The key inclusion criteria were patients with RA who met the criteria established by the American College of Rheumatology (ACR). Two groups were conformed based on the Disease Activity Score 28 (DAS28): a) with clinical activity (DAS28 > 3.6) and b) with clinical remission (DAS28 < 2.4). Key exclusion criteria were patients with any other inflammatory, autoimmune or neoplastic disease and patients with infections. The control group was represented by healthy patients