[Osteoporosis associated with rheumatoid arthritis]

Patients with rheumatoid arthritis(RA) develop both generalized and periarticular osteoporosis. Both of them are believed to be associated with increased production of inflammatory cytokines(TNF alpha, IL-1 beta, IL-6) and increased formation and activation of osteoclasts. Whether glucocorticoids work positively or negatively on generalized/periarticular osteoporosis is still controversial. RANKL has been shown to be expressed on T cells and fibroblast-like cells in the synovium, thus 'RANKL-RANK' pathway is likely to play an important role in periarticular osteoporosis and bone erosion as well as generalized osteoporosis. Among various therapies for generalized/periarticular osteoporosis in RA, anti-cytokine antibodies/antagonists and osteoclast inhibitors including bisphosphonates are promising.