Abstract: Objective To observe the changes of the peripheral blood lymphocyte subsets in patients with chronic hepatitis C treated by pegylated interferon α-2a combined with ribavirin. Methods The peripheral blood lymphocyte subsets were detected in 27 patients with chronic hepatitis C and 26 blood donors. The patients received pegylated interferon α-2a and ribavirin combination therapy for 48 weeks. Results The CD4⁺T lymphocytes increased in patients with chronic hepatitis C as compared with control group（P<0.01）,CD8⁺T lymphocyte reduced（P<0.01）,and CD4⁺/CD8⁺ ratio increased（P<0.05）;after PEG-interferon α-2a combined with ribavirin therapy for 24 weeks,the CD4⁺ decreased（P<0.05）,and CD4⁺/CD8⁺ ratio increased（P<0.05）. Conclusion Pegylated interferon combined with ribavirin for chronic hepatitis C patients has a regulatory role in cellular immunity.

Key words: Chronic hepatitis C, Lymphocyte subsets, Pegylated interferon-α-2a, Flow cytometry