title: Reduced Treponema pallidum-Specific Opsonic Antibody Activity in HIV-Infected Patients With Syphilis.
abstract: BACKGROUND
  Human immunodeficiency virus (HIV)-infected individuals may have poorer serological responses to syphilis treatment and may be more likely to experience neurosyphilis. Treponema pallidum is cleared from sites of infection by opsonization, ingestion, and killing by macrophages.
  
  
  METHODS
  Serum samples from 235 individuals with syphilis were tested for T. pallidum-specific opsonic activity. Blood T. pallidum concentrations were determined by real-time polymerase chain reaction amplification of the tp0574 gene, and T. pallidum was detected in cerebrospinal fluid (CSF) by reverse-transcriptase polymerase chain reaction of 16S ribosomal RNA.
  
  
  RESULTS
  Opsonic activity was higher with higher serum rapid plasma reagin titers (P < .001), and in those treated for uncomplicated syphilis before serum collection (P < .001). Opsonic activity was lower in HIV-infected than in HIV-uninfected individuals even after the above factors were taken into account (P = .006). In participants in whom blood T. pallidum was detectable, those with the highest opsonic activity had lower blood T. pallidum concentrations. In multivariable analyses, there was not a significant relationship between opsonic activity and detection of T. pallidum in CSF or CSF-VDRL reactivity.
  
  
  CONCLUSIONS
  Serum T. pallidum-specific opsonic activity is significantly lower in HIV-infected individuals. Impaired T. pallidum-specific immune responses could contribute to differences in the course of disease or treatment response.
authors.affiliation: Department of Neurology Department Medicine (Infectious Diseases).
authors.forename: Christina M
authors.initials: CM
authors.lastname: Marra
authors.affiliation: Department of Neurology.
authors.forename: Lauren C
authors.initials: LC
authors.lastname: Tantalo
authors.affiliation: Department of Neurology.
authors.forename: Sharon K
authors.initials: SK
authors.lastname: Sahi
authors.affiliation: Department Medicine (Infectious Diseases).
authors.forename: Shelia B
authors.initials: SB
authors.lastname: Dunaway
authors.affiliation: Department Medicine (Infectious Diseases) Department Global Health, Harborview Medical Center, University of Washington, Seattle.
authors.forename: Sheila A
authors.initials: SA
authors.lastname: Lukehart
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009895:Opsonin Proteins / Q000097:blood*; D013587:Syphilis / Q000150:complications* / Q000453:epidemiology*; D014210:Treponema pallidum / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D009895:Opsonin Proteins
keywords: immune response; neuroinvasion; neurosyphilis; opsonic antibody; syphilis