JC VIRUS (JCV) GENOTYPES IN BRAIN-TISSUE FROM PATIENTS WITH PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY (PML) AND IN URINE FROM CONTROLS WITHOUT PML - INCREASED FREQUENCY OF JCV TYPE-2 IN PML

Progressive multifocal leukoencephalopathy (PML) is caused by the huma n polyomavirus JC (JCV), and there are at least 4 different genotypes of JCV in the United States, Type 1 strains are of European origin, wh ereas type 2 and 3 strains are of Asian and African origin, respective ly, JCV type 4 strains are derived from a type 1/3 recombinant, In thi s study, the genotype distribution of JCV strains found in brain tissu e or cerebrospinal fluid of 50 PML patients was compared with JCV geno types excreted in the urine of 103 control subjects, Type determinatio n was based on the polymerase chain reaction-amplified partial sequenc e of the VP1 coding gene and the noncoding region left of ori, Brain t issues from patients with PML were infected with a significantly highe r proportion of JCV type 2 strains than were urine samples from the co ntrol group (P = .004), This evidence indicates a biologic difference between JCV genotypes and suggests a difference in their potential to cause PML.