Effect of radiofrequency ablation of the liver on cell-mediated immunity in rats.

We investigated the effect of radiofrequency ablation (RFA) of the liver on cell-mediated immunity in rats. Sprague-Dawley rats were divided into five groups: control group that did not have any procedure, a sham-operation group that underwent laparotomy, a lobectomy group that had left lateral lobectomy of the liver, a one-lobe RFA group that had RFA on the left lateral lobe of the liver, and a two-lobe RFA group that had RFA on the left lateral and left median lobe of the liver. Delayed-type hypersensitivity (DTH) was induced by challenging the ears of previously sensitized rats with 2,4-dinitro-1-fluorobenzene. Cell-mediated immunity was evaluated by direct measurement of the ear thickness and quantitative analysis of leukocytic infiltration of the tissue. The increased ear thickness was 42.0%, 69.2%, 61.8%, 46.7%, and 39.8% from the baseline one day after each procedure, and the mean leukocytic infiltration into the ear tissue was 3136.7, 3895.0, 3913.3, 2803.3, and 2316.7/mm(2) seven days after each procedure in the control, sham-operation, lobectomy, one-lobe RFA, and two-lobe RFA groups, respectively. In conclusion, RFA of the liver tissue can partially abolish the augmentation of DTH and leukocytic infiltration those were seen in the hepatic lobectomy and sham-operation groups. The procedure had a negative effect on cell-mediated immunity in rats, and the intensity of RFA showed a reverse correlation with cell-mediated immunity.