Taylor R N, Przybyszewski V A
Division of Assessment and Management Consultation Training, Centers for Disease Control, Atlanta, Georgia 30333.
Am J Clin Pathol. 1988 Jan;89(1):1-13. doi: 10.1093/ajcp/89.1.1.
During 1985 and 1986, the Centers for Disease Control conducted eight surveys to evaluate laboratory performance in testing for antibody to human immunodeficiency virus (HIV). (Other names for this virus include "human T-lymphotropic virus type III" and "lymphadenopathy associated virus.") The first survey was conducted with ten samples and 50 laboratories; the remaining surveys used six samples, but enrollment increased to as many as 475 laboratories. The purpose of these surveys was to measure test performance by the laboratories under the actual conditions of use. The surveys contained duplicate samples to permit measurement of within- and between-survey reproducibility. One survey included positive and negative reference materials as evaluation samples. Results of the Western blot (WB) test were not always positive on samples that were positive by enzyme immunoassay (EIA), and sometimes they were positive on samples that had negative results by EIA. The percentage of positive results reported by laboratories using Electronucleonics tests was lower than that reported by users of Abbott and of Litton tests. positive results on the negative reference material were reported by 13.7% of the Abbott EIA test users. The tests do not seem to be calibrated against an equivalent standard. Within-survey reproducibility was usually above 95% for EIA and WB methods and for the major manufacturers of EIA tests. Between-survey reproducibility was usually above 90%. Reproducibility was below 75% for some combinations of samples, method, and manufacturer. The test performance observed in these surveys may be lower than is actually achieved on patient samples because the samples were selected to measure technical competence and contain a higher frequency of samples with low reactivity than would be encountered with clinical samples. Stratification and weighting of the results in these surveys to estimate performance parameters for a blood bank population indicate that the tests are performing well in this application. If single EIA tests at the performance levels achieved in these surveys were used (no repeat and no confirmation), about 1 sample with positive results in every 50,000 samples tested would be missed and about 2.5% would be false positive results. Because tests are duplicated and confirmed in blood banks, better performance would be expected. Testing for antibody to HIV virus continues to undergo rapid change because of the introduction of new tests, changes in technical aspects of existing tests, and application of testing to changing populations. Such dynamic factors necessitate an ongoing, comprehensive monitoring of test performance.
1985年至1986年期间，疾病控制中心进行了八项调查，以评估实验室在检测人类免疫缺陷病毒（HIV）抗体方面的表现。（该病毒的其他名称包括“人类嗜T淋巴细胞病毒III型”和“淋巴结病相关病毒”。）第一次调查使用了10个样本和50个实验室；其余调查使用6个样本，但参与实验室增加到多达475个。这些调查的目的是在实际使用条件下衡量各实验室的检测性能。调查包含重复样本，以便能够衡量调查内和调查间的可重复性。有一次调查纳入了阳性和阴性参考材料作为评估样本。免疫印迹（WB）试验的结果在酶免疫测定（EIA）呈阳性的样本上并不总是呈阳性，而在EIA结果为阴性的样本上有时却呈阳性。使用电子学公司检测的实验室报告的阳性结果百分比低于使用雅培和利顿检测的用户报告的百分比。13.7%的雅培EIA检测用户报告了阴性参考材料的阳性结果。这些检测似乎未根据等效标准进行校准。对于EIA和WB方法以及EIA检测的主要制造商，调查内的可重复性通常高于95%。调查间的可重复性通常高于90%。对于某些样本、方法和制造商的组合，可重复性低于75%。在这些调查中观察到的检测性能可能低于对患者样本实际达到的性能，因为选择这些样本是为了衡量技术能力，并且与临床样本相比，低反应性样本的频率更高。对这些调查结果进行分层和加权以估计血库人群的性能参数表明，这些检测在该应用中表现良好。如果使用在这些调查中达到的性能水平的单一EIA检测（不重复且不确认），那么在每50000个检测样本中，大约会遗漏1个阳性结果样本，并且大约2.5%会是假阳性结果。由于血库中检测是重复进行且经过确认的，预计会有更好的性能。由于新检测方法的引入、现有检测技术方面的变化以及检测应用于不断变化的人群，HIV病毒抗体检测仍在迅速变化。这些动态因素使得有必要对检测性能进行持续、全面的监测。
