CD3 zeta expression of regional lymph node and peripheral blood lymphocytes in gastric cancer.

BACKGROUND AND AIM Impaired expression of the CD3 zeta chain in T cells associated with T cell anergy has been reported in cancer patients. However, few studies have investigated CD3 zeta expression in regional lymph node lymphocytes (LAL) in cancer patients. This study aims to confirm CD3 zeta expression levels by lymph node and peripheral blood lymphocytes (PBL) in gastric cancer patients and to discuss the clinical implications of intranodal or peripheral blood expression of CD3 zeta in gastric cancer. PATIENTS AND METHODS Twenty-two gastric cancer patients were enrolled. Macroscopically non-metastatic compartment 1 LNL (C1LNL), compartment 2 LNL (C2LNL) and PBL were surgically obtained. Two-color flow cytometry was then used to quantify the levels of CD3 zeta expression in C1LNL, C2LNL and PBL. RESULTS Impaired CD3 zeta expression was confirmed in 9.5% of C1LNL, 8.9% of C2LNL and 4.2% of PBL. There was a significant difference in CD3 zeta expression levels between C1LNL and PBL (p<0.01). CD3 zeta expression in PBL was significantly correlated with depth of invasion but not nodal involvement. Distinct differences between the respective lymph node compartments were not identified. CONCLUSION Immunological paralysis following CD3 zeta impairment may occur more frequently in LNL than in PBL in gastric cancer. Identifying such patients during the perioperative period using flow cytometric methods will increase the efficacy of cytokine therapy aiming to normalize CD3 zeta expression levels.