Long-term persistence of intrathecal viral antibody responses in postinfectious diseases of the central nervous system and in Rett syndrome.

Twenty patients: seven with herpes simplex virus encephalitis (HSVE), six with other severe central nervous system (CNS) infections and 7 with Rett syndrome were studied to determine whether they showed any intrathecal synthesis of virus-specific or total IgG in CNS. The study of the postinfectious patients was made a mean of 20 years after the primary infection in childhood. Four of seven patients with HSVE had an elevated IgG index and four showed intrathecal viral antibody production which was both specific (against HSV) and non-specific. One patient with congenital syphilis and one with tuberculotic meningitis showed non-specific intrathecal viral antibody synthesis. In three of seven patients with Rett syndrome intrathecal antibody production was observed. The clarification of the mechanism of polyclonal immunoactivation in postinfectious diseases would be of interest since similar persistent immunoactivation is a common feature in multiple sclerosis. In Rett syndrome the immunoactivation may also have pathogenetic significance.