Is JC polyoma virus the cause of ulcerative colitis and multiple sclerosis?

JC polyoma virus (JCV) is known to be the cause of the degenerative central nervous system white matter disease progressive multifocal leucoencephalopathy. Recently, JCV DNA has unexpectedly been found in significant quantity in normal colon mucosa and in tissue from colonic carcinomas, with increased quantities in the cancerous tissues. The yield of JCV DNA was increased by use of topoisomerase I, possibly because the JCV DNA was negatively supercoiled. The causes of ulcerative colitis tin which colon cancer is common) and multiple sclerosis are not known. Here I suggest that JCV may play a role in the pathogenesis of these diseases, and discuss methods for testing this hypothesis. (C) 2000 Harcourt Publishers Ltd.