抗瓜氨酸化纤维蛋白原β67-77肽抗体在类风湿关节炎诊断中的意义

Prevalence and significance of antibodies to citrullinated hmnan fibrinogen β67-77 peptide in rheumatoid arthritis

目的检测类风湿关节炎（RA）患者血清抗纤维蛋白原（FIB）β67-77肽（FIB β67-77）及抗瓜氨酸化纤维蛋白原（C—FIB）β67-77肽（C-FIB β67-77）抗体水平，评价IgG、IgA、IgM型抗C—FIB β67-77抗体在RA诊断中的价值。方法酶联免疫吸附法（ELISA）检测227例RA患者、188例疾病对照和100名健康对照组血清抗C—FIB β67-77抗体的水平，分析其在RA诊断中的意义。结果（1）RA患者IgG、IgA、IgM型抗C—FIB β67-77抗体滴度均值（分别为104．8、69．6和78．2）均高于其他对照组（P〈0．01）。而各组血清中抗FIB β67-77抗体的滴度差异无统计学意义。（2）抗C—FIB β67-77抗体IgG型、IgA型和IgM型在RA中诊断的敏感性分别为50．7％、48．5％和55．1％；特异性分别为94．8％、92．7％和92．4％。联合检测3个亚型敏感性为87．7％，特异性可达78．5％。（3）抗C—FIB β67-77抗体IgG型、IgM型和IgA型在IgM-RF阴性患者中的阳性率分别是52．9％、39．2％和54．9％；抗角蛋白抗体（AKA）、抗核周因子（APF）和抗环瓜氨酸肽（CCP）抗体3种抗体均阴性的患者中阳性率分别为48．5％、53．1％和37．5％。结论抗C—FIB β67-77抗体在RA诊断中具有较好的敏感性和特异性，尤其对IgM—RF、AKA、APF及抗CCP抗体阴性RA的诊断具有参考意义。

Objective To detect the antibodies against human fibrinogen （FIB） β67-77 peptide and citrullinated human FIB β67-77 peptide in rheumatoid arthritis （RA） and examine their diagnostic values in RA. Methods The antibodies against FIB β67-77 peptide and citrullinated FIB β67-77 peptide were detected by enzyme-linked immunosorbent assay （ELISA） in 227 RA patients, 188 other connective tissue disease and 100 healthy controls. And their clinical applications were analyzed in the diagnosis of RA. Results （ 1 ） The prevalence and titer of IgG, IgA and IgM isotypes of anti-citrullinated FIB β67-77 peptide antibodies in RA were significantly higher than those with other rheumatic diseases and healthy individuals. However, the prevalence of anti-FIB β67-77 peptide antibodies in RA patients was similar to those with other rheumatic diseases and healthy individuals （P 〉 0. 05 ）. （2） The diagnostic sensitivity of IgG, IgA and IgM of anti- FIB β67-77 peptide antibodies for RA were 50. 7% , 48.5% and 55.1% and the specificity 94. 8% , 92. 7% and 92. 4% respectively. The sensitivity of combined detection of 3 subtypes was up to 87.7% and the specificity 78.5%. （3） No significant correlations existed between anti-citrullinated FIB β67-77 peptide antibodies, RF, anti-CCP antibody, AKA and APF respectively. Moreover, the seropositive rates of IgG, IgM and IgA of anti-citrullinated FIB β67-77 peptide were 52. 9% , 39.2% and 54. 9% in IgM-RF negative patients Versus 48.5%, 53.1% and 37.5% in anti-CCP antibody, AKA and APF negative patients respectively. Conclusion IgG, IgM and IgA antibodies to citrullinated FIB β67-77 pcptide are sensitive and specific in the diagnosis of RA. And the test of anti-citrulfinated FIB β67-77 peptide antibodies is especially useful in diagnosing RA with other negative autoantibodies.