title: Progressive multifocal leucoencephalopathy in the era of natalizumab: a review and discussion of the implications.
abstract: Progressive multifocal leucoencephalopathy (PML) is an opportunistic demyelinating infection of immunocompromised patients, caused by the human polyomavirus, JC virus. Prior to 2005, PML had not been described in patients with MS. In early 2005, however, two cases of PML were reported in patients with MS treated with the alpha-antegrin inhibitor, natalizumab. A third case was subsequently described in a patient with Crohn's disease who had also received the agent. These three cases resulted in withdrawal of natalizumab from the market and have had major implications for its reintroduction into clinical use. In this review, we discuss current knowledge concerning PML and its causative agent, the possible role of natalizumab in initiating PML in patients with MS, and the challenges posed by the risk of this infection as the drug returns to clinical use.
authors.affiliation: Neurology Service, Veterans Affairs Medical Center, and Department of Neurology, University of Utah Health Sciences Center, Salt Lake City, UT, USA. john.greenlee@hsc.utah.edu
authors.forename: J E
authors.initials: JE
authors.lastname: Greenlee
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D001921:Brain / Q000473:pathology; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D007968:Leukoencephalopathy, Progressive Multifocal / Q000175:diagnosis / Q000188:drug therapy*; D008279:Magnetic Resonance Imaging; D000069442:Natalizumab
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D007155:Immunologic Factors; D000069442:Natalizumab