ANALYSIS OF PCR AS A TOOL FOR DETECTION OF JC VIRUS-DNA IN CEREBROSPINAL-FLUID FOR DIAGNOSIS OF PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY

Two polyomaviruses, JC virus (JCV) and BK virus (BKV), affect humans, JCV is the causative agent of progressive multifocal leukoencephalopat hy (PML), and detection of JCV in the central nervous system (CNS) is a prerequisite for confirmation of the disease. BKV is generally not a ssociated with neurological disease, but involvement of BKV in patient s with CNS disorders has been reported. In the present study polyomavi rus DNA was detected by a nested PCR at a sensitivity corresponding to the detection of 10 copies of JCV DNA in 10 mu l of cerebrospinal flu id (CSF), CSF samples from 212 patients with neurological symptoms and immunodeficiencies were investigated for the presence of polyomavirus DNA. Of 128 human immunodeficiency virus (HIV)-infected patients, 14 (11%) had JCV DNA in their CSF, and all 14 patients had clinical PML. BKV DNA was detected in one HIV-infected patient with neurological sym ptoms not compatible with PML. Among 84 HIV-negative patients, 6 (7%) had detectable JCV DNA in their CSF, confirming PML in patients with c linical conditions of T-cell lymphoma, chronic lymphatic leukemia, sta tus postliver transplantation, congenital immunodeficiency, sarcoidosi s, and immunodeficiency of unknown origin. The specificity of the PCR was confirmed by a clinical follow-up study which showed full agreemen t between the detection of JCV DNA in CSF and clinically manifest PML. The described PCR is a rapid, reproducible, and easily performed assa y.