Papovavirus of JC Type in Progressive Multifocal Leukoencephalopathy

Abstract

A papovavirus of the JC type was identified in the brain of a patient dying of progressive multifocal leukoencephalopathy (PML) complicating chronic lymphocytic leukemia. Rapid antigenic typing of the virus was carried out by fluorescent antibody staining of the brain and by electron microscopic agglutination of virus particles extracted directly from the brain. Subsequently, the virus was isolated from brain tissue in primary cell cultures of human fetal brain. This second association of JC virus with PML confirms that at least two antigenically distinct viruses may cause PML and demonstrates that methods are now available for the rapid identification of the papovaviruses that may be related to the disease.