Interruptions to tenofovir-based antiretroviral therapy (ART) among people living with HIV and hepatitis B virus (HBV) co-infection are common in the United States, yet monitoring for HBV reactivation during these interruptions remains suboptimal, according to a study published in EMJ Reviews.
Researchers analyzed electronic health records of 5,343 individuals with HIV and HBV who experienced 6,252 tenofovir interruptions – encompassing both tenofovir disoproxil fumarate and tenofovir alafenamide – between January 1, 2015 and December 31, 2022. The study categorized patients by their risk of HBV reactivation: high (HBsAg positive), moderate (HBsAg negative/HBcAb positive/HBsAb negative), and low (HBsAg negative/HBcAb positive/HBsAb positive).
The analysis revealed that 11% of interruptions occurred in high-risk patients, 19% in moderate-risk patients, and 69% in low-risk patients. While alanine transaminase (ALT) testing was performed during nearly all interruptions, HBV DNA and HBsAg testing were significantly less frequent, particularly in the moderate and low-risk groups. Specifically, HBV DNA testing occurred in 52% of high-risk interruptions, 8% of moderate-risk interruptions, and 5% of low-risk interruptions. HBsAg testing rates were 25%, 31%, and 28% respectively.
The overall HBV reactivation rate was 9.59 per 100 person-years among high-risk individuals (95% confidence interval: 7.91-11.64). This rate decreased substantially in moderate-risk (0.58 per 100 person-years; 95% CI: 0.36, 0.91) and low-risk (0.04 per 100 person-years; 95% CI: 0.02, 0.11) groups. The incidence of HBV reactivation accompanied by a hepatitis flare was lower across all risk categories, with the high-risk group experiencing a rate of 3.06 per 100 person-years (95% CI: 2.19-4.29).
“HBV reactivation rates were highest among the high-risk group, but much lower among the moderate-risk and low-risk groups,” the study authors wrote in the PubMed abstract. They also noted that the low frequency of HBV monitoring likely resulted in some reactivations being missed.
Laurence Brunet, PhD, of Epividian, and Gerald Pierone, MD, of Whole Family Health Center, contributed to the research. Dr. Brunet has received research funding from Gilead Sciences and the AIDS Healthcare Foundation, while Dr. Pierone has received grants from GSK, ViiV Healthcare, and Abbvie through his institution. Ricky K. Hsu, Karam Mounzer, Megan S. Dunbar, Joshua Gruber, Leland J. Yee, Catherine Frenette, and Gregory P. Fusco also contributed to the study.
The study emphasizes the need for improved HBV monitoring as a standard component of care and cautions against interrupting tenofovir therapy in individuals with HIV and HBV without careful consideration.
