Natural experiment of syphilis treatment with doxycycline or benzathine penicillin in HIV-infected patients.

BACKGROUND: Although doxycycline is widely used as an alternative to benzathine penicillin for the treatment of early and late latent syphilis, data on serological response following treatment with doxycycline among HIV-infected patients are limited. METHODS: In this study, we analysed serological response to syphilis treatment with doxycycline among HIV-infected patients treated during a benzathine penicillin shortage period and compared with treatment response among patients treated with benzathine penicillin. Cases with neurosyphilis and those treated with suboptimal doses or with concurrent medications in association with benzathine penicillin or doxycycline were excluded. RESULTS: Fifty patients treated with doxycycline from September 2014 to December 2016 were compared with 115 patients treated with benzathine penicillin for early, late latent or latent syphilis of unknown duration. Patients treated with doxycycline were slightly older [(median 49 years old, 95% confidence interval (95% CI) 43-56] than those in the penicillin group (median 44 years old, 95% CI 37-50; P = 0.007). Groups had no statistically significant differences regarding sex, HIV suppression under treatment and syphilis stages. Serological response to treatment, defined as a nonreagent Venereal Disease Research Laboratory (VDRL) or at least a four-fold reduction in VDRL titres measured 6-12 months after treatment, was seen in 72% (95% CI 58-84) of patients treated with doxycycline and 70% (95% CI 60-78) of patients treated with penicillin (P = 0.753). CONCLUSION: We found no statistically significant differences in serological response to treatment with doxycycline or benzathine penicillin among HIV-infected patients with early, late latent or latent syphilis of unknown duration. Our findings suggest that doxycycline is an acceptable treatment to HIV-infected patients with nontertiary stages of syphilis.

Asymptomatic anorectal Chlamydia trachomatis and Neisseria gonorrhoeae infections are associated with systemic CD8+ T-cell activation.

BACKGROUND: Oral preexposure prophylaxis (PrEP) has been established as a pivotal strategy in HIV prevention. However, bacterial sexually transmitted infections (STIs), such as Chlamydia trachomatis and Neisseria gonorrhoeae, are also highly prevalent. Although the presence of STI-related mucosal lesions is a known risk factor for HIV acquisition, the potential increase in risk associated with asymptomatic STIs is not completely understood. Recent data demonstrated higher T-cell activation is a risk factor for sexually acquired HIV-1 infection. We examined the effect of asymptomatic C. trachomatis and N. gonorrhoeae anorectal infection on systemic immune activation, potentially increasing the risk of HIV acquisition. METHODS: We analyzed samples from participants of PrEP Brasil, a demonstration study of daily oral emtricitabine/tenofovir disoproxil fumarate HIV PrEP among healthy MSM, for T-cell activation by flow cytometry. We included 34 asymptomatic participants with anorectal swab for C. trachomatis and/or N. gonorrhoeae infection, whereas negative for other STIs, and 35 controls. RESULTS: We found a higher frequency of human leukocyte antigen DRCD38 CD8 T cells (1.5 vs. 0.9%, P < 0.005) and with memory phenotype in the group with asymptomatic C. trachomatis and/or N. gonorrhoeae infection. Exhaustion and senescence markers were also significant higher in this group. No difference was observed in the soluble CD14 levels. CONCLUSION: Our findings suggest asymptomatic anorectal C. trachomatis and/or N. gonorrhoeae increase systemic immune activation, potentially increasing the risk of HIV acquisition. Regular screening and treatment of asymptomatic STIs should be explored as adjuvant tools for HIV prevention.