儿童抗核抗体不同稀释度检测结果分析

目的比较不同血清稀释滴度对儿童抗核抗体间接免疫荧光分析(ANA-IIF)结果的影响,探讨降低血清起始稀释度必要性。方法以间接免疫荧光法检测110例健康儿童系列稀释度血清标本抗核抗体(ANA),并与特异性ANA线性免疫(ANA-LIA)结果相比较;同时分析一组ANA-IIF阴性的临床患儿标本ANA-LIA结果。结果健康组标本随着稀释度从1∶80、1∶40、1∶20逐步减低,ANA-IIF阳性检出率有所上升,分别为7.3%、9.1%、10.9%,但差异无统计学意义(P0.05),弱阳性分别为7.3%、15.5%、31.8%,差异有统计学意义(P0.01)。110例健康体检儿童中8例标本检测出特异性ANA,阳性率为7.3%。8例IIF法稀释度1∶80阳性者中,特异性ANA阳性者2例;稀释度1∶40、1∶20新增的4例荧光ANA阳性标本中,有1例特异性ANA阳性。若视ANA-IIF(1∶80)或ANA-LIA任一阳性为ANA阳性,ANA阳性率从7.3%上升到12.7%。29例ANA-IIF(1∶80)为阴性的自身免疫肝病相关自身抗体检测患儿临床标本中,特异性ANA-LIA检测出5例阳性(17.2%)。结论降低儿童血清起始滴度并不能明显提高ANA-IIF阳性检出率,反而增加了非特异的弱阳性,因此,临床实验室不需改变儿童ANA常规标本稀释滴度,联合特异性ANA-LIA的检测有利于ANA的发现。

Analysis on detection results of different dilution titers of antinuclear antibodies in children

Objective To compare the influences of different dilution titers on the ANA detection by the indirect immunofluores‐cence assay(IIF) in children for investigating the necessity of reducing serum initial dilution titer .Methods Serum ANA was detec‐ted by using the indirect immunofluorescence assay at a serial of dilution titer in 110 healthy controls and the results were compared with the results of specific ANAs by the linear immunoassay (LIA);meanwhile the ANA‐LIA results in clinical children patients with ANA‐IIF negative were also analyzed .Results With the dilution titers gradual decrease from 1∶80 ,1∶40 and 1∶20 in the samples of the health group ,the positive detection rates of ANA‐IIF were risen ,which were 7 .3% ,9 .1% and 10 .9% respectively , but the differences were not statistically significant (P>0 .05) ,the weak‐positive rates were 7 .3% ,15 .5% and 31 .8% respective‐ly ,the differences were statistically significant (P<0 .01) .Among 110 healthy children under going the physical examination ,the specific ANA was detected out in 8 samples ,the positive rate was 7 .3% .Among 8 positive cases at the dilution titer of 1∶80 by the IIF method ,specific ANA was in 2 cases;in 4 added cases of fluorescence ANA positive samples at the dilution titers of 1∶40 and 1∶20 ,specific ANA was in 1 case .If with any positive of ANA‐IIF(1∶80) or ANA‐LIA as the ANA positive ,the ANA positive rate was risen from 7 .3% to 12 .7% .In the clinical samples among 29 cases of ANA‐IIF(1∶80) negative autoimmune liver disease related autoantibody detection ,the specific ANA‐LIA positive was detected in 5 cases (17 .2% ) .Conclusion Reducing the initial ti‐ter of children serum is unable to obviously increase the ANA‐IIF positive detection rate ,on the contrary increases the non‐specific weak positive .Therefore ,clinical laboratory does not change the dilution titer of children routine ANA sample .The detection by combining with the specific ANA‐LIA spectrum is conducive to find ANA .