Progressive Multifocal Leukoencephalopathy in a Patient With Progressive Multiple Sclerosis Treated With Ocrelizumab...

Area of Science:

• Neuroimmunology
• Infectious Diseases
• Oncology

Background:

• Progressive multifocal leukoencephalopathy (PML) is a rare, fatal opportunistic infection caused by the JC virus, typically seen in immunocompromised individuals.
• While other anti-CD20 therapies have been linked to rare PML cases, none had been reported with ocrelizumab monotherapy.
• Ocrelizumab is a B-cell depleting therapy used for multiple sclerosis.

Observation:

• A 78-year-old male with progressive multiple sclerosis developed PML while on ocrelizumab monotherapy for two years.
• Symptoms included visual disturbances and confusion, with MRI revealing a parietal lesion and CSF confirming JC virus.
• The patient experienced lymphopenia and rapid neurological decline despite treatment cessation and initiation of pembrolizumab.

Findings:

• The first documented case of PML associated with ocrelizumab monotherapy in a patient with no prior immunomodulatory treatment.
• JC virus was detected in cerebrospinal fluid, confirming PML.
• Autopsy confirmed PML, with findings likely linked to ocrelizumab's immunomodulatory effects and age-related immune decline.

Implications:

• This case underscores the potential risk of PML with ocrelizumab, even in the absence of prior immunosuppression.
• Physicians must carefully weigh the risks and benefits of ocrelizumab, particularly in elderly patients or those with other risk factors for infection.
• Enhanced vigilance and patient monitoring are crucial for early detection of opportunistic infections during ocrelizumab therapy.