Diagnosis and classification of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a systemic chronic inflammatory disease of unclear etiology that is manifested in by a progressive and destructive polyarthritis in association with serological evidence of autoreactivity. Its diagnosis is based on the classification criteria that involve four parameters: joint involvement, serology (rheumatoid factor and anti-cyclic citrullinated peptide--anti-CCP), levels of acute phase reactants and the duration of the symptoms Aletaha, et al. [1]. This classification simplifies the categorization of the patients with early RA; however, the diagnosis requires highly trained specialists who are able to differentiate early symptoms of RA from other pathologies.