Boston researchers say they've found that therapy for HIV infection is not as effective in restoring the immune system in people co-infected with hepatitis C.1 But whether this is detrimental in the long run to these patients or not is still not known.
Clarifying the Confusion
Christopher F. Rowley, MD, with the division of Infectious Diseases at Beth Israel Deaconess Medical Center in Boston and his colleagues wanted to clarify conflicting information about the effectiveness of highly-active anti-retroviral therapy (HAART), a cocktail of medications often prescribed for people with HIV as way to boost their sagging immune systems, when hepatitis C is also present.
"There are conflicting data in the medical literature regarding the degree of immune restoration in patients who commence highly active antiretroviral therapy (HAART) when coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV), compared with those with HIV infection alone," Rowley's team wrote.
Therapy Cocktail Against HIV
HAART was invented as a way to prevent HIV from becoming resistant to any one drug designed to suppress the virus. While this combination of drugs cannot suppress HIV completely, it can lower viral levels significantly, thereby slowing the progression of opportunistic infections that can occur in people with AIDS due to impaired immune systems. Thus, HAART provides a way for the immune system to remain intact and effective in these patients.2
But is HAART's ability to restore the immune system in those co-infected with hepatitis C and HIV impaired? To try and clear up the confusion, Rowley and his team from the National Cancer Institute conducted a review of previous clinical trials involving a collective total of more than 6,200 patients. The research team compared immune system restoration in co-infected people using HAART to that of people using the drug cocktail who were only infected with HIV.
Co-Infected Patients Had Less Immune Restoration
In all, the results of eight previously published trials were analyzed for this study. It was found that after beginning HAART therapy, people co-infected with HCV and HIV in these studies had an average increase in CD4 cells (a type of immune system cell) that was lower than those with HIV monoinfection taking the medication cocktail. All patients had been taking HAART for 48 weeks.
"The results of the meta-analysis [analysis of many previous studies] were independent of any one study, and were not influenced by the year in which HAART was started," Rowley's group wrote.
About HIV/HCV Coinfection
One shared factor associated with both hepatitis C and HIV infection is injection drug use. In fact, it's the main way that HIV patients can become infected with HCV. Estimates are that up to 90 percent of HIV-infected injection drug users are co-infected.
HCV infection is more serious in those also infected with HIV, leading to liver damage more quickly. Symptoms are often hidden in people who are coinfected. So, one of the best ways to determine whether you have both infections is to undergo a blood test.
According to the study researchers, nearly one-third of those with HIV also have hepatitis C infection.
This study wasn't able to determine if the blunted immune system restoration in co-infected individuals on HAART may be detrimental or not. Because of that, "future research should examine whether an impaired immunologic response corresponds with meaningful virologic and clinical outcomes," wrote Rowley and his team.
1. Miller MF, Haley C, Koziel MJ, Rowley CF. Impact of hepatitis C virus on immune restoration in HIV-infected patients who start highly active antiretroviral therapy: a meta-analysis. Clin Infect Dis 2005 Sep 1;41(5):713-20. Epub 2005 Jul 22.
2. National Institute of Allergy and Infectious Diseases. National Institutes of Health (NIH). Treatment of HIV Infection. Available at: http://www.niaid.nih.gov/factsheets/treat-hiv.htm. Accessed September 14, 2005.
John Martin is a long-time health journalist and an editor for Priority Healthcare. His credits include overseeing health news coverage for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.
