Immune profiling of a patient with alemtuzumab-associated progressive multifocal leukoencephalopathy

• Published in: Multiple sclerosis Vol. 25; no. 8; p. 1196
• Main Authors: Gerevini, Simonetta, Capra, Ruggero, Bertoli, Diego, Sottini, Alessandra, Imberti, Luisa
• Format: Journal Article
• Language: English
• Published: England 01.07.2019
• Subjects: Adult; Alemtuzumab - adverse effects; Female; Humans; Immunologic Factors - adverse effects; Leukoencephalopathy, Progressive Multifocal - chemically induced; Multiple Sclerosis - drug therapy; TRECs; KRECs; T-cell receptor repertoire; alemtuzumab; B-cell receptor repertoire; PML
• ISSN: 1477-0970
• DOI: 10.1177/1352458519832259

A 31-year-old woman affected by multiple sclerosis (MS) experienced generalized tonic-clonic seizures 2 months after the second alemtuzumab cycle. Positive JC virus (JCV)-DNA in cerebrospinal fluid (CSF) and lesion iconography at magnetic resonance imaging (MRI) were suggestive of progressive multifocal leukoencephalopathy (PML). After 1 month, during full-blown immune reconstitution inflammatory syndrome, JCV-DNA became negative and symptoms gradually improved. New T- and B-cell output and T- and B-cell diversity were low and lymphocytes poorly responded to stimulation. This is the first case of an alemtuzumab-treated patient with clinical symptoms and radiological features compatible with PML. The lack of large T- and B-cell diversity, necessary for JCV recognition, is likely to have concurred to PML insurgence.