Delayed type hypersensitivity testing in surgical patients.

DTH skin reactions can identify a population of surgical patients at increased risk for sepsis and related mortality. The usefulness of the technique is increased by repeating the test during the hospital course and by calculating a DTH score, which is the sum of the diameter of induration of all five or six tests expressed in millimeters. Regression analysis of factors that could possibly indicate development of sepsis and death after surgical treatment reveals that the most powerful predictors are serum albumin, DTH score and age of the patient. The population of patients who are anergic are more frequently malnourished than reactive patients, but the DTH response cannot be used to determine the malnourished state in individual patients. The lack of a DTH reaction (anergy) identifies an immune defect characterized by a failure of release of lymphokines in vivo. Lymphokines from normal individuals can restore to normal the absent response of anergic patients to specific antigens. In experimental animals made anergic by a heat injury, the mortality rate from bacterial peritonitis can be significantly lowered by lymphokines. Immunomodulation of demonstrated defects in host resistance is an exciting prospect for the future of surgical patients.