BK and JC Virus Infections in Pediatric Kidney Transplantation in Children: A Narrative Review of Risk Factors, Pathogenesis, and Monitoring Strategies

Abstract

BK virus (BKV) and John Cunningham virus (JCV) are the most common polyomaviruses infecting pediatric kidney transplant recipients. These infections primarily result from reactivation of latent viruses due to immunosuppression, and they progress through stages of viruria, viremia, and potentially polyomavirus-associated nephropathy, particularly BK virus-associated nephropathy (BKVAN). This narrative review compiles and analyzes existing data regarding the epidemiology, risk factors, virology, clinical features, and monitoring strategies of BKV and JCV in children undergoing kidney transplantation. Key risk factors include younger recipient age, male gender, obstructive uropathy as the cause of end-stage kidney disease, specific immunosuppressive regimens such as tacrolimus/MMF, and donor characteristics (older age and female sex). Molecular diagnostic techniques, particularly real-time quantitative PCR in plasma or urine, are widely used, while kidney biopsy remains the gold standard for diagnosing BKVAN. Management is centered on reducing the intensity of immunosuppression. International guidelines, including those from KDIGO, recommend routine viral load monitoring in the first year after transplant to detect reactivation early. In Indonesia, the lack of diagnostic facilities limits the ability to monitor these infections effectively. This review aims to inform clinicians about evidence-based surveillance and prevention strategies for polyomavirus infections in pediatric renal transplant recipients and underscores the urgent need for local research to develop region-specific clinical protocols.