Original Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Apr 7, 2012; 18(13): 1470-1478
Published online Apr 7, 2012. doi: 10.3748/wjg.v18.i13.1470
Immunological milieu in the peritoneal cavity at laparotomy for gastric cancer
Akira Yoneda, Shinichiro Ito, Seiya Susumu, Mitsutoshi Matsuo, Ken Taniguchi, Yoshitsugu Tajima, Susumu Eguchi, Takashi Kanematsu, Yasuhiro Nagata
Akira Yoneda, Shinichiro Ito, Seiya Susumu, Ken Taniguchi, Yoshitsugu Tajima, Susumu Eguchi, Takashi Kanematsu, Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8051, Japan
Mitsutoshi Matsuo, Department of Surgery, Yamaguchi Prefectural Medical Center, Yamaguchi 747-8511, Japan
Yasuhiro Nagata, Department of Surgery, National Hospital Organization Nagasaki Medical Center, Nagasaki 856-8562, Japan
Author contributions: Yoneda A performed the majority of experiments; Ito S, Susumu S, Matsuo M, Taniguchi K, Tajima Y, Eguchi S were involved in editing the manuscript; Kanematsu T and Nagata Y designed the study and final approval of the version to be published.
Supported by Grant-in-Aid for Scientific Research (C), No. 22591459
Correspondence to: Akira Yoneda, MD, Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. dm06034e@cc.nagasaki-u.ac.jp
Telephone: +81-95-8197316 Fax: +81-95-8197319
Received: December 19, 2011
Revised: February 3, 2012
Accepted: February 16, 2012
Published online: April 7, 2012
Abstract

AIM: To investigate the immunological repertoire in the peritoneal cavity of gastric cancer patients.

METHODS: The peritoneal cavity is a compartment in which immunological host-tumor interactions can occur. However, the role of lymphocytes in the peritoneal cavity of gastric cancer patients is unclear. We observed 64 patients who underwent gastrectomy for gastric cancer and 11 patients who underwent laparoscopic cholecystectomy for gallstones and acted as controls. Lymphocytes isolated from both peripheral blood and peritoneal lavage were analyzed for surface markers of lymphocytes and their cytokine production by flow cytometry. CD4+CD25high T cells isolated from the patient’s peripheral blood were co-cultivated for 4 d with the intra-peritoneal lymphocytes, and a cytokine assay was performed.

RESULTS: At gastrectomy, CCR7- CD45RA- CD8+ effector memory T cells were observed in the peritoneal cavity. The frequency of CD4+ CD25 high T cells in both the peripheral blood and peritoneal cavity was elevated in patients at advanced stage [control vs stage IV in the peripheral blood: 6.89 (3.39-10.4) vs 15.34 (11.37-19.31), P < 0.05, control vs stage IV in the peritoneal cavity: 8.65 (5.28-12.0) vs 19.56 (14.81-24.32), P < 0.05]. On the other hand, the suppression was restored with CD4+ CD25high T cells from their own peripheral blood. This study is the first to analyze lymphocyte and cytokine production in the peritoneal cavity in patients with gastric cancer. Immune regulation at advanced stage is reversible at the point of gastrectomy.

CONCLUSION: The immunological milieu in the peritoneal cavity of patients with advanced gastric cancer elicited a Th2 response even at gastrectomy, but this response was reversible.

Keywords: Cytokines, Gastric cancer, Lymphocytes, Peritoneal cavity, Regulatory T cell