 These studies will allow us to determine if treatment with Adalimumab has an effect on the number of circulating osteoclast precursors, on the generation of osteoclasts and on the bone-resorbing activity of these cells. It will also allow to determine if Adalimumab, in concentrations found in vivo, may have a direct impact on human osteoclastogenesis and bone resorption. Perhaps more importantly, correlation of the osteoclast results with the clinical parameters studied may allow us an insight on whether an eventual effect on osteoclasts may correlate with the clinical response to the medication, indicating a possible additional mechanism of action of Adalimumab in Rheumatoid Arthritis. 