Parathyroidectomy May Cause Remission of Uraemic Tumoral Calcinosis in Haemodialysis Patients

Few cases of uraemic tumoral calcinosis (UTC) have been reported. This study aimed to investigate the clinical efficacy of parathyroidectomy for UTC. Historical clinical data of patients with end-stage renal disease and UTC who underwent parathyroidectomy were analysed. Absorption of metastatic calcification was compared before and after operation. Changes in intact parathyroid hormone, serum calcium, phosphorus, and alkaline phosphatase levels were analysed before parathyroidectomy and at 1 week and 3, 6, and 12 months after parathyroidectomy. Eight patients met the enrolment criteria (men, 6; mean age, 38.6 SD 10.9 years). Uraemic tumoral calcinosis, which developed 2–8 years after dialysis began, was caused by secondary hyperparathyroidism. Massive calcium deposition was found in the shoulder (n = 6), hip (n = 3), and elbow (n = 2). Four patients had > 2 joints affected, and a single joint was involved for four patients. Seven patients had rapid remission (< 6 months) of the masses after parathyroidectomy. In one patient, the mass remained unabsorbed until 6 months postoperatively. Hypocalcaemia occurred in all patients where parathyroidectomy was successful, and calcium supplementation was required 1 year postoperatively. Serum intact parathyroid hormone levels on day 7 and at 3 and 6 months postoperatively decreased significantly from baseline and remained low 1 year postoperatively (22.015 SD33.134 pg/mL). Postoperative phosphorus levels were significantly lower than preoperative levels (p < 0.05), but no significant difference was found in alkaline phosphatase levels (p > 0.05). Parathyroidectomy has promising efficacy for UTC treatment and regulation of serum intact parathyroid hormone and phosphorus. Hypocalcaemia is a common complication after parathyroidectomy. Current Controlled Trials ChiCTR2000041311, date of registration: Dec. 23, 2020.

Differential diagnosis of hypercalcemia in a patient with CKD G5D

Patients with chronic kidney disease are characterized by the development of mineral disorders due to a decrease in the number of functioning nephrons. These changes manifest by the development of secondary hyperparathyroidism (the overproduction of intact parathyroid hormone (PTH) associated with the serum hypocalcemia, hyperphosphatemia), dysfunctional vitamin D metabolism, bone mineralization and also extraosseous calcifications. Decreased serum PTH levels associated with hypercalcemia are suspicious for adynamic bone disease, but at the same time requires an extended differential diagnostic search (e.g. metastatic processes). One of the rare causes of hypercalcemia is a defect in 24-hydroxylase (CYP24A1). We present a case of a patient on hemodialysis with atypical secondary hyperparathyroidism and an established CYP24A1 defect.

Relationship Between Changes in Serum Levels of Intact Parathyroid Hormone and Sclerostin After a Single Dose of Zoledronic Acid: Results of a Phase 1 Pharmacokinetic Study

Although changes in serum sclerostin levels at 12 months after infusion of zoledronic acid have been reported, the changes in sclerostin levels at earlier time points are poorly understood. We reanalyzed the study data of a previous phase 1 pharmacokinetic study and investigated the correlation between changes in sclerostin levels and relevant factors in calcium metabolism. A total of 24 Japanese female subjects with primary postmenopausal osteoporosis were administered a single 4- or 5-mg dose of zoledronic acid. Serum and urine samples were collected on days 15, 29, 90, 180, and 365 after administration. Serum levels of calcium, phosphate, intact parathyroid hormone (iPTH), and sclerostin were measured. Levels of serum sclerostin were unchanged from baseline on days 15 and 29, but increased significantly on day 90, subsequently decreased significantly on day 180, and returned to baseline levels on day 365. A significant negative correlation was observed between changes in iPTH levels at early time points and sclerostin levels at later time points. This suggests that sclerostin was negatively regulated by iPTH, and the decrease in sclerostin may indicate the start of bone formation during later time points after zoledronic acid injection.

The Relationship Between Intact Parathyroid Hormone and 25-Hydroxyvitamin D in United Kingdom Resident South Asians and Whites: A Comparative, Cross-Sectional Observational Study

Ethnic differences in intact parathyroid hormone (iPTH) at similar total 25 hydroxyvitamin D [25(OH)D] concentrations have been reported between US resident Whites, Blacks, and Hispanics, but this has not been studied between South Asians and Whites. We, therefore, compared the iPTH relationship to 25(OH)D in UK resident South Asians and Whites. A comparative, cross-sectional observational study in which demographic and laboratory data on South Asian and White residents of Wolverhampton, UK were analyzed. Log-log models measured the association between 25(OH)D and the interaction term of ethnicity and iPTH. Seven hundred and seventy-two patients consisting of 315 white subjects (208 women) and 457 South Asian subjects (331 women) were studied. Compared to South Asians, White subjects were older, had higher serum concentrations of 25(OH)D, creatinine (lower eGFR), adjusted calcium and magnesium, but similar concentrations of iPTH and phosphate. In an adjusted model, variables significantly associated with 25(OH)D included age, creatinine, adjusted calcium and ethnicity; but not iPTH and the interaction term of ethnicity and iPTH (beta coefficient –0.071, 95% CI –0.209, 0.067, p=0.32). In our study cohort, iPTH was not, per se, influenced by 25 (OH)D. We found no ethnic differences in the association between iPTH and 25(OH)D between South Asians and White UK residents

Severe hypercalcaemia from ectopic intact parathyroid hormone secretion treated with continuous renal replacement therapy in a patient with two malignancies

We present a 61-year-old Caucasian woman with endometroid carcinoma as well as a poorly differentiated adenocarcinoma who developed severe hypercalcaemia in the setting of an elevated intact parathyroid hormone. The patient was hospitalised twice for her condition. During her first hospitalisation, she was diagnosed with an endometroid carcinoma and hypercalcaemia. With medical management, she had a normal calcium level on discharge. She presented 3 weeks later with hypercalcaemia and encephalopathy. This time her hypercalcaemia was refractory to medical management, and required continuous renal replacement therapy (CRRT) to normalise her serum calcium. Lung biopsy revealed a poorly differentiated adenocarcinoma, suspicious for pancreatic primary. Due to her poor prognosis, rapid elevation of calcium with each attempt to discontinue CRRT, and the poor options for treatment of her cancers, she elected to pursue hospice care.