Coinfection

Tenofovir Usually Suppresses Hepatitis B in HIV/HBV Coinfected People

Tenofovir led to undetectable hepatitis B virus (HBV) levels in 87% of HIV positive coinfected individuals, and a similar proportion maintained viral suppression over 6 years, according to a study described in the June 20 advance edition of Hepatology.

Due to overlapping transmission routes, many people are coinfected with both HIV and HBV. Treatment guidelines recommend that such inidviduals include in their antiretroviral regimen drugs that are active against both viruses, such as tenofovir (Viread), emtricitabine (Emtriva), or lamivudine (3TC or Epivir). Tenofovir and emtricitabine are included in the Truvada, Atripla, Complera, and Stribild coformulations.

Anders Boyd from INSERM in Paris and fellow investigators with the French HIV-HBV Cohort Study looked at hepatitis B outcomes among 111 HIV/HBV coinfected patients on antiretroviral therapy containing tenofovir. Those also treated with entecavir (Baraclude) or pegylated interferon were excluded

Participants were prospectively followed for a median of 6.25 years, receiving HBV DNA viral load, hepatitis B surface antigen (HBsAg), and hepatitis B "e" antigen (HBeAg) measurements at baseline and every 6-12 months thereafter. Genetic sequencing was done for people with persistent HBV viremia to test for drug resistance.

Results

• 96 out of 111 participants (86.5%) achieved virological response (HBV DNA <60 IU/mL) after a median 75 months of follow-up.
• 86 of these 96 people (89.6%) maintained stable undetectable HBV viral load during follow-up.
• The remaining 10 patients (10.4%) had transient "blips" of detectable HBV DNA.
• In this group, all 9 of the patients with available samples had detectable plasma tenofovir levels, indicating good adherence.
• 11 out of 111 (9.9%) patients had low-level persistent HBV viremia (61-2000 IU/mL), of whom 8 of 9 with available samples had detectable plasma tenofovir levels.
• High-level persistent HBV viremia (>2000 IU/mL) was rare -- observed in only 4 patients (3.6%) -- and was associated with low plasma tenofovir levels indicating poor adherence.
• Participants with stable undetectable HBV viral load had significantly higher nadir (lowest-ever) CD4 T-cell counts at the time of tenofovir initiation, compared to those with transient or low-level HBV viremia.
• Serological responses -- HBeAg loss, HBeAg seroconversion, and HBsAg loss -- only occurred in people with stable HBV suppression.
• 2 participants with stable undetectable HBV viral load developed hepatocellular carcinoma.
• 2 people with low-level persistent HBV viremia died during follow-up, 1 of them due to a liver-related cause.

"Suboptimal HBV control during [tenofovir] treatment has a negative effect on serological outcomes, but not necessarily clinical events," the study authors concluded. "Immunoregulation may provide more insight into this phenomenon."

7/3/14

Reference

A Boyd, J Gozlan, S Maylin, et al. Persistent viremia in human immunodeficiency virus/hepatitis B coinfected patients undergoing long-term tenofovir: Virological and clinical implications. Hepatology. June 20, 2014 (Epub ahead of print).