García-Berrocal Belén, González Concepción, Pérez Marta, Navajo José A, Moreta Isabel, Dávila Carmen, González-Buitrago José M
Servicio de Bioquímica, Laboratorio de Autoinmunidad, Hospital Universitario, Salamanca 37007, Spain.
Clin Chim Acta. 2005 Apr;354(1-2):123-30. doi: 10.1016/j.cccn.2004.11.025.
Antibodies to citrullinated proteins have been described in patients with RA and these appear to be the most specific markers of the disease. The objective of this study was to analyse the improvement in diagnostic accuracy of anti-cyclic citrullinated peptide autoantibodies and IgA rheumatoid factor in patients with clinical suspicion of RA and who were IgM rheumatoid factor-positive. Anti-CCP antibodies were measured with three different second-generation enzyme immunoassays.
We chose 133 serum samples with IgM RF levels greater than 20 IU/mL sent to our Laboratory from Specialized Care Units. Subsequently, patients were classified according to their clinical records. Eighty-seven had rheumatoid arthritis and 46 had other diseases. In all samples anti-CCP and IgA RF were measured by the corresponding ELISAs.
Comparison of the three anti-CCP second-generation ELISAs revealed differences between them. Likewise, clinical performances in terms of sensitivity, specificity, and positive and negative likelihood ratios were different. In patients with IgM RF higher than 20 IU/mL, anti-CCP antibodies increased the clinical efficiency of IgM RF and offered better performance as compared with IgA RF.
The use of anti-CCP antibodies affords good clinical efficiency and modifies the pre-test probability of the occurrence of RA in patients with IgM rheumatoid factor higher than 20 IU/mL.
类风湿关节炎（RA）患者体内已发现抗瓜氨酸化蛋白抗体，这些抗体似乎是该疾病最具特异性的标志物。本研究的目的是分析抗环瓜氨酸肽自身抗体和IgA类风湿因子对临床怀疑患有RA且IgM类风湿因子呈阳性患者诊断准确性的改善情况。使用三种不同的第二代酶免疫测定法检测抗CCP抗体。
我们从专科护理单位选取了133份IgM RF水平高于20 IU/mL的血清样本送至我们实验室。随后，根据患者的临床记录进行分类。87例患有类风湿关节炎，46例患有其他疾病。在所有样本中，通过相应的ELISA法检测抗CCP和IgA RF。
三种抗CCP第二代ELISA法的比较显示它们之间存在差异。同样，在敏感性、特异性以及阳性和阴性似然比方面的临床性能也有所不同。在IgM RF高于20 IU/mL的患者中，抗CCP抗体提高了IgM RF的临床效率，并与IgA RF相比表现更佳。
抗CCP抗体的使用具有良好的临床效率，并改变了IgM类风湿因子高于20 IU/mL患者发生RA的检测前概率。
