Abstract
Objective. To investigate whether 3 rheumatoid arthritis–associated antibodies [rheumatoid factor (RF) and anticitrullinated protein antibodies (ACPA) or anticarbamylated protein (anti-CarP) antibodies] are present in hand osteoarthritis (HOA) and associate with erosive OA (EOA).
Methods. Anti-CarP IgG was measured by ELISA in baseline sera of patients with HOA from 3 cohorts: HOSTAS (n = 510, 27.2% EOA), ECHO (n = 47), and EHOA (n = 23), and in sera of healthy controls (HC; n = 196, mean age 44.1 yrs, 51.0% women). Moreover, ACPA-IgG and RF-IgM were additionally determined in HOSTAS and HC. The prevalence of autoantibodies was compared between HOA and HC and between erosive and nonerosive HOA. In HOSTAS, hand radiographs were scored (Kellgren-Lawrence, Osteoarthritis Research Society International osteophyte and joint space narrowing) and C-reactive protein (CRP) levels, representing inflammation, were assessed. Groups were compared using nonparametric tests.
Results. The prevalence of anti-CarP was low and not significantly different between the total HOA group and HC (6.6% vs 3.6%, p = 0.12). In HOSTAS, the prevalence of all tested autoantibodies was low (anti-CarP 7.1%, ACPA 0.8%, RF 6.1%), and there were no significant differences observed between HOA patients and HC or between erosive and nonerosive HOA. Further, radiographic damage and CRP levels were similar in anti-CarP+ and anti-CarP–, and RF+ and RF− HOSTAS patients.
Conclusion. The prevalence of autoantibodies is similar in HOA patients and HC, and these autoantibodies are not associated with erosive disease, structural damage, or inflammation in patients with HOA, indicating that another mechanism is driving erosive disease.
- OSTEOARTHRITIS
- EROSIVE HAND OSTEOARTHRITIS
- AUTOANTIBODIES
- ANTICITRULLINATED PROTEIN ANTIBODIES
- RHEUMATOID FACTOR
- ANTICARBAMYLATED PROTEIN ANTIBODIES
Footnotes
Supported by the Dutch Arthritis Foundation (14-2-402 and LLP-24), the Innovative Medicines Initiative Joint Undertaking (IMI JU)-funded project BeTheCure (115142-2) and the IMI JU-funded project under grant agreement number 115770, resources of which are composed of financial contributions from the European Union’s Seventh Framework Programme (FP7/2007-2013) and the European Federation of Pharmaceutical Industries and Associations (EFPIA) companies’ in-kind contribution. See www.imi.europa.eu and www.approachproject.eu. This communication reflects the views of the authors and neither IMI nor the European Union and EFPIA are liable for any use that may be made of the information contained herein. L.A. Trouw is supported by a ZON-MW Vidi grant (91712334). L.A. Trouw is listed as an inventor in a patent application regarding the detection of anticarbamylated protein antibodies for rheumatoid arthritis.
- Accepted for publication July 5, 2018.