Thymosin-α1 increases intrahepatic NKT cells and CTLs in patients with chronic hepatitis B

Abstract Background and aim: Thymosin-α1 (T-α1) influences T-cell maturation, production of Th1-type cytokines, and activity of NK cell-mediated cytotoxicity. The aim of this study is to evaluate the types of lymphocytes that contribute to the reduction in viral load in patients with chronic hepatitis B (CHB) following T-α1 treatment. Methods: Seven patients with CHB were treated with 1.2 mg of T-α1 for 24 weeks. Peripheral blood lymphocytes (PBL) and intrahepatic lymphocytes were analyzed by flow cytometry. Serum cytokines (IL-4 and IFN-γ) were measured by ELISA. Results: Forty-eight weeks after T-α1 treatment, two patients (28.6%) showed normalized alanine aminotransferase and decreased HBV-DNA to undetectable level from serum. The histology activity index score significantly decreased ( P + PBL appeared to be increased. CD56 + natural killer T (NKT) cells in PBL did not increase, these cells in the liver remained significantly augmented even at the end of treatment ( P + NKT cells slightly increased and the ratio of CD4 + T/CD8 + T cells decreased in the liver. T-α1 did not influence either double-positive CD4 + 8 + T or double-negative CD4 − 8 − cell subsets. Conclusion: NKT cells and CD8 + cytotoxic T lymphocytes augmented in the liver by T-α1 may eliminate hepatitis B virus infected hepatocytes.