Work

Real-world use of extracorporeal photopheresis for BK polyomavirus infection after kidney transplantation: results from the French multicenter registry

Year: 2026

Type: article

Abstract: Introduction BK polyomavirus (BKPyV) infection is a major complication after kidney transplantation (KT), primarily driven by over-immunosuppression. Reduction of immunosuppressive therapy remains the standard of care but increases the risk of acute rejection (AR) and graft loss. Extracorporeal photopheresis (ECP) is an immunomodulatory therapy that may help control viral replication while limiting alloimmune complications. Patients and methods We aimed to describe the real-world use, safety, and outcomes of ECP for BKPyV infection in KT recipients. We analyzed data from the French multicenter ECP registry, including 50 patients treated with ECP for BKPyV infection across 13 transplant centers. Patients were classified according to ECP initiation before the occurrence of rejection (BKPyV group, n=36) or in the setting of concomitant rejection (BKPyV + rejection group, n=14). Results At ECP initiation, BKPyV DNAemia had persisted for >3 months in 56% of patients; the median viral load was 4.3 log copies/mL, 63% had BKPyV DNAemia >4 log copies/mL, and 55% had biopsy-proven BKPyV nephropathy. Immunosuppression had already been substantially reduced before ECP initiation and was further minimized during follow-up. At 6 and 12 months, BKPyV DNAemia had decreased by >1 log in 70% and 75% of patients, respectively, while complete viral clearance was achieved in 49% and 55%. Renal function remained stable or improved in 58% of patients during the follow-up. De novo donor-specific antibodies developed in 10% of patients, AR occurred in 12%, graft loss in 8%, and only three ECP-related adverse events (6%) were reported. Compared with the BKPyV group, patients with concomitant AR achieved similar virological responses but tended to have less frequent stabilization or improvement of graft function (40% vs 65%), more AR (21% vs 8%), de novo DSA (14% vs 8%), and graft loss (15% vs 6%). Conclusion This study represents the largest published multicenter real-world cohort of KT recipients treated with ECP for BKPyV infection. ECP combined with immunosuppression minimization was associated with favorable virological and immunological outcomes and an excellent safety profile. Although this observational study cannot establish the efficacy of ECP, it provides a comprehensive description of current ECP practice for BKPyV infection and supports the rationale for prospective randomized controlled trials.

Source: Frontiers in Immunology

DOI: 10.3389/fimmu.2026.1936468