Host resistance in sepsis and trauma.

Host resistance to infection was measured by the in vivo response to 5 delayed hypersensitivity antigens and to sensitivity and challenge by dinitrochlorobenzene (DNCB) in 55 seriously ill or injured patients and in 50 preoperative patients. A close correlation between infections, septicemia, death related to infection and anergy was found in the postoperative and post injury patients and was predictive of these complications in the patients studied preoperatively. Decreased body cell mass was noted in both the anergic and non-anergic patients which was consistent with protein-calorie malnutrition but the two groups were not significantly different. A serum factor which inhibited cellular immunity in vitro was found in 4 patients. This factor disappeared in the two patients who recovered. The study suggests the therapeutic value of the in vivo measurement of delayed hypersensitivity in seriously ill and especially preoperative patients in whom specific or non-specific stimulation of cell mediated immunity might alter the risk of infection.