The Role of the Immune System in the Development of Osteoporosis and Fracture Risk

The concept of osteoimmunology is based on the growing insight into the links between the immune system and bone, at the anatomical, vascular, cellular, and molecular levels. In inflammatory rheumatic diseases, the bone is a target of inflammation. Activated immune cells at sites of inflammation produce a wide spectrum of cytokines in favor of increased bone resorption, resulting in bone erosions, osteitis, and peri-inflammatory and systemic bone loss. As a result, patients with inflammatory diseases have an increased fracture risk, and should be counseled about their fracture risk profile. Fracture risk evaluation includes clinical risk evaluation for falls and fractures, DXA, and imaging of the spine. Fracture prevention is advocated in high-risk patients, and includes general measures and antiosteoporosis drug treatment. Follow up is essential for compliance, tolerance, efficiency, and decision about switching and duration of therapy.