Researchers explore the dangers of hepatitis B and HIV coinfection
by Larry Buhl
New research suggests people with chronic hepatitis B virus (HBV) infection have twice the risk of dying from liver-related diseases as people with chronic hepatitis C virus (HCV), including those coinfected with HIV. The research was part of the long-running Multicenter AIDS Cohort Study (MACS) and presented at the 18th Conference on Retroviruses and Opportunistic Infections (CROI) in February in Boston. The study also found that the introduction of tenofovir (found in Viread, Truvada and Atripla) as a common part of antiretroviral (ARV) therapy significantly reduces the risk of dying in people with HBV.
Deaths from liver-related causes are now greater than all other causes of death in people with HIV. Ten percent of all people with HIV have chronic HBV infection and nearly a third of people with HIV are coinfected with HCV, and that both types of hepatitis are more aggressive in people with HIV than in people who don’t have HIV.
Until now few studies have compared deaths from HBV with deaths from HCV in people coinfected with HIV. To explore this, Oluwaseun Falade-Nwulia, MD, MPH, of Johns Hopkins University, and her colleagues compared rates of liver-related mortality between participants in the MACS cohort who were infected with HBV or HCV.
A total of 680 men were included and participants were followed for a median of seven years (ranging from just five months to twenty-five years). Of the participants, 472 men (sixty-nine percent) were HIV-positive, 337 had chronic hepatitis B, and 343 had chronic hepatitis C; thus, 229 were HIV/HBV coinfected and 243 were HIV/HCV coinfected. The average age of participants with HBV was thirty-two, and most were white. The average age of those with HCV was thirty-eight, and the majority were black or Latino.
The researchers obtained causes of death from death certificates, and compared rates of liver-related mortality and all-cause mortality in HBV-infected and HCV-infected men, adjusting for potential confounding factors. There were fifty-one liver-related deaths during a seven-year follow-up period—thirty-six in people with HBV and fifteen in people with HCV. The majority of deaths were in people coinfected with hepatitis and HIV. However, most of the increased risk of death occurred between 1984 and 2002, before the use of tenofovir became widespread among people with HIV.
• Liver-related death was about twice as high for the chronic hepatitis B group than the chronic hepatitis C group, after adjusting for race/ethnicity, age, HIV status, CD4 cell count, and alcohol use.
• A majority of participants (forty-six) who died from liver-related causes were HIV-positive.
• Among people with HIV, liver-related death remained about twice as high among HIV/HBV compared with HIV/HCV coinfected men after adjusting for race/ethnicity, age, CD4 count, alcohol use and use of antiretroviral drugs active against HBV.
• Use of antiretrovirals active against HBV and HIV did not independently predict less liver-related death, although mortality began declining in 2003 when tenofovir became widely available.
• Liver-related deaths from HBV were ninety-three percent lower in people with CD4 counts over 350 compared with people who had CD4 counts under 200.
The researchers concluded that the results underscore the need for expansion of HBV screening, vaccination to protect against HBV infection, and treatment of HIV/HBV coinfected individuals with dually active drugs.
Dr. Falade-Nwulia cautions people to understand the exact meaning of the results. “The results don’t mean that men with HBV died more often than those with HCV but that diseases of the liver are more common with those who have HBV.”
The good news, she says, is that hepatitis B is preventable, through immunization.
“Since the early 1980s hepatitis B has been a part of the routine immunization regimen for children. People born before then should be screened and immunized against HBV infection.” She added that, as with HCV, symptoms are often hidden with those who carry the hepatitis B virus. There is no vaccination to prevent hepatitis C.
She underscores the need for people with HIV to be particularly careful. “Ninety percent of the time people in the non-HIV positive population can clear HBV on their own. When there is immune suppression, which happens with people with HIV, even when they are on retrovirals, the immune system cannot handle hepatitis infection as well.”
MACS is an ongoing prospective study of the natural history and HIV treatment outcomes of men who have sex with men (MSM) in Baltimore, Chicago, Pittsburgh and Los Angeles. Dr. Falade-Nwulia plans to work on upcoming studies as a part of MACS, including an analysis of additional factors that contribute to mortality in coinfected people, who are most at risk, and how to best monitor the progression of liver disease.
Larry Buhl is a freelance journalist and screenwriter living in Los Angeles.