continues to play an important role in selected patients and achieves efficient control of hyperparathyroidism. The overall success rate and long-term control of renal hyperparathyroidism and optimal handling of postoperative metabolic effects also depend on the timely indication, individually suitable type of parathyroid resection and specialized endocrine surgery.

Clinicopathological correlates of hyperparathyroidism

Hyperparathyroidism is a common endocrine disorder with potential complications on the skeletal, renal, neurocognitive and cardiovascular systems. While most cases (95%) occur sporadically, about 5% are associated with a hereditary syndrome: multiple endocrine neoplasia syndromes (MEN-1, MEN-2A, MEN-4), hyperparathyroidism-jaw tumour syndrome (HPT-JT), familial hypocalciuric hypercalcaemia (FHH-1, FHH-2, FHH-3), familial hypercalciuric hypercalcaemia, neonatal severe hyperparathyroidism and isolated familial hyperparathyroidism. Recently, molecular mechanisms underlying possible tumour suppressor genes (MEN1, CDC73/HRPT2, CDKIs, APC, SFRPs, GSK3β, RASSF1A, HIC1, RIZ1, WT1, CaSR, GNA11, AP2S1) and proto-oncogenes (CCND1/PRAD1, RET, ZFX, CTNNB1, EZH2) have been uncovered in the pathogenesis of hyperparathyroidism. While bi-allelic inactivation of CDC73/HRPT2 seems unique to parathyroid malignancy, aberrant activation of cyclin D1 and Wnt/β-catenin signalling has been reported in benign and malignant parathyroid tumours. Clinicopathological correlates of primary hyperparathyroidism include parathyroid adenoma (80-85%), hyperplasia (10-15%) and carcinoma (<1-5%). Secondary hyperparathyroidism generally presents with diffuse parathyroid hyperplasia, whereas tertiary hyperparathyroidism reflects the emergence of autonomous parathyroid hormone (PTH)-producing neoplasm(s) from secondary parathyroid hyperplasia. Surgical resection of abnormal parathyroid tissue remains the only curative treatment in primary hyperparathyroidism, and parathyroidectomy specimens are frequently encountered in this setting. Clinical and biochemical features, including intraoperative PTH levels, number, weight and size of the affected parathyroid gland(s), are crucial parameters to consider when rendering an accurate diagnosis of parathyroid proliferations. This review provides an update on the expanding knowledge of hyperparathyroidism and highlights the clinicopathological correlations of this prevalent disease.

Feline hyperparathyroidism: pathophysiology, diagnosis and treatment of primary and secondary disease

PRACTICAL RELEVANCE

Hyperparathyroidism exists in primary and secondary forms. Primary hyperparathyroidism has typically been considered a disease that uncommonly affects cats, but this condition is more prevalent than previous diagnoses would suggest. Secondary hyperparathyroidism may be caused by either nutritional influences (ie, nutritional secondary hyperparathyroidism) or chronic kidney disease (ie, renal secondary hyperparathyroidism). Tertiary hyperparathyroidism has yet to be documented in veterinary medicine, but it is possible that this condition occurs in some cats following longstanding renal secondary hyperparathyroidism.

CLINICAL CHALLENGES

Diagnosis of this group of calcium metabolic disorders presents a number of challenges for the clinician. For example, clinical signs can be non-specific and, especially in the case of primary hyperparathyroidism, there is often a low index of suspicion for the disease; careful sample handling is required for testing of parathyroid hormone (PTH) and ionized calcium levels; and there is currently no feline-specific assay for PTH, which has implications for test sensitivity and interpretation of results.

AIMS

This article briefly outlines PTH and calcium physiology by way of introduction to a review of PTH measurement and interpretation. Various forms of feline hyperparathyroidism are then described, encompassing diagnosis and treatment options.

Dramatic alteration of the skull in a uremic patient with leontiasis ossea

The craniofacial skeleton represents a peculiar target of hyperparathyroidism in patients with end-stage renal disease who exhibit a dramatic pattern of uremic leontiasis ossea. Scant information regarding this condition is available in the renal literature, as the extreme and typical manifestations of leontiasis ossea have been described in only a small series of patients. We herein report a case of significant amelioration of massive modification of the facial appearance of a 30-year-old uremic Chinese woman with severe skeletal deformities who underwent total parathyroidectomy with a forearm autograft concurrently with effective drug treatment. This report may shed light on how to better understand and treat this metabolic derangement.