Objectives The objective of this study was to investigate the association between dual seropositive, single seropositive and seronegative rheumatoid arthritis (RA) with radiographic erosions, disease flares, and mortality. Methods We performed a retrospective, population‐based study of residents in southern Minnesota with incident RA who fulfilled criteria for RA in 2003‐2019. Radiographic erosions and flares were evaluated within one year of incident RA. All‐cause mortality was obtained from medical records and death certificates. Cox models adjusted for age, sex, smoking status, year of incident RA, and comorbidities were used. Results The study included 1,373 patients with RA. At RA incidence, 37% were dual seropositive, 13% seropositive for anti‐CCP only, 12% seropositive for RF only, and 38% seronegative. The highest proportion of radiographic erosions prior to or within one year of RA incidence was in the dual seropositive (31%) and lowest in those seropositive for anti‐CCP only (13%). Flares occurred in 69% of the dual seropositive and 51% of the seropositive for anti‐CCP only within the first year of RA incidence. Those seropositive for RF only had over a two‐fold increase in mortality compared to the seronegatives (adjusted Hazard Ratio aHR: 2.18 95%CI:1.47‐3.24). In contrast, the dual seropositives had only a >50% increase in mortality (aHR: 1.66 95%CI:1.21‐2.28) and those seropositive only for anti‐CCP had a >30% increase in mortality (aHR: 1.32 95%CI:0.83‐2.11). Conclusion RA patients seropositive for RF only have an increase in mortality compared to patients who are dual seronegative. RF positivity could be an indicator of inflammation that requires pharmacologic treatment to decrease mortality.
Brooks et al. (Tue,) studied this question.