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JC virus VP1 loop-specific polymorphisms are associated with favorable prognosis for progressive multifocal

Serena Delbue1, Emanuela Branchetti, Simone Bertolacci

  • 1Laboratory of Molecular Virology, Department of Biomedical Science and Technology, University of Milan, Milan, Italy.

Journal of Neurovirology
|December 2, 2008
PubMed

Insights

Mutations in the JC virus (JCV) VP1 protein outer loops are linked to slower progression of progressive multifocal leukoencephalopathy (PML). These findings suggest JCV VP1 loop variations may indicate a favorable prognosis for PML patients.

Area of Science:

  • Virology
  • Neurology
  • Immunology

Background:

  • Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disease caused by the JC virus (JCV), primarily affecting immunocompromised individuals.
  • Historically, PML has been characterized by rapid progression and a poor prognosis.
  • Recent research suggests that variations in the JCV capsid protein may influence the clinical course of PML.

Purpose of the Study:

  • To investigate the association between JC virus (JCV) VP1 protein mutations and the clinical progression of progressive multifocal leukoencephalopathy (PML).
  • To identify potential prognostic markers for PML by analyzing JCV strains from patients with different disease courses.
  • To explore the pathogenetic mechanisms underlying varying PML progression rates.

Main Methods:

  • Collected cerebrospinal fluid (CSF) and brain autopsy samples from PML patients with fast and slow progression.
  • Amplified, cloned, and sequenced the JCV VP1 coding region from patient samples.
  • Analyzed JCV strains from urine samples of PML patients and controls with other neurological diseases (ONDs).

Main Results:

  • Identified specific polymorphic residues (positions 74, 75, 117, 128) in the JCV VP1 outer loops of patients with slow PML progression.
  • Found no significant mutations in JCV isolated from urine samples.
  • Demonstrated a correlation between JCV VP1 loop mutations and a favorable prognosis in PML.

Conclusions:

  • JC virus (JCV) VP1 outer loop mutations are associated with a slower, more favorable clinical course of progressive multifocal leukoencephalopathy (PML).
  • These mutations may indicate a less virulent JCV strain with reduced replication capacity.
  • JCV VP1 loop variations represent potential biomarkers for predicting PML prognosis.

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