Progressive Multifocal Leukoencephalopathy and Rituximab: Time to Better Stratify the Risk?

Abstract

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease emerging as a complication of some novel monoclonal antibody therapies. Disease risk and severity show a wide variability, with fatality ranging from 30% to 90%, probably depending on many risk determinants as demonstrated for natalizumab-associated PML. Rituximab therapy is used to treat hematological malignancies and autoimmune disease, but little is known about PML risk stratification and management. We describe a clinical case with very early diagnosis, extensive treatment, but a fatal outcome, highlighting the need for future studies aimed to better understand PML risk.