系统性红斑狼疮患者自身抗体联合检测的意义

目的探讨抗核抗体（ANA），抗双链DNA（dsDNA）抗体，抗Smith（Sm）抗体和抗核小体抗体（AnuA）四种自身抗体单项及联合检测在系统性红斑狼疮（SLE）的诊断中的价值。方法测定56例SLE患者，108例其他结缔组织病患者及50例健康人群血清中的自身抗体。以间接免疫荧光法测定ANA，抗dsDNA抗体；以免疫印迹法测定抗Sm抗体，酶联免疫吸附试验（ELISA）测定AnuA。结果56例SLE患者血清自身抗体检测中：ANA、抗dsDNA抗体、抗Sm抗体、AnuA阳性率分别为：91．0％、44．6％、35．7％、64．3％；特异性分别为：70．9％，100％，98．7％，98．1％。在抗dsDNA抗体，抗Sm抗体，AnuA三者中，任何一项检测结果阴性时，其他两种自身抗体均出现一定阳性率，并以AnuA在抗dsDNA抗体、抗Sm抗体阴性时阳性检出率最高，达51．6％和61．1％。三者联合检测阳性率为83．9％。结论在检测的四种自身抗体中以ANA敏感性最高，其他三种特异性均可达97％以上，除AnuA敏感性稍高，其他两项检测值均低于50％。三者联合检测可较大程度提高SLE检测阳性率，并且特异性也与单独检测差异无显著性，且三者具有明显的互补作用。

The significance of combined detection of autoantibodies in SLE

Objective To investigate the specificity and sensitivity of autoantibody analyses for antinuclear antibody(ANA),anti-double stranded DNA antibody(anti-dsDNA),anti-Smith antibody(anti-Sm)and antinuclesome antibody(AnuA)in systemic lupus erythematosus(SLE),and evaluate the significance of combined detection of these autoantibodies in the diagnosis of SLE.Methods Fifty-six patients with SLE,108 patients with other autoimmune diseases and 50 healthy people were studied.ANA and anti-dsDNA were detected by indirect immunofluorescence assay,anti-Sm was detected by Western blot and AnuA was detected by ELISA.Results In the assays mentioned above,the serum positive rates of ANA,anti-dsDNA,anti-Sm and AnuA were 91%,44.6%,35.7% and 64.3%,and the specificities were 70.9%,100%,98.7%,and 98.1% respectively in patients with SLE.Among the antibodies of anti-dsDNA antibody,anti-Sm,and AnuA,when one antibody was negative,other two might show positive in some cases,and the highest positive rate of AnuA could reach 51.6% and 61.1% when anti-dsDNA and anti-Sm were negative.The positive rate of combined determination of anti-dsDNA,anti-Sm and AnuA was 87.1%.Conclusion The sensitivity of ANA detection is the highest,however,the sensitivities of the detection of other autoantibodies in this study is less than 50%.The specificity of the detection of anti-dsDNA,anti-Sm and AnuA is over 97%.The combined determination of anti-dsDNA,anti-Sm and AnuA improves the sensitivity of the detection for SLE without obvious change of the specificity.The detections of the three antibodies are complementary for the diagnosis of SLE.