Comparisons of Serologic Responses of Early Syphilis to Treatment with a Single-Dose Benzathine Penicillin G Between HIV-Positive and HIV-Negative Patients.

Abstract

INTRODUCTION:

Poorer serologic responses of early syphilis to treatment have been inconsistently reported in HIV-positive patients compared with HIV-negative patients, but the interpretation of previous studies is limited by discrepant study designs. The present study aimed to evaluate the effect of HIV infection on the treatment response to a single dose of benzathine penicillin G (BPG) for early syphilis.

METHODS:

From January 2015 to March 2020, adult patients with early syphilis who received a single dose of BPG were enrolled and rapid plasma reagin (RPR) titers were periodically determined. The primary outcome was serologic response, defined as at least a fourfold decline of RPR titer at 12 months of BPG treatment compared with that at baseline, which was examined in the intention-to-treat (ITT) and per-protocol analyses. Treatment failure included lack of at least a fourfold decline in RPR titers and at least a fourfold increase in RPR titers.

RESULTS:

We prospectively enrolled 184 HIV-positive and 68 HIV-negative participants with early syphilis, who were all men who have sex with men, with a higher proportion of previous syphilis (70.1%) and early latent syphilis (64.1%) among HIV-positive participants. In the ITT with last-observation-carried-forward analysis, HIV-positive participants had a significantly lower serologic response rate at 12 months of treatment than HIV-negative participants (73.4% vs. 91.2%). Of HIV-positive participants, 12.5% failed to achieve at least fourfold decline in RPR titers and 14.1% had at least a fourfold increase in RPR titers. The factors associated with 12-month serologic response were HIV infection (adjusted odds ratio [AOR] 0.33; 95% confidence interval [CI] 0.13-0.81) and RPR titer (per 1-log2 increase, AOR 1.36; 95% CI 1.23-1.51).

CONCLUSION:

HIV-positive patients with early syphilis had poorer serologic responses to BPG treatment than HIV-negative patients during a 12-month follow-up period.

• Authors: Kuan-Yin Lin, Chia-Jui Yang, Hsin-Yun Sun, Yu-Chung Chuang, Lan-Hsin Chang, Wen-Chun Liu, Yi-Ching Su, Sui-Yuan Chang, Chien-Ching Hung, Shan-Chwen Chang
• Journal: Infectious diseases and therapy (Infect Dis Ther) Vol. 10 Issue 3 Pg. 1287-1298 (Sep 2021) ISSN: 2193-8229 [Print] New Zealand
• PMID: 33948910 (Publication Type: Journal Article)
• Copyright: © 2021. The Author(s).