Abstract
Objective
To evaluate the predictive values for disease progression of various antibodies against citrullinated peptide proteins (ACPA) and their relation to PTPN22 1858C/T polymorphism and HLA-DRB1 alleles in early rheumatoid arthritis (RA).
Methods
The ACPA, e.g., antibodies against mutated citrullinated vimentin (MCV), cyclic citrullinated peptides (CCP) type 2 and 3 (both of IgG isotype) and 3.1 (of both IgG and IgA isotypes), were analyzed at baseline in patients with early RA (n = 210) and in population controls (n = 102) using an enzyme immunoassay. A receiver-operating characteristic curve was constructed for each antibody. Disease activity [swollen and tender joints, visual analog scale for global health, and erythrocyte sedimentation rate (ESR)] was evaluated at baseline and regularly for 24 months. Radiographs of hands and feet were graded using the Larsen score.
Results
Patients with anti-MCV antibodies had significantly less reduction in Disease Activity Score (DAS28) over time (p < 0.01), and significantly increased area under the curve (AUC) for DAS28 (p < 0.05), ESR (p < 0.01), C-reactive protein (p < 0.01), and swollen joint count (p = 0.057) compared to those without. Corresponding differences were not found in patients with anti-CCP2, CCP3, and CCP3.1 antibodies. Radiological progression (p < 0.0001–0.01) and radiological outcome (p < 0.0001–0.01) at 24 months were significantly predicted by all ACPA after baseline adjustments. PTPN22 T variant and HLA-DRB1 alleles were not related to radiological progression or inflammatory activity over time.
Conclusion
Anti-MCV antibodies are associated with a more severe RA disease, as measured by DAS28, ESR, and swollen joint count over time, compared with anti-CCP2, CCP3, and CCP3.1 antibodies. Radiological progression was predicted equally by all 4 autoantibodies.
Key Indexing Terms:Footnotes
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L. Innala, MD; H. Kokkonen, MSc, Department of Rheumatology; C. Eriksson, MD, Department of Clinical Immunology; E. Jidell, MD, Department of Transfusion Medicine; E. Berglin, MD, PhD; S. Rantapää Dahlqvist, MD, PhD, Department of Rheumatology, University Hospital.
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Supported by grants from the Swedish Research Council (K2003-74XD-14705-01), King Gustaf V’s 80-Year Fund, and the Swedish Rheumatism Association.
- Accepted for publication January 10, 2008.
