Reduced Rate of Diagnostic Positive Detection of JC Virus DNA in Cerebrospinal Fluid in Cases of Suspected Progressive Multifocal Leukoencephalopathy in the Era of Potent Antiretroviral Therapy

Fifty-nine human immunodeficiency virus (HIV)-infected patients with suspected progressive multifocal leukoencephalopathy and 224 controls were tested for JC virus (JCV) DNA in cerebrospinal fluid by PCR. The diagnostic positive detection rate dropped from 89.5% (95% confidence intervals of 75.5 to 103.5%) in the pre-highly active antiretroviral therapy (HAART) era to 57.5% (95% confidence intervals of 42.1 to 72.9%) in the HAART era; the specificity remained unchanged. Predictors of failure to detect JCV DNA were exposure to HAART at disease onset and higher CD4 counts.