Carson KR, Evens AM, Richey EA et al.
Northwestern University, Chicago, IL, USA
Blood 2009;113:4834–40.
Editor’s note: JC polyoma virus (JCV) infection is endemic, affecting over 90% of adults. In the presence of immuno-compromise – such as advanced HIV, intensive chemotherapy, or congenital immuno-deficiency – reactivation can occur, resulting in a demyelinating disease of the central nervous system (CNS) that is usually fatal. PML has now been associated with two novel immunomodulatory drugs: natalizumab, an antibody directed against α4 integrin and used in the treatment of multiple sclerosis, and rituximab, an antibody against CD20 and employed in hematological malignancies and autoimmune diseases.