The risk of individual autoantibodies, autoantibody combinations and levels for arthritis development in clinically suspect arthralgia. (11th September 2017)

• Record Type: Journal Article
• Authors: ten Brinck, Robin M.; van Steenbergen, Hanna W.; van Delft, Myrthe A. M.; Verheul, Marije K.; Toes, Rene E. M.; Trouw, Leendert A.; van der Helm – van Mil, Annette H. M.
• Is Part Of: Rheumatology. Volume 56:Number 12(2017)
• Page Start: 2145
• Page End: 2153
• Publication Date: 2017-09-11
• Subjects: rheumatoid arthritis -- autoantigens -- autoantibodies -- biomarkers -- inflammation -- epidemiology; Rheumatism -- Periodicals; Rheumatology -- Periodicals; 616.723005
• DOI: 10.1093/rheumatology/kex340
• Languages: English
• ISSNs: 1462-0324

Abstract

Abstract: Objectives: Autoantibody testing is helpful for predicting the risk of progression to clinical arthritis in subjects at risk. Previous longitudinal studies have mainly selected autoantibody-positive arthralgia patients, and consequently the predictive values of autoantibodies were evaluated relative to one another. This study assessed the risks for arthritis development of ACPA, RF and/or anti-carbamylated protein antibodies (anti-CarP) in arthralgia patients considered at risk for RA by rheumatologists, based on clinical characteristics (clinically suspect arthralgia, CSA). Methods: The baseline ACPA, RF and anti-CarP autoantibody status of 241 patients, consecutively included in the CSA cohort, was studied for risk of developing clinical arthritis during a median follow-up of 103 (interquartile range: 81–114) weeks. Results: Univariable associations for arthritis development were observed for ACPA, RF and anti-CarP antibodies; hazard ratios (HRs) (95% CI) were 8.5 (4.7–15.5), 5.1 (2.8–9.3) and 3.9 (1.9–7.7), respectively. In multivariable analysis, only ACPA was independently associated (HR = 5.1; 2.0–13.2). Relative to autoantibody-negative CSA patients, ACPA-negative/RF-positive patients had HRs of 2.6 (1.04–6.6), ACPA-positive/RF-negative patients 8.0 (2.4–27.4) and ACPA-positive/RF-positive patients 10.5 (5.4–20.6). Positive predictive values for development of clinical arthritis within 2 years were: 38% for ACPA-negative/RF-positive, 50% for ACPA-positive/RF-negative and 67% for ACPA-positive/RF-positive patients. Higher ACPA levels were not significantly associated with increased progression to clinical arthritis, in contrast to higher RF levels. Autoantibody levels were stable during follow-up. Conclusion: ACPA conferred the highest risk for arthritis development and had an additive value to RF. However, >30% of ACPA-positive/RF-positive CSA patients did not develop arthritis during the 2-year follow-up. Thus, CSA and information on autoantibodies is insufficient for accurately identifying imminent autoantibody-positive RA.