Central nervous system involvement in early syphilis. Part 1. Intrathecal immunoglobulin production.

The immunological activity in the cerebrospinal fluid (CSF) was studied in 47 patients with early syphilis. The immunoglobulin production within the central nervous system (CNS) was estimated by analysing immunoglobulin G and albumin in CSF and serum and constructing an IgG index according to Tibbling et al. and calculating daily CNS IgG synthesis, according to Tourtellotte. In 10 (21%) of the 47 patients, intrathecal immunoglobulin production was observed. The immunoglobulin production within the CNS was significantly correlated to the presence of syphilis antibodies and to pleocytosis. Eight of the patients demonstrated oligoclonal bands on electrophoresis. Total protein usually did not reveal an increased CNS immunoglobulin production but reflected a blood-brain barrier lesion. One year after penicillin treatment, 2 out of 9 patients still had slight intrathecal immunoglobulin production.