Acquired cystic kidney disease in children with kidney failure.

Background: This study aimed to evaluate the incidence, contributing factors, and clinical outcomes of acquired cystic kidney disease (ACKD) in children undergoing kidney replacement therapy (KRT).

Methods: We conducted a cross-sectional, territory-wide study at the designated pediatric nephrology center in Hong Kong. ACKD was defined as the presence of ≥ 3 cysts in the native kidneys, excluding congenital or hereditary cystic diseases. Between June to December 2023, all paediatric patients receiving KRT in Hong Kong underwent ultrasonography, non-contrast magnetic resonance imaging (MRI), or both. Contrast-enhanced computed tomography was performed for patients with complex cysts.

Results: Forty-three children (56% female; median age 14.7 years; IQR, 11.7-18.7) were included in the analysis. ACKD was detected in 18 children (42%). Nine subjects had complex cysts (grade 2, n = 5; grade 2F, n = 2; grade 3, n = 2). Most patients with ACKD (89%) were asymptomatic. One patient (5.5%) developed back pain and gross haematuria 72 months after initiation of KRT. Another patient (5.5%) developed infected cyst with back pain and clinical sepsis 60 months following KRT initiation. A dialysis duration of ≥ 28 months was the only significant factor associated with ACKD development (77.8% vs. 40%; p = 0.028; OR 6.09, 95% CI 1.43-25.82, p = 0.014). The diagnostic yield of paired ultrasound and MRI was superior to ultrasound alone.

Conclusions: ACKD is prevalent among children and adolescents with kidney failure, with most cases being asymptomatic, however serious complications may arise. Longer duration of dialysis is significantly associated with ACKD development. Therefore, early transplantation and active ACKD surveillance are crucial for children receiving KRT.