Session Information
Session Type: Abstract Submissions (ACR)
Background/Purpose: Autoantibodies against carbamylated proteins (anti-CarP) have been associated with more severe radiological damage in patients with rheumatoid arthritis (RA), including in a small subgroup seronegative for anti-citrullinated protein antibodies (ACPA) (1). The aims of this study were to i) validate these findings in a cohort of ACPA negative patients with early RA and ii) investigate the relationship between anti-CarP antibodies and markers of disease activity and disability cross-sectionally and over time.
Methods: The Norfolk Arthritis Register (NOAR) recruits adults with recent onset inflammatory polyarthritis (IP) (≥2 swollen joints for ≥4 weeks) from primary and secondary care in Norfolk, UK. At baseline, 5 and 10 years patients underwent a 51-tender and swollen joint count, gave a blood sample and completed a Health Assessment Questionnaire (HAQ). The 2010 ACR/EULAR classification criteria for RA were applied at baseline. X-rays of the hands and feet were performed at 5 years in all patients and at 10 years in those who were erosive at year 5. X-rays were read by two assessors using the Larsen method. ACPA and CRP measurements were performed in Manchester and anti-CarP antibodies were measured in the baseline sample in Leiden (IgG ELISA). Linear regression models tested for associations between anti-CarP antibodies and HAQ, joint counts, CRP at each assessment and Larsen score at 5 and 10 years, in ACPA negative patients with IP and those with ACPA negative RA. Multivariate models were adjusted for age, gender and disease duration.
Results: 292 patients were included in the analysis; 205 (72%) female; median age at symptom onset (IQR) 47 (36-56) years. Median symptom duration at baseline (IQR) was 26 (12-53) weeks. 87 (30%) patients were positive for anti-CarP antibodies and 161 (57%) patients satisfied the 2010 RA criteria. Anti-CarP positivity was not associated cross-sectionally with HAQ or joint counts at baseline, but there was a trend to association with CRP (table 1). X-rays were available on 240 patients at 5 years, 72 patients at 10 years. Anti-CarP positivity was associated with raised CRP at 5 years, but there was no association with Larsen score. At 10 years there was a significant association between anti-CarP antibodies and Larsen score in IP (adjusted ß-coefficient 16.2, 95% CI 2.73-29.7), and RA subgroup (adjusted ß-coefficient 21.2, 95% CI 3.00, 39.54).
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Conclusion: In a cohort of patients with ACPA negative IP and ACPA negative early RA, anti-CarP antibodies were associated with higher CRP at baseline and 5 years, and more severe radiographic disease at 10 years follow up in patients who were erosive at 5 years. Only a small proportion of patients had x-rays at 10 years, thus this association may be liable to selection bias. Nevertheless, anti-CarP antibodies may identify an important group of ACPA negative patients with poor long-term prognosis.
Reference: (1) Shi J et al PNAS 2011; 108:17373
Disclosure:
J. H. Humphreys,
None;
S. M. Verstappen,
None;
K. L. Hyrich,
None;
T. Marshall,
None;
A. Barton,
None;
R. E. M. Toes,
None;
L. A. Trouw,
Janssen Biologics,
9;
D. P. Symmons,
None.
« Back to 2013 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/anti-carbamylated-antibody-positivity-is-associated-with-more-severe-radiological-progression-in-patients-with-recent-onset-acpa-negative-rheumatoid-arthritis-results-from-the-norfolk-arthritis-regis/