Persistent hyperparathyroidism after kidney transplantation in children.

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. 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. Thirty-six patients (33.6%) had persistent hyperparathyroidism after KT. On univariable analysis, dialysis duration of 24 months or longer (p = 0.028) and pretransplant hyperphosphatemia (p = 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; p = 0.030). There was no significant difference in height Z score change between patients with and without persistent hyperparathyroidism (p = 0.97). However, persistent hyperparathyroidism was associated with poorer graft survival (log-rank p = 0.049). Six patients received cinacalcet and one underwent subtotal parathyroidectomy for refractory hypercalcemia. 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.