Lemos Ana, Ramos Maria Piedade, Furtado Maria Jose, Carvalho Carla, Santos Maria Jose, Silva J Canas, Ventura Humberto
Laboratório de Imunologia, Serviço de Patologia Clinica.
Acta Reumatol Port. 2007 Oct-Dec;32(4):345-9.
The presence of IgM class rheumatoid factor RF-M in the serum is one of the ACR criteria for the classification of rheumatoid arthritis RA .
To compare the sensitivity and specificity of two diagnostic markers for RA in Portuguese patients the 2nd generation anti-cyclic citrullinated peptide antibodies anti-CCP2 and the RF-M.
Serum samples from 56 patients with established RA 44 women and 12 men mean disease duration 9 5 -8 5 years were evaluated for the presence of anti-CCP2 and RF-M. Results were compared with 93 samples from a control group with identical demographic characteristics 43 from patients with spondylarthropaties and 50 from healthy blood donors . The determination of anti-CCP2 antibodies was performed by enzymatic fluroimunoassay and RF-M was measured by microElisa.
Anti-CCP2 antibodies were positive in 40 patients with RA 71 4 at a mean antibody concentration of 350 5 UA ml range 11-1670 UA ml and negative in all controls. The RF-M was positive in 34 patients with RA 60 7 in 4 patients with spondylarthropaties 9 3 and in one blood donor 2 . The sensitivity specificity positive predictive value and negative predictive value for RF-M was 60 7 90 7 89 5 and 63 9 and for anti-CCP2 was 71 4 100 100 and 72 9 respectively.
The anti-CCP2 assay showed an excellent specificity and a global performance superior to that of the RF-M test in this population with established RA.
血清中IgM类类风湿因子（RF-M）的存在是美国风湿病学会（ACR）类风湿关节炎（RA）分类标准之一。
比较葡萄牙患者中两种RA诊断标志物的敏感性和特异性，即第二代抗环瓜氨酸肽抗体（抗CCP2）和RF-M。
对56例确诊为RA的患者（44例女性，12例男性，平均病程9.5 - 8.5年）的血清样本进行抗CCP2和RF-M检测。将结果与93例具有相同人口统计学特征的对照组样本进行比较，其中43例来自脊柱关节病患者，50例来自健康献血者。抗CCP2抗体的检测采用酶联荧光免疫分析法，RF-M的检测采用微量酶联免疫吸附测定法。
40例RA患者抗CCP2抗体呈阳性（71.4%），平均抗体浓度为350.5 UA/ml（范围11 - 1670 UA/ml），所有对照组均为阴性。34例RA患者RF-M呈阳性（60.7%），4例脊柱关节病患者中4例呈阳性（9.3%），1例献血者呈阳性（2%）。RF-M的敏感性、特异性、阳性预测值和阴性预测值分别为60.7%、90.7%、89.5%和63.9%，抗CCP2分别为71.4%、100%、100%和72.9%。
在该确诊为RA的人群中，抗CCP2检测显示出优异的特异性，整体性能优于RF-M检测。
