DURATION OF POSTOPERATIVE IMMUNOSUPPRESSION ASSESSED BY REPEATED DELAYED-TYPE HYPERSENSITIVITY SKIN-TESTS

The duration of postoperative impairment in cell-mediated immunity was assessed by repeated skin testing with seven delayed type common antigens in 15 patients undergoing major elective abdominal surgery compared to a similar testing regimen in 10 healthy volunteers. All were skin tested four times, with 72-hour intervals, and in the surgical patients the first test was applied 2 days before surgery, followed by tests on postoperative days 1, 4 and 7. The tests were read after 48 h. Postoperatively, the skin test area decreased on day 3 (p < 0.01) and recurred to preoperative levels on day 9. In contrast, the skin test area in the volunteers increased from test to test (p < 0.001) during the study, confirming a previous finding of a vaccination effect. These results suggest that the postoperative immunosuppression is maintained for about 6-9 days.