Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Differences in Disease Severity and Response to Biologic Agents in a Racially Diverse US-Based Cohort of Patients with Rheumatoid Arthritis (RA).

Karpouzas2,  George A., Moran2,  Rosalinda, Dolatabadi1,  Soha, Weisman1,  Michael

Cedars Sinai
Harbor-UCLA

Background:

Descriptions of RA behavior and response to therapy originate largely from studies in Caucasians. Additionaly, most subjects in clinical practice do not fulfill inclusion criteria for most RA trials. These observations may question the generalizability of the results of such trials to racially diverse populations. We describe RA clinical, serologic parameters, conventional and biologic DMARD utilization and therapeutic outcomes in a large, minority-enriched cohort from a single academic Center in the US.

Methods:

We report on 433 pts fullfiling 1987 ACR criteria for RA and with regular follow-up. Patients were assessed quarterly, and Disease Activity Score (DAS28-3v-ESR) and functional outcomes (HAQ-DI, patient assessment of pain) were recorded. Good EULAR response (DAS28<3.2 and DAS28 change>1.2) was the only acceptable outcome and therapeutic adjustments were aimed at that goal. Continuous variables in unmatched and matched groups were analyzed with ANOVA and Wilcoxon's matched pairs test respectively. Categorical variables were analysed with Chi-square tests.

Results:

Hispanics (H) comprised 81%, African Americans (AA) 12%, Caucasians (C) 5.1%, and others 3.8%. H and AA were significantly more female, and H were younger. There was no difference in disease duration, ESR, CRP, Rheumatoid Factor (RF) status and titer, or erosions in any group. ACPA (a-cyclic citrullinated peptide Ab) prevailed in AA (p=0.049). H and AA overall showed higher cross-sectional disease severity compared to C (table-p=0.04). Fewer H and AA achieved DAS28<3.2 than C (p=0.02); to accomplish this, H had higher frequency of biologic utilization than both AA and C (p=0.003). H or AA allocated biologics did not have higher disease severity at biologic onset, nor were they prescribed biologics more frequently than C. Despite a robust and similar change in DAS28 from baseline compared to C, significantly less of biologic treated H and AA achieved DAS28<3.2 (p=0.003).

Conclusion:

US-based H and AA with RA have higher cross-sectional disease severity than C. In spite of similar disease activity at biologic onset, this likely reflects inferior response to biologic therapy; significantly fewer biologic-treated H and AA subjects achieved good disease control compared to C. The reasons for these disparities are under investigation.

Table. Patient Characteristics

N (%)Hispanic = 349 (80.6)AA = 50 (11.5)C = 22 (5.1)p-all groups
F/M (%)88/1292/864/36<0.0001
Age (±SD yrs)52.4 ± 11.256.4 ± 10.657.9 ± 8.90.01
DAS28-3v (M ± SEM)3.2 ± 0.063.4 ± 0.172.7 ± 0.20.04
>=1 DMARD (%)93.693.6100ns
Biologics (%)60.35059ns
DAS28 <=3.2 (%)534881.80.02
% with DAS28 <=3.2 on biologics64.341.655.60.003
DAS28 (M ± SEM) @biologic onset4.8 ± 0.094.9 ± 0.24.5 ± 0.5ns
Biologic prescribed @start (%)70.16059ns
D DAS28 (M ± SEM)1.48 ± 0.11.23 ± 0.271.41 ± 0.48ns
% of biologic Rx with DAS28 <=3.256.941.776.90.003

To cite this abstract, please use the following information:
Karpouzas, George A., Moran, Rosalinda, Dolatabadi, Soha, Weisman, Michael; Differences in Disease Severity and Response to Biologic Agents in a Racially Diverse US-Based Cohort of Patients with Rheumatoid Arthritis (RA). [abstract]. Arthritis Rheum 2010;62 Suppl 10 :305
DOI: 10.1002/art.28074

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