Therapy for persistent hypercalcemic hyperparathyroidism post-renal transplant: cinacalcet versus parathyroidectomy

Abstract

ABSTRACT Background: Persistent hyperparathyroidism post-transplant is associated with increases in the incidence of cardiovascular events, fractures, and deaths. The aim of this study was to compare both therapeutic options available: parathyroidectomy (PTX) and the calcimimetic agent cinacalcet. Methods: A single center retrospective study including adult renal transplant recipients who developed hypercalcemia due to persistent hyperparathyroidism. Inclusion criteria: PTH > 65 pg/mL with serum calcium > 11.5 mg/dL at any time after transplant or serum calcium persistently higher than 10.2 mg/dL one year after transplant. Patients treated with cinacalcet (n=46) were compared to patients treated with parathyroidectomy (n=30). Follow-up period was one year. Clinical and laboratory data were analyzed to compare efficacy and safety of both therapeutic modalities. Results: PTX controlled calcemia faster (month 1 x month 6) and reached significantly lower levels at month 12 (9.1±1.2 vs 9.7±0.8 mg/dL, p < 0.05); PTX patients showed significantly higher levels of serum phosphate (3.8±1.0 vs 2.9±0.5 mg/dL, p < 0.05) and returned PTH to normal levels (45±51 pg/mL). Cinacalcet, despite controlling calcium and phosphate in the long term, decreased but did not correct PTH (197±97 pg/mL). The proportion of patients that remained with PTH above normal range was 95% in the cinacalcet group and 22% in the PTX group. Patients treated with cinacalcet had better renal function (creatinine 1.2±0.3 vs 1.7±0.7 mg/dL, p < 0.05). Conclusions: Surgical treatment was superior to cinacalcet to correct the metabolic disorders of hyperparathyroidism despite being associated with worse renal function in the long term. Cinacalcet proved to be a safe and well tolerated drug.