Anti-hcv treatment for opiate addicts: Clinical and immunological issues

HCV infection is a major health concern worldwide, and the main cause of liver failure. A total of 180 million people is infected with HCV, and is the most frequent infection among drug addicts, with a frequency in the range of 50-90% in Europe. Chronic persistence of HCV infection and its progression are linked to a variety of factors, including the current exposure to opiate drugs themselves, because of their direct impact on the immune system. Opiates are believed to be immunosuppressant as a rule, but recent evidence has shown that opiates differ as regards their immunological properties. Methadone, which is commonly used for opiate addiction treatment, is a synthetic compound acting mainly on µ-opioid receptors; methadone happens to be free of immunosuppressant properties, at least when its slow-acting formulation is administered continuously. It is likely that such an action is achieved by its impact on suprarenal activity, as it restores the suprarenal abnormalities of heroin addicts, and the long-lasting tonic activation of µ-receptors in the central nervous system and activates a range of immune cells. The enrolment of methadone-maintained addicts in HCV treatment programmes may help to increase the effectiveness of HCV treatment by systematically impeding the transmission of HCV infection via the reservoir of drug addicts.