Intravenous immunoglobulin as rescue therapy for BK virus nephropathy

Abstract

BKVN has emerged as an important cause of pediatric renal allograft nephropathy, with significant graft dysfunction in majority of the cases. Reduced immunosuppression and cidofovir therapy are the most commonly used therapeutic options for the treatment of BKVN in these patients. Recently, a preliminary study in adult renal allograft recipients with BKVN showed a therapeutic response to a combined approach of immunosuppression reduction and IVIg administration. A therapeutic benefit of IVIg without another concomitant treatment intervention has not been evaluated. We report stabilization of renal functions, histological resolution of BKVN and significant reduction in BK viremia in pediatric renal transplant with the use of IVIg, after an inadequate response to immunosuppression reduction and cidofovir therapy. In addition, we review the current literature on the use of cidofovir in pediatric renal transplant patients with BKVN and the potential of IVIg use in this condition.

Intravenous Immunoglobulin in BK Virus Nephropathy

“…There reports provided some insight into the utility of IVIg combined with immunosuppression reduction without the confounding effects of other therapeutic agents. In the report by Sharma et al, stabilization of renal function and histological resolution of BKVN was seen with IVIg after recurrent BK viremia developed with discontinuation of cidofovir therapy [6].…”

“…It is however extremely nephrotoxic which limits its use for management of BKVN. It has also been associated with a recurrence of BK viremia and persistent BKVN after an initial response [6]. Leflunomide has anti-viral properties against BK virus and is an attractive option for treatment of BKVN since it has minimal nephrotoxicity.…”

“…We utilized low dose IVIg treatments (0.5 g/kg) given monthly over a 5 to 6 month period, which was similar to the protocol described by Sharma et al [6]. The most common side effect seen was post infusion headache, which was easily managed with acetaminophen.…”

“…BK viremia was confirmed by quantitative detection of BK virus in plasma. BK viral titers in urine and plasma at diagnosis were greater than 1 X 10 6 copies and 1.39 X 10 6 respectively. An allograft biopsy showed diffuse tubulointerstitial inflammation and a positive stain for Simian virus 40 (SV-40) large T-antigen.…”

“…The use of leflunomide, cidofovir, IVIg and fluoquinolones as adjunct therapy in addition to immunosuppression reduction in the management of BK virus nephropathy has been evaluated in several small clinical studies [3][4][5][6]. There have however been no prospective randomized studies to compare the various agents and provide much needed information on long-term benefits.…”