11 November 2013
Nearly 90% of people with chronic hepatitis B virus (HBV) infection in a Spanish group attained an undetectable HBV load after 96 weeks of tenofovir. Response rates did not differ between people with and without HIV infection.
Untreated HIV infection speeds progression of chronic HBV infection. But suppressing HBV replication slows liver damage. The antiretrovirals tenofovir, emtricitabine (FTC), and lamivudine (3TC) have anti-HBV activity. Because evidence on how HIV affects HBV response to tenofovir remains sparse, Spanish researchers conducted this study.
The analysis involved all patients positive for hepatitis B surface antigen (HBsAg) at four clinics in Spain. Of the 176 patients evaluated, 138 (78%) also had HIV infection. Most study participants had taken lamivudine, and nearly half of people with detectable HBV had resistance mutations.
Among 101 people with detectable HBV when they began tenofovir, 78 had HIV infection and 33 did not. Most people who took tenofovir took it coformulated with FTC (Truvada).
Similar proportions of tenofovir-treated people with and without HIV achieved undetectable HBV DNA at weeks 24, 48, and 96 of tenofovir therapy. By week 96 nearly 90% of tenofovir-treated people had undetectable HBV DNA.
HIV/HBV-coinfected people positive for hepatitis B e antigen (HBeAg), which indicates ongoing HBV replication, had a lower response to tenofovir than HBeAg-negative people. But in multivariate analysis, higher pretreatment HBV DNA emerged as the only independent predictor of virologic response to tenofovir. HBeAg status, resistance mutations, or coinfection with hepatitis C or hepatitis delta virus did not affect chances of response to tenofovir in the multivariate analysis.
Source: Zulema Plaza, Antonio Aguilera, Álvaro Mena, Eugenia Vispo, Rocío Sierra-Enguita, Santiago Tomé, José Pedreira, Carmen Rodriguez, Pablo Barreiro, Jorge del Romero, Vicente Soriano, Eva Poveda. Influence of HIV infection on response to tenofovir in patients with chronic hepatitis B. AIDS. 2013; 27: 2219-2224.
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