Varicella-zoster-associated encephalitis: detection of specific antibody in cerebrospinal fluid.

Varicella-zoster (VZ) antibody measured by indirect immunofluorescence was used to identify patients with encephalitis due to VZ virus. In 15 of 16 (94%) patients with VZ infection and clinical evidence of central nervous system involvement, VZ antibody was present at a titer of 1:2 or greater in cerebrospinal fluid. In contrast, no VZ antibody was detected in the cerebrospinal fluid of seven patients with VZ infections without clinical signs of central nervous system involvement, nor was any detected in the cerebrospinal fluid of 25 patients with malignant or demyelinating disease or encephalitis due to other viral or toxic agents. All of these patients had detectable serum VZ antibody. Thus, in this study the presence of detectable VZ antibody in cerebrospinal fluid measured by indirect immunofluorescence seemed to correlate with clinical evidence of central nervous system involvement due to this virus.