In vitro effect of thymosin-alpha1 and interferon-alpha on Th1 and Th2 cytokine synthesis in patients with eAg-negative chronic hepatitis B.

Thymosin alpha-1 (Talpha1) has been shown to be effective in chronic hepatitis B treatment. This study investigated the effect of Talpha1 and interferon-alpha (IFNalpha) on cytokine production by peripheral blood mononuclear cells (PBMCs) of 12 patients with eAg-negative chronic hepatitis B (HBV). We evaluated the effect of incubation with Talpha1, IFNalpha or both on the synthesis of T-helper 1 (Th1) cytokines [interleukin-2 (IL-2), IFNgamma] and Th2 cytokines (IL-4, IL-10) and of antiviral protein 2',5'-oligoadenylate synthetase (2',5'-OAS) in patients and in a group of 10 healthy controls. Concerning Th1 profile, controls showed lower IL-2 synthesis than HBV patients. In HBV setting, IFNalpha/Talpha1 combination was able to increase IL-2 production significantly, when compared with baseline condition. About the Th2-cytokines, controls showed statistically lower synthesis of IL-4 and higher production of IL-10, than HBV patients. In these latter, IFNalpha increased the synthesis of IL-10 compared with baseline. Interestingly, both Talpha1 alone and the IFNalpha/Talpha1 combination reversed this effect. Finally, compared with baseline, the synthesis of 2',5'-OAS was significantly higher in the presence of Talpha1 and IFNalpha alone, and in the presence of IFNalpha/Talpha1 association, while no differences were found between controls and HBV patients. In conclusion, in PBMCs from eAg-negative HBV patients, Talpha1 alone was able to increase the antiviral protein synthesis, while in association with IFNalpha, it stimulated the IL-2 synthesis and inhibited the IFN-induced IL-10 production. These results need further investigations, but reinforce the idea of an immunotherapeutic approach for chronic hepatitis B.

Immunological modifications during treatment with thymosin alpha1 plus antiviral therapy in chronic hepatitis C.

The current standard therapy for the treatment of chronic hepatitis C virus (HCV) is the combination of peginterferon and ribavirin, although many patients fail to clear the virus and their retreatment options are still unsatisfactory. Thymosin alpha1 (Talpha1) is an immunomodulating agent that has been proposed as complementary therapy for chronic HCV, especially in the setting of difficult-to-treat patients. The aim of this study was to evaluate, in patients nonresponsive to previous Peg-based therapy, the effect of standard antiviral therapy with or without Talpha1 on peripheral lymphocyte subsets. Twenty-four patients, 12 receiving Talpha1 and 12 standard therapy, were enrolled. Peripheral subpopulations were analyzed by flow cytometry. Although the addition of Talpha1 did not seem to significantly modify the T-lymphocyte subpopulations, as comparable behaviors were observed in the CD4 and CD8 longitudinal evaluation, Talpha1 produced an earlier increase of natural killer cells. An accurate selection of HCV patients who can benefit from immunomodulation is needed.