Background:Hyperparathyroidism is a frequent complication in chronic kidney disease and may persist after transplant in 20 to 50% of cases, manifest by hypercalcemia and hypophosphatemia. Persistent disease is associated with an increase in the incidence of cardiovascular events, fracture and death. Therapeutic options currently available are parathyroidectomy (PTX) and therapy with calcimimetic agent cinacalcet.
Methods: Single-center retrospective study including adult renal transplant recipients who developed hipercalcemia due to persistent hyperparathyroidism. Criteria for treatment: Elevated PTH with serum calcium > 11 mg/dL at any time after transplantation or serum calcium persistently higher than 10.2 mg/dl one year after transplantation. Patients treated with cinacalcet (n = 46) were compared to patients treated with parathyroidectomy (n = 30). The follow up period was 1 year. Demographic and laboratory data were analyzed. In the cinacalcet group, episodes of rejection and medication tolerance were also analyzed.
Results: PTX controlled the calcemia faster and reached significantly lower levels in the long term (p = 0.0073); PTX showed significantly higher levels of serum phosphate (p = 0.0012) and returned PTH to normal levels (p <0.0001). Cinacalcet, despite of controlling calcium and phosphorus in the long term, did not correct PTH. There was no difference in response to cinacalcet when subgroups were stratified by PTH (≤ 700 pg/ml vs. > 700 pg/ml). Patients treated with cinacalcet had better renal function (p = 0.0002). The drug was well tolerated and no rejection episode was detected.
Conclusions: The surgical treatment was superior to cinacalcet to correct the metabolic disorders of hyperparathyroidism; however, it was associated with worse renal function in the long term. Cinacalcet proved to be a safe and well tolerated drug.