Estimation of the local production of antibodies to Treponema pallidum in the central nervous system of patients with neurosyphilis.

In 76% of 149 patients with neurosyphilis local production of treponema-specific IgG antibodies in the central nervous system (CNS) was determined by estimating the cerebrospinal fluid (CSF)-to-serum ratio of TPHA-IgG titre per mg total IgG. With this formula synthesis of treponema-specific IgG antibodies in the CNS could be detected independently of the function of the blood-CSF barrier. A selective increase of total IgG in the CSF was not found in all cases. Forty-three patients with adequately treated or spontaneously resolved syphilis without clinical evidence of involvement of the CNS by Treponema pallidum served as controls.