Shi Jing, van de Stadt Lotte A, Levarht E W Nivine, Huizinga Tom W J, Toes René E M, Trouw Leendert A, van Schaardenburg Dirkjan
Leiden University Medical Center, Leiden, The Netherlands.
Arthritis Rheum. 2013 Apr;65(4):911-5. doi: 10.1002/art.37830.
Recently, we discovered a new autoantibody system in rheumatoid arthritis (RA): anti-carbamylated protein (anti-CarP) antibodies. These antibodies have value in predicting joint destruction; however, it is not clear whether they are present before the diagnosis of RA and whether they have value as predictors of RA development. Therefore, we studied whether anti-CarP antibodies are present in patients with arthralgia and whether their presence is associated with the development of RA.
Sera from 340 arthralgia patients who did not have clinical signs of arthritis but who were positive for IgM rheumatoid factor (IgM-RF) and/or anti-cyclic citrullinated peptide 2 (anti-CCP-2) and 32 healthy controls were tested for anti-CarP IgG antibodies. Of the patients with arthralgia, 111 were IgM-RF positive/anti-CCP-2 antibody negative and 229 were anti-CCP-2 antibody positive. Patients were observed for the development of RA (based on the 2010 American College of Rheumatology/European League Against Rheumatism classification criteria) during a median followup period of 36 months. Cox proportional hazards regression analysis was performed to compare the risk of developing RA between arthralgia patients who were positive for anti-CarP antibodies and those who were negative for anti-CarP antibodies during followup.
Anti-CarP antibodies were present in the sera of 39% of the patients. One hundred twenty patients developed RA, after a median of 12 months (interquartile range [IQR] 6-24). The presence of anti-CarP antibodies was associated with the development of RA in the entire arthralgia cohort after correction for RF and anti-CCP-2 antibody status (hazard ratio 1.56 [95% confidence interval 1.06-2.29], P=0.023), as well as in the anti-CCP-2 antibody-positive subgroup (odds ratio 2.231 [95% confidence interval 1.31-3.79], P=0.003).
Anti-CarP antibodies are present in patients with arthralgia, and their presence predicts the development of RA independent of anti-CCP-2 antibodies.
最近，我们在类风湿关节炎（RA）中发现了一种新的自身抗体系统：抗瓜氨酸化蛋白（抗CarP）抗体。这些抗体在预测关节破坏方面具有价值；然而，尚不清楚它们是否在RA诊断之前就已存在，以及它们作为RA发病预测指标是否具有价值。因此，我们研究了关节痛患者中是否存在抗CarP抗体，以及其存在是否与RA的发生有关。
检测了340例无关节炎临床体征但IgM类风湿因子（IgM-RF）和/或抗环瓜氨酸肽2（抗CCP-2）呈阳性的关节痛患者以及32名健康对照者血清中的抗CarP IgG抗体。在这些关节痛患者中，111例IgM-RF阳性/抗CCP-2抗体阴性，229例抗CCP-2抗体阳性。在中位随访期36个月期间观察患者是否发生RA（基于2010年美国风湿病学会/欧洲抗风湿病联盟分类标准）。进行Cox比例风险回归分析，以比较随访期间抗CarP抗体阳性的关节痛患者与抗CarP抗体阴性的关节痛患者发生RA的风险。
39%的患者血清中存在抗CarP抗体。120例患者发生了RA，中位时间为12个月（四分位间距[IQR]6 - 24）。在校正RF和抗CCP-2抗体状态后，抗CarP抗体的存在与整个关节痛队列中RA的发生相关（风险比1.56[95%置信区间1.06 - 2.29]，P = 0.023），在抗CCP-2抗体阳性亚组中也是如此（优势比2.231[95%置信区间1.31 - 3.79]，P = 0.003）。
关节痛患者中存在抗CarP抗体，其存在可独立于抗CCP-2抗体预测RA的发生。
