[Comment] Understanding risk of PML through multiple sclerosis

Progressive multifocal leukoencephalopathy (PML), first described in 1959, is an often-fatal disease caused by an opportunistic infection by JC virus (JCV), which most human beings carry throughout life without consequences.1,2 PML was a major cause of death in patients with AIDS, but its prevalence decreased sharply with the introduction of retroviral therapy. PML is now mostly seen in patients during chemotherapy or immunosuppression. The first PML cases in patients with multiple sclerosis who were treated with natalizumab came as a surprise in 20053,4 because PML had not been observed with other drugs for multiple sclerosis (interferon β and glatiramer acetate) and because, except for an autoimmune reaction against CNS tissue, patients with multiple sclerosis are immunologically healthy, cope well with infections, and show no increased risk of malignancies.
Source: Lancet Neurology - Category: Neurology Authors: Tags: Comment Source Type: research