Detection of herpes simplex virus and herpes simplex virus-antibodies in encephalitis and similar infectious diseases

ABSTRACT

The purpose of this study was to use the polymerase chain reaction [PCR] technique to detect herpes simplex virus genome in cerebrospinal fluid [CSF], together with enzyme immunoassay and antigen immunoblotting [AIB] to detect antibodies against herpes simplex virus, in 41 patients with encephalitis and similar infectious diseases of the central nervous system. None of the patients had the diagnosis of herpes simplex encephalitis. Cerebrospinal fluid and matched serum specimens were obtained within the first week of clinical symptoms. Oligoclonal IgG bands were found by isoelectric focusing in the cerebrospinal fluid of 20/41 patients of whom 9 had local synthesis and 11 had a systemic immune response. Antibody specific to herpes simplex virus was found by enzyme-linked immunosorbent assay [ELISA] in 10/33 patients tested. Herpes simplex virus-specific antibodies were found in the cerebrospinal fluid by antigen immunoblotting in 5/31 patients investigated, but these were of low affinity. There was no correlation between findings on ELISA and either the clinical diagnosis, the presence of oligoclonal IgG by isoelectric focusing, or the detection of specific antibodies by antigen immunoblotting. Careful interpretation of specific antibodies is necessary for they may result from non-specific activation by an unrelated agent. Polymerase chain reaction for herpes simplex virus deoxyribonucleic acid [DNA] may be used to help in the diagnosis of early cases of HSE and should also be considered in cases presenting with atypical clinical features and inconclusive results from laboratory tests