title: Gadolinium enhancement in brain magnetic resonance imaging in progressive multifocal leukoencephalopathy after natalizumab monotherapy: is it really atypical?
abstract: Progressive multifocal leukoencephalopathy (PML) generally occurs in patients with impaired cellular immunity. Monoclonal antibodies also predispose the patient to PML as they depress the immune system. PML was classically characterized by a lack of inflammation and absence of gadolinium enhancement. However, gadolinium enhancement of PML lesions was first described in HIV-positive patients under therapy. We present a case of gadolinium enhanced PML lesions occuring after natalizumab monotherapy of a relapsing multiple sclerosis. Radiologists must be aware of this particular feature, as confirmation of the diagnostic of PML becomes more challenging. Namely, distinction between starting PML and multiple sclerosis enhanced additional active lesion is difficult and diagnosis must be established by combined analysis of full clinical evolution, brain MRI scans, and polymerase chain reaction of cerebrospinal fluid.
authors.affiliation: Department of Radiology, Hôpital d'Instruction des Armées Percy, 101 Avenue Henri-Barbusse, 92141 Clamart Cedex, France. fx.arnaud@yahoo.fr
authors.forename: F-X
authors.initials: FX
authors.lastname: Arnaud
authors.forename: A
authors.initials: A
authors.lastname: Hissene
authors.forename: D
authors.initials: D
authors.lastname: Métivier
authors.forename: F
authors.initials: F
authors.lastname: Dutasta
authors.forename: O
authors.initials: O
authors.lastname: Berets
authors.forename: B
authors.initials: B
authors.lastname: N'guema
authors.forename: C
authors.initials: C
authors.lastname: A'teriitéhau
authors.forename: J
authors.initials: J
authors.lastname: Baccialone
authors.forename: J
authors.initials: J
authors.lastname: Potet
mesh_terms: D000328:Adult; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects*; D003287:Contrast Media; D005682:Gadolinium; D006801:Humans; D007968:Leukoencephalopathy, Progressive Multifocal / Q000139:chemically induced* / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009103:Multiple Sclerosis / Q000188:drug therapy*; D000069442:Natalizumab
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D003287:Contrast Media; D000069442:Natalizumab; D005682:Gadolinium