High-Dose Intravenous Immunoglobulin Therapy for Prevention of BK Virus Nephropathy in Pediatric Kidney Transplant Recipients
Background: BK virus nephropathy (BKVN) is diagnosed in 5%-16% of pediatric renal transplant recipients, and is preceded by BK-viremia/viruria. Despite irreversible renal damage associated with BKVN, there is lack of evidence-based guidelines for preventive measures in patients with BK viremia/viruria.
Aim: In this retrospective study we examined the safety and efficacy of high-dose intravenous immunoglobulin (HD-IVIG) therapy in preventing BKVN in pediatric kidney transplant recipients with significant BK-viremia/viruria.
Methods: All pediatric renal transplant recipients under our care underwent routine testing for urine and blood BK virus, using polymerase chain reaction (PCR) technique. Patients exhibiting BK-viruria above 107 copies/milliliter (ml) and/or BK-viremia above 103 copies/ml without no evidence of BKVN, were managed with 50% dose reduction of the immunosuppressive drug mycophenolate mofetil (MMF). Absence of BK viral load decline within two months from MMF dose reduction was managed with HD-IVIG (at 2 grams/kg body weight).
Results: 62 patients were followed over a 6-year period. 31 patients (50%) showed BK-viremia/viruria. 13/31 patients (42%) suffered from significant and persistent BK-viremia/viruria, unresponsive to MMF dose reduction, and were managed with HD-IVIG. 12/13 (92%) showed remarkable BK viral load reduction within 6 months from HD-IVIG therapy. Except for transient headache, no patient exhibited major adverse effects to HD-IVIG therapy, and none developed overt BKVN during the study period.
Conclusions: Preventive HD-IVIG therapy in pediatric renal transplant recipients with BK viremia/viruria unresponsive to MMF dose reduction is safe and effective in preventing the development of BKVN. Additional large-scale controlled studies are is necessary to establish our finding.