不同底物间接免疫荧光法检测细胞膜DNA抗体在儿童系统性红斑狼疮的临床价值研究

目的：比较两种细胞株为底物间接免疫荧光法( indirect immunofluorescence assay,IIF)检测细胞膜DNA( cell membrane DNA,cmDNA)抗体在儿童系统性红斑狼疮( juvenile systemic lupus erythema-tosus,JSLE)中的检测效果。评价cmDNA抗体单独及与核小体抗体( anti-nucleosome antibody,AnuA)、史密斯( Smith,Sm)抗体和双链DNA( double-stranded DNA,dsDNA)抗体联合检测对JSLE的诊断价值；探讨cmDNA抗体与临床特点的相关性。方法选取92例JSLE为研究对象,71例非JSLE风湿病患儿为对照组。留血清采用IIF分别观察培养的人B细胞株Raji、人早幼粒白血病细胞株HL60细胞膜的荧光图形；同时用IIF检测抗核抗体( antinuclear antibody,ANA)；联合酶联免疫吸附法( enzyme-linked immuno sorbent assay,ELISA)和IIF检测dsDNA抗体；联合应用免疫双扩散法和免疫印迹法检测Sm抗体、ELISA法测定AnuA,收集同期临床资料。结果以两种细胞株为底物检测JSLE患儿血清cmDNA抗体,发现Raji细胞株较HL60细胞株更易复苏、荧光图形亮度更强,表达效果更好。 cmDNA抗体在JSLE组较对照组有更高的阳性率。以Raji细胞株为底物检测cmDNA抗体,cmDNA抗体的敏感性明显高于Sm抗体及dsDNA抗体(P<0．01),特异性与dsDNA抗体相似(P>0．05),但低于Sm抗体及AnuA(P<0．01)。 cmDNA抗体分别与dsDNA抗体、Sm抗体及AnuA联合检测在SLE诊断中的敏感性均明显高于单独检测( P<0．05)。cmDNA抗体与SLE疾病活动度评分无相关性( P=0．907)。结论 cmDNA抗体对儿童SLE诊断的敏感性高,特异性强,可能成为儿童SLE诊断的相对特异性抗体之一。 cmDNA抗体与dsDNA抗体、Sm抗体及AnuA联合检测可提高对儿童SLE诊断的敏感性。选择Raji细胞株为底物检测cmDNA抗体较HL60细胞株更有优势。

Indirect immunofluorescence on different cell line in detection of cell membrane DNA antibody in juvenile systemic lupus erythematosus

Objective To detect anti-cell membrane DNA ( cmDNA) antibody with human B lym-phocyte Raji cells and human promyelocytic leukemia HL60 cells as substrates and to compare the diagnostic value of anti-cmDNA antibody with that of anti-nucleosome antibody ( AnuA ) , anti-Sm antibody and anti-double-stranded DNA ( dsDNA) antibody in juvenile systemic lupus erythematosus ( JSLE) patients. Meth-ods We recruited 92 JSLE patients and 71 patients with other rheumatic diseases. Anti-cmDNA antibody an-dantinuclear antibody ( ANA ) was detected in patient serum by indirect immunofluorescence assays ( IIF ) . Anti-dsDNA antibody were detected by combining enzyme-linked immuno sorbent assay ( ELISA) and IIF. Anti-Sm antibody were detected by double immunodiffusion assay and immunoblotting, while anti-nucleosome antibody ( AnuA) were detected by ELISA. We collected concurrent clinical data. Results Anti-cmDNA antibody demonstrated stronger intensity of fluorescent patterns in using Raji cells as substrate than HL60 cells. JSLE patients had a significantly higher positive percentage of anti-cmDNA than patients with other rheu-matoid diseases. The sensitivity of anti-cmDNA on cell line Raji was higher than that of anti-dsDNA and anti-Sm (P<0. 01), the specificity of anti-cmDNA was close to anti-dsDNA (P>0. 05) and was lower than anti-Sm and AnuA (P<0. 01). The sensitivity of anti-cmDNA was similar to AnuA (P>0. 05) and the specificity was lower than AnuA (P<0. 01). The sensitivities of anti-dsDNA, anti-Sm and AnuA by combining with an-ti-cmDNA were much higher than that of the above antibody detected respectively ( P<0. 05 ) . Anti-cmDNA had no correlation with SLE disease activity index ( P=0. 907 ) . Conclusion The high sensitivity and speci-ficity of anti-cmDNA antibody make it a valuable diagnostic tool for JSLE. Combined detection of anti-cmDNA and other autoantibody might further improve the sensitivity in JSLE. Anti-cmDNA detected with IIF on cell line Raji was better than cell line HL60.