Systematic review of surgical and medical treatment for tertiary hyperparathyroidism

Pre-Transplant Calcimimetic Use and Dose Information Improves the Accuracy of Prediction of Tertiary Hyperparathyroidism after Kidney Transplantation: A Retrospective Cohort Study

Tertiary hyperparathyroidism (THPT) is characterized by elevated parathyroid hormone and serum calcium levels after kidney transplantation (KTx). To ascertain whether pre-transplant calcimimetic use and dose information would improve THPT prediction accuracy, this retrospective cohort study evaluated patients who underwent KTx between 2010 and 2022. The primary outcome was the development of clinically relevant THPT. Logistic regression analysis was used to evaluate pre-transplant calcimimetic use as a determinant of THPT development. Participants were categorized into four groups according to calcimimetic dose, developing two THPT prediction models (with or without calcimimetic information). Continuous net reclassification improvement (CNRI) and integrated discrimination improvement (IDI) were calculated to assess ability to reclassify the degree of THPT risk by adding pre-transplant calcimimetic information. Of the 554 patients, 87 (15.7%) developed THPT, whereas 139 (25.1%) received pre-transplant calcimimetic treatment. Multivariate logistic regression analysis revealed that pre-transplant calcimimetic use was significantly associated with THPT development. Pre-transplant calcimimetic information significantly improved the predicted probability accuracy of THPT (CNRI and IDI were 0.91 [p < 0.001], and 0.09 [p < 0.001], respectively). The THPT prediction model including pre-transplant calcimimetic information as a predictive factor can contribute to the prevention and early treatment of THPT in the era of calcimimetics.

A comparison of surgical treatments for tertiary hyperparathyroidism. A systematic review

INTRODUCTION

Tertiary hyperparathyroidism develops in patients who have secondary hyperparathyroidism that persists despite successful kidney transplantation or in patients who are on chronic dialysis.

US-guided Percutaneous Radiofrequency Ablation for Secondary Hyperparathyroidism: Long-term Outcomes and Prognostic Factors

Background Although favorable outcomes have been reported with radiofrequency ablation (RFA) for secondary hyperparathyroidism (SHPT), the long-term efficacy remains insufficiently investigated. Purpose To evaluate the long-term efficacy and safety of US-guided percutaneous RFA in patients with SHPT undergoing dialysis and to identify possible predictors associated with treatment failure. Materials and Methods This retrospective study included consecutive patients with SHPT with at least one enlarged parathyroid gland accessible for RFA who were undergoing dialysis at seven tertiary centers from May 2013 to July 2022. The primary end point was the proportion of patients with parathyroid hormone (PTH) levels less than or equal to 585 pg/mL at the end of follow-up. Secondary end points were the proportion of patients with normal calcium and phosphorus levels, the technical success rate, procedure-related complications, and improvement in self-rated hyperparathyroidism-related symptoms (0-3 ranking scale). The Wilcoxon signed rank test and generalized estimating equation model were used to evaluate treatment outcomes. Univariable and multivariable regression analyses identified variables associated with treatment failure (recurrent or persistent hyperparathyroidism). Results This study included 165 patients (median age, 51 years [IQR, 44-60 years]; 92 female) and 582 glands. RFA effectively reduced PTH, calcium, and phosphorus levels, with targeted ranges achieved in 78.2% (129 of 165), 72.7% (120 of 165), and 60.0% (99 of 165) of patients, respectively, at the end of follow-up (mean, 51 months). For the RFA sessions, the technical success rate was 100% (214 of 214). Median symptom scores (ostealgia, arthralgia, pruritus) decreased (all P < .001). Regarding complications, only hypocalcemia (45.8%, 98 of 214) was common. Treatment failure occurred in 36 patients (recurrent [n = 5] or persistent [n = 31] hyperparathyroidism). The only potential independent predictor of treatment failure was having less than four treated glands (odds ratio, 17.18; 95% CI: 4.34, 67.95; P < .001). Conclusion US-guided percutaneous RFA was effective and safe in the long term as a nonsurgical alternative for patients with SHPT undergoing dialysis; the only potential independent predictor of treatment failure was a lower number (<4) of treated glands. © RSNA, 2024 Supplemental material is available for this article.

Overview of Thyroid and Parathyroid Disease-The Endocrinology Perspective

Thyroid and parathyroid disorders are quite common in the population and range from benign to malignant conditions that may be hormonally active or inactive. Select disorders of the thyroid and parathyroid can be managed medically, although there are a variety of circumstances that may require definitive management with surgery. Surgical intervention may be required for hormonal control, compressive symptoms, or for the removal and/or control of malignancy. The endocrinologist's perspective of the preoperative and postoperative management regarding thyroid and parathyroid surgeries will be discussed.

Surgical treatment of tertiary hyperparathyroidism: does one fit for all?

Background

Tertiary hyperparathyroidism (3HPT) is defined as a condition of excessive autonomous excretion of intact parathyroid hormone (iPTH) with persistent hypercalcemia (>10.5 mg/dL) that lasts for more than 12 months after a successful kidney transplantation, in the context of a long course secondary hyperparathyroidism (2HPT). The chronic high levels of iPTH cause a worsening of graft function, accompanied by systemic symptoms of hypercalcemia. The only curative therapy is parathyroidectomy (PTX). It remains unclear whether total parathyroidectomy with autotransplantation (TPTX-AT) or subtotal parathyroidectomy (SPTX) lead to better outcomes.

Aims

The aim of this retrospective, single-institution cohort study is to evaluate the rate of persistent or recurrent disease and postoperative calcium/iPTH disturbances in patients treated with TPTX-AT or SPTX for 3HPT.

Methods

A single-center retrospective analysis of 3HPT patients submitted to TPTX-AT or SPTX between 2007-2020 with at least 24 months follow-up was conducted. The outcome parameters included persistence/recurrence of disease, incidence of transitory hypocalcemia, and temporary/permanent hypoparathyroidism.

Results

A cohort of 52 patients was analyzed and divided in two groups: 38 (73%) were submitted for TPTX-AT, and 14 patients (27%) were submitted for SPTX. The TPTX-AT population showed lower plasmatic calcium concentrations compared with the SPTX group during the entire follow-up period (p<0.001). There were eight cases (21%) of transitory hypocalcemia in the TPTX-AT group and none in the SPTX group, with p=0.065. Two cases (5%) of temporary hypoparathyroidism occurred in the TPTX-AT group and none in the SPTX group, with p= 0.530. There were no cases of permanent hypoparathyroidism and no cases of persistent disease. No statistical difference was assessed for the recurrence of 3HPT between the TPTX-AT group and the SPTX group (N=1, 3% vs N=1, 7%) (p=0.470).

Conclusion

No significative difference was registered between the TPTX-AT and SPTX groups in terms of persistence/recurrence of disease, incidence of transitory hypocalcemia, and temporary/permanent hypoparathyroidism. Mean calcium levels iPTH values were statistically lower among the TPTX-AT group compared with the SPTX group while remaining always in the range of normality.

Does race impact outcomes after parathyroidectomy for secondary and tertiary hyperparathyroidism?

BACKGROUND

Racial disparities in care exist for diseases with heterogeneous treatment guidelines. The impact of these disparities on outcomes after parathyroidectomy for secondary(2HPT) and tertiary hyperparathyroidism(3HPT) was explored.

METHODS

The 2015-2019 NSQIP datasets were used. Patients who underwent parathyroidectomy for 2HPT and 3HPT were identified and analyzed separately. Patients were stratified by race (white vs. non-white); demographics, comorbidities, and outcomes were compared. Studied outcomes included 30-day morbidity, mortality, unplanned reoperation, readmission, and postoperative length of stay(LOS).

RESULTS

There were 1,150 patients with 2HPT and 262 with 3HPT. For 2HPT, 65.5% were non-white; morbidity, reoperation, and prolonged LOS(>3days) occurred disproportionately more often in non-white patients. Non-white race was independently associated with morbidity; higher ASA class and alkaline phosphatase levels were associated with prolonged LOS. For 3HPT, 53.1% were non-white; a prolonged LOS(>1day) occurred disproportionately more often in non-white patients. Higher alkaline phosphatase levels were independently associated with prolonged LOS.

CONCLUSION

Race and markers of advanced disease negatively impact outcomes after parathyroidectomy for 2HPT and 3HPT. Attention to racial disparities and earlier referral may positively impact outcomes.

Morbidity and long-term outcome of surgery for renal hyperparathyroidism: results from a prospective cohort

PURPOSES

Surgery remains an important treatment option for renal hyperparathyroidism (rHPT). The number of long-term outcome studies of parathyroidectomy is limited.

METHODS

All consecutive patients with a parathyroidectomy for rHPT between 09/2009 and 04/2021 in a Belgian tertiary referral hospital were prospectively enrolled. The main outcomes were (long-term) cured proportion and postoperative morbidity (hypocalcemia, recurrent laryngeal nerve (RLN) palsy, re-intervention for bleeding, and wound morbidity).

RESULTS

Sixty patients with a median age of 57 years were analyzed, including 23 patients before kidney transplantation, 23 patients without kidney transplantation, and 14 patients after kidney transplantation. Median time to transplant was 15 (6-24) months after parathyroidectomy. Morbidity was low with only two non-urgent returns to theatre (wound infection and non-compressive hematoma), two temporary RLN paralyses, and no 30-day mortality. Length of hospital stay was longer in patients with parathyroidectomy before kidney transplant, due to a more severe and prolonged need for calcium supplementation. After a median follow-up of 63 months, 37 patients (62%) were still alive, and 11 patients (18%) developed a recurrence.

CONCLUSIONS

This single-surgeon, single-center cohort with long-term follow-up confirms the safety and excellent 'cure' proportions of surgery for rHPT but stretches the importance of long-term follow-up.

Parathyroid Imaging

Primary hyperparathyroidism (1° HPT) is a relatively common endocrine disorder usually caused by autonomous secretion of parathormone by one or several parathyroid adenomas. 1° HPT causing hypercalcemia, kidney stones and/or osteoporosis should be treated whenever possible by parathyroidectomy. Accurate preoperative location of parathyroid adenomas is crucial for surgery planning, mostly when performing minimally invasive surgery. Cervical ultrasonography (US) is usually performed to localize parathyroid adenomas as a first intention, followed by 99mTc- sestamibi scintigraphy with SPECT/CT whenever possible. 4D-CT is a possible alternative to 99mTc- sestamibi scintigraphy. Recently, 18F-fluorocholine positron emission tomography/computed tomography (18F-FCH PET/CT) has made its way in the clinics as it is the most sensitive method for parathyroid adenoma detection. It can eventually be combined to 4D-CT to increase its diagnostic performance, although this results in higher dose exposure to the patient. Other forms of hyperparathyroidism consist in secondary (2° HPT) and tertiary hyperparathyroidism (3° HPT). As parathyroidectomy is not usually part of the management of patients with 2° HPT, parathyroid imaging is not routinely performed in these patients. In patients with 3° HPT, total or subtotal parathyroidectomy is often performed. Localization of hyperfunctional glands is an important aid to surgery planning. As 18F-FCH PET/CT is the most sensitive modality in multigland disease, it is the preferred imaging technic in 3° HPT patients, although its cost and availability may limit its widespread use in this setting.

Factors Associated With Persistent Post-transplant Hyperparathyroidism After Index Renal Transplantation

INTRODUCTION

Secondary hyperparathyroidism (SHP) is common in end-stage renal disease and may progress to persistent post-transplant hyperparathyroidism (PTHP) following renal transplantation (RT). We sought to describe the frequency and determine factors associated with the incidence of PTHP for patients undergoing RT at a single institution that restricts RT for patients with uncontrolled SHP with a parathyroid hormone (PTH) of >800pg/mL at time of initial transplant evaluation.

METHODS

We conducted a single-institution retrospective study of adults undergoing index RT from 2012 to 2020 who had a calcium and PTH level within 12 mo prior to RT and at least 6 mo following RT. PTHP was defined as calcium of >10 mg/dL with an elevated PTH > 88pg/mL at six or more months following RT. Univariate analysis and multivariable logistic regression were performed for factors associated with developing PTHP.

RESULTS

We identified 1110 patients with RT, 65 were excluded for prior RT, 549 did not have a pre-RT and post-RT calcium, and PTH laboratories for inclusion, yielding 496 for analysis. Following RT, 39 patients (7.9%) developed PTHP, compared to those who did not develop PTHP; these patients had significantly higher pre-RT PTH, pre-RT calcium, and frequency of calcimimetic therapy. In multivariable logistic regression factors significantly associated with PTHP were pre-RT calcium of more than 10 mg/dL with an odds ratio (OR) of 3.57 (95% confidence interval [CI] 1.52-8.39, P = 0.003) and pre-RT calcimimetic therapy with an OR 1.30 (95% CI 1.06-2.85, P = 0.041). Compared with patients who had a pre-RT PTH of less than 200 pg/mL, a PTH of 200-399 pg/mL increased risk of PTHP with an OR of 4.52 (95% CI 1.95-21.5, P = 0.048) and a PTH of > 400 pg/mL increased risk of PTHP with an OR of 7.17 (95% CI 1.47-34.9, P = 0.015). In this cohort, 11 patients (28.2%) with PTHP underwent parathyroidectomy (PTx) at a mean of 1.4 y post-RT (standard deviation 0.87).

CONCLUSIONS

For patients required to have a PTH < 800pg/mL for initial transplant candidacy, the subsequent incidence of PTHP is relatively low at 7.9%. Risk factors for PTHP include higher pre-RT calcium and PTH levels and pre-RT calcimimetic therapy. PTx remains underused in the treatment of PTHP. Further study is warranted to determine the optimal PTH cutoff for transplant candidacy and recommendation for PTx in patients requiring calcimimetic therapy for SHP.

Missed Opportunities to Diagnose and Treat Tertiary Hyperparathyroidism After Transplant

INTRODUCTION

Tertiary hyperparathyroidism (3HPT) is common after renal transplant. However, guidelines for diagnosis are not clear and few patients are treated surgically. This study aims to determine rates of diagnosis and treatment of 3HPT in renal transplant patients with hypercalcemia.

MATERIALS AND METHODS

This retrospective chart review identified all renal transplant recipients at a single tertiary care institution between 2011 and 2021. Patients with post-transplant hypercalcemia (> 10.2 mg/dL) were identified. The time in months of index hypercalcemia was noted. Measurement of parathyroid hormone (PTH) levels after index hypercalcemia was determined and noted as elevated if > 64 pg/mL at least 6 mo after transplant. Documentation of symptoms of hyperparathyroidism, a diagnosis of hyperparathyroidism in the electronic medical record, and medical or surgical management of patients with classic 3HPT (elevated calcium and PTH) were determined.

RESULTS

Of 383 renal transplant recipients, hypercalcemia was identified in 132 patients. The majority of hypercalcemic patients had PTH levels measured (127, 96.2%). PTH was elevated in 109 (82.6%). Among the 109 patients with classic 3HPT, 54 (49.5%) had a documented diagnosis of hyperparathyroidism in the electronic medical record (P = 0.01). Kidney stones or abnormal DEXA scan were present in 16 (14.7%) and 18 (16.5%), respectively. Most patients were managed non-surgically (101, 92.6%); calcimimetics were prescribed for 42 (38.5%, P = 0.01). Eight (7.3%) patients with classic 3HPT were referred to a surgeon (P = 0.35); all were initially prescribed calcimimetics (P = 0.001).

CONCLUSIONS

3HPT is underdiagnosed in patients with elevated calcium and PTH levels post-transplant. A significant percentage of these patients go without surgical referral and curative treatment.

Ultrasound-guided microwave ablation for tertiary hyperparathyroidism in patients with renal transplantation

OBJECTIVE

To explore the safety and efficacy of ultrasound-guided microwave ablation (MWA) for tertiary hyperparathyroidism (THPT) in patients with renal transplantation (RT).

METHODS

In total, fifteen patients with THPT after renal transplantation who underwent MWA were enrolled in the study. The pre- and post-MWA intact parathyroid hormone (iPTH), serum calcium, phosphorus, creatinine, urea nitrogen and estimated glomerular filtration rate (eGFR) values were compared.

RESULTS

A total of 38 parathyroid hyperplastic nodules in 15 RT patients were treated with ultrasound-guided MWA. The mean (median, range) size of the hyperplastic parathyroid nodules was 11.5 mm (11 mm, 5-25 mm), and the average (median, range) ablation time was 163.5s (121 s, 44-406 s). The average levels of serum iPTH and calcium at 1 d, 7 d, 1 month, 3 months, 6 months, 1 year post-MWA and at the end of follow-up were significantly lower than those pre-MWA (all p < 0.05). Compared with the pre-MWA value (0.76 mmol/L), the serum phosphorus levels at 1 d post-MWA (0.63 mmol/L) were significantly decreased, and those at 7 d, 1 month, 3 months, 6 months, 1 year post-MWA and at the end of follow-up were significantly increased, but all were within the normal range. There was no significant difference in serum creatinine and eGFR pre-MWA and post-MWA. No major MWA-related complications occurred.

CONCLUSION

Ultrasound-guided MWA shows potential as a viable treatment for THPT in RT patients. However, further studies are required to confirm its safety and effectiveness in larger cohorts of longer duration.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Secondary and Tertiary Renal Hyperparathyroidism

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate treatment of secondary (SHPT) and tertiary (THPT) renal hyperparathyroidism.

BACKGROUND

Hyperparathyroidism is common among patients with chronic kidney disease, end-stage kidney disease, and kidney transplant. The surgical management of SHPT and THPT is nuanced and requires a multidisciplinary approach. There are currently no clinical practice guidelines that address the surgical treatment of SHPT and THPT.

METHODS

Medical literature was reviewed from January 1, 1985 to present January 1, 2021 by a panel of 10 experts in SHPT and THPT. Recommendations using the best available evidence was constructed. The American College of Physicians grading system was used to determine levels of evidence. Recommendations were discussed to consensus. The American Association of Endocrine Surgeons membership reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines present the epidemiology and pathophysiology of SHPT and THPT and provide recommendations for work-up and management of SHPT and THPT for all involved clinicians. It outlines the preoperative, intraoperative, and postoperative management of SHPT and THPT, as well as related definitions, operative techniques, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Preoperative and Perioperative Care, Surgical Planning and Parathyroidectomy, Adjuncts and Approaches, Outcomes, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal management of secondary and tertiary renal hyperparathyroidism.

Impact of parathyroidectomy on kidney graft function in post-transplant tertiary hyperparathyroidism: a comparative study

PURPOSE

Parathyroidectomy to treat tertiary hyperparathyroidism (THPT) is now on a par with calcimimetic treatment. The effects of cinacalcet and parathyroidectomy on kidney transplant function remain controversial. The aim of this study was to evaluate kidney transplant function in THPT patients treated either by parathyroidectomy, cinacalcet, or not treated.

METHODS

Between 2009 and 2019, 231 patients with functional grafts presenting THPT, defined either by calcaemia superior to 2.5 mmol/L with elevated PTH level or hypercalcaemia with non-adapted PTH level 1 year after kidney transplantation, were included. Hyperparathyroid patients treated by cinacalcet and parathyroidectomy were matched for age, sex, graft rank, and baseline eGFR with cinacalcet-only and untreated patients. Conditional logistic regression models were used to compare eGFR variations 1 year after parathyroidectomy between operated patients and matched controls. Five-year survivals were compared with the Mantel-Cox test.

RESULTS

Eleven patients treated with parathyroidectomy and cinacalcet were matched with 16 patients treated by cinacalcet-only and 29 untreated patients. Demographic characteristics were comparable between groups. Estimated odds ratios for eGFR evolution in operated patients compared with cinacalcet-only and untreated patients were 0.92 [95%CI 0.83-1.02] and 0.99 [0.89-1.10] respectively, indicating no significant impairment of eGFR 1 year after surgery. Five-year allograft survival was not significantly impaired in operated patients.

CONCLUSIONS

Parathyroidectomy did not appear to substantially alter or improve graft function 1 year after surgery or 5-year allograft survival. It could be hypothesized that in addition to its known benefits, parathyroidectomy can be safely performed vis-à-vis graft function in tertiary hyperparathyroidism.

Surgery is Underutilized in the Management of Tertiary Hyperparathyroidism

INTRODUCTION

Tertiary hyperparathyroidism (3HPT) is observed in up to 40% of renal transplant patients. Standard guidelines defining 3HPT and indications for operative intervention are not well described.

METHODS

We conducted a retrospective, single-institution cohort study of patients who underwent renal transplant between January 1, 2012 and January 30, 2018, with a minimum of 13-month follow-up and at least 1 y of allograft function. We defined 3HPT as having elevated serum level parathyroid hormone (>88 pg/mL) after successful renal transplantation or multiple instances of elevated serum calcium starting at least 3 mo after transplant. We compared graft failure rates after stratifying the cohort based on management strategy: expectant, medical management with cinacalcet, and parathyroidectomy.

RESULTS

Out of the 381 transplanted patients with functional grafts at 1 y, 178 patients (46.6%) were found to have 3HPT. One hundred twenty-nine patients (72.5%) were managed expectantly without medications, 35 patients (19.7%) were managed medically, and 14 patients (7.8%) were managed with parathyroidectomy. Twenty-two patients (17.1%) in the observation group had graft failure, 4 patients (11.4%) in the medically managed group had graft failure, and 0 patients in the surgery group had graft failure. Surgical intervention was associated with decreased renal allograft failure when compared to the combined cohort of nonoperative 3HPT patients (P = 0.03). All patients who underwent parathyroidectomy were cured and did not have graft failure as of December 30, 2019. Calcium elevation, but not PTH elevation, was associated with referral for parathyroidectomy on multivariable logistic regression analysis (P < 0.01).

CONCLUSIONS

At our institution, the referral rate for parathyroidectomy among patients with 3HPT remains low. Parathyroidectomy was associated with high cure rates and reduced graft failure. Surgery may be underutilized in the management of 3HPT.

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.

Clinical Prediction of High-Turnover Bone Disease After Kidney Transplantation

Bone histomorphometric analysis is the most accurate method for the evaluation of bone turnover, but non-invasive tools are also required. We studied whether bone biomarkers can predict high bone turnover determined by bone histomorphometry after kidney transplantation. We retrospectively evaluated the results of bone biopsy specimens obtained from kidney transplant recipients due to the clinical suspicion of high bone turnover between 2000 and 2015. Bone biomarkers were acquired concurrently. Of 813 kidney transplant recipients, 154 (19%) biopsies were taken at a median of 28 (interquartile range, 18-70) months after engraftment. Of 114 patients included in the statistical analysis, 80 (70%) presented with high bone turnover. Normal or low bone turnover was detected in 34 patients (30%). For discriminating high bone turnover from non-high, alkaline phosphatase, parathyroid hormone, and ionized calcium had the areas under the receiver operating characteristic curve (AUCs) of 0.704, 0.661, and 0.619, respectively. The combination of these markers performed better with an AUC of 0.775. The positive predictive value for high turnover at a predicted probability cutoff of 90% was 95% while the negative predictive value was 35%. This study concurs with previous observations that hyperparathyroidism with or without hypercalcemia does not necessarily imply high bone turnover in kidney transplant recipients. The prediction of high bone turnover can be improved by considering alkaline phosphatase levels, as presented in the logistic regression model. If bone biopsy is not readily available, this model may serve as clinically available tool in recognizing high turnover after engraftment.

Prevalence and risk factors for tertiary hyperparathyroidism in kidney transplant recipients

BACKGROUND

Tertiary hyperparathyroidism after kidney transplantation has been associated with graft dysfunction, cardiovascular morbidity, and osteopenia; however, its true prevalence is unclear. The objective of our study was to evaluate the prevalence of and risk factors for tertiary hyperparathyroidism.

METHODS

A prospective cohort of 849 adult kidney transplantation recipients (December 2008-February 2020) was used to estimate the prevalence of hyperparathyroidism 1-year post-kidney transplant. Tertiary hyperparathyroidism was defined as hypercalcemia (≥10mg/dL) and hyperparathyroidism (parathyroid hormone≥70pg/mL) 1-year post-kidney transplantation. Modified Poisson regression models were used to evaluate risk factors associated with the development of both persistent hyperparathyroidism and tertiary hyperparathyroidism.

RESULTS

Among kidney transplantation recipients, 524 (61.7%) had persistent hyperparathyroidism and 182 (21.5%) had tertiary hyperparathyroidism at 1-year post-kidney transplantation. Calcimimetic use before kidney transplantation was associated with 1.30-fold higher risk of persistent hyperparathyroidism (adjusted prevalence ratio = 1.30, 95% CI: 1.12-1.51) and 1.84-fold higher risk of tertiary hyperparathyroidism (adjusted prevalence ratio = 1.84, 95% CI: 1.25-2.72). Pre-kidney transplantation parathyroid hormone ≥300 pg/mL was associated with 1.49-fold higher risk of persistent hyperparathyroidism (adjusted prevalence ratio = 1.49, 95% CI = 1.19-1.85) and 2.21-fold higher risk of tertiary hyperparathyroidism (adjusted prevalence ratio = 2.21, 95% CI = 1.25-3.90). Pre-kidney transplantation tertiary hyperparathyroidism was associated with an increased risk of post-kidney transplantation tertiary hyperparathyroidism (adjusted prevalence ratio = 1.71, 95% CI = 1.29-2.27), but not persistent hyperparathyroidism. Furthermore, 73.0% of patients with persistent hyperparathyroidism and 61.5% with tertiary hyperparathyroidism did not receive any treatment at 1-year post-kidney transplantation.

CONCLUSION

Persistent hyperparathyroidism affected 61.7% and tertiary hyperparathyroidism affected 21.5% of kidney transplantation recipients; however, the majority of patients were not treated. Pre-kidney transplantation parathyroid hormone levels ≥300pg/mL and the use of calcimimetics are associated with the development of tertiary hyperparathyroidism. These findings encourage the re-evaluation of recommended pre-kidney transplantation parathyroid hormone thresholds and reconsideration of pre-kidney transplantation secondary hyperparathyroidism treatments to avoid the adverse sequelae of tertiary hyperparathyroidism in kidney transplantation recipients.

OUP accepted manuscript

Chronic kidney disease mineral and bone disorder may persist after successful kidney transplantation. Persistent hyperparathyroidism has been identified in up to 80% of patients throughout the first year after kidney transplantation. International guidelines lack strict recommendations about the management of persistent hyperparathyroidism. However, it is associated with adverse graft and patient outcomes, including higher fracture risk and an increased risk of all-cause mortality and allograft loss. Secondary hyperparathyroidism may be treated medically (vitamin D, phosphate binders and calcimimetics) or surgically (parathyroidectomy). Guideline recommendations suggest medical therapy first but do not clarify optimal parathyroid hormone targets or indications and timing of parathyroidectomy. There are no clear guidelines or long-term studies about the impact of hyperparathyroidism therapy. Parathyroidectomy is more effective than medical treatment, although it is associated with increased short-term risks. Ideally parathyroidectomy should be performed before kidney transplantation to prevent persistent hyperparathyroidism and improve graft outcomes. We now propose a roadmap for the management of secondary hyperparathyroidism in patients eligible for kidney transplantation that includes the indications and timing (pre- or post-kidney transplantation) of parathyroidectomy, the evaluation of parathyroid gland size and the integration of parathyroid gland size in the decision-making process by a multidisciplinary team of nephrologists, radiologists and surgeons.

High bone turnover and hyperparathyroidism after surgery for tumor-induced osteomalacia: A case series

Tumor-induced osteomalacia (TIO) is an ultrarare disorder that is caused by renal phosphate wasting due to uncontrolled tumoral production of fibroblast growth factor 23 (FGF23) from phosphaturic mesenchymal tumors. Surgical removal of the tumor is curative. There is limited information on the biochemical changes in mineral metabolism and bone remodeling activity after surgery, but it is reported that surgery is followed by a hungry bone syndrome (HBS) with hypocalcemia and secondary hyperparathyroidism. We report the biochemical response to surgery in two patients, who presented with severe TIO, as manifested by proximal myopathy, multiple stress fractures, high FGF23, low serum phosphate, low maximum renal phosphate reabsorption threshold (TmP/GFR), and low 1,25-dihydroxy-vitamin D (1,25(OH)₂D). Prior to surgery, both patients developed secondary hyperparathyroidism and one case had progressed to tertiary hyperparathyroidism. After surgery there was normalization of FGF23, TmP/GFR, and phosphate. High 1,25(OH)₂D was recorded. One patient had hypocalcaemia and worsening secondary hyperparathyroidism consistent with HBS; the other patient did not have hypocalcemia but had worsening tertiary hyperparathyroidism that only resolved with cinacalcet. There was a marked increase in bone remodeling markers, both resorption and formation, consistent with a high bone turnover state. There was a different pattern of change in bone specific alkaline phosphatase, reflecting healing of osteomalacia. Biochemical monitoring in the post-surgical management of TIO is warranted for guiding adjustments in medical intervention, both short-term and long-term. Future use of burosumab prior to surgery for TIO may ameliorate the immediate post-surgery effects.

Association Between Treatment of Secondary Hyperparathyroidism and Posttransplant Outcomes

BACKGROUND

Secondary hyperparathyroidism (SHPT) affects nearly all patients on maintenance dialysis therapy. SHPT treatment options have considerably evolved over the past 2 decades but vary in degree of improvement in SHPT. Therefore, we hypothesize that the risks of adverse outcomes after kidney transplantation (KT) may differ by SHPT treatment.

METHODS

Using the Scientific Registry of Transplant Recipients and Medicare claims data, we identified 5094 adults (age ≥18 y) treated with cinacalcet or parathyroidectomy for SHPT before receiving KT between 2007 and 2016. We quantified the association between SHPT treatment and delayed graft function and acute rejection using adjusted logistic models and tertiary hyperparathyroidism (THPT), graft failure, and death using adjusted Cox proportional hazards; we tested whether these associations differed by patient characteristics.

RESULTS

Of 5094 KT recipients who were treated for SHPT while on dialysis, 228 (4.5%) underwent parathyroidectomy, and 4866 (95.5%) received cinacalcet. There was no association between treatment of SHPT and posttransplant delayed graft function, graft failure, or death. However, compared with patients treated with cinacalcet, those treated with parathyroidectomy had a lower risk of developing THPT (adjusted hazard ratio, 0.56; 95% confidence interval, 0.35-0.89) post-KT. Furthermore, this risk differed by dialysis vintage (Pinteraction = 0.039). Among patients on maintenance dialysis therapy for ≥3 y before KT (n = 3477, 68.3%), the risk of developing THPT was lower when treated with parathyroidectomy (adjusted hazard ratio, 0.43; 95% confidence interval, 0.24-0.79).

CONCLUSIONS

Parathyroidectomy should be considered as treatment for SHPT, especially in KT candidates on maintenance dialysis for ≥3 y. Additionally, patients treated with cinacalcet for SHPT should undergo close surveillance for development of tertiary hyperparathyroidism post-KT.

Therapy for persistent hypercalcemic hyperparathyroidism post-renal transplant: cinacalcet versus parathyroidectomy

Background:

Persistent hyperparathyroidism post-transplant is associated with increases in the incidence of cardiovascular events, fractures, and deaths. The aim of this study was to compare both therapeutic options available: parathyroidectomy (PTX) and the calcimimetic agent cinacalcet.

Methods:

A single center retrospective study including adult renal transplant recipients who developed hypercalcemia due to persistent hyperparathyroidism. Inclusion criteria: PTH > 65 pg/mL with serum calcium > 11.5 mg/dL at any time after transplant or serum calcium persistently higher than 10.2 mg/dL one year after transplant. Patients treated with cinacalcet (n=46) were compared to patients treated with parathyroidectomy (n=30). Follow-up period was one year. Clinical and laboratory data were analyzed to compare efficacy and safety of both therapeutic modalities.

Results:

PTX controlled calcemia faster (month 1 x month 6) and reached significantly lower levels at month 12 (9.1±1.2 vs 9.7±0.8 mg/dL, p < 0.05); PTX patients showed significantly higher levels of serum phosphate (3.8±1.0 vs 2.9±0.5 mg/dL, p < 0.05) and returned PTH to normal levels (45±51 pg/mL). Cinacalcet, despite controlling calcium and phosphate in the long term, decreased but did not correct PTH (197±97 pg/mL). The proportion of patients that remained with PTH above normal range was 95% in the cinacalcet group and 22% in the PTX group. Patients treated with cinacalcet had better renal function (creatinine 1.2±0.3 vs 1.7±0.7 mg/dL, p < 0.05).

Conclusions:

Surgical treatment was superior to cinacalcet to correct the metabolic disorders of hyperparathyroidism despite being associated with worse renal function in the long term. Cinacalcet proved to be a safe and well tolerated drug.

Pediatric hyperparathyroidism: review and imaging update

Hyperparathyroidism, due to increased secretion of parathyroid hormones, may be primary, secondary or tertiary. Most pediatric patients with sporadic primary hyperparathyroidism will be symptomatic, presenting with either end-organ damage or nonspecific symptoms. In younger patients with primary hyperparathyroidism, there is a higher prevalence of familial hyperparathyroidism including germline inactivating mutations of the calcium-sensing receptor genes that result in either neonatal severe hyperparathyroidism or familial hypocalciuric hypercalcemia. Parathyroid scintigraphy and ultrasound are complementary, first-line imaging modalities for localizing hyperfunctioning parathyroid glands. Second-line imaging modalities are multiphase computed tomography (CT) and magnetic resonance imaging. In pediatrics, multiphase CT protocols should be adjusted to optimize radiation dose. Although, the role of these imaging modalities is better established in preoperative localization of hyperfunctioning parathyroid glands in primary hyperparathyroidism, the same principles apply in secondary and tertiary hyperparathyroidism. In this manuscript, we will review the embryology, anatomy, pathophysiology and preoperative localization of parathyroid glands as well as several subtypes of primary familial hyperparathyroidism. While most of the recent imaging literature centers on adults, we will focus on the issues that are pertinent and applicable to pediatrics.

Parathyroidectomy or cinacalcet: Do we still not know the best option for graft function in kidney-transplanted patients? A meta-analysis

BACKGROUND

Tertiary hyperparathyroidism occurs in 25% to 50% of kidney-transplanted patients. Indication of parathyroidectomy is now discussed, since the calcimimetic agent, cinacalcet, is an alternate option. The effects of either of these treatments on graft function remain controversial, studied only in small cohorts showing either decrease or absence of modification. We performed a meta-analysis to evaluate the evolution of graft function after surgical or medical treatment.

METHODS

Studies assessing graft function in tertiary hyperparathyroidism after parathyroidectomy or cinacalcet introduction were enrolled into quantitative analysis using Pubmed, Embase, and Cochrane databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis reporting guidelines. Among 68 screened studies, 18 had no missing data and were included for statistical analyses. We performed random effect meta-analysis to determine changes in serum creatinine and estimated glomerular filtration rate.

RESULTS

Seven studies assessing the evolution of graft function 6 and/or 12 months after parathyroidectomy and 13 after administration of cinacalcet were included. Meta-analysis found no significant variations after parathyroidectomy in serum creatinine (6 studies, 314 patients) and estimated glomerular filtration rate (2 studies, 105 patients). No significant variation was found after administration of cinacalcet in serum creatinine (10 studies, 404 patients) and estimated glomerular filtration rate (6 studies, 149 patients). A significant heterogeneity between the studies (P < .01, Cochran's Q) was found.

CONCLUSION

Meta-analysis shows that parathyroidectomy and cinacalcet do not significantly impair graft function in patients with tertiary hyperparathyroidism. However, the significant heterogeneity between selected studies, partially explained by the lack of consensual definition of tertiary hyperparathyroidism, limits the conclusions of all previously published series.

Pharmacogenetic and safety analysis of cinacalcet hydrochloride in healthy Chinese subjects

BACKGROUND

Our study aims to explore the effect of genetics on the pharmacodynamics (PD) and pharmacokinetics (PK) of cinacalcet in healthy Chinese subjects; to investigate the effect of dietary factors on cinacalcet, and to evaluate the safety of cinacalcet under fasting and non-fasting conditions using a bioequivalence trial.

METHODS

We investigated the relationship of cinacalcet PK with single nucleotide polymorphisms (SNPs) of CYP3A4, CYP1A2 and CYP2D6, and of cinacalcet PD with SNPs of calcium-sensitive receptors (CASR) and vitamin D receptors (VDR) in 65 healthy Chinese subjects recruited to participate in this study. Our study was a phase I, open-label, randomized, two-period, two-sequence crossover, a single-center clinical study designed under both fasting and non-fasting conditions to investigate the effect of dietary factors on cinacalcet. Plasma cinacalcet concentrations were analyzed using a validated HPLC-MS/MS assay. Clinical laboratory tests evaluated safety. Thirteen SNPs of CASR, VDR, and CYP genes were selected for pharmacogenetic analysis.

RESULTS

CYP3A4 rs4646437 was found to be associated with the PK of cinacalcet under fasting conditions (P<0.01). Subjects carrying T alleles of rs4646437 appeared to metabolize cinacalcet poorly. The C_max and AUC of subjects in the non-fasting group were significantly higher (P<0.0001) than those in the fasting group. The T_max, CL/F, and Vd/F in the fasting group were significantly higher (P<0.0001) than those in the non-fasting group. In the fasting group, the geometric least square mean ratios (T/R) of the C_max and AUC_0-t were 109.89% and 105.33%, and the corresponding 90% CIs were 98.36-122.79% and 98.04-113.15%, respectively. In the non-fasting group, the T/R of the C_max and AUC_0-t were 100.74% and 99.09%, and the corresponding 90% CIs were 92.65-109.54% and 94.79-103.58%, respectively. All adverse events (AEs) were mild, and no serious adverse events (SAEs) occurred during the bioequivalence trial.

CONCLUSIONS

Following our investigation, we reached the following conclusions: CYP3A4 rs4646437 may affect cinacalcet PK; the reference and test preparations of cinacalcet were bioequivalent under fasting and non-fasting conditions and were safe to use; and dietary factors had a significant effect on the PK of cinacalcet, in that exposure to the drug increased when cinacalcet was taken after eating.

Type of subtotal parathyroidectomy and evolution of parathyroid hormone levels in end-stage renal disease patients: a retrospective cohort study

PURPOSE

Parathyroidectomy (PTX) is performed in end-stage renal disease (ESRD) for the treatment of secondary hyperparathyroidism. Whether and how the number of glands removed affects parathyroid hormone (PTH) levels remain controversial. The objective of this study is to compare the biochemical and pharmacological evolution after subtotal PTX according to the number of glands removed in ESRD.

METHODS

This is a unicenter longitudinal retrospective cohort study of ESRD patients who have undergone PTX [< 3 glands (group 1) vs ≥ 3 glands (group 2)] from April 2006 to October 2014 at CHU de Québec, Canada. Demographic data, comorbidities, pharmacological and biochemical parameters were collected before, 3, 6, 12 and 24 months after PTX. Linear mixed model was performed to compare the biochemical and pharmacological evolution.

RESULTS

We included 37 (13 in group 1, 24 in group 2) ESRD patients with a median age of 53 (46-58) years. The population is 68% male with a median dialysis vintage of 30.7 (18.0-61.2) months. The two groups were similar in terms of demographics and comorbidities. Compared to baseline, PTH levels in groups 1 and 2 dropped significantly at 2 years (1239-361 ng/L and 1542-398 ng/L, p < 0.05) but the evolution was comparable between the two groups.

CONCLUSIONS

Our results show the efficacy of subtotal PTX in lowering PTH levels in our ESRD cohort. However, the results were not different according to the number of glands removed.

Timing of parathyroidectomy for tertiary hyperparathyroidism with end-stage renal disease: A cost-effectiveness analysis

BACKGROUND

Tertiary hyperparathyroidism associated with end-stage renal disease is characterized by progression from secondary hyperparathyroidism to an autonomous overproduction of parathyroid hormone that leads to adverse health outcomes. Rates of parathyroidectomy (PTX) have decreased with the use of calcimimetics. Optimal timing of PTX in relation to kidney transplant remains controversial. We aimed to identify the most cost-effective strategy for patients with tertiary hyperparathyroidism undergoing kidney transplant.

METHODS

We constructed a patient level state transition microsimulation to compare 3 management schemes: cinacalcet with kidney transplant, cinacalcet with PTX before kidney transplant, or cinacalcet with PTX after kidney transplant. Our base case was a 55-year-old on dialysis with tertiary hyperparathyroidism awaiting kidney transplant. Outcomes, including quality-adjusted life years, surgical complications, and mortality, were extracted from the literature, and costs were estimated using Medicare reimbursement data.

RESULTS

Our base case analysis demonstrated that cinacalcet with PTX before kidney transplant was dominant, with a lesser cost of $399,287 and greater quality-adjusted life years of 10.3 vs $497,813 for cinacalcet with PTX after kidney transplant (quality-adjusted life years 9.4) and $643,929 for cinacalcet with kidney transplant (quality-adjusted life years 7.4).

CONCLUSION

Cinacalcet alone with kidney transplant is the least cost-effective strategy. Patients with end-stage renal disease-related tertiary hyperparathyroidism should be referred for PTX, and it is most cost-effective if performed prior to kidney transplant.

Long-term results of a randomized study comparing parathyroidectomy with cinacalcet for treating tertiary hyperparathyroidism

Tertiary hyperparathyroidism is a common cause of hypercalcemia after kidney transplantation (KT) and has been associated with renal dysfunction, bone mineral density loss, and increased risk of fracture and cardiovascular events. In a previous 12-month clinical trial, we demonstrated that subtotal parathyroidectomy was more effective than cinacalcet for controlling hypercalcemia. In the current study, we retrospectively evaluate whether this effect is maintained after 5 years of follow-up. In total, 24 patients had data available at 5 years, 13 in the cinacalcet group and 11 in the parathyroidectomy group. At 5 years, 7 of 11 patients (64%) in the parathyroidectomy group and 6 of 13 patients (46%) in the cinacalcet group (P = .44) showed normocalcemia. However, recurrence of hypercalcemia was only observed in the cinacalcet group (P = .016). Subtotal parathyroidectomy retained a greater reduction in intact parathyroid hormone (iPTH) compared with cinacalcet group. No differences were observed in kidney function and incidence of fragility fractures between both groups. Cinacalcet was discontinued in 5 out of 13 patients. In conclusion, in kidney transplant patients with tertiary hyperparathyroidism recurrence of hypercalcemia after 5-year follow-up is more frequent in cinacalcet than after subtotal parathyroidectomy.

Influence of Parathyroidectomy on Kidney Graft Function in Secondary and Tertiary Hyperparathyroidism

BACKGROUND

Timing of parathyroidectomy (PTX) remains controversial in candidates for kidney transplant with concomitant renal hyperparathyroidism (HPT). The aim of this retrospective study was to identify the influence of early vs late posttransplant PTX compared to pretransplant PTX on renal graft function and morbidity.

METHODS

This single-center cohort study includes 57 patients with renal HPT and kidney transplantation treated between 2007 and 2017. Ninety-six patients had surgery for renal HPT between 2007 and 2017 as a consecutive sample. Group 1 (n = 30; tertiary HPT), group 2 (n = 66; secondary HPT). Of group 1, 4 patients were excluded for PTX before and after kidney transplantation. In group 2, 20 patients were excluded since they had not undergone kidney transplantation during follow-up. Twelve patients were excluded because of short follow-up (kidney transplantation in 2018), and 3 patients were excluded because of transplant failure within 90 days. Twenty-six patients underwent posttransplant PTX (10 patients within 12 months after transplant), and 31 patients had undergone PTX prior to kidney transplantation. Graft function, serum calcium concentrations, parathyroid hormone (PTH) levels, postoperative morbidity, and 90-day mortality were recorded.

RESULTS

Median age was 53.1 years in group 1 and 49.1 years in group 2. Most patients were male (53.8% in group 1; 54.8% in group 2). Median preoperative PTH levels were significantly different with 331.6 pg/mL in group 1 and 667.5 pg/mL in group 2 (P = .003). Creatinine levels changed little from 1.4 mg/dL (range, 0.8-2.5) to 1.7 mg/dL (range, 0.7-7.3) in group 1, and no difference was seen between early or late PTX after transplantation. In group 2, creatinine levels were 8.5 mg/dL (range, 4.6-11.7) before PTX and 8.7 mg/dL (range, 5.1-11.9) after PTX. We saw no correlation between postoperative PTH and kidney function. Thirty-five patients with postoperative PTH < 15 pg/mL displayed a mean postoperative creatinine of 5.5 mg/dL (range, 4.3-6.8), similar to other patients. Both the 30-day and 90-day mortality rates were zero.

CONCLUSIONS

PTX had no negative effect on graft function, whether performed before or after (early or late) kidney transplantation. Surgical cure of renal HPT should be performed as soon as possible to prevent secondary complications and can also be safely carried out early after transplantation.

Brown tumors of the oral cavity: presentation of 4 new cases and a systematic literature review

OBJECTIVE

The aim of this study was to obtain data from a review of cases of brown tumors (BT), which are benign lesions of bone characterized by giant cells that arise during hyperparathyroidism (HPTH). BTs may affect the maxillofacial area and manifest as a brownish, slow-growing swelling causing difficulty in the differential diagnosis.

STUDY DESIGN

We present data from 4 new cases of oral BTs based on a systematic literature review conducted by searching EMBASE, Medline, and CENTRAL databases, according to the PRISMA guidelines. Only articles in English were considered. Individual patient data were analyzed to identify risk factors for multiple or extraoral maxillofacial BTs.

RESULTS

In total, 167 cases (163 from 136 articles and 4 new cases; mean age 36.6 years; male-to-female ratio 1:2) were retrieved. The onset of extraoral maxillofacial BTs (odds ratio [OR] 176.3; 95% confidence interval [CI] 18.7-1657.8; P < .05) and maxillary BTs (OR 17.5; 95% CI 6.0-50.8; P < .05) were the risk factors for multiple oral BTs, whereas the presence of a BT in the mandible (OR 0.01; 95% CI 0.001-0.1; P < .05) was a negative predictor for the presence of other extraoral maxillofacial BTs.

CONCLUSIONS

The results of this systematic review suggested that the mandible is the most frequent oral location of BTs. Whenever a BT is detected in the maxilla or when multiple oral BTs are diagnosed, more BTs in the maxillofacial area should be suspected.

The role of 18F-FCH PET/CT in patients with uremic hyperparathyroidism compared with 99mTc-sestaMIBI SPECT/CT and ultrasonography

BACKGROUND

The aim of this study was to evaluate the diagnostic efficacy of ¹⁸F-fluorocholine (¹⁸F-FCH) PET/CT for uremic hyperparathyroidism (uHPT) compared to ^99mTc-sestaMIBI SPECT/CT and ultrasonography (US).

METHODS

A total of 17 uHPT patients with stage 5 chronic kidney disease (CKD) were prospectively enrolled. All patients underwent US, ^99mTc-sestaMIBI SPECT/CT, and ¹⁸F-FCH within 2 months and received surgical treatment. Visual and quantitative methods were used for image analyses. Intraoperative localization and postoperative histological results of the reference standard as well as the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the three modalities were analyzed using Pearson's χ² tests. In addition, the diagnostic efficacy of ¹⁸F-FCH PET/CT for uHPT was evaluated. The relationships between PET parameters and laboratory parameters were assessed using the Spearman correlation coefficient.

RESULTS

A total of 63 parathyroid hyperplasia lesions were resected in 17 uHPT patients, and 53 lesions were detected using ¹⁸F-FCH PET/CT with no false-positive results. The sensitivity, specificity, accuracy, PPV, and NPV were 84.13%, 100%, 86.49%, 100%, and 52.38%, respectively. In comparison, the corresponding values for ^99mTc-sestaMIBI SPECT/CT and US were 63.49%, 90.91%, 67.57%, 97.56%, and 30.30% and 61.90%, 81.82%, 64.86%, 95.12%, and 27.27%, respectively. The volume of hyper-functioning parathyroid glands was significantly different between lesions positive in ¹⁸F-FCH PET/CT and negative in ¹⁸F-FCH PET/CT (mean volume 1.36 ± 0.55 cm³ vs. 0.83 ± 0.26 cm³; P = 0.019). US misidentified intrathyroidal parathyroid hyperplasia as thyroid nodules in three patients, while ¹⁸F-FCH PET correctly identified the anatomy. No significant associations were observed between PET parameters and laboratory parameters in uHPT.

CONCLUSION

¹⁸F-FCH PET/CT was more sensitive and accurate for uHPT than ^99mTc-sestaMIBI SPECT/CT and US, and had better preoperative diagnostic efficacy, particularly for lesions diagnosed as a thyroid nodule by US.

Parathyroid Pathology

Proliferative pathologic lesions of parathyroid glands encompass a spectrum of entities ranging from benign hyperplastic processes to malignant neoplasia. This review article outlines the pathophysiologic classification of parathyroid disorders and describes histologic, immunohistochemical, and molecular features that can be assessed to render accurate diagnoses.

Secondary and Tertiary Hyperparathyroidism: A Narrative Review

End-stage renal disease is often complicated by the occurrence of secondary and eventually tertiary hyperparathyroidism, characterized by increased parathormone, calcium, and phosphate concentrations. Related symptoms include pruritus and osteodynia, concentration difficulties, and feelings of depression may be present. In the long-term, end-stage renal disease patients with hyperparathyroidism have an increased risk of all-cause and cardiovascular mortality. Among treatment options are vitamin D supplements, phosphate binders, calcimimetics, and surgical parathyroidectomy. Determining the optimal treatment for the individual patient is challenging for nephrologists and endocrine surgeons. This review resumes the pathogenesis of hyperparathyroidism, clinical presentation, required diagnostic work-up, and discusses indications for the available treatment options for patients with secondary and tertiary hyperparathyroidism.

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.

Parathyroidectomy versus cinacalcet for tertiary hyperparathyroidism; a retrospective analysis

Introduction

Tertiary hyperparathyroidism (tHPT), i.e., persistent HPT after kidney transplantation, affects 17–50% of transplant recipients. Treatment of tHPT is mandatory since persistently elevated PTH concentrations after KTx increase the risk of renal allograft dysfunction and osteoporosis. The introduction of cinacalcet in 2004 seemed to offer a medical treatment alternative to parathyroidectomy (PTx). However, the optimal management of tHPT remains unclear.

Methods

A retrospective analysis was performed on patients receiving a kidney transplantation (KT) in two academic centers in the Netherlands. Thirty patients undergoing PTx within 3 years of transplantation and 64 patients treated with cinacalcet 1 year after transplantation for tHPT were included. Primary outcomes were serum calcium and PTH concentrations 1 year after KT and after PTx.

Results

Serum calcium normalized in both the cinacalcet and the PTx patients. PTH concentrations remained above the upper limit of normal (median 22.0 pmol/L) 1 year after KT, but returned to within the normal range in the PTx group (median 3.7 pmol/L). Side effects of cinacalcet were difficult to assess; minor complications occurred in three patients. Re-exploration due to persistent tHPT was performed in three (10%) patients.

Conclusion

In patients with tHPT, cinacalcet normalizes serum calcium, but does not lead to a normalization of serum PTH concentrations. In contrast, PTx leads to a normalization of both serum calcium and PTH concentrations. These findings suggest that PTx is the treatment of choice for tHPT.

Recurrent tertiary hyperparathyroidism due to supernumerary parathyroid glands in a patient receiving long-term hemodialysis: a case report

BACKGROUND

Renal hyperparathyroidism is a common complication of chronic kidney disease (CKD) or end-stage renal disease (ESRD) characterized by elevated parathyroid hormone levels secondary to derangements in the homeostasis of calcium, phosphate, and vitamin D. Rapid correction of severe and prolonged hyperparathyroidism by surgical parathyroidectomy in long-term hemodialysis patients occasionally causes hungry bone syndrome. These patients then exhibit severe and long-lasting secondary or tertiary hyperparathyroidism with high bone turnover.

CASE PRESENTATION

We report a case of recurrent tertiary hyperparathyroidism after total parathyroidectomy due to supernumerary parathyroid gland in a patient with long-term hemodialysis. Supplementation with intravenous calcium, oral calcium, and vitamin D immediately after patient surgery helps to prevent and treat hungry bone syndrome.

CONCLUSIONS

We should prompt a search for the supernumerary parathyroid glands in ESRD patients, who have recurrent or persistent hyperparathyroidism after total parathyroidectomy. ESRD patients are more likely to develop hungry bone syndrome after parathyroidectomy. Prevention and treatment of hungry bone syndrome may be required after ectopic parathyroidectomy in clinical practice.

Mineral and Bone Disease in Kidney Transplant Recipients

PURPOSE OF REVIEW

Despite metabolic improvements following kidney transplantation, transplant recipients still often suffer from complex mineral and bone disease after transplantation.

RECENT FINDINGS

The pathophysiology of post-transplant disease is unique, secondary to underlying pre-transplant mineral and bone disease, immunosuppression, and changing kidney function. Changes in modern immunosuppression regimens continue to alter the clinical picture. Modern management includes reducing cumulative steroid exposure and correcting the biochemical abnormalities in mineral metabolism. While bone mineral density screening appears to help predict fracture risk and anti-osteoporotic therapy appears to have a positive effect on bone mineral density, more data regarding specific treatment is necessary. Patients with mineral and bone disease after kidney transplantation require special care in order to properly manage and mitigate their mineral and bone disease. Recent changes in clinical management of transplant patients may also be changing the implications on patients' mineral and bone disease.

Renal failure parathyroidectomy - Is pre-operative imaging worthwhile?

BACKGROUND

Tertiary hyperparathyroidism is a significant issue in renal failure patients and some require surgery to control their serum calcium. A number of imaging techniques are used to localise the position of the parathyroid glands prior to surgery. Currently, a combination of ultrasound and isotope preoperative localisation imaging is accepted as useful in parathyroid surgery for primary disease. However, the use of pre-operative imaging in parathyroid surgery in renal failure patients is uncertain. The role of pre-operative imaging of the parathyroid glands in patients with renal failure hyperparathyroidism was assessed with imaging outcomes compared to operative and pathological findings in two cohorts of patients undergoing parathyroid surgery - primary and tertiary.

METHODS

All data were collected prospectively over a 10-year period (2003-2013) from the practice of a single surgeon. Patients were grouped into either primary hyperparathyroidism (49 patients) or tertiary hyperparathyroidism (41 patients). The majority, 63 of 90 (70%) patients, underwent both ultrasound (US) and isotope (MIBI) pre-operative imaging. Pre-operative imaging was correlated with operative and pathological findings.

FINDINGS

Comparison of the results of the two groups using ordinal regression analysis confirmed these imaging techniques are significantly more accurate in primary than tertiary parathyroid surgery (p = 0.022).

CONCLUSIONS

While accepted practice of pre-operative combined USS and MIBI imaging is essential in unilateral imaged-focused neck exploration for primary disease, these imaging techniques have a more limited use pre-operatively in renal failure parathyroidectomy.