BONE MINERAL METABOLISM IN RHEUMATOID ARTHRITIS

Rheumatoid arthritis is characterized by: - Loss of articular cartilage, - Local erosions, - Bone disease and systemic bone disease without apparent signs of repair. Systemic bone loss is associated with high prevalence of osteoporosis. Risk factors are represented by severe vitamin D deficiency and secondary hyperparathyroidism associated. The goal of my thesis research is to arrive at the knowledge of the pathophysiological mechanisms responsible for bone lesions in Rheumatoid Arthritis in relation to the mechanisms responsible for bone remodeling and metabolism. The obtained results have shown: - That there is an inverse relationship between serum vitamin D levels and disease activity - That serum levels of PTH are associated with the presence of bone erosions by a mechanism independent of vitamin D deficiency and correlate however with significant elevations of serum Dkk-1. Therefore PTH in rheumatoid arthritis may be the link between bone metabolism and bone damage to the system with Dkk-1 especially in relation to bone erosion.