Abstract
BACKGROUND: T-helper (Th) lymphocyte cytokine production may be important in the immune pathogenesis of hepatitis C virus (HCV) infections. Th1 cytokines such as; interleukin-2 (IL-2), and interferon gamma (IFN-gamma) are necessary for host antiviral immune responses, while Th2 cytokines (IL-4, IL-10) can inhibit the development of these effector mechanisms. OBJECTIVES: The aim of the present study was to assess the serum profile of Th1 and Th2 cytokines in treated and non-treated HCV infected individuals. PATIENTS AND METHODS: This study was carried out in 63 HCV infected patients (31 under treatment and 32 untreated) and 32 matched HCV-sero negative healthy subjects. Serum samples were checked with an enzyme-linked immune sorbent assay (ELISA) for IL-2, IL-4, IL-10 and IFN-gamma. RESULTS: Levels of circulating IL-2, IL-4, IL-10 and IFN-gamma were significantly elevated in HCV patients versus normal controls (2 822.6 ± 1 259.92 vs. 950.8 ± 286.9 pg/mL; 1 987 ± 900.69 vs. 895.91 ± 332.33 pg/mL; 1 688.5 ± 1 405.1 vs. 519.03 ± 177.64 pg/mL and 1 501.9 ± 1 298 vs. 264.66 ± 71.59 pg/mL, respectively; P < 0.001). The serum levels of all cytokines were significantly lower in the patients under treatment than those of the untreated patients (P < 0.001). CONCLUSIONS: On the basis of our data, the simultaneous increase of Th1 and Th2 related cytokines may indicate that both Thl and Th2 cytokines are involved in the pathogenesis of HCV infections. Moreover, this activated T-cell response in HCV infected patients may be regulated by treatment.