Effect of tenofovir-based HIV pre-exposure prophylaxis against HBV infection in men who have sex with men

Abstract

Background and Aims: Men who have sex with men (MSM) are vulnerable to contracting HBV as a sexually transmitted infection. We evaluated the incidence of HBV infection (HBI) and the prophylactic effect of tenofovir-based pre-exposure prophylaxis (PrEP) on HBI in an MSM cohort. Methods and Results: MSM who were older than 16 years were enrolled from January 2018 and followed up until June 2021 and tested for HIV, bacterial sexually transmitted infections, and HBsAg/ HBsAb and HBcAb every 3 months based on inclusion criteria, including HBsAg, HBcAb, HBsAb, and HIV negativity at enrollment. HBI was defined as seroconversion of HBsAg or HBcAb status. The log-rank test was used to evaluate the prophylactic effect of PrEP against HBI. As a substudy, individuals excluded from the main study due to HBs Ab positivity were evaluated for HBI incidence. Among 1577 MSM, 786 participants (546 PrEP nonusers, 131 daily PrEP users, and 109 event-driven PrEP users) met the criteria and were included. The annual incidence of HBV among PrEP nonusers (3.8%, 21 infections, with 559.5 person-years) was significantly higher (p = 0.018, log-rank test) than that among daily PrEP users [0.77%, 1 infection (admitted nonadherence), with 129.3 person-years] and event-driven PrEP users (no infection with 93.8 person-years). Although the incidence of HBI and HIV infection decreased with PrEP use, the incidence of other sexually transmitted infections was higher in both daily and event-driven PrEP users. The annual incidence of HBV among HBsAb-positive and HBcAb-negative PrEP nonusers was 1.8% (3 infections, with 167.5 person-years). Conclusions: Tenofovir-based PrEP prevented HBI among MSM in a real-world setting.

Reply: Effect of tenofovir-based HIV pre-exposure prophylaxis against HBV infection in men who have sex with men

“…To the editor, We appreciate Hung and colleagues' interest in our article that examined the effect of tenofovir-based HIV pre-exposure prophylaxis (PrEP) against HBV infection in men who have sex with men (MSM). [1] We also thank them for highlighting several limitations in our study and particularly for raising a reasonable question on the prophylactic effect of PrEP against HBV.…”

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To the editor, We appreciate Hung and colleagues' interest in our article that examined the effect of tenofovir-based HIV pre-exposure prophylaxis (PrEP) against HBV infection in men who have sex with men (MSM). [1] We also thank them for highlighting several limitations in our study and particularly for raising a reasonable question on the prophylactic effect of PrEP against HBV.First, they argued the possibility of a false positive result in 3 MSM defined as HBV infection based on anti-HBc antibody alone and required HBV DNA tests for them. Although HBV DNA measurements were unavailable, this serological characteristic tends to be a true positive rather than a false positive among high-risk MSM.

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Letter to the Editor: Effect of tenofovir-based HIV pre-exposure prophylaxis against HBV infection in men who have sex with men

“…According to the article, the 22 participants who developed HBV infection were characterized. Among them, 3 (13.6%; case 5, case 6, and case 21) were positive for anti-HBc antibody alone and negative for both anti-HBs antibody and HBsAg 1 . The serologic finding of anti-HBc positivity alone could possibly be attributed to a previous HBV infection or a false-positive result, especially in those without risk factors for HBV infection in countries with low HBV prevalence 2 .…”

“…We read with great interest the article “Effect of tenofovir-based HIV pre-exposure prophylaxis against HBV infection in men who have sex with men” by Mizushima Daisuke et al 1 We appreciate the authors’ efforts to demonstrate the prophylactic effect of tenofovir-based pre-exposure prophylaxis against HBV infection among men who have sex with men in a real-world setting. However, we believe that certain issues need to be addressed to strengthen the conclusions of the study.…”

Preventing 2 viral infections with 1 tablet

“…In this issue, Mizushima et al 8 demonstrated in a real-world setting that TFV-based PrEP prevented incident HBV infections among HIV-negative MSM at a high risk. In this study, the serologic markers of HBV (HBsAg; HBcAb, and HBsAb) were prospectively tested every 3 months along with tests for HIV and other bacterial STIs, which could ensure a more precise and frequent detection of asymptomatic infections.…”