Postoperative depression of lymphocyte transformation response to microbial antigens

Cell mediated immunofunction, as expressed by total lymphocyte count, B and T cell count, in vitro blastogenic response to unspecific mitogens (phytohaemagglutinin and poke weed mitogen) and microbial antigens (Candida albicans, purified protein derivative, Staphylococcus aureus and Escherichia coli), was assessed in 8 otherwise normal patients undergoing elective, uncomplicated gastric surgery. The results showed a significant depression in all parameters on the first and/or third postoperative day, except for the blastogenic response to unspecific mitogens, which was unchanged throughout the study. Compared with the preoperative value, the total lymphocyte count decreased by 48% with a similar fall in both T and B cells. The blastogenic response to C. Albicans, purified protein derivative, Staph. aureus and E. coli decreased by 45, 42, 75 and 76% respectively. When measured on the seventh and ninth postoperatively days all parameters had returned to preoperative levels. Thus, even during clinically uncomplicated surgery, significant cell mediated immunodepression can be demonstrated by the blastogenic response of peripheral lymphocytes to common microbial antigens. The results suggest that this phenomenon may be secondary to the disappearance of specific reactive lymphocytes from the peripheral blood following surgical trauma.