Endocrine effects of cytokines.

Recent trends in antineoplastic therapy include the increasing use of cytokine-containing regimens. These widely distributed, naturally occurring substances play a pivotal role in the physiology of the neuroendocrine/immune system. It is not known to what extent the chronic administration of pharmacologic doses of exogenous cytokines may create hormonal and metabolic derangements that may, in themselves, complicate their therapeutic efficacy. This article reviews the endocrine functions of a variety of cytokines. The interferons, for example, induce insulin resistance and impaired glucose tolerance, are associated with thyroid dysfunction, and can stimulate the ACTH/cortisol axis and growth hormone. The hormonal/metabolic actions of the interleukins are being intensively studied, especially by bone metabolism, reproductive, and thyroid physiologists. Tumor necrosis factor has a profound impact on bone metabolism and remodeling, decreases lipoprotein lipase, and can affect thyroid function.