The impact of seropositivity on the effectiveness of biologic anti-rheumatic agents: results from a collaboration of 16 registries.

Objectives: RF and ACPA are used as diagnostic tools and their presence has been associated with clinical response to some biologic DMARDs (bDMARDs) in RA. This study compared the impact of seropositivity on drug discontinuation and effectiveness of bDMARDs in patients with RA, using head-to-head comparisons in a real-world setting.

Methods: We conducted a pooled analysis of 16 observational RA registries.