Progressive Multifocal Leukoencephalopathy in a Patient without ImmunodeficiencyAuthor Response

# {#article-title-2} The case report by Tan et al.1 of a 62-year-old man with progressive multifocal leukoencephalopathy (PML) without immunodeficiency was interesting given our experience with AIDS-related PML and current literature.2 The authors assume that their patient's disease was due to reactivation of latent JC virus infection caused by a transient dysfunction of cellular immunity triggered by another subclinical viral infection such as parvovirus B19. …