To evaluate associations between the presence of anti-cyclic citrullinated protein antibodies (anti-CCP) and rheumatoid factor (RF) and other outcomes, including joint erosions and both clinical and economic endpoints, in patients with rheumatoid arthritis (RA).
Data from the Brigham and Women's Hospital Rheumatoid Arthritis Sequential Study (BRASS), a prospective registry of adult RA patients with established or recent-onset RA, were analyzed. Logistic regression models were constructed to test associations between anti-CCP/RF seropositivity and erosive disease and the presence of anti-CCP/RF seropositivity plus erosive disease and (1) RA severity; (2) hospitalizations; (3) durable medical equipment (DME) use; and (4) worker productivity (e.g., employment status). Covariates in these models included patient age, gender, race, body mass index (BMI), number of comorbidities, and treatment.
Among 1309 registrants, those who were positive (vs. negative) for anti-CCP were 2.72 times more likely to have erosions (OR = 2.72; 95% CI: 1.77-4.18; P < 0.001). Individuals positive (vs. negative) for RF were 36% more likely to have erosions (95% CI: 0.88-2.08; P = 0.162). Patients with anti-CCP seropositivity and erosions were significantly more likely to: (1) have higher disease activity as measured by the Disease Activity Score in 28 joints C-reactive protein (DAS28-CRP ≥ 2.6); (2) be hospitalized; (3) use DME; and (4) be unemployed, disabled, or long-term disabled.
For the first time in a "real-world" setting including patients with both recent-onset and chronic RA, this study demonstrated that the combination of anti-CCP seropositivity and erosions were significantly associated with more adverse clinical and health-economic consequences, including a lower probability of low disease activity and higher health resource utilization, despite use of biologic disease-modifying antirheumatic drugs by many patients. This dual presentation may signal a need for more intensive therapies, even when observed in patients with chronic, as well as recent-onset, RA. Trial registration [Brigham and Women's Hospital (BWH) Rheumatoid Arthritis Sequential Study; Registry URL: https://clinicaltrials.gov/ct2/show/NCT01793103; ClinicalTrials.gov Identifier NCT01793103].