Longitudinal study of two cases of progressive multifocal leukoencephalopathy with a clinical benign evolution

Area of Science:

• Neurovirology
• Immunology
• Neurology

Background:

• Progressive multifocal leukoencephalopathy (PML) is a fatal CNS demyelinating disease caused by JC virus (JCV).
• Highly Active Antiretroviral Therapy (HAART) has altered PML prognosis in HIV+ patients, but it remains a significant cause of morbidity.
• Accurate and timely diagnosis of PML is crucial for patient management.

Observation:

• Two HIV+ patients with PML presented with different clinical, CSF, and MRI features but shared a benign clinical course.
• JC virus (JCV) DNA detection in brain biopsies and a JCV-specific T-cell response preceded JCV detection in cerebrospinal fluid (CSF) by months.
• Inflammatory findings in CSF and MRI, coupled with negative JCV detection in CSF, complicated diagnosis in one patient.

Findings:

• A JC virus (JCV) antigen-specific T-cell response was observed in both cases, correlating with a benign disease course.
• Early detection of JCV DNA in brain biopsies and specific T-cell responses can precede CSF detection.
• The study highlights the diagnostic challenges in PML, particularly when CSF JCV is initially undetectable.

Implications:

• Brain biopsy indications for uncertain HIV-related leukoencephalopathies require careful consideration.
• JC virus (JCV) specific T-cell response serves as a valuable additional marker for PML diagnosis.
• Identifying a JCV-specific T-cell response may predict a favorable prognosis in PML patients.