Acute syphilitic meningitis in a man with seropositivity for human immunodeficiency virus infection and normal numbers of CD4 T lymphocytes.

Coinfection with the human immunodeficiency virus (HIV) and Treponema pallidum may predispose to accelerated neurosyphilis. The mechanism underlying this interaction is undefined, but usually presumed to result from HIV-induced suppression of cell-mediated immunity as reflected in the CD4 T-lymphocyte count. We report a patient infected with HIV who developed aggressive neurosyphilis despite a CD4 count of 1000/mm3. The CD4 cells constituted 17% of his total lymphocytes. Our case suggests that while severe neurosyphilis can occur in HIV-infected persons with normal absolute CD4 counts, the percentage of CD4 cells may be a better indicator of the risk of neurosyphilis. These observations are relevant to designing treatment strategies for patients coinfected with HIV and T pallidum based on measures of their immunocompetence.