ACPA fine-specificity profiles in early rheumatoid arthritis patients do not correlate with clinical features at baseline or with disease progression
1 Department of Biomolecular Chemistry, Institute for Molecules and Materials and Nijmegen Center for Molecular Life Sciences, Radboud University Nijmegen, PO Box 9101, NL-6500 HB Nijmegen, The Netherlands
2 Department of Rheumatology, Leiden University Medical Center, PO Box 9600, NL-2300 RC Leiden, The Netherlands
3 Department of Analytical Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, PO Box 9010, NL-6500 GL Nijmegen, The Netherlands
4 Ssens BV, Pantheon 1, NL-7521 PR, Enschede, The Netherlands
5 Euro Diagnostica AB, Toernooiveld 1, NL-6525 ED Nijmegen, The Netherlands
6 ModiQuest BV, Pivot Park RE2142, Molenweg 79, NL-5349 AC Oss, The Netherlands
7 Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, PO Box 9600, NL-2300 RC Leiden, The Netherlands
Arthritis Research & Therapy 2013, 15:R140 doi:10.1186/ar4322Published: 1 October 2013
Autoantibodies against citrullinated peptides/proteins (ACPA) are found in approximately 75% of the sera of patients with rheumatoid arthritis (RA). The RA-specific ACPA are frequently present prior to disease onset and their presence associates with a more erosive disease course. ACPA can therefore be used to aid the diagnosis and prognosis of RA. Recently, it became clear that ACPA are very heterogeneous, both in an individual patient and among different patients. The aim of this study was to investigate whether clinically meaningful ACPA profiles exist in early RA patients.
Twenty citrullinated peptides and the corresponding non-citrullinated control peptides were immobilized on microarray sensor chips. Sera from 374 early arthritis patients were analyzed by surface plasmon resonance imaging (iSPR) of biomolecular interactions on the sensor chip.
Cluster analysis of the reactivities with the citrullinated peptides, after subtraction of the reactivities with the corresponding control peptides confirmed the heterogeneity of the ACPA response in RA and revealed 12 distinct ACPA profiles. The association of the 5 most frequent profiles with clinical features at diagnosis and during the disease course was examined, showing no statistically significant associations.
Compared to the detection of ACPA in RA sera by CCP-based assays, ACPA profiling in early arthritis patients did not reveal associations with disease activity and progression scores.