title: Predictors of serological failure after treatment in HIV-infected patients with early syphilis in the emerging era of universal antiretroviral therapy use.
abstract: BACKGROUND
  The optimal treatment of early syphilis (primary, secondary and early latent) in HIV-infected patients remains controversial. The Center for Diseases Control STD Treatment Guidelines recommended 1 dose of benzathine penicillin G (BPG) regardless of HIV infection. However, many providers modify the treatment for early syphilis.
  
  
  METHODS
  We performed a retrospective chart review of all cases of early syphilis with positive serologic test results in HIV-infected patients from May 2006 to May 2011 in 2 large, urban HIV clinics. Early syphilis includes primary, secondary, and early latent syphilis. Serological failure was defined as a lack of 4-fold decrease in rapid plasma reagent (RPR) titers 9 to 12 months after syphilis treatment. Patients whose RPR titers decreased after treatment and subsequently increased 4-fold at 9 to 12 months were excluded from the analysis of serological response because of possibility as "reinfection". Baseline characteristics were tested as predictive factors of serological failure using a univariate and multivariate logistic regression model, respectively.
  
  
  RESULTS
  Of 560 patients with confirmed cases of early syphilis, 51 (9.0%) experienced serological failure. Multivariate logistic regression modeling demonstrated that the predictive factors associated with serological failure after early syphilis treatment were baseline RPR titer ≤ 1:16 (OR 3.91 [95% CI, 2.04-7.47]), a previous history of syphilis (OR 3.12 [95% CI, 1.55-6.26]), and a CD4 T-cell count below 350 cells/ml (OR 2.41 [95% CI, 1.27-4.56]). Of note, type of syphilis treatment (1 dose versus 3 doses of BPG) did not appear to affect the proportion of serological failure (4% versus 10%, P = 0.29), however the power of this study to detect small differences was limited.
  
  
  CONCLUSIONS
  HIV-infected patients with baseline RPR titer ≤1:16, syphilis history, and/or a CD4 T-cell count <350 cells/ml should be closely monitored for serologic failure after early syphilis treatment. This study did not detect a substantial difference between treatment with > 1 dose of BPG and decreased frequency of serological failure, supporting the current recommendation that one dose of BPG is adequate treatment for early syphilis in HIV-infected patients.
authors.affiliation: Department of Medicine, AIDS Healthcare Foundation, Los Angeles, CA USA. sadaoj@gmail.com.
authors.forename: Sadao
authors.initials: S
authors.lastname: Jinno
authors.forename: Bryan
authors.initials: B
authors.lastname: Anker
authors.forename: Parveen
authors.initials: P
authors.lastname: Kaur
authors.forename: Claire C
authors.initials: CC
authors.lastname: Bristow
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Klausner
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000188:drug therapy* / Q000276:immunology*; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D016903:Drug Monitoring; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010401:Penicillin G Benzathine / Q000627:therapeutic use*; D012189:Retrospective Studies; D012698:Serologic Tests; D013587:Syphilis / Q000188:drug therapy* / Q000276:immunology; D016896:Treatment Outcome
chemical_list: D019380:Anti-HIV Agents; D010401:Penicillin G Benzathine