The Impact of Preexisting Disease Conditions for Host Defense Integrity in Traumatized and Critically Ill Patients

Trauma affects both components of host defense in that specific immunity is altered as well as nonspecific immunity. The question remains whether these changes are beneficial or detrimental for the host. Preexisting disease conditions such as cancer, inflammatory diseases, nutritional deficits, infection, and immunosuppressive drugs are all associated with alterations in host defense that may influence changes in host immunocompetence seen following trauma [1]. There are several methods for testing the host defense capacity of trauma victims. Some of these use single in vitro measurements such as lymphocyte responses to phytohemaglutinin (PHA). Others use in vitro multiple measures such as measurement of the cytokines tumor necrosis factor (TNF), interleukin-1 (IL-1), IL-2, IL-6, IL-8 or several of the immunoglobulins. Lastly, there are in vivo measurements such as response to skin test antigens [2].