Denosumab effectively treats low bone mineral density in kidney transplant recipients (KTRs), a new study finds. But it can also lead to prolonged elevation of parathyroid hormone (PTH) that necessitates treatment.
Hypocalcemia occurred within a mean 15.6 days of denosumab initiation in 18 studied KTRs, Gaetano La Manna, MD, of IRCCS Azienda Ospedaliero-Universitaria di Bologna in Italy and colleagues reported in the American Journal of Nephrology. Afterward, PTH levels increased.
“Denosumab induces hypocalcemia by reducing osteoclast activity and bone reabsorption with consequent influx of calcium from the circulation into the bone,” Dr Manna’s team explained.” Although chronic kidney disease predisposes patients treated with denosumab to hypocalcemia, in this study, only the degree of lumbar osteoporosis significantly associated with denosumab-induced hypocalcemia.
The investigators reported that calcitriol treatment was required on top of routine cholecalciferol and oral calcium supplementation to control serum calcium and PTH in these KTRs.
Prior to denosumab administration, all KTRs had stable PTH (mean 95.4 ng/mL) and normal serum calcium and phosphorus levels. None took calcimimetics or vitamin D analogs after surgery until denosumab treatment.
At 1 year after denosumab administration, areal bone mineral density increased by a nonsignificant 1.74% at the lumbar spine and a 0.25% and 0.30% increase at the neck and total femoral site, respectively. No patients experienced hypocalcemia requiring intravenous supplementation, urinary tract infections after denosumab administration, or new fracture events.
“In conclusion,” the authors wrote, “we believe that denosumab is an effective treatment for bone disease in KTRs; we suggest future research aimed to identify the most appropriate clinical contexts where to introduce this treatment in consideration of the complex scenario of bone pathology in patients who have undergone renal transplantation.”
Cianciolo G, Tondolo F, Barbuto S, et al. Denosumab-induced hypocalcemia and hyperparathyroidism in de novo kidney transplant recipients. Am J Nephrol. Published online September 8, 2021. doi:10.1159/000518363