Incidence of melanoma and other malignancies among rheumatoid arthritis patients treated with methotrexate.

Objective: To determine cancer risk in a cohort of 459 rheumatoid arthritis (RA) patients treated with methotrexate in community practice.

Methods: All RA patients who started methotrexate prior to June 1986 and were attending 1 of 6 rheumatologists were studied. Demographic data were matched to the State Cancer Registry to identify all malignancies (except nonmelanoma skin cancer) for 1983-1998, and to the National Death Index to identify all deaths to the end of 1999.

Osteoprotegerin reduces osteoclast numbers and prevents bone erosion in collagen-induced arthritis.

Rheumatoid arthritis is characterized by progressive synovial inflammation and joint destruction. While matrix metalloproteinases (MMPs) are implicated in the erosion of unmineralized cartilage, bone destruction involves osteoclasts, the specialized cells that resorb calcified bone matrix. RANK ligand (RANKL) expressed by stromal cells and T cells, and its cognate receptor, RANK, were identified as a critical ligand-receptor pair for osteoclast differentiation and survival.