Progressive multifocal leucoencephalopathy associated with lupus and methotrexate overdose

Area of Science:

• Neurology
• Infectious Diseases
• Immunology

Background:

• Systemic lupus erythematosus (SLE) can present with diverse neurological manifestations.
• Neuropsychiatric lupus (NSLE) diagnosis can be challenging, often requiring exclusion of other conditions.
• JC virus (JCV) causes Progressive Multifocal Leukoencephalopathy (PML), a rare but serious CNS demyelinating disease.

Observation:

• A case of PML in a patient with SLE is presented.
• The patient was receiving supra-therapeutic doses of methotrexate.
• PML was initially considered in the differential diagnosis of the patient's neurological symptoms.

Findings:

• PML, a CNS infection by JC virus, rarely occurs in lupus patients.
• PML can be misdiagnosed as antiphospholipid antibody syndrome or NSLE.
• The presented case highlights PML as a critical consideration in SLE patients with CNS symptoms.

Implications:

• Central nervous system (CNS) infections must be considered before initiating immunosuppressants for NSLE.
• Supra-therapeutic methotrexate doses may increase the risk of opportunistic infections like PML in SLE patients.
• This case underscores the importance of vigilant diagnosis in SLE to differentiate infectious from autoimmune neurological conditions.