The role of host defense mechanisms in surgical infections.

As far as the immunologic responses and infections in surgery are concerned, there are many exciting areas of advancement at the present time. Of these, nutritional factors seem of major importance. Even though much has been learned in the past few years, there is much to be learned, particularly related to selected amino acid deficiencies and their interactions and the potential for fortification with certain amino acids in dietary therapy. Whether the immune response can be made better than normal by increased or selective nutrition is something that remains to be determined. Certain immunomodulators given to high risk groups of patients will be able to restore immunologic competence in many instances and make it better than normal in others, with a resultant increase in resistance to all types of microbial infection. As far as passive therapy with plasma, plasma products, or some combination of these is concerned, it would appear at the present time that such treatment may benefit a few patients. However, in the adequately nourished patient, plasma therapy should be of relatively minor consideration.