From the Guidelines
The diagnostic criteria for rheumatoid arthritis (RA) are based on the 2010 American College of Rheumatology/European League Against Rheumatism classification criteria, which focus on joint involvement, serology, acute-phase reactants, and symptom duration, with a score of 6 or more out of 10 possible points indicating a diagnosis of RA. The criteria are outlined in the 2012 study published in the Mayo Clinic Proceedings 1, which provides a score-based algorithm for classification. The criteria include joint involvement, with points assigned based on the number and size of affected joints, serologic findings, such as rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA), acute-phase reactants, such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), and duration of symptoms.
Key Points to Consider
- Clinical evaluation should include a thorough joint examination, assessment of morning stiffness, and exclusion of other conditions that might mimic RA.
- Early diagnosis is crucial as prompt treatment with disease-modifying antirheumatic drugs (DMARDs) like methotrexate can prevent joint damage and improve long-term outcomes.
- The 2010 ACR/EULAR classification criteria are used for classification of new patients, and patients with erosive disease typical of RA with a history compatible with fulfillment of the 2010 criteria should be classified as having RA.
- The criteria are not applicable to patients with long-standing disease, including those with inactive disease, who should be classified based on retrospectively available data.
Important Considerations
- The diagnostic criteria should be used in conjunction with clinical evaluation and expert opinion to ensure accurate diagnosis and treatment.
- Patients with a score of 6 or more out of 10 possible points should be classified as having RA, while those with a score less than 6 should be reassessed over time to determine if the criteria are fulfilled cumulatively.
- The use of DMARDs, such as methotrexate, is recommended for patients at risk of developing persistent or erosive arthritis, as early treatment can improve long-term outcomes, as suggested by the 2007 EULAR recommendations for the management of early arthritis 1.
From the Research
Diagnostic Criteria for Rheumatoid Arthritis
The diagnostic criteria for rheumatoid arthritis (RA) involve several parameters, including:
- Joint involvement: having at least one joint with definite swelling that is not explained by another disease 2
- Serology: presence of rheumatoid factor or anti-citrullinated protein antibody 2, 3
- Levels of acute phase reactants: elevated C-reactive protein level or erythrocyte sedimentation rate 2, 3
- Duration of symptoms: the duration of the symptoms is also an important factor in the diagnosis of RA 3
Classification Criteria
The American Rheumatism Association (ARA) "Criteria for the Classification of Rheumatoid Arthritis-Diagnostic Criteria for Rheumatoid Arthritis" were published in 1958 and have become a standard 4. These criteria are empiric and attempt to incorporate reasonable combinations of sensitivity and specificity. However, it is recognized that these criteria should be expected to change with improved knowledge.
Diagnosis and Treatment
Early diagnosis and treatment of RA can avert or substantially slow progression of joint damage in up to 90% of patients, thereby preventing irreversible disability 5. The treatment target is remission or a state of at least low disease activity, which should be attained within 6 months 5. Methotrexate is first-line therapy and should be prescribed at an optimal dose of 25 mg weekly and in combination with glucocorticoids 5. If this treatment fails, sequential application of targeted therapies, such as biologic agents or Janus kinase inhibitors in combination with methotrexate, have allowed up to 75% of these patients to reach the treatment target over time 5.
Assessment of Disease Activity
The clinical parameter of morning stiffness is widely used to assess the status of RA, but its accurate quantitative assessment in a clinical setting has not yet been successful 6. A novel technology has been developed to assess passive resistance of the MCP III joint (stiffness) and its passive range of motion (PRoM), which has shown high sensitivity with respect to disease status as well as medication effect in RA patients 6.