Background Early undifferentiated arthritis (EUA) include early arthritis (EA) patients who fulfill less than 6 points of the 2010 ACR/EULAR classification criteria for rheumatoid arthritis (RA). The key element is to find predictors for differentiating patients with a limited disease from those developing a persistent erosive or non-erosive disease and to adapt treatment, accordingly.[1,2] On the other hand, the over treatment risk cannot be neglected.

Objectives This study was aimed to evaluate EUA patients and to characterize the disease during the first year of evolution in patients fulfilling more items or less items of the 2010 ACR/EULAR criteria at the first visit.

Methods Out of the EA patients registered in our EA database, those who were constantly present at each 3 months follow-up visit and who fulfilled less than 6 points of the 2010 ACR/EULAR criteria at the first visit were selected.

Patients were divided in two groups, according to the criteria fulfilled at baseline: group A (3 or 4 points) and group B (5 points). Clinical and paraclinical data from baseline and from the 12 months follow-up visit were registered. Clinical remission and the EULAR response criteria were evaluated. The final diagnosis at one year was noted.

Ultrasound (US) assessment was performed by the same experienced sonographer at specific anatomical sites of hands and feet, to detect synovial inflammation and bone damage.

Results Eighteen patients (ten in group A and 8 in group B) were included in the study. A female majority was seen in group A (9:1) compared to group B (1:1). The mean number of swollen joints was 2.1 (A) vs. 5.1 (B). Increased acute phase reactants were detected in 20% (A) and in 75% of patients (B). Twenty percent of patients (A) were anti-CCP antibodies positive vs. 37.5% (B). Hydroxychloroquine (HQ) was prescribed in 30% of cases (A) vs. none (B) and Methotrexate (MTX) in 75% (B) vs. 40% (A). Mean DAS28 score significantly decreased from 3.77 to 2.82 (A) and from 4.65 to 2.6 (B). The percentage of patients showing synovial hypertrophy at least at one examined site significantly decreased from 87.5% to 30% (B). US bone erosions were seen in 62.5% of patients both at baseline and at 1 year (B) and in 40% and 60% at baseline and at 1 year, respectively (A). The analysis of the response criteria showed 62.5% of patients (B) having a good EULAR response vs. 50% (A). An increased percentage of patients receiving combination therapy was seen in group A at 12 months. At one year, 7 (70%) patients (A) and 5 (62.5%) patients (B) fulfilled the 2010 ACR/EULAR criteria.

Conclusions The evolution towards an erosive disease was seen in milder forms of EUA, treated less aggressive initially. These patients expressed clinical and biological characteristics apparently benign, but developed more frequently RA. Studies on larger series of patients and the analysis of all signs of disease progression are needed to confirm the results.

References

1. Symmons DP, Silman AJ. Aspects of early arthritis. What determines the evolution of early undifferentiated arthritis and rheumatoid arthritis? An update from the Norfolk Arthritis Register. Arthritis research & Therapy.2006;8(4):214

2. vam der Helm-van Mil AH, et al. A prediction rule for disease outcome in patients with recent-onset udifferentiated arthritis how to guide individual treatment decisions. Arthritis Rheum 2007;56(2):433-440

Disclosure of Interest None declared

DOI 10.1136/annrheumdis-2014-eular.1388