Effect of paricalcitol on mineral bone metabolism in kidney transplant recipients with secondary hyperparathyroidism

Abstract

Introduction: Secondary hyperparathyroidism is highly prevalent in kidney transplant recipients, and commonly results in hypercalcaemia; an association to osteopenia and bone fractures has also been observed. Paricalcitol has proved effective to control secondary hyperparathyroidism in chronic kidney disease in both dialysed and non-dialysed patients, with a low hypercalcaemia incidence. Currently available experience on paricalcitol use in kidney transplant recipients is scarce. Our main aim was to show the effect of paricalcitol on mineral bone metabolism in kidney transplant recipients with secondary hyperparathyroidism. Material and methods: A retrospective multicentre study in kidney transplant recipients aged >18 years with a 12-month or longer post-transplantation course, stable renal function, having received paricalcitol for more than 12 months, with available clinical follow-up for a 24-month period. Results: A total of 69 patients with a 120 ± 92-month post-transplantation course were included. Baseline creatinine was 2.2 ± 0.9 mg/dL and GFR-MDRD was 36 ± 20 mL/min/1.73 m2. Paricalcitol doses were gradually increased during the study: baseline 3.8 ± 1.9 μg/week, 12 months 5.2 ± 2.4 μg/week; 24 months 6.0 ± 2.9 μg/week (P 10 mg/dL showed gradually decreasing levels. Fifteen (21.7%) patients had received prior calcitriol therapy. When shifted to paricalcitol, such patients required paricalcitol doses significantly larger than those not having received calcitriol. Paricalcitol was used concomitantly to cinacalcet in 11 patients with significant PTH reductions being achieved; clinical course was similar to other patients and paricalcitol doses were also similar. Conclusions: Paricalcitol is an effective therapy for secondary hyperparathyroidism in kidney transplant recipients. Overall, no significant changes were observed in calcium and phosphorus levels or urinary excretion. Patients having previously received calcitriol required higher paricalcitol doses. When used in patients receiving cinacalcet, paricalcitol results in a significant PTH fall, with paricalcitol doses being similar to those used in patients not receiving cinacalcet.

Keywords

• Secondary hyperparathyroidism
• Renal transplantation
• Paricalcitol
• Cinacalcet
• Calcitriol