Christina Marra, MD
Professor, Department of Neurology

Our laboratory investigations focus on syphilis and neurosyphilis. We began a study of neurosyphilis 11 years ago and have enrolled over 800 subjects. The original goal of the study was to test the hypothesis that concomitant HIV infection impairs clearance of Treponema pallidum (the bacterium that causes syphilis) from the cerebrospinal fluid (CSF), thus making central nervous system syphilis less likely to be controlled. The results of our studies support this hypothesis. Individuals with more pronounced HIV-mediated immunosuppression are more likely to have neurosyphilis, and they are less likely to normalize CSF abnormalities after treatment for neurosyphilis.

Our more recent investigations focus on identifying clinical and laboratory features that predict neurosyphilis and its treatment response. These include studies of CSF cellular phenotype, chemokine and cytokine concentrations, and T. pallidum strain types. We are also working on devising simple diagnostic tests for neurosyphilis that can be used in resource-limited settings.