THE INFLUENCE OF SURGICAL STRESS ON T-CELLS - ENHANCEMENT OF EARLY PHASE LYMPHOCYTE-ACTIVATION

For the control of postoperative infection, it may be important to und erstand the possible influences of surgical stress on the host immune system. To this end, we examined how the early phase of lymphocyte act ivation was affected in patients after major surgery (eight patients w ith esophageal carcinoma and six undergoing cardiac surgery) using a f low cytometric assay based on expression of the early activation antig en, CD69. Freshly isolated T cell in preoperative and post operative s amples did not express CD69. When peripheral blood mononuclear cells w ere stimulated in vitro, the expression of CD69 was greatly enhanced i n both CD4 and CD8 T cells, compared with the preoperative samples. Th e proportion of lie novo CD69-expressing cells in the CD4 subset was a pproximately 3 times (Postoperative Day 1) and 4 times (Postoperative Days 2, 3, 5, and 7) greater than those preoperatively, whereas the pr oportion of de novo CD69-expressing cells in the CD8 subset was approx imately 1.5 times (Postoperative Days 2 and 5) and 2 times (Postoperat ive Day 3) greater than those pre: operatively. The proportion of CD69 (+) cells was significantly greater in the CD4(+) subset than in the C D8(+) subset during the postoperative period. Implications: Our result s show that major surgical stress enhances the early phase of lymphocy te activation. The augmentation of activation was greater in CD4 (help er) T cells than in CD8 (cytotoxic)T cells.