POLYMERASE CHAIN-REACTION IN THE INVESTIGATION OF RELAPSE FOLLOWING HERPES-SIMPLEX ENCEPHALITIS

Five cases of apparent relapse of herpes encephalitis were investigate d. All patients recovered after antiviral and corticosteroid therapy. Samples of CSF taken from the patients at intervals through the initia l and subsequent encephalitic episode were examined. PCR amplification of a 351 bp sequence from the Herpesvirus simplex (HSV) thymidine kin ase gene demonstrated the presence of HSV DNA in CSF taken during the initial encephalitic illness but not during the second encephalitic ep isode. Intrathecal synthesis of HSV antibody (HSV antibody index > 1.9 ) was observed in all cases following the first episode, and there app eared to be no significant increase in intrathecal antibody synthesis in the second episode. High levels of CSF myelin basic protein were fo und during the acute phases of both the initial and the subsequent enc ephalitic illnesses. These data suggest that at least in our series of five patients, relapse following HSE may not be due to active viral r eplication. (C) 1996 Wiley-Liss, Inc.