Improvement in Hypercalcemia with Cinacalcet after Kidney Transplantation

Abstract

Cinacalcet, a calcimimetic, was evaluated in persistent hyperparathyroidism after kidney transplantation (Tx). Ten kidney transplant recipients and one kidney-pancreas recipient with persistent post-Tx hypercalcemia (serum calcium [SCa] > 10.2 mg/dl), stable graft function, and intact parathyroid hormone (iPTH) >2 times normal received 30 mg/d cinacalcet between 2 mo and 5 yr after Tx. SCa, serum phosphorus (SP), and iPTH were measured before and after cinacalcet. Mean pre-cinacalcet SCa was 10.9 mg/dl (8.6 to 11.9 mg/dl). Average pre-cinacalcet SP was 2.9 mg/dl (1.8 to 4.0 mg/dl). Mean pre-cinacalcet iPTH was 267.0 pg/ml (99 to 723 pg/ml). After cinacalcet, SCa decreased on average by 1.6 mg/dl (95% confidence interval 1.2 to 2.1; P < 0.0001). Post-cinacalcet SP increased on average 0.45 mg/dl (P ‫؍‬ 0.046). Post-cinacalcet iPTH averaged 156.9 mg/dl (P ‫؍‬ 0.10). Graft function remained stable. Cinacalcet lowers SCa and raises SP in the short term in patients with persistent post-Tx hyperparathyroidism; long-term bone effects and persistent hyperparathyroidism merit further study.Clin J Am Soc Nephrol 1: 323-326, 2006323-326, . doi: 10.2215 H ypercalcemia is a frequent complication that ensues after successful kidney transplantation (KTx) (1). Persistent hyperparathyroidism (HPT) is the most frequent cause of post-KTx hypercalcemia (1). The usual management of hypercalcemia after KTx involves a period of conservative management followed by parathyroidectomy in cases with unremitting hypercalcemia Ͼ6 to 12 mo after KTx (1). In recent years, intravenous vitamin D 3 and other vitamin D analogs have been used in dialysis patients to suppress parathyroid hormone (PTH) levels (2). After successful KTx, these agents are discontinued abruptly, followed by an increase in PTH levels, a change in the known natural history of HPT attendant to renal failure. Recently, the calcimimetic agent cinacalcet was approved to treat the HPT that accompanies renal failure (3,4). We hypothesized that cinacalcet may be effective in lowering serum calcium (SCa) and PTH levels in some patients with persistent post-KTx hypercalcemia. We report herein our experience with cinacalcet in the management of persistent HPT and hypercalcemia after KTx. We also compare and contrast our experience with the recently published experience of two other groups that have used cinacalcet in a similar manner (5,6). Materials and MethodsThis study is a retrospective review of the clinical experience with cinacalcet at the University of Florida Kidney Transplant Program. Ten KTx patients (nine deceased donor, two living donor; six male, five female) and one simultaneous kidney-pancreas Tx patient with stable renal allograft function and persistent hypercalcemia after KTx (SCa Ͼ10.2 mg/dl), intact PTH (iPTH) greater than twice the upper limit of normal and stable graft function were started on a single daily oral dose of 30 mg cinacalcet. Cinacalcet was started between 2 mo and 5 yr (median 3 yr) after KTx. We measured SCa, phosphorus (P), and iPTH before and...

Measuring Total Blood Calcium Displays a Low Sensitivity for the Diagnosis of Hypercalcemia in Incident Renal Transplant Recipients

“…Control of serum calcium may be achieved by a parathyroidectomy, but this often occurs at the expense of transient or persistent hypoparathyroidism (41,42). Data from several small series indicate that treatment with cinacalcet, a calcimimetic, might be an attractive alternative for the treatment of hypercalcemia in renal transplant recipients (43)(44)(45)(46)(47)(48)(49). A randomized, double-blind, placebo-controlled study has been initiated to evaluate the efficacy and safety of using cinacalcet to correct hypercalcemia in incident renal transplant recipients with autonomous hyperparathyroidism (EudraCT 207-000573-29).…”

Bone Disease after Renal Transplantation

“…Similarly, Serra et al (81) showed in a short study of 10 wk duration that cinacalcet was effective in correcting the hypercalcemia and reducing PTH values in patients who received a transplant and had persistent hyperparathyroidism. Finally, a recent retrospective study showed that cinacalcet was able to lower the serum calcium and increase serum phosphorus, with no significant changes in the PTH values (82). Nevertheless, Boulanger et al (83) showed a therapeutic failure of cinacalcet in a single case report.…”

Calcium, Calcimimetics and Clinical Outcomes

“…As shown by Srinivas et al, calcimimetic agents can effectively suppress serum Ca in patients who have persistent secondary hyperparathyroidism and hypercalcemia after kidney transplant (8). Using low-dose cinacalcet, the investigators were able to effectively treat hypercalcemia while modestly suppressing PTH.…”