Jaskowski T D, Schroder C, Martins T B, Mouritsen C L, Litwin C M, Hill H R
Associated Regional and University Pathologists (ARUP), Salt Lake City, Utah, USA.
Am J Clin Pathol. 1996 Apr;105(4):468-73. doi: 10.1093/ajcp/105.4.468.
Indirect fluorescent antibody (IFA) ia most widely used method in clin clinical laboratories to screen for autoantibodies against a wide variety of nuclear antigens. Recently, a number of antinuclear antibody (ANA) enzyme immunoassay (EIA) screens have become commercially available and claim to be an alternative method to screen for ANAs. Given the subjectivity of technical interpretation of IFA and the high number of ANA negative samples, a suitable EIA method for ANA screening would be beneficial to clinical laboratories with large samples volumes. Five ANA EIA screens were compared (Elias, Helix, Sanofi, TheraTest and Zeus) to IFA using a human epithelial cell line (HEp-2). Sera from 601 patients submitted to our reference laboratory for autoimmune testing, and from 202 normal healthy blood donors, were included in this study. Samples with discordant results between IFA and EIA were further analyzed using single antigen EIAs for SSA, SSB, Sm, RNP, Scl-70, histones, dsDNA, and ssDNA. Analyses were based on clinically significant IFA titers of > or equal to 1:160 as positive and <1:40 as negative. When compared to IFA, agreement, sensitivity and specificity for each ANA EIA screen were as follows: Elias: 87.0%, 69.5% and 97.9%; Helix: 94.6%, 90.2%, and 97.3%; Sanofi: 95.0%, 93.7%, and 95.9%; TheraTest: 95.3%, 97.7%, and 93.5%; Zeus: 87.1%, 96.2%, and 81.4%, respectively. In conclusion, screening for ANAs by EIA using several commercial assays was both sensitive and specific when compared to IFA. Moreover, the EIA is objective and much less labor intensive when screening a large number of clinical specimens. None of the EIAs were 100% sensitive and, thus, may fail to detect a few of the nonspecific ANAs that demonstrate atypical as well as classical IFA patterns. The advantages of employing these nonsubjective assays to screen out the vast majority of ANA negative sera is clear. The authors still recommend confirming titers and patterns of sera with positive EIA screens using classical IFA methods employing HEp-2 cells.
间接荧光抗体（IFA）是临床实验室中最广泛用于筛查针对多种核抗原自身抗体的方法。最近，一些抗核抗体（ANA）酶免疫测定（EIA）筛查方法已商业化，并声称是筛查ANA的替代方法。鉴于IFA技术解读的主观性以及大量ANA阴性样本，一种适用于ANA筛查的EIA方法将对处理大量样本的临床实验室有益。使用人上皮细胞系（HEp-2）将五种ANA EIA筛查方法（Elias、Helix、赛诺菲、TheraTest和Zeus）与IFA进行比较。本研究纳入了提交至我们参考实验室进行自身免疫检测的601例患者的血清以及202例正常健康献血者的血清。对于IFA和EIA结果不一致的样本，使用针对SSA、SSB、Sm、RNP、Scl-70、组蛋白、双链DNA和单链DNA的单抗原EIA进行进一步分析。分析基于具有临床意义的IFA滴度，即≥1:160为阳性，<1:40为阴性。与IFA相比，每种ANA EIA筛查方法的一致性、敏感性和特异性如下：Elias：87.0%、69.5%和97.9%；Helix：94.6%、90.2%和97.3%；赛诺菲：95.0%、93.7%和95.9%；TheraTest：95.3%、97.7%和93.5%；Zeus：分别为87.1%、96.2%和81.4%。总之，与IFA相比，使用几种商业检测方法通过EIA筛查ANA既敏感又特异。此外，在筛查大量临床标本时，EIA客观且劳动强度小得多。没有一种EIA是100%敏感的，因此可能无法检测出一些显示非典型以及经典IFA模式的非特异性ANA。采用这些非主观检测方法筛选出绝大多数ANA阴性血清的优势是显而易见的。作者仍然建议使用采用HEp-2细胞的经典IFA方法确认EIA筛查呈阳性的血清的滴度和模式。
