Predictors of tertiary hyperparathyroidism: Who will benefit from parathyroidectomy?

BACKGROUND: Tertiary hyperparathyroidism (3°HPT) is hyperparathyroidism with hypercalcemia after renal transplantation. With unclear guidelines for parathyroidectomy (PTX), this study aims to determine which renal transplant patients develop 3°HPT and would benefit from PTX. METHODS: We performed a retrospective review of patients who received a renal transplant between 1994 and 2013; 105 patients who underwent near total PTX (NTPTX) were compared with 180 renal transplant control patients who did not undergo NTPTX. RESULTS: Calcium and PTH varied significantly between groups (P < .001). One year before transplant, the mean serum calcium was 9.7 ± 1.1 mg/dL in the NTPTX group versus 9.1 ± 0.9 mg/dL in the control group (P < .01). One month after transplant, the mean calcium in the NTPTX group was 10.4 ± 1.1 versus 9.4 ± 0.6 mg/dL in the control group (P < .001). One year before renal transplant, the median serum PTH level was 723 pg/mL (range, 557-919) in the NTPTX group versus 212 pg/mL (range, 160-439) in the control group (P < .01). One-month post renal transplant, the NTPTX group had a median PTH of 351 pg/mL (range, 199-497) versus 112 pg/mL (range, 73-178) pg/mL in the control group (P < .01). CONCLUSION: Before and after renal transplantation, PTH and calcium levels can serve as predictors of 3°HPT.