Progressive Multifocal Leukoencephalopathy in a Kidney Transplant Recipient

Area of Science:

• Neuroscience
• Immunology
• Infectious Diseases

Background:

• Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease of the central nervous system caused by the John Cunningham virus (JCV).
• Immunosuppression, particularly in organ transplant recipients, is a major risk factor for PML development.
• Early and accurate diagnosis of PML is crucial for timely intervention and management.

Observation:

• A 39-year-old kidney transplant recipient on tacrolimus, mycophenolate sodium, and meprednisone developed left-sided hemiparesis.
• Brain MRI showed a lesion in the thalamus and internal capsule with hypercellularity.
• Cerebrospinal fluid analysis and cytology were unremarkable for infection or malignancy.

Findings:

• Clinical presentation, imaging, and biopsy-confirmed demyelination suggested PML as a primary diagnosis.
• Neurological symptoms improved significantly after the discontinuation of tacrolimus and mycophenolate sodium.
• The absence of JCV polymerase chain reaction (PCR) testing regionally complicated definitive diagnosis, as negative PCR does not exclude PML.

Implications:

• This case underscores the diagnostic complexities of PML in immunosuppressed patients.
• Immunosuppressive therapy modification, specifically withdrawal of certain agents, can lead to clinical improvement in suspected PML.
• The need for accessible JCV PCR testing or alternative diagnostic modalities for PML is highlighted.