Bone Biology, Osteoimmunology and Rheumatic Diseases

Abstract

Osteoimmunology (OI) is a relatively new field in medicine, improving our understanding of the pathogenesis of the rheumatic diseases. OI focuses on the relationship and interaction between the immune and the musculoskeletal systems, observing these processes in three main aspects: regulating the bone resorption by the immune system, the impact of inflammation on the bone formation, the role of bone and bone marrow as a depot for immune cells. Changes in the bone architecture may be due to the activation of the immune system. Proinflammatory cytokines leading in the pathogenesis ofthe inflammatory joint disease are potent activators of nuclear factor-kB receptor activator (RANKL) expression and thus promote the osteoclast differentiation. This link explains why therapy whose target are the cytokines , especially TNF inhibition, is very effective in delaying structural damage in rheumatic diseases. Knowledge of these mechanisms would allow better use of medical therapies to reduce skeletal damage.