Polymerase chain reaction for detection of JC virus DNA in cerebrospinal fluid: a quality control study. European Union Concerted Action on Viral Meningitis and Encephalitis.

The sensitivity and specificity of PCR of CSF for the diagnosis of progressive multifocal leuko encephalopathy is estimated at 75 and 98.5%, respectively. However, inter-laboratory and inter-technique variations have been shown to produce wide variations. A 10-fold dilution series of JC virus in cerebrospinal fluid was prepared and circulated for 'blind' evaluation in laboratories participating in a European Union Concerted Action on Virus Meningitis and Encephalitis. Six of seven laboratories returned results with sensitivity of between 10 and 1 JCV DNA copy equivalents per 10 microl of CSF, one laboratory detected 10(5) copies per 10 microl of CSF. These results demonstrate the feasibility of using virus diluted in CSF for comparison of PCR techniques, and that the range of sensitivity of JCV PCR in proficient laboratories is between 10 and 1 copy equivalents per 10 microl of CSF.