ABSTRACT
It is well established that the immune system has both local and systemic components that are influenced by a variety of disease processes. Impaired host defense is associated with neoplasia, severe trauma including surgery and bums (1-9), blood transfusions (10--13), administration of immunosuppressive agents (14), and protein-calorie malnutrition (PCM) (Table 1) (15). PCM can occur as marasmus (protein-calorie deficiency), kwashiorkor (protein deficiency), or a combination of both and may be primary or secondary in type. Primary PCM is prevalent, occurring in 25-40% of children worldwide (16) and accounting for more than 50% of deaths in children under 5 years of age (17). PCM remains a common problem in developed countries also, occurring in small-for-gestational age infants, the elderly, and up to 50% of hospital patients (secondary PCM). The extent of immunological impairment depends not only on the severity of PCM, but on the presence of coexisting infection and the age of onset of nutritional deprivation, among other factors. In hospitalized patients, the underlying disease, stress of injury/operation, and treatment modalities exacerbate nutritional deficiencies and affect immune function.
