Risk factors for persistent hyperparathyroidism in children with stable renal function after kidney transplantation

Abstract

This study aimed to investigate the risk factors for PHPT in children with stable renal function who received KT. We retrospectively analyzed the clinical findings and laboratory results of patients who underwent KT below 19 years of age, between 1996 and 2016 at our hospital. Patients were followed up for more than 1 year after KT. We calculated the mean ± standard deviation or median [minimum - maximum] for each parameter. We included a total of 46 patients (male:female = 26:20). Twelve patients (26.1%) were included in the PHPT group, and 34 (73.9%) were in the nPTH group. The dialysis duration was 57.1 ± 49.9, 44 [0-145] months in the PHPT group and 23.5 ± 25.8, 15 [1-121] months in the nPTH group (P = .040). The post-KT total CO level was significantly higher in the PHPT group (P = .022). The pre- (P = .021) and post-KT (P = .005) and 3-month average (P = .018) iPTH levels were also significantly higher in PHPT group. The height z-score showed a negative correlation, and the pre-KT, 3-month average phosphorus and alkaline phosphate levels showed positive correlations with iPTH levels, at 1 year after KT. Patients who undergo prolonged durations of dialysis, have increased iPTH levels before and after KT, and have low bicarbonate levels after KT are at risk of PHPT and should be monitored carefully.

Determinants of hyperparathyroidism in children after kidney transplantation

“…2 Multiple studies have indicated a strong correlation between dialysis vintage and HPT. 3,4,6,7,21 Both prolonged dialysis vintage and severe HPT are detrimental to growth, long-term cardiovascular and bone health in children, thus underscoring the need to encourage preemptive transplantation in children. Secondary HPT is an important contributor to MBD, commencing as early as CKD stage 2 in some children.…”

“…Several factors have been associated with HPT including longer dialysis vintage and greater severity of pre-transplant HPT. 3,4,6,7 Long-standing secondary HPT before transplantation can lead to autonomous functioning of the parathyroid glands resulting in tertiary HPT, which is clinically manifested by hypercalcemia. Parathyroid hyperplasia develops when secondary HPT is prolonged and may lead to nodular hyperplasia and adenoma formation.…”

“…2 However, in some children, elevated PTH levels can be seen after KTx and may be associated with an increased risk of bone and cardiovascular disease. [3][4][5][6][7] It is estimated that 20% to 78% of children at 6 months, and about 50% at 1 year, have HPT after KTx. 3,4,7 Post-transplant HPT is defined in various studies as having a level greater than 65-73 pg/ml.…”

Timing of parathyroidectomy for kidney transplant patients with secondary hyperparathyroidism: A practical overview

“…Patients with pre-KT PTH levels of 300-599 pg/mL are likely to develop PHPT, and the higher the preoperative level, the more possibility PHPT developing (22). In addition, a dialysis vintage > 6 years is a strong predictor of PHPT (21,42). The parathyroid mass grows gradually and progresses over time in patients undergoing long term dialysis, indicating a high possibility of parathyroid gland autonomy (42).…”

Persistent hyperparathyroidism after kidney transplantation in children

“…Nevertheless, comprehensive data on persistent hyperparathyroidism among children undergoing KT are limited [17,18]. Only a few studies in Asia have examined the epidemiology of persistent hyperparathyroidism and its risk factors among children [19].…”