Effect of thymosin-α(1) on T-helper 1 cell and T-helper 2 cell cytokine synthesis in patients with hepatitis B virus e antigen-positive chronic hepatitis B.

Thymosin-α(1) (TA(1)) has been shown to be effective treatment for chronic hepatitis B virus (HBV) infection. This study investigated the immune response after TA(1) monotherapy in 25 HBV e antigen (HBeAg)-positive patients randomized to receive either 1.6 mg active TA(1) (group A), 1.6 mg recombinant TA(1) (group B) or 3.2 mg recombinant TA(1) (group C) monotherapy for 52 weeks. The percentages of T-helper 1 (T(h)1) cytokine-producing T-cells (interleukin-2 [IL-2], interferon-γ [IFN-γ], tumour necrosis factor-α) and T(h)2 cytokine-producing T-cells (IL-4) were analysed using flow cytometry. In all patients treated with TA(1), cytokine levels and the proportion of peripheral blood mononuclear cells producing these cytokines were significantly increased, compared with baseline and healthy controls. The proportions of each cytokine-producing cell increased gradually over time and were restored to normal levels, and proportions of IFN-γ and IL-4-producing cells reached higher levels than in normal (healthy) controls. The results showed that treatment with TA(1) increased cytokine production, especially IFN-γ, and higher-dose TA(1) exhibited better efficacy against HBV, compared with other treatments studied.