RESUMO
Preoperative oral immunonutrition was demonstrated to improve immune response and to decrease the infection rate in patients with cancer. This study aimed to assess how immunonutrition could influence the immune cell response in the mucosal microenvironment of esophageal adenocarcinoma. Therefore, A prospective cohort of consecutive patients undergoing esophagectomy for esophageal adenocarcinoma was enrolled. A subgroup of them was given preoperative oral immunonutrition with Oral Impact® and was compared to those who received no preoperative supplementation. Mucosal samples from healthy esophagus were obtained at esophagectomy. Histology, immunohistochemistry, gene expression analysis, and cytofluorimetry were performed. Markers of activation of antigen-presenting cells (CD80, CD86, and HLA-I), innate immunity (TLR4 and MyD88), and cytotoxic lymphocyte infiltration and activation (CD8, CD38, CD69, and CD107) were measured. In all, 50 patients received preoperative Oral Impact® and 129 patients received no nutritional support. CD80, CD86, MyD88, and CD69 messenger RNA expression was significantly increased in patients receiving immunonutrition compared to controls. In the subgroup of patients with stages I-II cancer, the rate of epithelial cells expressing CD80 and HLA-ABC was significantly higher in those receiving immunonutrition compared to controls as well as CD8+ CD28+ cell rate. Immunonutrition administration before surgery was significantly associated to increased degranulating CD8 and natural killer cells (CD107+) infiltrating the healthy esophageal mucosa. All the comparisons were adjusted for cancer stage and preoperative therapy. In conclusion, in healthy esophageal mucosa of patients undergoing esophagectomy, a 5-day course of immunonutrition enhances expression of antigen-presenting cells activity and increased CD8+ T cell activation and degranulating activity. Further studies are warranted to understand the clinical implication in terms of cancer recurrence.