Presentation: Associations of Anti-CCP and Rheumatoid Factor Concentrations with Future Disease Activity in Rheumatoid Arthritis (ACR/ARHP Annual Scientific Meeting)

Sunday, October 18, 2009: 9:00 AM - 11:00 AM

Hall D (Pennsylvania Convention Center)

Ben J. Miriovsky¹, Kaleb D. Michaud², Geoffrey M. Thiele³, James R. O'Dell⁴, Gw Cannon⁵, G.S. Kerr⁶, J.S. Richards⁷, Dannette S. Johnson⁸, Liron Caplan⁹, A.M. Reimold¹⁰, R.S. Hooker¹¹ and T. R. Mikuls⁴, ¹University of Nebraska Medical Center, Omaha, NE, ²University of Nebraska and NDB, Omaha, NE, ³Univ of NE Medical Ctr, Omaha, NE, ⁴U Nebraska, Omaha, NE, ⁵VA and University of Utah, Salt Lake City, UT, ⁶VAMC, Georgetown University, Washington, DC, ⁷Veterans Affairs Medical Ctr, Washington, DC, ⁸University of MS Med Ctr, Jackson, MS, ⁹Univ of CO Denver School of Med, Aurora, CO, ¹⁰VAMC, University of Texas Southwestern Medical Center, Dallas, TX, ¹¹Department of Veterans Affairs, Dallas, TX

Presentation Number: 332

Poster Board Number: 332

Purpose: To examine and compare associations of anti-CCP antibody (aCCP) and rheumatoid factor (RF) concentrations with future disease activity in patients with established rheumatoid arthritis (RA).

Methods: Study participants were U.S. veterans with RA (n = 855). Measures of disease activity included: 1) proportion of observation in remission, 2) remission for ≥ 3 consecutive months, and 3) area under the curve [AUC] for DAS28. Baseline aCCP and RF were examined dichotomously, as ordered categorical variables, and continuously. Associations of autoantibody status with disease activity outcomes were examined using multivariate regression.

Results: Patients were predominantly men (91%) with mean (SD) age of 66 (11) years and 2.3 (1.2) years of follow-up. Most were aCCP (75%) and RF (80%) positive. Associations of aCCP and RF status with sustained remission are shown in the figure below. After multivariate adjustment for age, sex, race/ethnicity, education, disease duration, follow-up time, smoking status, comorbidity, pharmacologic interventions, and disease status (DAS28 ≤ 2.6 vs. DAS28 > 2.6) at enrollment, aCCP and RF concentrations (per 100 unit increments) were associated with a lower proportion of observation in remission (b = -0.004, p = 0.054 and b = -0.002, p = 0.014, respectively), and greater AUC DAS28 (b = 0.02, p = 0.05 and b = 0.01, p = 0.002, respectively). In a sub-analysis of autoantibody discordant groups, higher aCCP concentrations in aCCP+ / RF- patients were associated with an increased likelihood of achieving remission (OR 1.10; 95% CI 1.00-1.20) (data not shown). In contrast, among aCCP- / RF+ patients, higher RF concentrations trended towards an inverse association with remission (OR 0.81; 95% CI 0.58-1.13) (data not shown).

Conclusions: Although higher aCCP concentrations are associated with greater future disease burden in patients with established RA, these associations appear to be related to concomitant elevations in serum RF.

Figure: Age- and sex-adjusted (■) and multivariate (○) ORs of aCCP and RF with the achievement of sustained remission (DAS28 ≤ 2.6). Shapes (■ and ○) correspond to ORs, horizontal bars represent 95%

CIs. ORs and CIs for ‘continuous level' correspond to 100 unit increments.

Presentation: Associations of Anti-CCP and Rheumatoid Factor Concentrations with Future Disease Activity in Rheumatoid Arthritis (ACR/ARHP Annual Scientific Meeting)

332 - Associations of Anti-CCP and Rheumatoid Factor Concentrations with Future Disease Activity in Rheumatoid Arthritis