TreatmentUpdate 68, Volume 8, No 4; May-June 1996
Sean Hosein

At least 50% of people infected with hepatitis C virus (HCV) develop a state of chronic infection where HCV-infected liver cells continue to produce viruses and the liver is slowly destroyed. These events happen despite the production of antibodies that attack HCV. Many hemophiliacs have been infected with HCV because the clotting factors they used were contaminated with the virus. Today, clotting factors, if they come from blood, are supposed to be treated to destroy virus. Standard treatment for HCV infection is interferon-alpha. This drug is expensive and does not work in all patients. Currently, most treatment regimens using interferon-alpha call for longer periods of treatment, usually over 12 months.

Study details

Researchers enrolled 31 subjects (1 female, 30 male) for this study. All subjects had HCV infection and six were also infected with HIV. Twenty subjects had hemophilia A, eight had hemophilia B and three had von Willebrand disease. Subjects received interferon-alpha 2a (made by Roche-Syntex) "3 million units three times per week [injected under the skin]...for 24 weeks."

Results---liver enzymes

People with chronic HCV infection often have higher than normal levels of liver enzymes in their blood. When people recover from HCV infection, high levels of liver enzymes fall. Only 8 of the 29 subjects had their liver enzymes fall to normal levels. Four other subjects had their liver enzyme levels fall by 50%. The remaining 60% of subjects did not have decreases in their liver enzyme levels while receiving interferon-alpha.

Results---production of HCV

At the end of the study, technicians could not detect HCV in blood samples from seven subjects. Levels of HCV fell to 1/100 of their pre-study level in two other subjects. However, in 70% of subjects, use of interferon-alpha did not reduce production of HCV.

Who benefits from interferon?

Researchers tried to find out why some subjects benefited from interferon-alpha. The following factors were studied and found not to make a difference:

* weight

* HIV-infection

* length of time infected with HCV

* severity of hemophilia

* levels of iron in the blood

* amount of clotting factor used per year

Results--toxicity

Twenty-nine subjects completed "6 months [use] of interferon-alpha.". One subject left the study because of side effects such as temporary hearing loss; another left because of decreasing levels of white blood cells.

Timing

Finally, levels of HCV in blood samples fell "within 8 weeks of starting interferon in seven [subjects] who responded to (interferon-alpha therapy)." Thus, monitoring levels of HCV may suggest which subjects will improve when treated. Those subjects whose levels of HCV do not fall within 8 weeks of therapy may not benefit from further interferon.

Beyond interferon

According to the researchers, three months after the end of the study, "only two [subjects had normal levels of liver enzymes and technicians could not detect HCV in their blood samples]." Perhaps longer courses of interferon-alpha may increase the number of patients recovering from HCV infection.

REFERENCES:

1. Hanley JP, Jarvis LM, Andrews J, et al. Interferon treatment for chronic hepatitis C infection in hemophiliacs---influence of viral load, genotype and liver pathology on response. Blood 1996;87(5):1704-1709.

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