Epidural anaesthesia blocks changes in peripheral lymphocytes subpopulation during gastrectomy for stomach cancer

To examine the effects of surgery and anaesthesia on cell-mediated and humoral immunity, we investigated changes in subpopulations of peripheral T cells and B cells during gastrectomy. Twenty-one patients with gastric cancers who underwent total or subtotal gastrectomy were randomly assigned to receive thiopental/N2O general anaesthesia supplemented with either epidural (epidural group, n = 12) or enflurane(enflurane group, n = 9). The changes in peripheral lymphocyte subpopulations were detected and quantified using single and double label analysis of monoclonal antibodies against lymphocyte membrane surface markers (Leu series). Subpopulations were measured before induction, and 1 and 2 hours after skin incision. In the enflurane group, B cells (Leu12+), total T cells (Leu4+), inducer T cells (CD4+, Leu8+) and the CD4/CD8 ratio decreased and suppressor T cells (CD8+, Leu15+) increased significantly after skin incision. Whereas, the epidural group showed no change in the number of B cells and each T cell subpopulation during the study. These data suggest that epidural anaesthesia blocks the effect of stress induced by major surgery on fluctuation of peripheral lymphocyte subpopulations which may be associated with suppression of immunity.