The 2010 ACR/EULAR criteria were derived to classify rheumatoid arthritis (RA) earlier in time. Previous studies indeed observed that the 2010 criteria were fulfilled earlier than the 1987 criteria. This study determined whether the 2010 criteria perform equally in early classification of autoantibody-positive and autoantibody-negative RA.
From the total Leiden-EAC (n = 3448) and ESPOIR (n = 813) RA patients who fulfilled the 1987 RA criteria at 1 year but not at presentation were selected (n = 463 and n = 53, respectively), as these patients were classified with delay with the 1987 criteria. These RA patients were studied on fulfilling the 2010 criteria at baseline (as 2010 positivity indicated that these RA patients were earlier identified) and these analyses were stratified for patients with and without anti-citrullinated protein antibodies (ACPA) and rheumatoid factor (RF). Analyses were repeated for DMARD start within the first year as reference for RA (instead of fulfilling the 1987 criteria).
In the EAC, 75% of the selected RA patients did already fulfill the 2010 criteria at baseline. In ESPOIR this was 57%, indeed demonstrating early classification with the 2010 criteria. Among the selected autoantibody-positive RA patients of the EAC, 93% was already identified at baseline with the 2010 criteria. Within autoantibody-negative RA this was 51% (p < 0.001), indicating that 49% of autoantibody-negative RA patients were not early classified with the 2010 criteria. Similarly, within autoantibody-positive RA patients in ESPOIR 92% were 2010 positive at baseline, whereas this was only 25% within autoantibody-negative RA (p < 0.001), indicating that 75% of autoantibody-negative RA patients were not early classified with the 2010 criteria. Similar results were obtained when DMARD start was the reference for RA.
The 2010 criteria perform well in the early identification of autoantibody-positive RA, but autoantibody-negative RA patients are still frequently missed with these criteria. This implies that other diagnostics are required for ACPA-negative patients.