Polyomaviruses After Allogeneic Hematopoietic Stem Cell Transplantation

Abstract

Polyomaviruses (PyVs) are non-enveloped double-stranded DNA viruses that can cause significant morbidity in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients, particularly BK polyomavirus (BKPyV) and JC polyomavirus (JCPyV). BKPyV is primarily associated with hemorrhagic cystitis (HC), while JCPyV causes progressive multifocal leukoencephalopathy (PML). The pathogenesis of these diseases involves viral reactivation under immunosuppressive conditions, leading to replication in tissues such as the kidney, bladder, and central nervous system. BKPyV-HC presents as hematuria and urinary symptoms, graded by severity. PML, though rare after allo-HSCT, manifests as neurological deficits due to JCPyV replication in glial cells. Diagnosis relies on nucleic acid amplification testing for DNAuria or DNAemia as well as clinical criteria. Management primarily involves supportive care, as no antiviral treatments have proven consistently effective for either virus and need further research. This review highlights the virology, clinical presentations, and management challenges of PyV-associated diseases post-allo-HSCT, emphasizing the need for improved diagnostic tools and therapeutic approaches to mitigate morbidity and mortality in this vulnerable population.

Keywords: BK virus; JC virus; hematopoietic stem cell transplant; hemorrhagic cystitis; polyomavirus; progressive multifocal leukoencephalopathy.

Figure 1

Three-stage model of BKPyV-HC pathophysiology. GVHD—graft versus host disease; allo-HSCT—allogeneic hematopoietic stem cell transplant; CMI—cell mediated immunity, BKPyV—BK polyomavirus; HC—hemorrhagic cystitis. Created in BioRender (Version December, 2024). Mendoza, M. (2025) https://BioRender.com/c75x266, accessed on 10 December 2024.