[Immunologic response in herpes encephalitis: development of the antibody serum/cerebrospinal fluid ratio in 13 cases].

Serological monitoring was performed in 13 cases of herpetic encephalitis (one infant and 12 adults). Samples taken simultaneously from blood and cerebrospinal fluid (CSF) were tested before and after initiation of antiviral treatment. Antiherpesvirus (anti-HSV) antibodies were assayed by an ELISA method. The state of the blood-brain barrier was controlled by assaying other antiviral antibodies. Immune response was studied during the 3-to-4 weeks of the course of the infection. Anti-HSV IgG levels in CSF increased markedly after 12 days. At the same time, antibody serum/CSF ratios dropped below a value of 20, indicating intrathecal secretion of the antibody. Based on results in monitoring these 13 cases, it may be suggested that 3 samples of serum and CSF are required to confirm the herpetic etiology, including 2 samples taken during the second week of the course of encephalitis.