Abstract: Objective To investigate the changes of peripheral T lymphocyte subsets in patients with primary liver cancer（PLC）underwent microwave ablation. Method 152 patients with PLC were recruited and received microwave ablation treatment. One day before,and 1 week and 4 weeks after the treatment,the distributions of peripheral T lymphocyte subsets were determined by flow cytometry,and serum levels of alpha fetoprotein were measured by a automatic biochemical immune analyzer. Contrast-enhanced CT scans were performed in all patients one month after the treatment. Results The percentages of CD4⁺ or CD8⁺T lymphocytes and the ratio of CD4⁺/CD8⁺in this series one day before the treatment were （21.4±4.1）%,（58.6±7.8）% and（0.98±0.45）,respectively,while the percentages of CD4⁺T lymphocytes increased to （26.5±3.8）% and（32.3±5.1）%,and the CD4⁺/CD8⁺ratio increased to（1.12±0.43）and（1.51±0.40）,but CD8⁺T lymphocytes decreased to（47.2±7.7）% and （28.1±7.3）%,respectively（P<0.05）one week and 4 weeks after microwave ablation; serum alpha fetoprotein levels were significantly decreased from the baseline [（1109±727） ng/ml] to （890±681） ng/ml 1 week or （215±18） ng/ml 4 weeks after ablation（P<0.01）;contrast-enhanced CT scans revealed a complete ablation rate of 97.37%（148/152） for tumors one month after therapy. Conclusions Microwave ablation for PLC shifts the distribution of peripheral blood T lymphocyte subsets toward a CD4⁺ cells-favorite status,which might play a role in improving the efficacy of the therapy.

Key words: Hepatoma, Microwave ablation, T lymphocyte subsets