Neutralizing antibodies as key players in preventing BK polyomavirus replication: Insights from bench to bedside

We read with considerable interest the paper by Sato et al, 1 Sato N. Shiraki A. Mori K.P. et al. Preemptive intravenous human immunoglobulin G suppresses BK polyomavirus replication and spread of infection in vitro. Am J Transplant. 2023; S1600-6135 (00862-00866)https://doi.org/10.1016/j.ajt.2023.11.007 Abstract Full Text Full Text PDF Scopus (0) Google Scholar titled "Preemptive intravenous human immunoglobulin G suppresses BK polyomavirus replication and spread of infection in vitro." This study demonstrates, through an in vitro model, that BK polyomavirus (BKPyV) infection can be effectively curtailed by intravenous immunoglobulin (IVIG) treatment, provided it is administered within a 3-hour window postinfection. However, the effectiveness of IVIG wanes when given beyond this time frame because it only partially inhibits viral spread by neutralizing the released virus without preventing BKPyV replication. These results highlight the critical role of timely and preventive IVIG administration in controlling BKPyV spread, a finding that aligns with our previous in vivo observations. 2 Solis M. Velay A. Porcher R. et al. Neutralizing antibody-mediated response and risk of BK virus-associated nephropathy. J Am Soc Nephrol. 2018; 29: 326-334https://doi.org/10.1681/ASN.2017050532 Crossref PubMed Scopus (58) Google Scholar In our earlier research, we discovered that a low neutralizing antibody (NAb) titer, specifically below 4 log10 IC50, was linked to an increased risk of BKPyV viremia. 2 Solis M. Velay A. Porcher R. et al. Neutralizing antibody-mediated response and risk of BK virus-associated nephropathy. J Am Soc Nephrol. 2018; 29: 326-334https://doi.org/10.1681/ASN.2017050532 Crossref PubMed Scopus (58) Google Scholar Moreover, we found that early posttransplant IVIG administration significantly lowered the occurrence of BKV viremia and nephropathy in kidney transplant recipients (KTRs) with low-NAb titers. 3 Benotmane I. Solis M. Velay A. et al. Intravenous immunoglobulin as a preventive strategy against BK virus viremia and BKV-associated nephropathy in kidney transplant recipients-results from a proof-of-concept study. Am J Transplant. 2021; 21: 329-337https://doi.org/10.1111/ajt.16233 Abstract Full Text Full Text PDF PubMed Scopus (19) Google Scholar Preemptive Intravenous Human Immunoglobulin G Suppresses BK Polyomavirus Replication and Spread of Infection In VitroAmerican Journal of TransplantationPreviewBK polyomavirus (BKPyV) infection causes various diseases in immunocompromised patients. Cells from human lung and kidney were infected with BKPyV and treated with commercially available intravenous immunoglobulin G (IVIG). Its effects on BKPyV replication and spread of infection were investigated, focusing on administration timing. IVIG treatment 3 hours after infection suppressed BKPyV replication assessed by real-time PCR and expression of the viral capsid protein 1 and large T-antigen. IVIG effectively reduced the number of BKPyV-infected cells 2 weeks after infection in an antibody titer-dependent manner. Full-Text PDF Open Access