Timing of Parathyroidectomy Does Not Influence Renal Function After Kidney Transplantation

BackgroundParathyroidectomy (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 HPTbefore or after kidney transplantation (KTx)is subject of debate.MethodsPatients 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).ResultsThe 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 5years after transplantation, eGFR was similar in the PTxKTx group (eGFR 44.54.0ml/min/1.73m(2)) and KTxPTx group (40.0 +/- 6.4ml/min/1.73m(2), p=0.43). The unadjusted GEE model showed that timing of PTx was not correlated with graft function over time (mean difference -1.0ml/min/1.73m(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.