The delayed hypersensitivity response and host resistance in surgical patients. 20 years later

A 20-year follow-up was conducted on research into the implications of a lack of a delayed-type hypersensitivity (DTH) skin test response among surgical patients.

The authors' original report showed that a failed DTH response was associated with increased hospital mortality, but the role of specific and nonspecific host defense elements, comorbid factors, nutritional supplementation, and the mechanism for anergy in this adverse outcome was unknown.

A data base of 4292 patients was analyzed and reported on individual studies designed to answer some of the above questions.

Prospective studies showed a strong association between the DTH response and mortality: reactive patients, 2.9% (75/2576); anergic patients, 20.9% (239/1142, chi square = 265, p < 0.0000001). Antibody response to protein antigens was reduced in anergic patients. Antibody response to polysaccharide antigens was normal in all patients. The hallmark of anergy is a lack of T cells in the skin, as measured by mRNA signal (CD3) for T cells. The nonspecific component of host defense, as measured by circulating and exudate polymorphonuclear cell function, showed no statistically significant difference between elective reactive and elective anergic patients. Notwithstanding some mild malnutrition in anergic patients, parental nutrition failed to correct the DTH response or many of the cellular immune functions measured.

Over the last 5 years, because of a reduction in overall patient mortality, the contribution of a reduced DTH response to septic related mortality has lost statistical significance in elective surgical patients. A reduced DTH response maintains its strong association to sepsis-related mortality in intensive care/trauma patients, and this is the group on which future research efforts should be concentrated.