Joint damage in rheumatoid arthritis progresses in remission according to the Disease Activity Score in 28 joints and is driven by residual swollen joints

Abstract

Objective: Remission has been defined as the ultimate target for patients with rheumatoid arthritis. The Disease Activity Score in 28 joints (DAS28) has been criticized for the amount of disease activity that remains in patients despite their achieving DAS28 remission. This study was undertaken to investigate the significance of residual inflammation in remission in relation to radiographic progression.

Methods: We pooled 1-year clinical data, kindly provided by the respective sponsors, on 864 patients in methotrexate monotherapy arms of recent pivotal trials. We identified patients who had attained persistent DAS28 remission from month 6 through month 12 (a DAS28(6-12) of <2.6). Among these patients we then assessed radiographic progression in total Sharp/van der Heijde scores (SHS) from baseline to 12 months between those with residual joint swelling (defined as a swollen joint count from month 6 through month 12 [SJC(6-12) ] of ≥2) and those without residual joint swelling (defined as an SJC(6-12) of <2).

Results: One hundred fourteen patients (13.2%) achieved a DAS28(6-12) of <2.6, of whom those without residual joint swelling (n = 92, 80.7%) had less radiographic progression over 1 year than those with residual joint swelling (n = 22, 19.3%) (mean ± SD SHS progression 0.2 ± 2.6 versus 2.2 ± 4.2; P = 0.11). Likewise, the proportion of patients with a total SHS progression of >0.5/year was significantly lower among those without joint swelling than among those with joint swelling (27.2% versus 50.0%; P = 0.039). DAS28 remitters without joint swelling showed progression comparable to that in the total group of remitters by the Simplified Disease Activity Index (remission defined as ≤3.3) and Clinical Disease Activity Index (remission defined as ≤2.8), namely, 0.2 versus -0.07 versus 0.16, respectively (P = 0.66).

Conclusion: Radiographic progression with nonbiologic treatment is minimal only when patients in DAS28 remission have no persistent residual joint swelling. Under these conditions, progression is comparable to that in patients with disease in remission according to other disease activity indices.