Intrathecal synthesis of specific IgG in syphilitic patients with human immunodeficiency virus 1 infection.

Intrathecal synthesis of immunoglobulin G (IgG) specific to Treponema pallidum, ssp. pallidum, or to the human immunodeficiency virus 1 (HIV-1) was investigated in patients with contemporary treponemal and HIV-1 infections. Using a T. pallidum and an HIV-1 IgG enzyme-linked immunosorbent assay, specific antibody units per milligram of total IgG were estimated in serum and cerebrospinal fluid (CSF) of 13 patients infected with both agents. Synthesis of anti-treponemal IgG in the central nervous system (CNS) was shown in three and of anti-HIV-1 IgG in nine patients with neurological disorders. It is concluded that a differentiation of local IgG immune response in the CNS to one or both infectious agents is possible.