Growth hormone and the immune response to bacterial infection

Growth hormone (GH) and insulin-like growth factor 1 (IGF-1), especially the former, have immunoregulatory effects in addition to anabolic effects. The hormones may act to protect the host from lethal bacterial infection by promoting the maturation of myeloid cells, stimulating phagocyte migration, priming phagocytes for the production of superoxide anions and cytokines, and enhancing opsonic activity. GH administration may be beneficial for the prevention, as well as treatment, of severe sepsis in critical illness.