Expression of the chemokine IP-10 correlates with the accumulation of hepatic IFN-γ and IL-18 mRNA in chronic hepatitis C but not in hepatitis B

Authors

  • Sabine Mihm,

    Corresponding author
    1. Department of Internal Medicine, Division of Gastroenterology and Endocrinology, Georg-August-Universität, Goöttingen, Germany
    • Georg-August-Universität, Zentrum Innere Medizin, Abteilung Gastroenterologie und Endokrinologie, Robert-Koch-Strasse 40, D-37075 Göttingen, Germany.
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  • Stefan Schweyer,

    1. Department of Pathology, Division of Pathology, Georg-August-Universität, Göttingen, Germany
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  • Giuliano Ramadori

    1. Department of Internal Medicine, Division of Gastroenterology and Endocrinology, Georg-August-Universität, Goöttingen, Germany
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Abstract

The pathogenesis of hepatitis C virus-induced chronic liver disease is still poorly understood. Previous studies revealed enhanced hepatic expression of the Th1 prototype cytokine IFN-γ in individuals with chronic hepatitis C. In accordance with several animal models of experimentally induced hepatitis, a Th1 lymphocyte driven inflammatory process, which involves newly infiltrated as well as resident monocytes/macrophages, has been proposed. An involvement of the interferon-γ-inducible chemokine IP-10, which is chemoattractive for stimulated Th1 cells and monocytes, is also suggested. Using an HBV transgenic mouse model, a reduction of hepatic infiltration and liver disease was achieved recently by administration of antibodies directed against the interferon-γ-inducible chemokine Mig and against IP-10. In the present study, expression of IP-10 was investigated both in serum and in the liver of patients with chronic hepatitis C and hepatitis B. Patients with liver diseases of non-viral etiologies served as controls. IP-10 expression was highest in hepatitis C. In chronic hepatitis C, but not in chronic hepatitis B nor in liver disorders unrelated to viral infections, IP-10 expression was strongly correlated with the amount of transcripts for IFN-γ and to the amount of transcripts for the constitutively expressed macrophage derived cytokine IL-18. Hepatic inflammatory activity, however, was found to be associated more closely with IFN-γ than with IP-10 or IL-18 mRNA expression. The data support the hypothesis that IP-10 is responsible for the recruitment of Th cells and monocytes in chronic hepatitis C, and suggest that its role in chronic hepatitis B is less determining. Moreover, they deliver additional support for the view that IFN-γ still has to be considered as a mediator that determines the outcome of inflammation, e.g., via its ability to activate IL-18 expressing cells and to initiate a delayed type hypersensitivity reaction. J. Med. Virol. 70:562–570, 2003. © 2003 Wiley-Liss, Inc.

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