Critérios Diagnósticos - Artrite Reumatóide

Inflammatory arthritis involving three or more joints (see "Clinical features of rheumatoid arthritis", section on 'Physical findings')
Positive rheumatoid factor (RF) and/or anti-citrullinated peptide/protein antibody (such as anti-CCP) testing (see "Clinically useful biologic markers in the diagnosis and assessment of outcome in rheumatoid arthritis", section on 'Anti-citrullinated peptide antibodies')
Elevated levels of C-reactive protein (CRP) or the erythrocyte sedimentation rate (ESR) (see "Clinically useful biologic markers in the diagnosis and assessment of outcome in rheumatoid arthritis", section on 'Erythrocyte sedimentation rate')
Diseases with similar clinical features have been excluded, particularly psoriatic arthritis, acute viral polyarthritis, polyarticular gout or calcium pyrophosphate deposition disease, and systemic lupus erythematosus. (See 'Differential diagnosis' below.)
The duration of symptoms is more than six weeks.
These criteria are consistent with the 2010 ACR/EULAR classification criteria for RA.

Fonte: PJW Venables, et al. Diagnosis and differential diagnosis of rheumatoid arthritis. Uptodate, Mar 28, 2012.