流式点阵免疫发光法检测抗染色质抗体在结缔组织病诊断中的价值

Role of anti-chromatin antibody determined by automatic multiplex bead immunoassay in the diagnosis of connective tissue diseases

目的探讨流式点阵免疫发光法检测抗染色质抗体在结缔组织病诊断中的价值。方法采用流式点阵免疫荧光法检测384例结缔组织病患者[系统性红斑狼疮(SLE)243例、多肌炎(PM)39例、混合性结缔组织病(MCTD)15例、干燥综合征(SS)51例、系统性硬化症(SSc)7例、类风湿关节炎(RA)29例]、200例非风湿病患者(疾病对照组)、200名体检正常者(正常对照组)血清抗染色质抗体的表达,同时采用酶联免疫吸附试验(ELISA)检测抗双链DNA(dsDNA)抗体、抗组蛋白抗体及抗核小体抗体,采用间接免疫荧光法检测抗核抗体(ANA)。采用Spearman相关分析评估系统性红斑狼疮疾病活动度指数(SLEDIA)评分与抗染色质抗体的相关性。采用受试者工作特征(ROC)曲线分析各项指标诊断SLE的价值。结果正常对照组、疾病对照组、SLE组、MCTD组、PM组、SS组、SSc组及RA组抗染色质抗体阳性率分别为0.00%、1.00%、70.78%、73.33%、23.08%、17.65%、28.57%及10.34%。抗染色质抗体阳性率随ANA滴度的增高而增高。将MCTD组、PM组、SS组、SSc组及RA组归为非SLE组,SLE组血清抗染色质抗体水平显著高于非SLE组(P<0.0001)。SLE组中抗染色质抗体、抗dsDNA抗体、抗核小体抗体和抗组蛋白抗体中仅单个抗体阳性而其他3种抗体均阴性的比例分别为45.39%、32.34%、13.42%和7.37%,4种抗体之间均有一定比例的交叉阳性。抗核小体抗体、抗染色质抗体、抗dsDNA抗体及抗组蛋白抗体诊断SLE ROC曲线的曲线下面积(AUC)分别为0.813、0.779、0.777及0.613。抗染色质抗体与SLEDAI评分无相关性(r=0.1246,P=0.1770)。SLE患者未合并肾炎者与合并肾炎者之间血清抗染色质抗体水平差异无统计意义(P>0.05)。结论流式点阵免疫荧光法检测抗染色质抗体在结缔组织病诊断中有一定的临床价值。

Objective To investigate the role of anti-chromatin antibody determined by automatic multiplex bead immunoassay in the diagnosis of connective tissue diseases.Methods The expressions of anti-chromatin antibody in 384 patients with connective tissue diseases[243 cases of systemic lupus erythematosus(SLE),39 cases of polymyositis(PM),15 cases of mixed connective tissue disease(MCTD),51 cases of Sj?gen's syndrome(SS),7 cases of systemic sclerosis(SSc)and 29 cases of rheumatoid arthritis(RA)],200 nonrheumatic disease patients(disease control group)and 200 healthy subjects(healthy control group)were determined.Anti-double-stranded DNA(dsDNA)antibodies,anti-histone antibodies and anti-nucleosome antibodies were determined by enzyme-linked immunosorbent assay(ELISA).Anti-nuclear antibodies(ANA)were determined by indirect immunofluorescence.The correlation between systemic lupus erythematosus disease activity index(SLEDAI)score and anti-chromatin antibody was evaluated.Receiver operating characteristic(ROC)curve was used to analyze the roles of these indicators for the diagnosis of SLE.Results The positive rates of anti-chromatin antibodies in healthy control,disease control,SLE,MCTD,PM,SS,SSc and RA groups were 0.00%,1.00%,70.78%,73.33%,23.08%,17.65%,28.57%and 10.34%,respectively.The positive rate of anti-chromatin antibodies increased with the increase of ANA titer.MCTD,PM,SS,SSc and RA groups were merged into non-SLE group.Serum anti-chromatin antibody level in SLE group was higher than that in non-SLE group(P<0.0001).For anti-chromatin antibody,anti-dsDNA antibody,anti-nucleosome antibody and anti-histone antibody in SLE group,the rates of single-antibody positive and the other 3-antibody negative was 45.39%,32.34%,13.42%and 7.37%,respectively.There were some cross-positive rates among the 4 antibodies.The areas under curves(AUC)of anti-nucleosome antibody,anti-chromatin antibody,anti-dsDNA antibody and anti-histone antibody for the diagnosis of SLE were 0.813,0.779,0.777 and 0.613,respectively.There was no correlation between anti-chromatin antibodies and SLEDAI score(r=0.1246,P=0.1770).There was no statistical significance in serum anti-chromatin antibodies between SLE patients without nephritis and those with nephritis(P>0.05).Conclusions Automatic multiplex bead immunoassay for the determination of anti-chromatin antibody plays a role in the diagnosis of connective tissue diseases.