Rheumatoid arthritis, cytokines and hypoxia

R arthritis (RA) is a chronic recurrent, systemic inflammatory disease primarily involving the synovial membranes of multiple joints, followed by cartilage and bone destruction, which eventually leads to joint deformities and loss of articular functions.1 The clinical course of the disorder is extremely variable, ranging from mild, selflimiting arthritis to rapidly progressive multi-system inflammation with profound morbidity and mortality.2 The predominant symptoms of RA are pain, stiffness, and swelling of peripheral joints. These symptoms are accompanied by signs of articular inflammation, including swelling, warmth, erythema, and tenderness on palpation. At the onset of the disease small joints of the hand and feet are involved. Large joints such as