<p>Clinical Efficacy of Intravenous Immunoglobulin for BK Polyomavirus-Associated Nephropathy After Living Kidney Transplantation</p>

Abstract

Purpose: BK polyomavirus (BKPyV)-associated nephropathy (BKPyVAN) is one of the most difficult infections to be treated after kidney transplantation. Although patients with BKPyVAN usually received a reduction of immunosuppressive agents, the majority of these patients undergo the loss of the graft kidney without any effective treatment afterward. Therefore, development of more effective therapy for BKPyVAN is eagerly expected. Patients and Methods: Among patients who underwent a kidney transplantation between January 2016 and April 2019 at our hospital, there were five cases of BKPyVAN. After the initial diagnosis, all patients discontinued administration of mycophenolate mofetil (MMF), which was not enough to diminish decoy cells in urine cytology test. Therefore, all patients received additional intravenous immunoglobulin (IVIG) (100 mg/kg/day) therapy for five days and were evaluated for the therapeutic effect of IVIG with immunohistochemical examination using re-biopsy samples of the graft kidney. Results: After IVIG therapy, 2 cases showed negative decoy cells in urine and 3 cases showed a drastic decrease of plasma BK virus load. Importantly, simian virus (SV) 40 large T antigens diminished after IVIG administration in all cases, which degraded polyomavirus nephropathy classification. Conclusion: Although it is difficult to treat BKPyVAN after kidney transplant, IVIG therapy was considered to a promising treatment to improve severity of BKPyVAN especially in cases that dose reduction of immunosuppressive agents was ineffective.

BK Polyomavirus Nephropathy in Kidney Transplantation: Balancing Rejection and Infection

“…Meanwhile, IVIG has powerful indirect immunomodulatory effects [ 176 , 177 ]. Successful case series of viremia-lowering adjunctive therapy with IVIG had been reported after the failure of IS dose reduction and leflunomide administration [ 178 , 179 , 180 ]. An additional IVIG group presented cleared viremia and BKPyV immunohistochemistry evident from repeated tissue sampling [ 181 ].…”

Is there a case for early treatment with IVIG for BK transplant nephropathy?

“…1 Moreover, among the treated patients, there was significant variation in the timing and peak BK qPCR at pre-and post-IVIG, limiting our ability to comment on the effect of therapy. Whereas IVIG has been associated with improved graft function in retrospective studies of patients with BKVN, 7,8 most of the literature has evaluated IVIG co-administered with antiviral therapy or in cases of disease refractory to antivirals.…”

Conversion to mTOR-Inhibitors Plus IV Immunoglobulins in Kidney-Transplant Recipients with BKV Infection: A Retrospective Comparative Study

“…IVIg administration is associated with an increase in BKV antibody titers in KT recipients, especially for the genotype I BKV (which is the most common) [17]. However, the efficacy of IVIg as a potential treatment for PvAN is controversial [18][19][20][21][22][23]. Overall, the strategy to reduce the tacrolimus level to reduce the risk of BKV added to the potential antiviral effect of mTORi and IVIg may be an interesting approach to treat BKV DNAemia.…”