Persistent Hyperparathyroidism Research Articles

#1286 Utility of cinacalcet treatment in kidney transplant recipients with persistent hyperparathyroidism

Abstract Background and Aims Secondary hyperparathyroidism occurs in the majority of patients with chronic kidney disease (CKD). It may persist in up to 50-66% of patients despite the initial decrease in PTH levels after successful kidney transplantation (KT). Maintaining parathyroid hormone (PTH) levels within the normal range during the post-transplant period is crucial because it is related to hypercalcemia, hypophosphatemia, and reduced bone mass in KT recipients. Studies have already demonstrated that persistent hyperparathyroidism is associated with graft loss and all-cause mortality. Vitamin D, vitamin D analogs, and calcimimetics are most commonly used to manage hyperparathyroidism. However, studies about the long-term effect of calcimimetic therapy on the allograft are still limited. In this study, we aim to investigate the long-term allograft results of patients who received cinacalcet treatment for hyperparathyroidism. Method This study was conducted in Gazi University nephrology dialysis and transplantation unit with 312 patients who were transplanted between 1996 and 2019 and continued routine follow-up visits. Persistent hyperparathyroidism is defined as elevated PTH levels after the first year of KT (serum PTH>88 pg/mL). All patients without concurrent hypercalcemia were treated with vitamin D or analogs according to their vitamin D levels. Patients with non-functional allograft and parathyroidectomy after KT were excluded from this study. In addition, patients with rejection episodes, which could be confounding factor for allograft survival, were excluded to evaluate the isolated effect of cinacalcet on the allograft function. We identified 115 patients with persistent hyperparathyroidism, of whom were treated with cinacalcet (n = 21) or not (n = 94). We analyzed the baseline characteristics, comorbidities, and immunosuppressive treatments of the groups. Additionally, annual eGFR changes (Δ eGFR) calculated based on baseline (post-transplantation 6th month) eGFR after KT was also examined to evaluate the effect of cinacalcet on the graft. Results The mean age of the patients was 44.3 ± 12.6 years, and 47 (41%) were women. The median follow-up time of the patients was 87 (49-117) months. Twenty-nine patients (25%) underwent cadaveric transplantation, and 47 (41%) patients received anti-thymoglobulin (ATG) in induction therapy. While all patients were given glucocorticoids as maintenance immunosuppressive therapy, 93 (81%) of the patients received tacrolimus and, 9 (8%) cyclosporin as CNI, 78 (68%) received anti-metabolite therapy. Fifty-eight patients (19%) were used mTORi. A total of 21 patients with persistent hyperparathyroidism (21%) were treated with cinacalcet. Dialysis time is longer in the cinacalcet-treated group than in the patients not treated with cinacalcet (p < 0.001). The preemptive transplantation rate was lower (p = 0.03), and the delayed graft function was higher in the cinacalcet-treated group (p = 0.04). In the first year after KT, serum median PTH levels were 227 (167-341) pg/ml in the cinacalcet group and 110 (86-160) pg/ml in the other group, respectively (<0.001). Also, serum phosphate level is lower in the treatment group (2.7 ± 0.4 mg/dl vs. 3.1 ± 0.7 mg/dl, p = 0.03). At the last visit of patients, we observed similar median PTH levels between groups [141 (100-222) vs. 108 (73-159), p = 0.08]. During the follow-up, CMV episodes and BKV nephropathy diagnosis rates were similar between the groups (Table 1). Δ eGFRs in the first year (p = 0.7), second year (p = 0.2), third year (p = 0.4), and fifth year (p = 0.6) after KT were similar between both groups. Conclusion Our study suggests that cinacalcet treatment could be a safe and effective treatment for patients with persistent hyperparathyroidism. In long-term follow-up, there is no evidence of a reduction of kidney function. However, more trials are still required for other clinical outcomes such as fracture risk and cardiovascular morbidity and mortality.

#1692 Prevalence and risk factors for persistent hyperparathyroidism in long-term kidney transplant recipients

Abstract Background and Aims Secondary hyperparathyroidism, associated with fractures and cardiovascular mortality in end-stage kidney disease, often resolves after kidney transplantation (KT). However, limited knowledge exists regarding persistent hyperparathyroidism (persist-PTH) after long-term KT. We aimed to define the prevalence and risk factors of persist-PTH in KT recipients at ≥3 years post-KT. Method A historical cohort study was conducted in adult KT recipients at Srinagarind Hospital, Khon Kaen University, Thailand, from 2015 to 2020. Persist-PTH is defined as serum parathyroid hormone (PTH) exceeding twice the upper limit of normal (>130 pg/mL) after ≥3 years post-KT. Results A total of 281 patients were included, with a median age of 41.4 years (interquartile range (IQR), 32.7-49.1), and 117 patients (41.6%) were female. The median post-KT follow-up was 71 months (IQR, 54-89) with a glomerular filtration rate (GFR) of 61.8 mL/min/1.73 m² (IQR, 48.2-76.9). The respective median pre-KT and post-KT PTH were 403 pg/mL (IQR, 196.3-862) and 96.7 pg/mL (IQR, 67.3-166). Post-KT PTH levels correlated with pre-KT PTH levels (r²=0.18; P<0.001). Persist-PTH occurred in 100 patients, with a prevalence of 35.6% (95% confidence interval (CI), 30.2-41.4%). Multivariate analysis revealed significant associations between persist-PTH and a longer dialysis vintage (odds ratio (OR) 1.13 per 6-month increase; 95% CI, 1.06-1.20; P<0.001), lower GFR (OR, 0.76 per 10 mL/min/1.73 m² increase; 95% CI, 0.63-0.92; P=0.004), and higher pre-KT PTH (HR, 1.06 per 50 pg/mL increase; 95% CI, 1.02-1.10; P=0.001). Furthermore, persist-PTH with hypercalcemia (>10.2 mg/dL) occurred in 44 patients (15.7%; 95% CI, 11.8-20.4%), and with hypophosphatemia (<2.5 mg/dL) in 23 patients (8.2%; 95% CI, 5.5-12.0%). Conclusion Persist-PTH occurred in over one-third of long-term post-KT recipients, particularly in those with extended dialysis vintage, impaired graft function, and elevated pre-KT PTH levels. This underscores the need for optimal pre-KT PTH control and vigilant graft function monitoring to prevent persist-PTH.

Pretransplant Parathyroidectomy in Patients with Severe Secondary Hyperparathyroidism and Long-Term Effectiveness After Kidney Transplantation.

Kidney transplantation (KT) is the best option for patients with end-stage renal disease, but recipients still have legacy bone mineral disease from the pretransplant period, especially patients with severe secondary hyperparathyroidism (sHPT). Patients who had severe sHPT and underwent KT were analyzed retrospectively. Two groups were identified (patients with severe sHPT who had parathyroidectomy or calcimimetic before KT). Bone mineral density (BMD) was measured in the first year and last follow-up at the femoral neck, total hip, and lumbar spine using the dual-energy X-ray absorptiometry (DXA). Persistent hyperparathyroidism (perHPT) incidence was significantly higher in the calcimimetic group (75% vs. 40%, p=0.007). In patients with parathyroidectomy, BMDs were higher at femoral neck (0.818±0.114 vs. 0.744±0.134, p=0.04) and lumbar spine (1.005±0.170 vs. 0.897±0.151, p=0.01) at the first assessment. The BMD comparison between patients treated with parathyroidectomy and calcimimetic found a significant difference only in the femoral neck at second evaluation (0.835±0.118 vs. 0.758±0.129; p=0.03). In multivariate, linear regression revealed a positive association between the last BMD of the femoral neck with body mass index (CC: 0.297, 95% CI, 0.002-0.017) and parathyroidectomy (CC: 0.319, 95% CI, 0.021-0.156). Parathyroidectomy is associated with a significantly better femoral neck BMD and a lower incidence of perHPT in patients with severe sHPT.

Surgical outcomes in primary hyperparathyroidism: addressing factors predicting persistent or recurrent hyperparathyroidism

Surgical outcomes in primary hyperparathyroidism: addressing factors predicting persistent or recurrent hyperparathyroidism

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.

Intraoperative radio-guided localization of parathyroid adenomas using 3D freehand SPECT technology.

Parathyroidectomy for primary hyperparathyroidism (PHPT) could have poor outcomes, even with accurate preoperative localization of the adenomas, because their intraoperative localization can be challenging. Freehand single photon emission computed tomography (fhSPECT) is a new technique for radio-guided intraoperative navigation. Its use during parathyroidectomy could be useful and such data are limited. We herein present our experience on the feasibility of fhSPECT for intraoperative detection of abnormal parathyroid glands. We retrospectively reviewed the clinical data of 55 patients (30-77years old) with PHPT due to parathyroid adenomas, that were subjected to parathyroidectomy from 12/2017 to 7/2022. In average, 111 ± 74MBq of Tc-99m Sestamibi were injected intravenously, approximately 2h before the operation and fhSPECT was used to generate 3D images during parathyroidectomy. Measurements of PTH and calcium levels were performed preoperatively, postoperatively and 4-6months after the procedure. FhSPECT successfully identified the parathyroid adenoma in all the patients. It took 3min (median time) for fhSPECT to detect at least one radioactive spot in all patients. The mean duration of the operation was 66.6 ± 7.3min. Forty-nine patients out of 55 had solitary and 6/55 had multiple adenomas, whereas 6/55 had ectopic abnormal parathyroid glands. None of the patients had persistent hyperparathyroidism during follow-up. To the best of our knowledge, this is the largest series of patients with PHPT that underwent fhSPECT assisted parathyroidectomy. Our data suggest that this navigation system is helpful in identifying parathyroid adenomas intraoperatively.

Association of Coronary Calcium Score on Cardiac PET During Pre-Kidney Transplant Assessment with Persistent Hyperparathyroidism: A Retrospective Study.

BACKGROUND Secondary hyperparathyroidism and coronary calcifications are common complications in chronic kidney disease. However, the relation between coronary calcium score (CCS) and persistent hyperparathyroidism (pHPT) after kidney transplantation (KT) remains unknown. MATERIAL AND METHODS This was a single-center retrospective study of KT candidates from January 2017 to May 2020. We collected patients' demographics, cardiovascular (CV) risk factors, and the findings of pre-KT CV imaging. We also collected parathyroid hormone (PTH) values before KT, at 1-6 months, 6-12 months, and 12-24 months after KT. We defined pHPT as PTH ≥25.5 pmol/L after 12 months post-KT. RESULTS A total of 111 KT recipients (KTRs) with a mean age of 50.4 years were included, of which 62.2% were men and 77.5% were living-donor KTRs. Dialysis modality used before KT was peritoneal dialysis in 9.9% and hemodialysis in 82.9%. Dialysis vintage was 3±2.9 years. The prevalence of pHPT was 24.3% (n=27), and the prevalence of severe coronary calcifications (CCS >400 Agatston units) was 19.8% (n=22). PTH values at baseline, 1-6 months, 6-12 months, and 12-24 months were not different among between CCS >400 or CCS <400 groups. However, pHPT after KT was significantly more prevalent in KTRs with severe CCS (37% vs 14.3%, p=0.014). Severe CCS was associated with less improvement of PTH values after KT (r=0.288, p=0.020). Otherwise, the findings of cardiac PET and coronary angiogram were not significantly different between pHPT and non-pHPT patients. CCS >400 was independently associated with pHPT after transplant (aOR=18.8, P=0.012). CONCLUSIONS Severe CCS on pre-KT cardiac assessment is associated with pHPT after KT.

Predictive factors for persistent hypercalcemia following parathyroidectomy in patients with persistent hyperparathyroidism after kidney transplantation: a retrospective cohort study.

Surgery for irreversible hyperparathyroidism is the preferred management for kidney transplant patients. The authors analyzed the factors associated with persistent hypercalcemia after parathyroidectomy in kidney transplant patients and evaluated the appropriate extent of surgery. The authors retrospectively analyzed 100 patients who underwent parathyroidectomy because of persistent hyperparathyroidism after kidney transplantation at a tertiary medical center between June 2011 and February 2022. Patients were divided into two groups: 22 with persistent hypercalcemia after parathyroidectomy and 78 who achieved normocalcemia after parathyroidectomy. Persistent hypercalcemia was defined as having sustained hypercalcemia (≥10.3mg/dl) 6 months after kidney transplantation. The authors compared the biochemical and clinicopathological features between the two groups. Multivariate logistic regression analysis was used to identify potential risk factors associated with persistent hypercalcemia following parathyroidectomy. The proportion of patients with serum intact parathyroid hormone (PTH) level is greater than 65pg/ml was significantly high in the hypercalcemia group (40.9 vs. 7.7%). The proportion of patients who underwent less than subtotal parathyroidectomy was significantly high in the persistent hypercalcemia group (17.9 vs. 54.5%). Patients with a large remaining size of the preserved parathyroid gland (≥0.8cm) had a high incidence of persistent hypercalcemia (29.7 vs. 52.6%). In the multivariate logistic regression analysis, the drop rate of intact PTH is less than 88% on postoperative day 1 (odds ratio 10.3, 95% CI: 2.7-39.1, P =0.001) and the removal of less than or equal to 2 parathyroid glands (odds ratio 6.8, 95% CI: 1.8-26.7, P =0.001) were identified as risk factors for persistent hypercalcemia. The drop rate of intact PTH is less than 88% on postoperative day 1 and appropriate extent of surgery for controlling the autonomic function were independently associated with persistent hypercalcemia. Confirmation of parathyroid lesions through frozen section biopsy or intraoperative PTH monitoring can be helpful in preventing the inadvertent removal of a parathyroid gland and achieving normocalcemia after parathyroidectomy.

Preoperative diagnosis of parathyroid gland pathology in patients with persistent or recurrent primary hyperparathyroidism: a retrospective study

INTRODUCTION: Localization of abnormal parathyroid glands in persistent or relapsed patients with primary hyperparathyroidism presents problems for surgeons before repeated surgery. There is no clear standard for the choice of diagnostic modality for localization of PG in this group of patients.OBJECTIVE: To search for the optimal diagnostic protocol of the parathyroid pathology preoperative diagnosis in patients with primary hyperparathyroidism with persistent or recurrent disease.MATERIALS AND METHODS: 55 patients diagnosed with persistence or recurrence of PHPT who underwent repeated surgical treatment were included in the study. Before surgical intervention all patients underwent laboratory and instrumental investigations in the volume of: blood tests for PTH, TTH, ionized calcium, 25(OH)D, creatinine, phosphorus, neck ultrasound, parathyroid scintigraphy by washout method, dual-isotope subtractive scintigraphy of parathyroid glands (early and delayed phases), SPECT of parathyroid glands (with uptake correction), computed tomography of the neck with intravenous bolus contrast.RESULTS: CT and planar subtraction dual-isotope scintigraphy showed the highest DA in the overall group (persistence and recurrence) (78% and 78%), with the DA of these methods differing slightly (88% and 92%) and overall accuracy being higher for CT (90% and 87%). Neck ultrasound showed the lowest rates among all methods (DA — 46%, DS — 80%, OA — 67%). Planar scintigraphy (washout) and SPECT were comparable in their informativeness: DA — 67% and 65%, DS — 96% and 98%, OA — 85% and 86%.DISCUSSION: The most commonly used current diagnostic search algorithm before reoperation is visualization of the thyroid gland by two modalities: Neck ultrasound and parathyroid scintigraphy (washout/subtraction) or SPECT-CT. In doubtful cases, the second step is computed tomography of the neck with contrast or PET/CT. It is extremely difficult to choose one optimal diagnostic method, as none of them has 100% diagnostic accuracy. In addition, each study has limitations, and the availability of some modalities is limited. In our study, the location of pathologically altered thyroid was correctly recognized in 90% of cases by CT with contrast and in 87% of cases by planar subtraction dual-isotope scintigraphy. The informativeness of neck ultrasound showed the lowest values of all modalities. SPECT and planar washout scintigraphy took an intermediate position in terms of diagnostic accuracy.CONCLUSION: Isolated ultrasonography of the neck has low diagnostic accuracy in patients with primary hyperparathyroidism with persistent or recurrent disease. We recommend the combination of US with contrast-enhanced computed tomography of the neck or US with dual isotope subtraction scintigraphy of the parathyroid glands, which have the same diagnostic accuracy. SPECT and planar washout scintigraphy can be used for the diagnosis of abnormal parathyroid glands in persistent or recurrent patients with primary hyperparathyroidism when more informative techniques are unavailable. When the techniques were combined, the combination of ultrasound/CT with contrast and ultrasound/planar subtraction dual isotope scintigraphy showed the best results with DA of 85% and 86%.

Ultrasound-Guided Radiofrequency Ablation in Tertiary Hyperparathyroidism: A Prospective Study.

To prospectively evaluate the outcomes of ultrasound (US)-guided radiofrequency ablation (RFA) in tertiary hyperparathyroidism (THPT). Patients with THPT underwent RFA between September 2017 and January 2022. Laboratory parameters, including serum intact parathyroid hormone (iPTH) levels, were monitored for 48 months after RFA and compared with the levels at baseline. Complications related to RFA and changes in hyperparathyroidism-related clinical symptoms were recorded before and after RFA. A total of 42 patients with THPT were recruited for this study. Ultimately, 36 patients with renal failure and 2 patients who underwent successful renal transplantation (male:female, 17:21; median age, 54.5 years) were enrolled. The follow-up time was 21.5 ± 19.0 months in the 36 patients with renal failure. In these 36 patients, iPTH levels were significantly decreased to 261.1 pg/mL at 48 months compared with the baseline value of 1284.9 pg/mL (P = 0.012). Persistent hyperparathyroidism, defined as iPTH levels maintained at > 585.0 pg/mL for 6 months after treatment, occurred in 4.0% of patients (1/25). Recurrent hyperparathyroidism, defined as iPTH levels > 585.0 pg/mL after 6 months, were 4.0% (1/25) and 0.0% (0/9) at 6 months and 4 years after treatment, respectively. In two patients with THPT after successful renal transplantation, iPTH decreased from the baseline value of 242.5 and 115.9 pg/mL to 171.0 and 62.0 pg/mL at 6 months after treatment. All complications resolved within 6 months of ablation without medical intervention, except in 10.5% (4/38) patients with permanent hypocalcemia. The overall symptom recovery rate was 58.8% (10/17). The severity scores for bone pain, arthralgia, and itchy skin associated with hyperparathyroidism improved after treatment (P < 0.05). US-guided RFA is an effective and safe alternative to surgery in the treatment of patients with TPTH and improves hyperparathyroidism-related clinical symptoms.

Long-term effects of hypercalcemia in kidney transplant recipients with persistent hyperparathyroidism.

Hypercalcemia is highlyprevalent in kidney transplant recipients with hyperparathyroidism. However, its long-term impact on graft function is uncertain. We conducted a prospective cohort study investigating adverse graft outcomes associated with persistent hypercalcemia (free calcium > 5.2mg/dL in ≥ 80% of measures) and inappropriately elevated intact parathyroid hormone (> 30pg/mL) in kidney transplant recipients. Asymptomatic mild hypercalcemia was monitored unless complications developed. We included 385 kidney transplant recipients. During a 4-year (range 1-9) median follow-uptime, 62% of kidney transplant recipients presented persistent hypercalcemia. Compared to kidney transplant recipients without hypercalcemia, there were no significant differences in graft dysfunction (10% vs. 12%, p = 0.61), symptomatic urolithiasis (5% vs. 3%, p = 0.43), biopsy-proven calcium deposits (6% vs. 5%, p = 1.0), fractures (6% vs. 4%, p = 0.64), and a composite outcome of urolithiasis, calcium deposits, fractures, and parathyroidectomy indication (16% vs. 13%, p = 0.55). In a subset of 76 kidney transplant recipients, subjects with persistent hypercalcemia had higher urinary calcium (median 84 [43-170] vs. 38 [24-64]mg/day, p = 0.03) and intact fibroblast growth factor 23 (median 36 [24-54] vs. 27 [19-40]pg/mL, p = 0.04), and lower 25-hydroxyvitamin D levels (11.3 ± 1.2 vs. 16.3 ± 1.4ng/mL, p < 0.001). In multivariate analysis, pretransplant intact parathyroid hormone < 300pg/mL was associated with a reduced risk of post-transplant hypercalcemia (OR 0.51, 95% CI 0.32-0.80). Long-term persistent mild hypercalcemia (tertiary hyperparathyroidism) was frequent in kidney transplant recipientsin our series. This condition presented with lower phosphate and 25-hydroxyvitamin D, and higher urinary calcium and intact fibroblast growth factor 23 levels compared to kidney transplant recipients without hypercalcemia, resembling a mild form of primary hyperparathyroidism. Despite these metabolic derangements, the risk of adverse graft outcomes was low.

Treatment of Hypercalcemic Hyperparathyroidism After Kidney Transplantation Is Associated With Improved Allograft Survival.

Hyperparathyroidism (HPT) and malignancy are the most common causes of hypercalcemia. Among kidney transplant (KT) recipients, hypercalcemia is mostly caused by tertiary HPT. Persistent tertiary HPT after KT is associated with allograft failure. Previous studies on managing tHPT were subjected to survivor treatment selection bias; as such, the impact of tertiary HPT treatment on allograft function remained unclear. We aim to assess the association between hypercalcemic tertiary HPT treatment and kidney allograft survival. We identified 280 KT recipients (2015-2019) with elevated post-KT adjusted serum calcium and parathyroid hormone (PTH). KT recipients were characterized by treatment: cinacalcet, parathyroidectomy, or no treatment. Time-varying Cox regression with delayed entry at the time of first elevated post-KT calcium was conducted, and death-censored and all-cause allograft failure were compared by treatment groups. Of the 280 recipients with tHPT, 49 underwent PTx, and 98 received cinacalcet. The median time from KT to first elevated calcium was 1 month (IQR: 0-4). The median time from first elevated calcium to receiving cinacalcet and parathyroidectomy was 0(IQR: 0-3) and 13(IQR: 8-23) months, respectively. KT recipients with no treatment had shorter dialysis vintage (P = .017) and lower PTH at KT (P = .002), later onset of hypercalcemia post-KT (P < .001). Treatment with PTx (adjusted hazard ratio (aHR) = 0.18, 95%CI 0.04-0.76, P = .02) or cinacalcet (aHR = 0.14, 95%CI 0.004-0.47, P = .002) was associated with lower risk of death-censored allograft failure. Moreover, receipt of PTx (aHR = 0.28, 95%CI 0.12-0.66, P < .001) or cinacalcet (aHR = 0.38, 95%CI 0.22-0.66, P < .001) was associated with lower risk of all-cause allograft failure. This study demonstrates that treatment of hypercalcemic tertiary HPT post-KT is associated with improved allograft survival. Although these findings are not specific to hypercalcemia of malignancy, they do demonstrate the negative impact of hypercalcemic tertiary HPT on kidney function. Hypercalcemic HPT should be screened and aggressively treated post-KT.

Long-Term Effects of Hypercalcemia in Kidney Transplant Recipients with Persistent Hyperparathyroidism

Long-Term Effects of Hypercalcemia in Kidney Transplant Recipients with Persistent Hyperparathyroidism

Efficacy of Cinacalcet in the Treatment of Persistent Hyperparathyroidism in Late Kidney Transplantation

Efficacy of Cinacalcet in the Treatment of Persistent Hyperparathyroidism in Late Kidney Transplantation

The Importance of Parathormone Control in Kidney Transplant Candidates to Avoid Persistent Hyperparathyroidism and Graft Dysfunction

The Importance of Parathormone Control in Kidney Transplant Candidates to Avoid Persistent Hyperparathyroidism and Graft Dysfunction

Persistent primary hyperparathyroidism in parathyroid glands ectopic to the mediastinum (clinical observation and long-term results)

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SAT187 A Case Of CDC73 Mutation Related Primary Hyperparathyroidism With Ectopic Parathyroid Hyperplasia

Abstract Disclosure: T. Wu: None. N. Dhir: None. M. Bollineni: None. Introduction: Primary hyperparathyroidism is the most common cause of hypercalcemia, and most cases are sporadic. However, in 5-10% cases, it may occur as a syndromic and hereditary disease, like Multiple endocrine neoplasia type 1, type 2A, type 4, or CDC73 mutation related hereditary benign or malignant hyperparathyroidism. In patients with severe or early onset primary hyperparathyroidism, screening for genetic etiology should be considered. Case Presentation: A 35-year-old woman with a medical history of hypertension, kidney stones, and post-operative hypothyroidism presented to the endocrinology clinic due to recurrent hyperparathyroidism. She initially had a parathyroidectomy in 2008 and her calcium corrected at that time. She was again diagnosed with hypercalcemia due to primary hyperparathyroidism in 2021. She underwent re-exploration and had a right thyroid lobectomy with removal of three parathyroid glands. Her PTH was still 309 pg/mL (9-77 pg/mL) and calcium was 11.2 mg/dL (8.6-10.5 mg/dL), and she was started on Cinacalcet. The patient continued to have elevated calcium, bone pain, fatigue, and constipation. A 4D CT scan was ordered, which localized activity to a 1.5 cm arterial enhancing nodule in the anterior mediastinum, with intrathymic location. She underwent right video-assisted thoracoscopic total thymectomy with en bloc and the nodule was found to be ectopic parathyroid tissue. Post-operatively, her calcium normalized to 8.6 mg/dL and PTH was undetectable. She underwent genetic testing due to her recurrent hyperparathyroidism, which showed a CDC73 mutation. She is currently on calcitriol and calcium supplements, and serum calcium has been maintained in the low-normal range. Discussion: The CDC73 gene encodes a protein called parafibromin, which acts as a tumor suppressor, prohibiting cells from proliferating. Mutations in this gene are linked to jaw-tumor syndrome, familial isolated primary hyperparathyroidism (FIHP), and parathyroid carcinoma. These three CDC73-related disorders are clinically overlapping and inherited in an autosomal dominant manner. Biallelic mutations of the CDC73 gene are associated with a high risk of parathyroid cancer since the parafibromin protein is usually absent in parathyroid carcinoma and occasionally in atypical adenomas. FIHP tends to have a more severe clinical presentation with earlier onset (younger than 45 years). Additionally, patients with CDC73 related disorders are more prone to developing ossifying fibroma(s) of the jaw, uterine tumors, and various renal lesions. In summary, this case highlights the diagnostic and therapeutic challenges in a patient with persistent primary hyperparathyroidism after a failed second surgery. Genetic testing is vital for early detection, surveillance, and familial genetic counseling in patients with CDC73 related disorders. Presentation: Saturday, June 17, 2023

FRI690 Should Treatment For Osteoporosis Be Started In Patients With Primary Hyperparathyroidism Within The First Year After Parathyroidectomy?

Abstract Disclosure: K. Swe: None. A. Chiu: None. E. Pelley: None. Osteoporosis is one of the indications for parathyroidectomy in patients with primary hyperparathyroidism. Studies show the improvement of bone mineral density (BMD) in the lumbar spine and hip within the first year after parathyroidectomy. Therefore, the decision to treat osteoporosis has usually been delayed until a follow-up bone densitometry scan (DXA) at least one year after parathyroidectomy. To study the BMD changes with or without osteoporosis treatment till first follow-up DXA after parathyroidectomy, we retrospectively reviewed a prospective database of patients undergoing parathyroidectomy for primary hyperparathyroidism between 2010 to 2017 at our institution. We included both male and female patients between the ages 50 to 80, with a history of fragility fracture and/ or T score less than -2.4, and normal renal function. We excluded patients with persistent hyperparathyroidism post-surgery, osteoporosis medication within 3 years before surgery, and DXA performed outside of our facility. Patients who received osteoporosis medication between surgery and the first follow-up DXA were compared to those who underwent surgery alone. We compared the changes in BMD at the total hip and lumbar spine (L1-L4) between baseline and the first follow-up DXA for the two groups. Data was evaluated using a student’s t-test. A total of 386 patients underwent parathyroidectomy during the study period of which 92 patients met the inclusion criteria. Among them, 28 patients were treated after surgery and 64 patients had parathyroidectomy alone. The mean duration to treatment initiation after surgery was approximately 4 months (SD +/- 3 months), and the mean duration until the first follow-up DXA after the surgery was 17 months (SD +/- 8 months). There was no difference in the change of BMD at the total hip between two groups. Both increased by 0.01 g/cm2 (p=0.74). However, there was a greater increase in BMD at the lumber spine for those treated (0.047 g/cm2 increase) compared to surgery alone (0.019 g/cm2 increase) (p=0.02). We concluded that initiation of osteoporosis treatment within the first year after parathyroidectomy led to similar BMD outcomes at the total hip, but the treatment group experienced greater gains in BMD at the lumbar spine compared to parathyroidectomy alone, in patients with primary hyperparathyroidism and osteoporosis. Presentation: Friday, June 16, 2023

Parathyroid adenoma apoplexy mimicking a thyroid bleeding cyst: a seemingly innocent condition that can be life-threatening.

Primary hyperparathyroidism most commonly presents with hypercalcaemia. Rarely, parathyroid apoplexy or haemorrhage mimicking a thyroid bleeding cyst is the first presentation of a parathyroid adenoma. A woman presented with a sudden-onset painful 'goitre'. Ultrasound showed a cystic nodule located posterior to rather than in the right thyroid lobe, suggesting parathyroid adenoma bleeding. Biochemistry showed mild primary hyperparathyroidism. 99mTc-pertechnetate/sestamibi showed no uptake in the nodule, which was interpreted as a cold thyroid nodule. 18F-fluorocholine PET/CT showed uptake in the nodule, suggestive of a parathyroid adenoma. Persistent mild primary hyperparathyroidism complicated by nephrolithiasis and osteopenia favoured parathyroidectomy over a wait-and-see approach. The patient was referred for parathyroidectomy along with right thyroid lobectomy. Pathology showed an adenoma, with an eccentrically located cystic structure filled with red blood cells surrounded by a thickened fibrous capsule. In conclusion, cervical pain/haemorrhage with hypercalcaemia points to the diagnosis of parathyroid apoplexy, mimicking a thyroid bleeding cyst. Workup with ultrasound and, if available, 18F-choline PET/CT allows for timely surgery, minimizing the risk of recurrent and severe bleeding. A bleeding cyst may be located posterior to rather than in the thyroid, suggesting a parathyroid haemorrhage. Neck pain and/or haemorrhage along with primary hyperparathyroidism point to parathyroid apoplexy. A two-step presentation has been described, with a first phase of local symptoms to be followed by visible and possibly life-threatening compressing bleeding. Therefore, an expedited workup is needed, allowing for timely surgery.

Radiofrequency ablation for patients with recurrent or persistent secondary hyperparathyroidism after parathyroidectomy: initial experience.

Reoperation for recurrent or persistent secondary hyperparathyroidism (SHPT) after parathyroidectomy is challenging due to surgical scars and postoperative adhesions. Therefore, there is an increasing need to develop a new minimally invasive therapy. To analyze the efficacy of ultrasound (US)-guided radiofrequency ablation (RFA) in patients with recurrent or persistent SHPT after parathyroidectomy. From March 2013 to January 2022, 20 enlarged parathyroid glands in 10 patients with recurrent or persistent SHPT were treated with US-guided RFA. The levels of serum intact parathyroid hormone (iPTH), calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP), as well as clinical symptoms, were compared before and after RFA. The ablation procedure-related complications were also evaluated. The target range for iPTH levels was approximately 2-9 times the upper limit of normal (130-585 pg/mL). The mean follow-up time was 49.6 ± 34.5 months (range from 6 to101 months). The levels of serum iPTH, Ca, and P decreased significantly one day post-ablation. Six months after RFA, 70% of patients reached the targets for iPTH, and 50% of patients reached targets at the end of follow-up. Two patients underwent repeat ablation at 9 months and 6 years after RFA, respectively, due to persistently elevated iPTH levels, and both had serum iPTH concentrations in the recommended range at the recent follow-up visit. The patients' clinical symptoms significantly improved after ablation. Major complications after RFA included hoarseness (2/10) and permanent hypoparathyroidism (1/10). Severe hypocalcemia occurred in four patients (4/10) after ablation. US-guided percutaneous RFA for recurrent or persistent SHPT is safe, efficacious, and repeatable, and can significantly improve hyperparathyroidism-related symptoms.