Vannini A, Cheung K, Fusconi M, Stammen-Vogelzangs J, Drenth J P H, Dall'Aglio A C, Bianchi F B, Bakker-Jonges L E, van Venrooij W J, Pruijn G J M, Zendman A J W
Department of Internal Medicine, Cardioangiology, Hepatology, University of Bologna, and Azienda Ospedaliero-Universitaria S. Orsola-Malpighi, Bologna, Italy.
Ann Rheum Dis. 2007 Apr;66(4):511-6. doi: 10.1136/ard.2006.058933. Epub 2006 Sep 19.
Antibodies directed against citrullinated proteins (eg anti-cyclic citrullinated peptide (CCP)) have excellent diagnostic and good prognostic potential for rheumatoid arthritis. Type 1 autoimmune hepatitis (AIH-1) is a chronic liver disease characterised by a variety of serum autoantibodies. Recently, in a large group of patients with AIH-1 without clear rheumatoid arthritis overlap, a relatively high percentage (9%) of anti-CCP2 positivity was scored.
To characterise the citrulline-dependence of the observed anti-CCP2 positivity in AIH-1 sera as well as in other groups of patients without rheumatoid arthritis (mainly rheumatic diseases).
Serum samples of 57 patients with AIH-1 and 66 patients without rheumatoid arthritis, most of them reported as anti-CCP positive, were tested for citrulline-specific reactivity with a second generation anti-CCP kit, with the citrullinated and the corresponding non-citrullinated (arginine-containing) antigen. A subset of AIH-1 sera was also tested with a CCP1 ELISA (and arginine control).
The anti-CCP2 reactivity of most non-rheumatoid arthritis rheumatic diseases samples (87-93%) was citrulline-specific, whereas a relatively high percentage of AIH-1 samples (42-50%) turned out to be reactive in a citrulline-independent manner. The use of citrullinated and non-citrullinated CCP1 peptides confirmed a high occurrence of citrulline-independent reactivity in AIH-1 samples.
In rheumatoid arthritis and most non-rheumatoid arthritis rheumatologic disease sera, anti-CCP positivity is citrulline-dependent. However in some patients, particularly patients with AIH-1, citrulline-independent reactivity in the anti-CCP2 test can occur. A positive CCP test in a non-rheumatic disease (eg liver disease) should therefore be interpreted with care, and preferably followed by a control ELISA with a non-citrullinated antigen.
针对瓜氨酸化蛋白的抗体（如抗环瓜氨酸肽（CCP））对类风湿关节炎具有出色的诊断价值和良好的预后评估潜力。1型自身免疫性肝炎（AIH - 1）是一种以多种血清自身抗体为特征的慢性肝病。最近，在一大组无明确类风湿关节炎重叠的AIH - 1患者中，抗CCP2阳性率相对较高（9%）。
明确AIH - 1血清以及其他无类风湿关节炎患者群体（主要为风湿性疾病）中观察到的抗CCP2阳性对瓜氨酸的依赖性。
使用第二代抗CCP试剂盒，对57例AIH - 1患者和66例无类风湿关节炎患者（其中大多数报告为抗CCP阳性）的血清样本进行瓜氨酸特异性反应性检测，检测瓜氨酸化和相应的非瓜氨酸化（含精氨酸）抗原。还使用CCP1 ELISA（及精氨酸对照）对一部分AIH - 1血清进行检测。
大多数非类风湿关节炎风湿性疾病样本（87 - 93%）的抗CCP2反应性是瓜氨酸特异性的，而相对较高比例的AIH - 1样本（42 - 50%）以不依赖瓜氨酸的方式产生反应。使用瓜氨酸化和非瓜氨酸化的CCP1肽证实了AIH - 1样本中存在高比例的不依赖瓜氨酸的反应性。
在类风湿关节炎和大多数非类风湿关节炎风湿性疾病血清中，抗CCP阳性是瓜氨酸依赖性的。然而，在一些患者中，特别是AIH - 1患者，抗CCP2检测中可能出现不依赖瓜氨酸的反应性。因此，在非风湿性疾病（如肝病）中CCP检测呈阳性时应谨慎解读，最好随后用非瓜氨酸化抗原进行对照ELISA检测。
