Detection of herpes simplex virus DNA by polymerase chain reaction in the cerebrospinal fluid of patients with viral meningoencephalitis using primers for the glycoprotein D gene.

A novel set of primers for polymerase chain reaction (PCR) which amplified the portion of US6 sequence coding for the main type-common neutralizing epitope of glycoprotein D (gD) was used for detection of herpes simplex virus (HSV) DNA in 44 cerebrospinal fluid (CSF) samples from 29 patients with clinical symptoms of viral meningitis or meningoencephalitis. The primers in question amplified the DNA of 9 out of 10 low-passage HSV-1 isolates and of 5 out of 10 HSV-2 low-passage isolates as well as the DNA of all laboratory strains examined when tested in the supernatant fluid of infected cells cultures. The PCR was positive in 5 CSF samples (taken on days 2, 4, 8, 10 and 56 after the onset of symptoms, but not later than day 8 after starting acyclovir (ACV) therapy) obtained from 4 patients with intrathecal antibody response. The PCR was repeatedly negative in CSF of 15 patients who had antibodies to HSV in serum and CSF, but did not show intrathecal antibody production. It was also negative in 10 patients who had no HSV antibodies in CSF. Our results confirmed that positive PCR for HSV DNA in the CSF is an indication for starting and/or continuing ACV therapy even in the absence of classical symptoms of HSV encephalitis.