Persistent hyperparathyroidism after kidney transplantation in children.

Background: Persistent hyperparathyroidism after kidney transplantation (KT) has been reported in up to 50% of adult recipients, but pediatric data remain limited. We evaluated the prevalence, skeletal manifestations, and risk factors for persistent hyperparathyroidism in children following KT.

Methods: In this retrospective cohort study, 107 pediatric KT recipients (58% male; median age 10.3 years) transplanted between 2004 and 2019 were analyzed. Persistent hyperparathyroidism was defined as a median parathyroid hormone (PTH) > 65 pg/mL between 3 and 12 months post-KT. Risk factors for persistent hyperparathyroidism, post KT clinical features, and treatment status were analyzed.

Results: Thirty-six patients (33.6%) had persistent hyperparathyroidism after KT. On univariable analysis, dialysis duration of 24 months or longer ( = 0.028) and pretransplant hyperphosphatemia ( = 0.026) were significantly associated with persistent hyperparathyroidism. The multivariable model identified pretransplant hyperphosphatemia as an independent predictor (OR 2.70, 95% CI 1.10-6.87;  = 0.030). There was no significant difference in height Z score change between patients with and without persistent hyperparathyroidism ( = 0.97). However, persistent hyperparathyroidism was associated with poorer graft survival (log-rank  = 0.049). Six patients received cinacalcet and one underwent subtotal parathyroidectomy for refractory hypercalcemia.

Conclusions: Persistent hyperparathyroidism is relatively common in pediatric KT recipients, affecting one-third of patients by one-year post-transplant. Prolonged dialysis and pre-existing hyperphosphatemia before KT may be risk factors. These findings underscore the importance of optimizing chronic kidney disease-mineral bone disease management and routine PTH monitoring before and after transplant in children.