RESUMO
<p><b>OBJECTIVE</b>To assess the local immune response in patients with hepatocellular carcinoma after percutaneous microwave coagulation therapy (PMCT).</p><p><b>METHODS</b>Seventy-eight patients with hepatocellular carcinoma underwent PMCT. Both cancerous and adjacent liver tissue were taken before, and 3, 17 and 30 days after PMCT using ultrasound-guided liver biopsy. Specimens were stained by immunohistochemical techniques for detecting CD3, CD45RO, CD56, CD68, and CD20 positive cells.</p><p><b>RESULTS</b>A few CD3, CD45RO, CD56, CD68 and CD20 positive cells were observed in the cancer stroma and surrounding sinusoids in liver tissue pre-PMCT. The number of immunocytes, except for CD20 positive cells, was significantly increased both within the cancer and the adjacent liver tissue, with a larger increase in tumor tissue at day 3 post-PMCT compared with pre-PMCT. These immunocytes were enlarged in size. The number of CD3, CD45RO and CD56 positive cells peaked at day 17 and CD68 positive cells peaked at days 3 post-PMCT. At day 30 post-PMCT, this increase still existed. These infiltrating immunocytes distributed in the parenchyma of the tumor, and within the lumen of small blood vessels after PMCT. In addition, more infiltrated immune cells were seen in cancer cell spaces.</p><p><b>CONCLUSIONS</b>A change in immunocyte infiltration takes place in number, configuration and location after patients with HCC are treated with percutaneous microwave coagulation, suggesting that local immune function is enhanced post-PMCT.</p>