AMSTERDAM—Early diagnosis through enhanced clinical vigilance and optimal management of progressive multifocal leukoencephalopathy (PML) may improve outcomes, according to data presented at the ECTRIMS/ACTRIMS 5th Joint Triennial Congress. Survival rates in excess of 80% were seen in the first 133 postmarketing natalizumab-associated PML cases, reported Ludwig Kappos, MD, from the Departments of Neurology and Biomedicine, University Hospital, Basel, Switzerland, and colleagues. Improved survival was associated with younger age (median 43 versus 51.5) and less disability (median EDSS 4.0 versus 5.5) at diagnosis, shorter time from symptom onset to diagnosis (mean 40 versus 53 days), and more localized disease on brain MRI, as compared with fatal cases.
Of 159 PML cases identified in the post-marketing setting, 130 patients were still alive as of September 1, 2011 (82% survival rate). In survivors with more than six months of follow-up, 13% had mild disability, 47% had moderate disability, and 40 % had severe disability.