AIDS 2012: Triple infection with HBV promotes HCV clearance in people with HIV
Competition between HBV and HCV in HIV positive people with triple infection appears to promote spontaneous HCV clearance, but lower CD4 T-cell counts and greater liver inflammation reduce the likelihood of clearance.
Competition between hepatitis B virus (HBV) and hepatitis C virus (HCV) in HIV positive people with triple infection appears to promote spontaneous HCV clearance, but lower CD4 T-cell counts and greater liver inflammation reduce the likelihood of clearance, Chinese researchers reported at the XIX International AIDS Conference (AIDS 2012) last month in Washington, DC.
Prior studies have shown that HBV and HCV seem to interfere with each other's replication, usually to the advantage of HBV. Yuan Dong from Fudan University in Shanghai and colleagues looked at viral interactions, liver inflammation, viral genotypes, and other factors that might affect spontaneous clearance in individuals with HBV/HCV/HIV triple infection.
This cross-sectional analysis included 529 injection drug users in Yunnan Province. They competed interviews about demographics, risk behavior, and treatment history, and blood samples were tested for CD4 T-cell counts, ALT levels, HBV and HCV antibodies, hepatitis B antigens, and HCV viral load and genotype.
Most participants (about 87%) were men and the median age was about 33 years. Just over half were undergoing "compulsory detoxification" and about 20% were recruited at a labor camp.
o Chronic HBV infection: odds ratio (OR) 4.97, or about 5-fold higher likelihood;
o CD4 count > 400 cells/mm3: OR 1.88, or nearly twice the likelihood;
o Use of antiretroviral therapy was of borderline significance (P=0.06): OR 2.87.
o Higher ALT significantly reduced the likelihood of clearance by one-third to one-half (OR 0.37 for 40-80 U/mL and OR 0.45 for > 80 U/mL).
"Our results suggested that the reserved host immune function (high CD4+ T [cell] counts) and HBV coinfection (chronic HBV) could improve HCV clearance in HIV-infected IDUs, whereas the damage in [the] liver (high level of ALT) was associated with the non-clearance of HCV," the researchers concluded.
"We demonstrated that the clearances of different HCV genotypes might be facilitated by different factors," they continued. "HBV chronic infection seemed to facilitate HCV genotype 3 clearance but not genotype 1 and 6."
In response to audience questions, Dong said that the researchers did not look at IL28B gene patterns and did not measure HBV DNA viral load. "Very few" participants were treated for hepatitis C, she said, and half were lost to follow-up.
By Liz Highleyman
Y Dong, C Qiu, X Xia, et al. HCV genotype and HBV co-infection associate with HCV clearance in HIV-positive subjects. XIX International AIDS Conference (AIDS 2012). Washington, DC, July 22-27, 2012. Abstract TUAC0504.