Hypercalcemia in Renal Transplant Patients: Prevalence and Management in Canadian Transplant Practice

Hypercalcemia, occurring in up to 25% of patients within 12 months following renal transplantation, and persistent hyperparathyroidism were evaluated following renal transplantation, by retrospective chart review of 1000 adult patients transplanted between January 1, 2003 and January 31, 2008 with at least six months follow-up. Serum calcium, parathyroid hormone, and phosphate levels were recorded at 12, 24, 36, and 48 months. Average follow-up was 766 (535) d (mean (SD); median 668 d). Majority were first transplants (85%); deceased donor 57%. Point prevalence of hypercalcemia (serum Ca(2+) > 2.6 mM) was 16.6% at month 12, 13.6% at month 24, 9.5% at month 36, and 10.1% at month 48. Point prevalence of serum parathyroid hormone (PTH) > 10 pM was 47.6% at month 12, 51.1% at month 24, 43.4% at month 36, and 39.3% at month 48. Estimated glomerular filtration rate (GFR) was maintained throughout and was not different between patients with or without hypercalcemia or elevated PTH. Cinacalcet was prescribed in 12% of patients with hypercalcemia and persistent hyperparathyroidism; parathyroidectomy was performed in 112/1000 patients, 15 post-transplant. Persistent hyperparathyroidism, often accompanied by hypercalcemia, is common following successful renal transplantation, but the lack of clear management suggests the need for further study and development of evidence-based guidelines.