Immunologic aspects of osteoporosis

Osteoporosis is a major cause of morbidity in older people, There are a large number of risk factors for the development of osteoporosis, However, these risk factors eventually must mediate their effects through modulation of bone remodeling, A variety of compounds including hormones and mutrients modulate bone remodeling, In addition to these well-characterized substances, the immune system plays a role in bone remodeling through pro-inflammatory cytokines, Specifically, interleukin-1 (IL-1), IL-11, interferon-g are known to influence osteoclasts and osteoblasts. Recently, the cytokine IL-6 has joined ranks with these cytokines as a bone reactive agent, IL-6 has been shown to increase with age and menopause, Additionally, murine models suggest that IL-6 plays a central role in bone resorption, Finally, in vitro studies demonstrate that IL-6 induces osteoclast activity, In this review, we will discuss the pathogenesis of osteoporosis in the context of aging and IL-6. (C) 1997 Elsevier Science Ltd. All rights reserved.