 Rheumatoid arthritis patients with more than 6 months and less than 5 years of active evolution DAS28 3.2 or SDAI 11 and which start treatment with biologic therapy for the first time independently of the combination with synthetic DMARDs. The patients will be evaluated according to clinical practice clinical evaluation and inflammation markers at baseline and 3 and 6 months after the initiation of the treatment with the biologic DMARD. 