Progressive multifocal leukoencephalopathy in systemic lupus erythematosus treated with pembrolizumab

Area of Science:

• Neuroimmunology
• Infectious Neurology
• Rheumatology

Background:

• Systemic lupus erythematosus (SLE) is an autoimmune disease often requiring immunosuppressive therapy.
• Progressive multifocal leukoencephalopathy (PML) is a rare, fatal demyelinating disease caused by John Cunningham polyomavirus (JCV) reactivation.
• Immunosuppression, particularly with agents like azathioprine, is a known risk factor for PML.

Observation:

• A case report details an SLE patient on low-dose azathioprine who developed PML.
• The patient was treated with pembrolizumab, an immune checkpoint inhibitor, showing initial clinical improvement.
• Following the fourth dose of pembrolizumab, the patient experienced rapid clinical deterioration.

Findings:

• The patient's condition worsened significantly after pembrolizumab administration, leading to treatment cessation.
• This case underscores the potential risks associated with immune checkpoint inhibitors in immunocompromised patients with underlying autoimmune conditions.
• The complex interplay of immunosuppression, SLE, and potential genetic factors in PML pathogenesis is highlighted.

Implications:

• The use of pembrolizumab in SLE patients, particularly those with or at risk for opportunistic infections like PML, requires cautious evaluation.
• Further research is needed to understand the safety profile of immune checkpoint inhibitors in the context of SLE and PML.
• Clinical management strategies must consider the delicate balance between immunosuppression for SLE and the risk of severe opportunistic infections.