Early rheumatoid factor decline predicts subsequent clinical remission in rheumatoid arthritis: the ANSWER cohort.

Abstract

Objectives: To compare early changes in RF across classes of biological or targeted synthetic DMARDs (b/tsDMARDs) and assess whether early RF decline was associated with 12-month clinical remission in RA.

Methods: We retrospectively analysed 1423 newly initiated b/tsDMARD treatment courses from the multicentre ANSWER cohort that continued for ≥12 months and had RF measured at baseline and 3 months. Early RF decline was defined as a ≥20% reduction at 3 months. Multivariable regression assessed factors associated with RF change and 12-month Clinical Disease Activity Index (CDAI) remission. Twelve-month remission rates were also compared across four categories of RF reduction.

Results: RF reduction differed across classes, with Janus kinase inhibitors (JAKi) showing the greatest decline. Compared with TNF inhibitors (TNFi), JAKi were associated with a greater RF reduction (β = -14.50, 95% CI: -20.04 to -8.97; P < 0.001). The direction was similar in multiple sensitivity analyses and remained significant in propensity score-matched analyses. Early RF decline was independently associated with 12-month CDAI remission (adjusted OR 1.39, 95% CI: 1.04-1.88; P = 0.029). A significant overall trend towards higher 12-month remission rates was observed across categories of greater RF reduction (P for trend = 0.004).

Conclusion: Early RF decline differed across b/tsDMARD classes and was associated with 12-month remission. Longitudinal RF dynamics may provide clinically useful prognostic information in RA.