Trace elements and immune responses.

The common association of malnutrition and infection has led to many studies that have examined the effects of nutritional status on immunocompetence. Children with the syndromes of marasmus and kwaskiorkor show marked impairment of cell-mediated immunity (CMI), complement system, microbicidal function of polymorphonuclear leukocytes (PMN), and secretory IgA antibody response. The extensive literature on this burgeoning field has been summarized(1-5,40) Clinical malnutrition, however, is a complex combination of the deficiencies of many nutrients, including proteins, lipids, carbohydrates, vitamins, macrominerals and trace elements. Thus it is of fundamental importance to examine the influence of individual dietary factors on immune responses and disease (Fig. 1). Here Ranjit Chandra discusses the role of trace elements in host resistance to infection and other pathological diseases.