Coinfection

CROI 2012: Detectable HIV Raises Risk of Incomplete Hepatitis B Suppression

HIV/HBV coinfected people with detectable HIV viral load and higher baseline HBV viral load were less likely to completely suppress hepatitis B after a year on tenofovir (Viread), but CD4 cell count did not show an effect, researchers reported at the 19th Conference on Retroviruses and Opportunistic Infections (CROI 2012) this month in Seattle.

HIV positive people coinfected with hepatitis B virus (HBV) tend to experience more severe liver disease progression and do not respond as well to hepatitis B treatment, but whether this is due to immune dysfunction or some other reason is not clear.

Jeffrey Hafkin from the University of Pennsylvania and colleagues evaluated the likelihood of and risk factors for incomplete HBV suppression among HIV/HBV coinfected patients taking antiretroviral therapy (ART) containing tenofovir  for 1 year.

Tenofovir and its usual companion NRTIs, emtricitabine (Emtriva, coformulated as Truvada) and lamivudine (3TC; Epivir), are dually active against both HIV and HBV. Current guidelines recommend that one of these combinations be included in ART regimens for HIV/HBV coinfected patients.

This retrospective cohort study looked at data from 142 HIV/HBV coinfected people treated at 5 HIV clinics in Philadelphia and Atlanta. Most (87%) were men, two-thirds were black or Hispanic, and the median age was 43 years; 86% were hepatitis B "e" antigen (HBeAg) positive.

Participants were included if they received tenofovir-containing ART, had detectable HBV DNA at baseline, and had an HBV viral load measurement at 1 year on ART. Two-thirds took tenofovir with emtricitabine and one-quarter with lamivudine. The primary outcome was HBV suppression (defined as HBV DNA < 2.6 log IU/mL) by 1 year.

Results

• 80 participants, or 56%, had incomplete HBV suppression at 1 year.
• After controlling for baseline CD4 count, baseline HIV RNA, and hepatitis C virus triple infection, the following factors were significantly associated with incomplete HBV suppression:
  • Detectable HIV viral load (defined as HIV RNA > 75 copies/mL) at 1 year: OR 3.02, or triple the risk.
  • Higher baseline HBV DNA: OR 2.40 per additional 1 log IU/mL;
  • Younger age: odds ratio (OR) 3.7, or nearly 4-fold higher risk, per additional 10 years of age.
• However, even among patients with undetectable HIV RNA at 1 year, 41% still did not to achieve undetectable HBV DNA.
• Among those with detectable HIV viral load, higher baseline HIV RNA did not predict greater likelihood of incomplete HBV suppression.
• Baseline CD4 cell count -- an indicator of immune function -- was also not significantly associated with HBV suppression.

"Failure to suppress HBV viral load by 1 year occurred in a sizeable proportion of [tenofovir]-treated HIV/HBV patients in clinical practice," the investigators concluded. "Younger age, higher baseline HBV DNA, and detectable HIV viremia at 1 year -- though not baseline CD4, HIV RNA, [or] HBeAg status -- were associated with incomplete HBV suppression."

"These data highlight the need to develop interventions to increase HBV suppression rates among HIV/HBV patients," they added.

3/9/12

Reference

J Hafkin, M Osborn, J Kostman, et al. Incidence and Risk Factors for Incomplete HBV Suppression among Tenofovir-treated HIV/HBV-co-infected Patients. 19th Conference on Retroviruses and Opportunistic Infections (CROI 2012). Seattle, WA. March 5-8, 2012. Abstract 796.