Turesson C, Jacobsson L T H, Sturfelt G, Matteson E L, Mathsson L, Rönnelid J
Department of Rheumatology, Malmö University Hospital, Södra Förstadsgatan 101, S-205 02 Malmö, Sweden.
Ann Rheum Dis. 2007 Jan;66(1):59-64. doi: 10.1136/ard.2006.054445. Epub 2006 Aug 10.
To study antibodies to cyclic citrullinated peptides (anti-CCP) and rheumatoid factor in patients with active, severe extra-articular rheumatoid arthritis (ExRA) compared with controls without ExRA.
35 consecutive patients with severe ExRA manifestations according to predefined criteria were studied. 70 patients with rheumatoid arthritis, but no ExRA manifestations, individually matched for age, sex and disease duration, served as controls. Patients were included when ExRA was diagnosed, before any new treatment was started. Anti-CCPs were detected with ELISA, rheumatoid factor was quantified using nephelometry and anti-nuclear antibodies (ANA) were investigated using indirect immune fluorescence.
Anti-CCPs were detected in 77% of patients with ExRA versus 56% of controls without ExRA (p = 0.03). Anti-CCP levels also tended to be higher in patients with ExRA (p = 0.09). Rheumatoid factor was detected in 94% v 71% of patients and controls, respectively (p = 0.006), and rheumatoid factor levels were higher in patients with ExRA (median interquartile range (IQR) 245 IU/ml (94-604) v 73 IU/ml (not detected-165); p = 0.001). Levels and occurrence of ANA did not differ between patients with ExRA and controls. Patients with ExRA had higher swollen joint counts and C reactive protein levels, but no correlations were found between anti-CCP or rheumatoid factor levels and these measures within the ExRA group.
Rheumatoid factor is strongly associated with severe ExRA manifestations in patients with rheumatoid arthritis, and a similar but weaker association exists for anti-CCPs. This suggests a role for rheumatoid factor and anti-CCP in the pathogenesis of ExRA.
研究活动性重度关节外类风湿关节炎（ExRA）患者与无ExRA的对照者体内抗环瓜氨酸肽抗体（抗CCP）和类风湿因子情况。
根据预定义标准，对35例有重度ExRA表现的连续患者进行研究。70例有类风湿关节炎但无ExRA表现的患者，按年龄、性别和病程进行个体匹配，作为对照。当确诊ExRA且在开始任何新治疗前纳入患者。采用酶联免疫吸附测定法检测抗CCP，用散射比浊法测定类风湿因子，用间接免疫荧光法检测抗核抗体（ANA）。
ExRA患者中77%检测到抗CCP，无ExRA的对照者中为56%（p = 0.03）。ExRA患者的抗CCP水平也有升高趋势（p = 0.09）。患者和对照者中类风湿因子检测率分别为94%和71%（p = 0.006），ExRA患者的类风湿因子水平更高（中位数四分位间距（IQR）245 IU/ml（94 - 604）对73 IU/ml（未检测到 - 165）；p = 0.001）。ExRA患者和对照者之间ANA水平和发生率无差异。ExRA患者的肿胀关节计数和C反应蛋白水平更高，但在ExRA组内抗CCP或类风湿因子水平与这些指标之间未发现相关性。
类风湿因子与类风湿关节炎患者的重度ExRA表现密切相关，抗CCP与之存在类似但较弱的关联。这提示类风湿因子和抗CCP在ExRA发病机制中起作用。
