Intravenous immunoglobulin in BK virus nephropathy

The incidence of post transplant viral infections has increased with the use of more potent immunosuppressive regimens. Consequently, BK virus nephropathy (BKVN) has arisen as a significant cause of graft dysfunction and loss. Reduction of immunosuppression is the first line management of post-transplant viral infections. Other therapies such as intravenous immunoglobulin (IVIg), cidofovir, leflunomide and fluoroquinolones have been tried with varying degrees of success. We report our experience with IVIg in three pediatric renal transplant recipients who presented with allograft dysfunction. First, we describe two cases of biopsy proven BKVN, one diagnosed with undetectable viral titers in plasma, demonstrating that BKVN can occur even at low viral loads. We also present a pediatric renal transplant recipient with persistent BK viremia and allograft dysfunction who responded to therapy with recovery of renal function and clearance of viremia. Therefore we conclude that IVIg is efficacious in the treatment of persistent BK viremia and BKVN. The appropriate dose, frequency and duration of therapy require further study.