Background/Purpose:

The 2010 ACR/EULAR
classification criteria for rheumatoid arthritis (2010 RA criteria) facilitate
early classification of rheumatoid arthritis (RA). The criteria yield a score ranging
0-10, with the cut-off for definite RA set at 6 or more points. In general,
diagnostic certainty increases with an increasing number of criteria points.
Our objective was to study the 2-year outcome in a cohort of patients (pts)
with very early arthritis fulfilling the 2010 RA criteria at baseline,
according to the contribution from the 4 different criteria components (joint involvement,
serology, acute phase reactants, duration).

Methods:

1118 pts (age 18-75 years) with arthritis
of maximum 16 weeks’ duration were included in the NOR-VEAC (Norwegian Very
Early Arthritis Clinic) study from 2004 to 2010. All pts who fulfilled the 2010 RA criteria at baseline and had
follow-up data were included in the current analyses. Two clinical outcome
groups were defined: “Persistent disease” (pts prescribed with DMARDs, with a final
clinical diagnosis of RA and/or one or more swollen joints at last visit) and “self-limiting
arthritis” (no DMARD use ever, final clinical diagnosis not RA and no swollen
joints at last visit). The association between the components of the 2010 RA
criteria and outcome was examined by univariable and multivariable logistic
regression. Additionally, we performed subgroup analyses in the pts with only 6
criteria points.

Results:

Of the 256 pts fulfilling the 2010 RA
criteria (age 52.8±13.9 years, 63.3% females,
median (25-75 perc.) duration of joint swelling 63.5 (40.0-83.0) days, 57.4% anti-CCP
positive, DAS28 5.2±1.3), 36 had self-limiting arthritis.
The pts with self-limiting vs persistent disease more often had 5 joint involvement
points (77.8 vs 55.9%, p=0.013), 0 serology points (63.9 vs 24.5%, p<0.0005)
and 0 duration points (47.2 vs 22.3%, p=0.002). Multivariable logistic
regression showed that absence of serology points (OR 4.7, [2.2-10.1]) and duration points (OR 2.4, [1.1-5.1]) were independent predictors of self-limiting
arthritis.

A total of 66 pts had only 6 criteria points,
and 52.8% (19/36) of the pts with self-limiting arthritis belonged to this
group. When the 6 points consisted of 5 joint involvement points and 1 acute phase
point, 43.3% had self-limiting arthritis, as opposed to 16.7% for other 6-point
combos (p=0.017). Pts with an additional duration point (5 joint involvement points,
1 acute phase point and 1 duration point) less frequently had self-limiting
arthritis (19.5 vs 43.3%, p=0.03).

Conclusion:

In this study of 256 pts fulfilling the
2010 RA criteria at baseline, we found that not having a duration point or any serology
points were associated with self-limiting arthritis. Pts with 6 criteria points
made up by 5 joint involvement points and 1 acute phase point had a high
likelihood of having self-limiting arthritis during the 2-year follow-up.