The ACR/EULAR 2010  criteria are a mean of classifying patients has having Rheumatoid Arthritis or not. It is a joined initiative from the American College of Rheumatology (ACR) and the EUropean League Against Rheumatism (EULAR). ACR/EULAR 2010 is the successor of the former ACR/EULAR 1987, which had been criticized for their lack of sensitivity in early disease.
On which patient should the criteria be applied?
- have at least 1 joint with definite clinical synovitis (swelling)*
- with the synovitis not better explained by another disease**
ACR/EULAR 2010 and RheumaKit?
These criteria are a standard in clinical studies for having a coherent group of RA patients. Nevertheless, they lack sensitivity and specificity. On our reference cohort of undifferentiated arthritis patients , they showed a sensitivity of 51% while RheumaKit on the same patients provided 93.5% sensitivity. The positive predicted value (i.e. the rate at which the criteria are right when they predict RA) was 72% on these patients while RheumaKit reached 84.9% on the same patients. More information about how to use RheumaKit for arthritis differential diagnosis and about its performances are available online.
How to use ACR/EULAR 2010?
ACR/EULAR 2010 takes the following elements into account:
- Joint involvement refers to any swollen or tender joint on examination, which may be confirmed by imaging evidence of synovitis. Distal interphalangeal joints, first carpometacarpal joints, and first metatarsophalangeal joints are excluded from assessment. Categories of joint distribution are classified according to the location and number of involved joints, with placement into the highest category possible based on the pattern of joint involvement. "Large joints" refers to shoulders, elbows, hips, knees, and ankles. "Small joints" refers to the metacarpophalangeal joints, proximal interphalangeal joints, second through fifth metatarsophalangeal joints, thumb interphalangeal joints, and wrists.
- Negative refers to IU values that are less than or equal to the upper limit of normal (ULN) for the laboratory and assay;
- Low-positive refers to IU values that are higher than the ULN but ≤3 times the ULN for the laboratory and assay;
- high-positive refers to IU values that are >3 times the ULN for the laboratory and assay.
- Where rheumatoid factor (RF) information is only available as positive or negative, a positive result should be scored as low-positive for RF.
- RF stands for Rheumatoid Factor.
- ACPA stands for anti−citrullinated protein antibody.
- Normal/abnormal is determined by local laboratory standards.
- CRP stands for C-reactive protein.
- ESR stands for erythrocyte sedimentation rate.
- Duration of symptoms refer to patient self-report of the duration of signs or symptoms of synovitis (e.g., pain, swelling, tenderness) of joints that are clinically involved at the time of assessment, regardless of treatment status.
Additional note: Although patients with a score of <6/10 are not classifiable as having RA, their status can be reassessed and the criteria might be fulfilled cumulatively over time.
* The criteria are aimed at classification of newly presenting patients. In addition, patients with erosive disease typical of rheumatoid arthritis (RA) with a history compatible with prior fulfillment of the 2010 criteria should be classified as having RA. Patients with longstanding disease, including those whose disease is inactive (with or without treatment) who, based on retrospectively available data, have previously fulfilled the 2010 criteria should be classified as having RA.
** Differential diagnoses vary among patients with different presentations, but may include conditions such as systemic lupus erythematosus, psoriatic arthritis, and gout. If it is unclear about the relevant differential diagnoses to consider, an expert rheumatologist should be consulted.