(posted March 1, 2011)
Chronic hepatitis C virus infection has become a leading cause of non-AIDS related illness and death among individuals infected with HIV. Due to overlapping routes of transmission, co-infection is common: in the United States, 30 percent of HIV-infected people have chronic hepatitis C. While hepatitis C is spread via contaminated blood, often through injection drug use, recent research suggests it may also be transmitted sexually among HIV-infected men who have sex with other men.
However, many HIV-infected men do not receive ongoing hepatitis C screening and testing, according to a new study led by Miriam Hospital researchers published in a recent issue of the journal Clinical Infectious Diseases. Although more than 1,800 HIV-infected men from across the U.S. participating in the study initially tested negative for hepatitis C when they began receiving HIV care, 36 men acquired HCV infection over time.
Until recently, HCV has been thought to precede HIV infection in most cases, said lead author Lynn E. Taylor, M.D., an HIV/AIDS physician at The Miriam Hospital. As a result, current U.S. primary care guidelines for HIV-infected people endorse HCV antibody testing only at the time of HIV diagnosis. HIV-infected patients who initially test negative for hepatitis C are not systematically screened afterward.
Taylor points out that hepatitis C is typically a silent infection. Symptoms may not develop until the later stages of the disease, so individuals may not realize they have been infected, she said. Unfortunately, the later the virus is diagnosed the harder it may be to successfully treat in HIV-infected persons, and the more time that has passed with infected individuals possibly transmitting infection unknowingly.
The standard of care needs to change; screening HIV-infected patients for hepatitis C only once upon entry into HIV care is not sufficient, Taylor added. Individuals living with HIV should have access to ongoing screening for hepatitis C.
An estimated five million people in the U.S. have chronic hepatitis C virus infection, a liver disease that may result in long-term health problems, including liver scarring, liver failure and liver cancer. According to the Centers for Disease Control and Prevention, approximately 12,000 people die every year from hepatitis C-related liver disease. In HIV-infected patients, the liver damage is often more significant and may happen more quickly. Hepatitis C infection itself is an indication to introduce antiviral medications for HIV early in the course of HIV disease in order to slow hepatitis C disease progression.
The current study was a collaborative effort involving a group of researchers from the Adult AIDS Clinical Trials Group, the largest HIV Clinical Trials organization in the world. Researchers studied 1,830 men from a national sample who had an initial negative hepatitis C antibody test and at least one subsequent test. The majority of study participants were in their early 40s and 70 percent had attended college. At the time of the initial test, 94 percent of men were receiving highly active antiretroviral therapy (HAART) for their HIV infection and only six percent reported history of injection drug use. Overall, 36 men ended up testing positive for HCV within several years. Three-quarters of these patients reported no current or previous injection drug use.
Researchers say these findings suggest most study participants acquired hepatitis C through non-classic means, including sexual transmission.
We face a number of barriers with hepatitis C testing, including stigma and a lack of awareness among both patients as well as physicians, said Taylor, who is also an assistant professor of medicine at The Warren Alpert Medical School of Brown University. Unfortunately for HIV-infected people, hepatitis C disease progression is often aggressive. Treatment is not as effective and may be more toxic than it is for people who have hepatitis C alone, without dual infection with HIV. Therefore, new approaches for the prevention, diagnosis and treatment of hepatitis C are crucial for populations co-infected with both viruses.
The study was supported by grants from the National Institute of Allergy and Infectious Disease, National Institute on Drug Abuse, Lifespan/Tufts/Brown Center for AIDS Research, Center for Drug Abuse and AIDS Research and the National Institutes of Health. Co-authors included Karen Tashima, M.D. and Kenneth H. Mayer, M.D., from The Miriam Hospital and Alpert Medical School; Marisa Holubar, M.D., of Stanford University, a former Alpert Medical School medicine-pediatrics resident who worked with Taylor and had a longitudinal clinic at The Miriam Immunology Center; Kunling Wu, M.Sc., and Ronald J. Bosch, Ph.D., of the Harvard School of Public Health; David L. Wyles, M.D., of the University of California, San Diego; John A. Davis, M.D., of Ohio State University; and Kenneth E. Sherman, M.D., of the University of Cincinnati College of Medicine.