Progressive Multifocal Leukoencephalopathy: In Situ JC Viral Detection with Terminally Biotin-Labeled, Site Specific Oligonucleotide Probes

AbstractWe describe a classic case of progressive multifocal leu- koencephalopathy (PML) proven by histologic, ultrastruc- tural, and immunocytochemical analysis in a 58 yo female with a history of deteriorating neurologic status and a brain mass observed on magnetic resonance imaging. The presence of JC viral genomes was confirmed by a rapid 70 min automated in situ DNA hybridization assay utilizing either commercially available, nick translated, whole genomic DNA probes or site specific, synthetic 3′ multibiotinylated 18 meroligonucleotide probes constructed to hybridize with the JC virus tandem repeat or agnoprotein gene regions. All probes localized JC virus genomes in the nuclei of enlarged, swollen oligodendrocytes and rare bizarre astrocytes, but the oligonucleotide probes showed stronger hybridization signals when the probe concentrations were equalized. The most potent in situ hybridization signals were obtained when a nonsense 15 mer composed of 5 repeating units of the sequence 5′-TAG-3′ was ad...