Parathyroidectomy After Kidney Transplantation

This study aims to clarify whether surgical treatment of persistent hyperparathyroidism after kidney transplantation offers clinically meaningful benefits compared with a conservative treatment strategy. Kidney transplant recipients (\>6 mo after transplantation) with persistent hyperparathyroidism (elevated PTH and either hypercalcemia or hypophosphatemia) will be randomized in a 1:1 ratio to either subtotal parathyroidectomy or conservative management according to standard clinical practice. The study is conducted as an open-label, randomized controlled pilot trial with a 12-month follow-up period. Outcomes include bone density, physical function, quality of life and symptom burden.

Inclusion criteria * Age \> 18 years and legally competent and able to understand spoken and written Danish * Kidney transplantation ≥6 months prior (no upper limit of time after transplantation) * Stable kidney graft function, defined as estimated GFR ≥ 30 ml/min/1.73m3 * On minimum two separate biochemical measurements: PTH \> upper normal limit of assay and * serum ionized calcium ≥1.33 mmol/L or * serum total calcium ≥2.60 mmol/L or * serum phosphate ≤0.60 mmol/L despite sufficient dietary intake with measurements obtained within * 3 months in patients 6-12 months post-transplant * 6 months in patients \>12 months post-transplant and not attributable to calcium supplementation or treatment with thiazide diuretics or lithium. Exclusion criteria * Inability to provide written, informed consent * Current anti-resorptive therapy (bisphosphonate, denosumab) * Current bone anabolic therapy (teriparatide, romosozumab) * Previous surgical parathyroidectomy * Not considered fit for surgery (including pregnancy) * Ionized calcium ≥1.50 mmol/L or albumin-corrected calcium ≥3.00 mmol/L despite discontinuation of calcium supplements.