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

BACKGROUND: Hyperparathyroidism (HPT) and malignancy are the most common causes of hypercalcemia. Among kidney transplant (KT) recipients, hypercalcemia is mostly caused by tertiary HPT. Persistent tertiary HPT after KT is associated with allograft failure. Previous studies on managing tHPT were subjected to survivor treatment selection bias; as such, the impact of tertiary HPT treatment on allograft function remained unclear. We aim to assess the association between hypercalcemic tertiary HPT treatment and kidney allograft survival. MATERIALS AND METHODS: We identified 280 KT recipients (2015-2019) with elevated post-KT adjusted serum calcium and parathyroid hormone (PTH). KT recipients were characterized by treatment: cinacalcet, parathyroidectomy, or no treatment. Time-varying Cox regression with delayed entry at the time of first elevated post-KT calcium was conducted, and death-censored and all-cause allograft failure were compared by treatment groups. RESULTS: Of the 280 recipients with tHPT, 49 underwent PTx, and 98 received cinacalcet. The median time from KT to first elevated calcium was 1 month (IQR: 0-4). The median time from first elevated calcium to receiving cinacalcet and parathyroidectomy was 0(IQR: 0-3) and 13(IQR: 8-23) months, respectively. KT recipients with no treatment had shorter dialysis vintage (P = .017) and lower PTH at KT (P = .002), later onset of hypercalcemia post-KT (P < .001). Treatment with PTx (adjusted hazard ratio (aHR) = 0.18, 95%CI 0.04-0.76, P = .02) or cinacalcet (aHR = 0.14, 95%CI 0.004-0.47, P = .002) was associated with lower risk of death-censored allograft failure. Moreover, receipt of PTx (aHR = 0.28, 95%CI 0.12-0.66, P < .001) or cinacalcet (aHR = 0.38, 95%CI 0.22-0.66, P < .001) was associated with lower risk of all-cause allograft failure. CONCLUSIONS: This study demonstrates that treatment of hypercalcemic tertiary HPT post-KT is associated with improved allograft survival. Although these findings are not specific to hypercalcemia of malignancy, they do demonstrate the negative impact of hypercalcemic tertiary HPT on kidney function. Hypercalcemic HPT should be screened and aggressively treated post-KT.

Resolution of Secondary Hyperparathyroidism After Kidney Transplantation and the Effect on Graft Survival.

OBJECTIVE: Hyperparathyroidism (HPT) is nearly universal in patients with end-stage kidney disease. Kidney transplantation (KT) reverses HPT in many patients, but most studies have only focused on following calcium and not parathyroid hormone (PTH) levels. We sought to study the prevalence of persistent HPT post-KT at our center and its effect on graft survival. METHODS: Patients who underwent KT from January 2015 to August 2021 were included and characterized by post-KT HPT status at the most recent follow-up: resolved (achieving normal PTH post-KT) versus persistent HPT. Those with persistent HPT were further stratified by the occurrence of hypercalcemia (normocalcemic versus hypercalcemic HPT). Patient demographics, donor kidney quality, PTH and calcium levels, and allograft function were compared between groups. Multivariable logistic regression and Cox regression with propensity score matching were conducted. RESULTS: Of 1554 patients, only 390 (25.1%) patients had resolution of renal HPT post-KT with a mean (±SD) follow-up length of 40±23 months. The median (IQR) length of HPT resolution was 5 (0-16) months. Of the remaining 1164 patients with persistent HPT post-KT, 806 (69.2%) patients had high PTH and normal calcium levels, while 358 (30.8%) patients had high calcium and high PTH levels. Patients with persistent HPT had higher parathyroid hormone (PTH) at the time of KT [403 (243-659) versus 277 (163-454) pg/mL, P <0.001] and were more likely to have received cinacalcet treatment before KT (34.9% vs. 12.3%, P <0.001). Only 6.3% of patients with persistent HPT received parathyroidectomy. Multivariable logistic regression showed race, cinacalcet use pre-KT, dialysis before KT, receiving an organ from a deceased donor, high PTH, and calcium levels at KT were associated with persistent HPT post-KT. After adjusting for patient demographics and donor kidney quality by propensity score matching, persistent HPT (HR 2.5, 95% CI 1.1-5.7, P =0.033) was associated with a higher risk of allograft failure. Sub-analysis showed that both hypercalcemic HPT (HR 2.6, 95% CI 1.1-6.5, P =0.045) and normocalcemic HPT (HR 2.5, 95% CI 1.3-5.5, P =0.021) were associated with increased risk of allograft failure when compared with patients with resolved HPT. CONCLUSION: Persistent HPT is common (75%) after KT and is associated with a higher risk of allograft failure. PTH levels should be closely monitored after kidney transplantation so that patients with persistent HPT can be treated appropriately.

Association Between Surgical Indication and Outcomes for Outpatient Adrenalectomy.

INTRODUCTION: Despite a favorable risk-benefit profile, inpatient admission postoperatively for minimally invasive adrenalectomy (MIA) has remained common. Prior studies have shown that outpatient MIA was not associated with an increased 30-day complications or readmission. However, this has not been explored in-depth by adrenalectomy indication. We aimed to examine whether the safety profile of outpatient MIA varies by adrenal indication. MATERIALS AND METHODS: Clinicopathologic parameters were examined for all MIAs entered into an adrenal database at our institution from 2012 to 2021. Predictor variables included patient demographics, surgical indication, and operative time. Outcomes were 30-day emergency department visit, readmission, and complication rates between surgical indications, comparing outpatient and inpatient groups. Statistical analyses were performed using Kruskal-Wallis, Wilcoxon, Mann-Whitney, and Chi-squared tests, as appropriate. RESULTS: A total of 185 MIA patients were included. Outpatient MIA was performed in 53 patients (28.6%). Outpatient discharge post-MIA was related to both surgical indication and operative time. Pheochromocytoma (PC) patients were less likely to be discharged as an outpatient postoperatively when compared to all other indications (13.0% versus 33.8%, P = 0.007). Among all patients with operations 2-3 h in length, PC patients were less likely to be discharged home as an outpatient (10% versus 33.3%, P = 0.040). No significant differences were identified between outpatient and inpatient MIA groups for complications, emergency department visits, or readmission (P > 0.05 for all). Only six outpatient MIA patients had any complication (11.3%) and six were readmitted (11.3%). CONCLUSIONS: Outpatient MIA was demonstrated to be associated with similar, low complication and readmission rates compared to inpatient MIA, although it was used less often for patients with PC or prolonged operative times. Our study highlights potential evidence that outpatient MIA can be safely used in selected patients across all indications for adrenal surgery.