title: Immunoregulatory cytokines in chronic hepatitis C virus infection: pre- and posttreatment with interferon alfa.
abstract: T lymphocytes and immunoregulatory cytokines may be important in the host response to hepatitis C virus (HCV) infection. T-helper type 1 (Th1) cytokines (interleukin [IL]-2, interferon gamma [IFN-gamma]) are required for host antiviral immune responses, including cytotoxic T-cell generation and natural killer cell activation, while T-helper type 2 (Th2) cytokines (IL-4,IL-10) can inhibit the development of these effector mechanisms. In this study, the serum levels of Th1 and Th2 cytokines in patients (n = 23) infected with HCV were measured and compared with biochemical (alanine transaminase [ALT]) and viral (HCV RNA) indicators of infection. Serial cytokine levels were measured in a subset of 11 patients at 1 and 12 weeks during and at 1 week after interferon alfa (IFN-alpha) therapy (n = 33 samples). Levels of circulating IL-2, IL-4, IL-10, and IFN-gamma were significantly elevated in HCV patients versus normal controls (128 vs. 25 pg/mL, 3,045 vs. 29 pg/mL, 2,949 vs. 18 pg/mL, and 307 vs. 24 pg/mL respectively; P < .01). Treatment with IFN-alpha decreased the levels of IL-4 (321 +/- 224 pg/mL), and IL-10 (1,011 +/- 344 pg/mL), which paralleled a decrease in HCV RNA (114 +/- 27 vs. 25 +/- 20 Eq/ml X 10(5), pre- vs. post-IFN-alpha [12 weeks];P <.05). These findings indicate that an activated T-cell response, as manifest by increased circulating immunoregulatory cytokines, is present in patients with HCV liver disease. Furthermore, treatment with HCV liver disease. Furthermore, treatment with IFN-alpha diminishes the Th2 cytokine response. Thus, modulation of T-cell function and cytokine production may be one mechanism whereby IFN-alpha therapy results in reduced viral burden.
authors.affiliation: Department of Transplantation, California Pacific Medical Center, San Francisco, CA, USA.
authors.forename: T V
authors.initials: TV
authors.lastname: Cacciarelli
authors.forename: O M
authors.initials: OM
authors.lastname: Martinez
authors.forename: R G
authors.initials: RG
authors.lastname: Gish
authors.forename: J C
authors.initials: JC
authors.lastname: Villanueva
authors.forename: S M
authors.initials: SM
authors.lastname: Krams
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D016207:Cytokines / Q000097:blood*; D005500:Follow-Up Studies; D016174:Hepacivirus / Q000302:isolation & purification*; D006526:Hepatitis C / Q000097:blood / Q000276:immunology* / Q000628:therapy*; D006801:Humans; D016898:Interferon-alpha / Q000627:therapeutic use*; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000097:blood; D007376:Interleukin-2 / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D012367:RNA, Viral / Q000097:blood; D012016:Reference Values; D013997:Time Factors
chemical_list: D016207:Cytokines; D016898:Interferon-alpha; D007376:Interleukin-2; D012367:RNA, Viral; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma; D000410:Alanine Transaminase