Progressive Multifocal Leukoencephalopathy in Chimeric Antigen Receptor T-Cell Therapy Recipients: A Case Study

Area of Science:

• Oncology
• Immunology
• Infectious Diseases

Background:

• Chimeric antigen receptor (CAR) T-cell therapy offers significant responses in refractory hematologic malignancies like multiple myeloma (MM).
• CAR T-cell therapy is associated with known toxicities, including cytokine release syndrome (CRS) and neurotoxicity.
• Patients undergoing CAR T-cell therapy face increased infection risks due to immune dysfunction, prior treatments, and prolonged B-cell aplasia.

Purpose of the Study:

• To report a case of progressive multifocal leukoencephalopathy (PML) in a multiple myeloma patient post-CAR T-cell therapy.
• To discuss the potential link between CAR T-cell therapy-induced immunosuppression and opportunistic infections like PML.
• To review current and needed treatment strategies for PML in immunocompromised patients.

Main Methods:

• Case report presentation of a patient with refractory multiple myeloma treated with ciltacabtagene autoleucel.
• Clinical observation and diagnostic workup for opportunistic central nervous system infections post-therapy.
• Literature review on PML pathogenesis, risk factors, and treatment in the context of CAR T-cell therapy.

Main Results:

• A patient treated with ciltacabtagene autoleucel for refractory multiple myeloma developed PML approximately two months after therapy.
• The case illustrates the potential for PML development in immunocompromised patients, possibly linked to persistent B-cell aplasia and hypogammaglobulinemia.
• Current PML treatments primarily focus on immune reconstitution, but established strategies remain limited.

Conclusions:

• CAR T-cell therapy, while effective, necessitates vigilance for opportunistic infections like PML due to profound immunosuppression.
• Persistent B-cell aplasia and hypogammaglobulinemia may contribute to the risk of PML following CAR T-cell treatment.
• Further research is crucial to establish effective treatment protocols for PML in the setting of advanced cancer immunotherapies.