Effects of denosumab on hypercalcemia and bone mineral density loss in kidney transplant recipients
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Background: Hypercalcemia and bone mineral density (BMD) loss are serious problems associated with post-transplant chronic kidney disease-mineral and bone disorder. The present study aimed to clarify the effects of denosumab on hypercalcemia complicated with BMD loss in kidney transplant recipients. Materials and methods: Among 100 consecutive adult kidney transplant recipients, 16 patients with serum corrected Ca (cCa) levels >= 11.0 mg/dL were included in a severe hypercalcemia group. In 14 patients (excluding 2 patients who underwent parathyroidectomy) with severe hypercalcemia and low BMD at the lumbar spine (T-score < -1.0), 60 mg of denosumab were administered by subcutaneous injection at 6-month intervals. Serum cCa and alkaline phosphatase (ALP) levels were analyzed before and after denosumab administration. Lumbar spinal BMD was compared between, before, and 12 months after denosumab administration. Results: Both serum cCa (11.7 mg/dL) and ALP (525 U/L) levels declined promptly after denosumab administration, with only the cCa level showing rebound. Additionally, serum cCa and ALP levels were significantly lower after denosumab administration (all time points) than before denosumab administration. Lumbar spinal BMD increased significantly 12 months after denosumab administration when compared with the value before denosumab administration in both anterior-posterior (increase rate: 5.0%) and lateral (increase rate: 5.4%) projections. Conclusion: Denosumab could improve hypercalcemia and BMD loss in kidney transplant recipients. Therapeutic intervention involving denosumab should be considered for hypercalcemia and BMD loss associated with post-transplant chronic kidney disease-mineral and bone disorder.