Nutritional factors in epidemic Kaposi's sarcoma

Abstract

The role of nutritional factors in the management of acquired immunodeficiency syndrome-related, or epidemic, Kaposi's sarcoma (EKS) is complex, since there are known interactions between malnutrition, immunodeficiency, and cancer. Malnutrition is a well-established cause of immune aberrations, which are seen in deficiencies of both protein and energy, as well as specific nutrients, particularly trace metals. Conversely, malnutrition is a common result of both cancer and immunodeficiency. Cancer patients without an obviously immunological pathogenesis frequently have malnutrition and cachexia, mainly as a result of a decreased dietary intake and poorly defined host-tumor interactions (commonly labeled "hypermetabolic"). Patients with primary immunodeficiency syndromes similarly experience a triad of diarrhea, malabsorption, and weight loss, which are responsible for the development of malnutrition. This triad is common in patients with AIDS, with or without the presence of Kaposi's sarcoma. The specific mechanisms of these interactions in EKS patients are largely unexplored; although some can be explained by the enteropathic effects of opportunistic infections, others can not. Some investigators have advocated careful nutritional evaluation of all AIDS patients, with vigorous nutritional support to be provided where assessment reveals suboptimal nutritional status. Specific nutrient deficiencies have been reported, of which selenium may be the most interesting; preliminary data indicate that it may be responsible for a malnutrition-related immunodepression seen with AIDS. Such supportive measures may significantly improve symptomatic relief, but there is as yet no evidence that they alter the course of the disease.