Reactivity of locally produced CSF antibodies in patients with neurosyphilis against antigens of Treponema pallidum

The reactivity and specificity of locally produced cerebrospinal fluid (CSF) antibodies against antigens of Treponema pallidum were assessed by Western blotting in patients with clinical signs of parenchymal or meningovascular neurosyphilis. All nine patients showed local production of treponeme-specific antibodies in the central nervous system (CNS). In most of the patients serum and CSF antibodies were bound to the same antigens: the common treponemal 48/45 kDa protein and the putative specific T. pallidum protein in the range of 12-14 kDa. In some patients the intensity of staining obtained by CSF antibodies was higher than that derived from serum, indicating locally produced antibodies. In contrast to other more acute inflammatory CNS diseases, no expanded or different antigen binding of the CSF antibodies compared with serum antibodies was found in neurosyphilic patients. The results presented are discussed with regard to the role of the blood-brain barrier in antibody concentrations of CSF and serum.