Background Ethnic minorities with RA suffer greater disability than Caucasians, but prospective data on disease burden is absent.
Objectives To assess RA disease burden in ethnic minorities over time.
Methods EMRAC participants with any recorded followup clinical data were analyzed. RA inflammatory and clinical indices as well as drug usage were evaluated by racial/ethnic group. Repeated measure linear regression models were used to estimate association of inflammatory indices with clinical indices adjusting for race, disease duration and drug use.
Results 392 EMRAC participants with a total 1207 visits were available for analysis. At baseline, African-American (AA) had significantly higher ACPA titers (mean 181±89) compared to Caucasian (CA) (mean 91±108) and Other races (mean 125±113) (P=0.005). Both ESR and CRP were also elevated in AA compared to the other races (P<0.001 for both) at baseline. Racial differences persisted throughout followup as AA laboratory measures remained significantly higher than CA and Other. However, baseline and followup composite disease activity scores (RAPID3, DAS28 and CDAI) did not differ between AA, CA and Other when evaluated in unadjusted analysis. Repeated measures analysis estimated significant positive association between ESR and CRP with RAPID3, DAS28, and CDAI (P≤0.001 for all), but not ACPA, adjusting for race, duration and concurrent drug use.
Conclusions ACPA is not a significant predictor of RA disease burden and regardless of serology and race all patients should be treated aggressively. The implications of higher inflammatory indices in AA with RA, such as smoking and cardiovascular disease, needs to be examined further.
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Acknowledgements EMRAC (L. Espinoza, E. Treadwell, S. Dowell, M. Quinones, R. Perez Alamino, I. Garcia Valladares, Y. Sherrer, A. Mosley-Williams, T. Lawrence Ford, C. Flowers, A. Ince, H. Tian, A. Godoy, J. Amatruda, C. Stephens)
Disclosure of Interest : G. Kerr Grant/research support: Genentech, Pfizer, Bristol Myers Squibb, C. Swearingen Grant/research support: Genentech, Pfizer, Bristol Myers Squibb, Y. Yazici Grant/research support: Genentech, Pfizer, Bristol Myers Squibb