Characteristics of Persistent Hyperparathyroidism After Renal Transplantation

Persistent hyperparathyroidism (HPT) after renal transplantation (RTx), termed tertiary HPT (THPT), is not uncommon. However, risk factors and appropriate operative procedures for THPT are poorly understood.

A retrospective study of patients who underwent RTx without pre-transplant parathyroidectomy (PTx) was performed at our hospital between January 2001 and March 2011. Risk factors for the development of THPT were investigated by comparing THPT and non-THPT groups. We retrospectively analyzed patients with THPT who underwent total PTx with forearm autograft. Pre- and postoperative (1 year after PTx) laboratory results were analyzed for PTx efficacy.

Data for 520 patients were analyzed. On multivariate analysis, long dialysis duration (p = 0.009, hazard ratio (HR) 1.01), large maximum parathyroid gland size before RTx (p = 0.003, HR 1.23), pre-RTx high intact parathyroid hormone (iPTH) (p = 0.041, HR 1.01), post-RTx (<2 weeks) high calcium (Ca) (p < 0.001, HR 25.04), and post-RTx high alkaline phosphatase (ALP) (p = 0.027, HR 0.99) were identified as risk factors for THPT. Patients who underwent PTx showed significant improvement compared with baseline for serum Ca, phosphorus, iPTH, and ALP. Serum creatinine showed no significant difference.

Several risk factors for THPT development were identified. PTx for patients with THPT significantly improved serum Ca, iPTH, ALP, and phosphorous levels. There was no significant difference in renal function after PTx. Therefore, total PTx with forearm autograft may be an appropriate surgical approach for patients with THPT.