Progressive Multifocal Leukoencephalopathy Pathogenesis and Treatment Strategies

Progressive multifocal leukoencephalopathy (PML) is a life-threatening demyelinating disorder of the central nervous system caused by unchecked replication of the JC polyomavirus in oligodendrocytes. Typically arising in the setting of profound immunosuppression—whether due to HIV infection, haematological malignancy, organ transplant or immunomodulatory therapies—PML presents with multifocal neurological deficits that reflect disruption of myelin integrity. Pathogenically, reactivation of latent JC virus, viral entry into glial cells and direct lytic injury combine with host inflammatory responses to drive progressive white-matter lesions. Risk stratification increasingly relies on viral load in cerebrospinal fluid and magnetic resonance imaging, alongside clinical predictors such as age and baseline functional status. In the absence of a licensed antiviral, restoration of antiviral immunity remains the cornerstone of management. Immune reconstitution through reduction of immunosuppression or initiation of antiretroviral therapy has improved outcomes, though at the cost of potential immune reconstitution inflammatory syndrome. Experimental approaches aim to augment virus-specific immunity further, including adoptive transfer of targeted T-lymphocytes and engineered neutralising antibodies. Parallel efforts explore small molecules and entry inhibitors to disrupt viral attachment and spread. A holistic strategy that integrates early diagnosis, modulation of host immunity and direct antiviral measures is emerging as the most promising route to arrest disease progression and preserve neurological function.

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Progressive Multifocal Leukoencephalopathy Pathogenesis and Treatment Strategies publication trend

The graph below shows the total number of articles in progressive multifocal leukoencephalopathy pathogenesis and treatment strategies across all publications each year (not limited to Nature Index journals).

Technical terms

JC polyomavirus (JCV): A ubiquitous human virus that establishes latent infection in the kidney and can reactivate in the central nervous system, causing PML.

Oligodendrocyte: A glial cell type responsible for myelin production in the central nervous system; primary target of JC virus lytic infection.

Immune reconstitution: Restoration of immune competence following reduction of immunosuppression or initiation of antiretroviral therapy, often crucial for PML control.

Virus-specific T cells: Lymphocytes selected or engineered to recognise viral antigens and mediate targeted cytotoxicity against infected cells.

Extracellular vesicle (EV): Membrane-bound particle released by cells that can carry viral particles or host factors, facilitating intercellular communication and pathogen dissemination.

References

1. Directly Isolated Allogeneic Virus–Specific T Cells in Progressive Multifocal Leukoencephalopathy. JAMA Neurology (2024).
2. JC Polyomavirus Uses Extracellular Vesicles To Infect Target Cells. mBio (2019).