Timing of Parathyroidectomy Does Not Influence Renal Function After Kidney Transplantation

Abstract

Background Parathyroidectomy (PTx) is the treatment of choice for end-stage renal disease (ESRD) patients with therapy-resistant hyperparathyroidism (HPT). The optimal timing of PTx for ESRD-related HPT-before or after kidney transplantation (KTx)-is subject of debate. Methods Patients with ESRD-related HPT who underwent both PTx and KTx between 1994 and 2015 were included in a multicenter retrospective study in four university hospitals. Two groups were formed according to treatment sequence: PTx before KTx (PTxKTx) and PTx after KTx (KTxPTx). Primary endpoint was renal function (eGFR, CKD-EPI) between both groups at several time points post-transplantation. Correlation between the timing of PTx and KTx and the course of eGFR was assessed using generalized estimating equations (GEE). Results The PTxKTx group consisted of 102 (55.1%) and the KTxPTx group of 83 (44.9%) patients. Recipient age, donor type, PTx type, and pre-KTx PTH levels were significantly different between groups. At 5 years after transplantation, eGFR was similar in the PTxKTx group (eGFR 44.5 ± 4.0 ml/min/1.73 m 2) and KTxPTx group (40.0 ± 6.4 ml/min/1.73 m 2 , p = 0.43). The unadjusted GEE model showed that timing of PTx was not correlated with graft function over time (mean difference-1.0 ml/min/1.73 m 2 , 95% confidence interval-8.4 to 6.4, p = 0.79). Adjustment for potential confounders including recipient age and sex, various donor characteristics, PTx type, and PTH levels did not materially influence the results. Conclusions In this multicenter cohort study, timing of PTx before or after KTx does not independently impact graft function over time.

Making the Cut: Parathyroidectomy Before or After Kidney Transplantation?

“…In contrast, the median post‐PTx PTH level in our study was higher at 66.2 pg/mL in the post‐KT PTx group. Other studies with benign renal outcomes in post‐KT PTx reported similar postoperative median PTH levels of 7.7 pmol/L (73.3 pg/mL) [20] and 46.9 pg/mL [21]. PTH has a positive hemodynamic effect on renal blood flow and [26] we hypothesize that a higher postoperative PTH level may be appropriate in KT patients.…”

“…Our study adds to existing reports that show the safety of post‐KT PTx on allograft function. Frey et al [19], van der Plas et al [20] and Bures et al [21]. Some studies have shown an adverse effect of PTx on allograft function.…”

“…The effect of PTx on allograft function is controversial, with some concern that post‐KT PTx adversely affects allograft function. Lee et al [14], Patecki et al [15] Okada et al [16] Littbarski et al [17], Evenepoel et al [18], Frey et al [19], van der Plas et al [20] and Bures et al [21] the impact of PTx on postoperative hypocalcemia, supplemental calcium requirement, and calcium deposition in post‐PTX kidney biopsies is sparse. Existing studies also represent less diverse populations, especially Black/African Americans.…”

Treatment of Hypercalcemic Hyperparathyroidism After Kidney Transplantation Is Associated With Improved Allograft Survival

“… 22 Several studies reported a decline in allograft function following PTx 10 , 23-26 or the use of cinacalcet. 27 However, other studies found no changes in allograft function following PTx 8 , 23 , 28 , 29 or cinacalcet. 30 The discrepancy is partly due to variation in length of follow-up and a lack of a control group to adjust the confounding effect of tertiary HPT itself.…”

Is There an Optimal Time for Parathyroidectomy in Patients with Secondary Hyperparathyroidism?

“…In this issue, Ivarsson et al and van der Plas et al studied the effects of parathyroidectomy on renal function after kidney transplantation and the incidence of cardiovascular events after parathyroidectomy in patients with secondary HPT, respectively [4,5]. Utilizing data from four university hospitals over a 21-year period, van der Plas et al compared renal function (as defined by glomerular filtration rate [GFR]) in patients, according to whether parathyroidectomy was performed before or after renal transplantation.…”