Treatment of immobilization-related hypercalcaemia with denosumab

Rare Causes of Hypercalcemia

This article discusses rare causes of hypercalcemia. Hypercalcemia can rarely be associated with immobilization, genetic diseases in children such as Williams-Beuren syndrome, Hypophosphatasia, Jansen Metaphyseal Chondrodysplasia (JMC), cosmetic injection, milk-alkali syndrome (MAS), calcium sulfate beads administration, manganese intoxication, postacute kidney failure recovery, and Paget's disease.

Extreme hypercalcaemia caused by immobilisation due to acute spinal cord injury

Hypercalcaemia due to immobilisation is an uncommon diagnosis and requires extensive evaluation to rule out common causes of hypercalcaemia such as primary hyperparathyroidism and malignancy.

We report an unusual case of profound hypercalcaemia due to immobilisation in a young man due to acute spinal cord ischaemia, leading to paraplegia. Other causes of hypercalcaemia were ruled out and elevated bone turnover markers supported our hypothesis. Conventional treatment with intravenous fluids, bisphosphonates and diuretics was insufficient. Subcutaneous calcitonin lowered the plasma calcium acutely and was continued for 8 weeks. Subsequent normocalcaemia was sustained for 2 years.

Use of denosumab to treat refractory hypercalcemia in a peritoneal dialysis patient with immobilization and tertiary hyperparathyroidism

Hypercalcemia due to excess parathyroid hormone (PTH) production is a common condition among patients with end-stage renal disease (ESRD), often referred to as tertiary hyperparathyroidism. There are limited effective medical treatment options currently available for such patients. Denosumab is a monoclonal antibody that inhibits osteoclast activation, thereby reducing calcium release from bones. Denosumab has been used to treat medically-refractory hypercalcemia in non-ESRD patients with hyperparathyroidism. Denosumab has also been used to treat non-PTH-mediated hypercalcemia in patients with advanced chronic kidney disease and ESRD. In this case report, we describe the use of denosumab to successfully treat a case of medically refractory hypercalcemia due to immobilization in a patient on peritoneal dialysis with severe underlying tertiary hyperparathyroidism. In spite of persistently elevated PTH, hypercalcemia quickly resolved after a single dose of denosumab. The patient subsequently developed temporary hypocalcemia requiring medical intervention. Our case report, which is the first described use of denosumab for treatment of hypercalcemia in the setting of tertiary hyperparathyroidism in a peritoneal dialysis patient, adds to the body of literature suggesting denosumab is a useful therapeutic agent in patients with ESRD. Issues with post-treatment electrolyte management and other therapeutic considerations are also discussed.

Denosumab for treatment of immobilization-related hypercalcemia in a patient with end-stage renal disease

The efficacy and safety of denosumab for the treatment of immobilization-related hypercalcemia in end-stage renal disease remain uncertain. We describe the case of a hemodialysis patient with immobilization-related hypercalcemia who was successfully treated with denosumab. A 79-year-old man admitted for hemodialysis after sustaining an acute kidney injury developed immobilization-related hypercalcemia due to the impairment resulting from an acute myocardial infarction, acute heart failure, and catheter-related bloodstream infection. After admission, the patient's corrected serum calcium rose to 12.9 from 8.8 mg/dL. A bisphosphonate (alendronate) was administered, but it was ineffective. Subsequently, treatment with denosumab proved to be effective and his corrected serum calcium level declined to 9.3 mg/dL within 1 week. Hypocalcemia, which is an adverse effect of denosumab, was prevented using active vitamin D and calcium supplementation, and his calcium level stabilized. Thus, our case demonstrates that denosumab is a viable therapeutic option for dialysis patients experiencing immobilization-related hypercalcemia.

Organic anxiety in a woman with breast cancer receiving denosumab

Hypocalcemia can induce heterogeneous psychiatric manifestations, and its etiology can be multifactorial. Herein, we describe a patient who had previously undergone resection of parathyroid glands, who presented with extreme anxiety and hypocalcemia after denosumab treatment for cancer-related bone metastasis. The anxiety subsided soon after correction of her serum calcium level. When denosumab is prescribed for patients with predisposing factors of hypocalcemia, such as hypoparathyroidism, clinicians should be aware of symptomatic hypocalcemia.