Parathyroidectomy (PTx) after kidney transplantation (Tx) has been reported to have adverse effects on the allograft. In this study, we analyzed the course of patients before and after PTx to understand which patients may be at risk of graft deterioration.

From a cohort of 877 patients who were transplanted between 2000 and 2008, 48 patients (n=23 female, n=25 male, 47.7±11.4 years old) were identified with a PTx after Tx. PTx was intended as subtotal resection or total resection with auto-transplantation and was performed at a medium time of 19.5 months after Tx (range: 4-80 months). In the patients with PTx, 83% received deceased donor Tx. Five patients were re-transplanted. Delayed graft function occurred in 29%. Best GFR within the first 6 months was 67±25 ml/min. 66% of patients had pre-transplant hyperparathyroidism (HPT).

Mean parathormone (PTH) at 6 weeks after Tx was 365 pg/ml (293±227) and 442 pg/ml (377±379) at 6 months. Serum calcium levels at 6 weeks were 2.53±0.21 and 2.65±0.17 mmol/l at 6 months, suggesting that HPT was rather tertiary in the majority of patients. Mean serum phosphate levels were 0.73±0.29 and 0.91±0.27 mmol/l between Tx and 6 months post-Tx. There was a correlation between serum phosphate and PTH levels with r²=0.33 at 6 weeks and r²=0.32 at 6 months (p<0.05). Directly before PTx, mean PTH was 537 pg/ml (380±420), serum calcium 2.66±0.20 mmol/l, and phosphate 0.95±0.26 mmol/l. PTH values were inversely correlated with serum calcium (r²=0.36; p<0.05) suggesting that there was some negative feedback regulation, albeit on a higher set point. Post-operatively PTH dropped to a mean of 46 pg/ml (21±75), serum calcium levels to 2.28±0.27 mmol/l, and phosphate rose to 1.16±0.35 mmol/l. 11% of the patients were within the normal PTH range, 68% were below the lower normal, and 18% between the upper normal and 300 pg/ml. One patient had no satisfactory response to PTx (PTH 467pg/ml). One year after PTx, mean PTH was 44 pg/ml (23±57) and serum calcium was 2.23±0.26 mmol/l. GFR directly before PTx was 60±26 ml/min and dropped to 46±18 ml/min after surgery (p<0.001). GFR remained stable at one and three years after PTx (50±20; 49 ±20 ml/min). There were no graft losses. Median annual GFR change before PTx was -0.5 ml/min and +1.0 ml/min after PTx.

Parathyroidectomy is an effective and save treatment of HPT in kidney transplant patients resulting in a normalization of PTH, serum calcium and serum phosphate levels. Ptx leads to an immediate drop in graft function, with stabilization in the long-term.

CITATION INFORMATION: Patecki M, Scheffner I, Haller H, Gwinner W. Long-Term Renal Allograft Outcome After Parathyroidectomy. Am J Transplant. 2016;16 (suppl 3).

« Back to 2016 American Transplant Congress