系统性红斑狼疮47例中六种抗体阳性率比较

目的评价抗核小体抗体(Anua)、抗核抗体(ANA)、抗双链DNA(ds-DNA)抗体、抗Sm抗体、抗组蛋白抗体(AHA)、抗SSA抗体6种抗体对系统性红斑狼疮(SLE)诊断的敏感性。方法选取我院2008年10月至2010年12月在我院风湿免疫科住院SLE患者及门诊健康体检者,用酶联免疫吸附试验(ELISA)法检Anua和AHA水平,用间接免疫荧光检测ANA和抗ds-DNA抗体,用酶联免疫斑点法检测抗Sm抗体和抗SSA抗体,并用免疫双扩散法证实抗Sm抗体和抗SSA抗体的结果。结果 Anua阳性率为77%,AHA阳性率为43%,抗ds-DNA抗体阳性率为32%,抗Sm抗体阳性率为28%,ANA阳性率为94%,抗SSA抗体阳性率为17%。结论 Anua的阳性率明显高于抗ds-DNA抗体和抗Sm抗体阳性率可能是诊断SLE比抗ds-DNA抗体更特异的指标,尤其对于抗ds-DNA抗体阴性的SLE患者的诊断更具有临床应用价值;抗ds-DNA抗体和抗Sm抗体,这2种抗体对诊断SLE特异性高,但因其灵敏度低,故阳性率不高;ANA因阳性率高,而特异性低,只适宜作为SLE的筛选试验;SSA抗体阳性率在6种抗体中最低,不适宜作为筛查项目,但其真阴性率高。因此6种抗体联合检测可互相弥补其缺陷,有利于SLE诊断及治疗。

Positive rates of six antibodies in systemic lupus erythematosus: a comparative analysis in 47 cases

Objective To estimate the sensitivity of six antibodies in diagnosing systemic lupus erythematosus （SLE）. Methods SLE patients in Division of Rheumatology and health checkup subjects from our hospital between October 2008 and December 2010 were selected and studied for ANUA and AHA with enzyme-linked immunosorbent assay （ELISA）, ANA and anti-dsDNA antibody with immunofluorescence, Anti-SSA and anti-SSA antibodies with en- zyme linked immunoblot assay. The results of anti-SSA and anti-SSA antibodies were confirmed by double immunod- iffnsion. Results The positive rate was 77% for ANUA, 43% for AHA, 32% for anti-dsDNA antibody, 28% for anti- Sm antibody, 94% for ANA, and 17% for anti-SSA antibody. Conclusion Positive rate of ANUA （77%） was evidently higher than that of anti-dsDNA antibody （32%） and anti-Sm antibody （28%） （P〈O.05）, and therefore ANUA may be a more specific indicator than anti-dsDNA antibody in diagnosing SLE, especially useful for anti-dsDNA-negative pa- tients. Anti-dsDNA and anti-Sm antibodies are highly specific in diagnosing SLE, but low sensitivity of them leads to low positive rates. Although with a high positive rate, AHA shows low specificity and hence is suitable only for SLE screening test. The lowest positive rate of anti-SSA （17%） among the six antibodies dismisses its use for screening, but its true negative rate appears high. Combined detection of 6 antibodies may minimize the limitations of single ones, and may be useful in diagnosis and treatment of SLE.