Variation in T helper cell/T cytotoxic-suppressor cell index during cardiac operations

After surgical procedures, humoral and cell-mediated immunity responses decrease. Both anesthesia and surgical trauma play an important role in this effect. Cardiac operations induce a greater decrease in immunologic response than other surgical operations. On the other hand, identification of functional lymphocyte subclasses by means of appropriate monoclonal antibodies appears to provide an accurate measurement of cellular immune competence. Employing these methods, we found a significant decrease of T helper cell/T cytotoxic-suppressor cell ratio in the periperal blood of 20 patients undergoing cardiac operations. This decrease during the period of anesthesia (before surgical incision) is due as much to a decrease of T helper cell percentage as to an increase of T cytotoxic cell percentage. However, during the surgical trauma period (surgical incision to the end of the operation) it is due to a greater increase of T cytotoxic-suppressor cell percentage without significant changes in the percentage of T helper cells.