White P Lewis, Posso Raquel B, Barnes Rosemary A
Public Health Wales Microbiology Cardiff, Cardiff, United Kingdom
Infection, Immunity and Biochemistry, School of Medicine, Cardiff University, Cardiff, United Kingdom.
J Clin Microbiol. 2017 Aug;55(8):2356-2366. doi: 10.1128/JCM.00411-17. Epub 2017 May 17.
With the proposal to include PCR in the revised European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) definitions for fungal disease, commercially manufactured assays may be required to provide standardization and accessibility. The PathoNostics AsperGenius assay represents one such test that has the ability to detect a range of species as well as azole resistance in Its performance has been validated on bronchoalveolar lavage (BAL) fluid and serum specimens, but recent evidence suggests that testing of plasma may have enhanced sensitivity over that with serum. We decided to evaluate the analytical and clinical performances of the PathoNostics AsperGenius assay for testing of plasma. For the analytical evaluations, plasma was spiked with various concentrations of genomic DNA before extraction following international recommendations, using two automated platforms. For the clinical study, 211 samples from 10 proven/probable invasive aspergillosis (IA) and 2 possible IA cases and 27 controls were tested. The limits of detection for testing of DNA extracted using the bioMérieux EasyMag and Qiagen EZ1 extractors were 5 and 10 genomes/0.5-ml sample, respectively. In the clinical study, true positivity was significantly greater than false positivity ( < 0.0001). The sensitivity and specificity obtained using a single positive result as significant were 80% and 77.8%, respectively. If multiple samples were required to be positive, specificity was increased to 100%, albeit sensitivity was reduced to 50%. The AsperGenius assay provided good clinical performance, but the predicted improvement of testing with plasma was not seen, possibly as a result of target degradation attributed to sample storage. Prospective testing is required to determine the clinical utility of this assay, particularly for the diagnosis of azole-resistant disease.
随着将聚合酶链反应（PCR）纳入修订后的欧洲癌症研究与治疗组织/侵袭性真菌感染合作组及美国国立过敏与传染病研究所真菌病研究组（EORTC/MSG）真菌病定义的提议，可能需要商业生产的检测方法来实现标准化和可及性。PathoNostics AsperGenius检测就是这样一种检测方法，它能够检测多种真菌物种以及唑类耐药性。其性能已在支气管肺泡灌洗（BAL）液和血清样本中得到验证，但最近的证据表明，血浆检测可能比血清检测具有更高的灵敏度。我们决定评估PathoNostics AsperGenius检测在血浆检测中的分析性能和临床性能。在分析评估中，按照国际建议，在提取前向血浆中加入不同浓度的基因组DNA，使用两个自动化平台。在临床研究中，对来自10例确诊/疑似侵袭性曲霉病（IA）和2例可能的IA病例以及27例对照的211份样本进行了检测。使用生物梅里埃EasyMag和Qiagen EZ1提取仪提取DNA进行检测的检测限分别为5和10个基因组/0.5毫升样本。在临床研究中，真阳性率显著高于假阳性率（P<0.0001）。将单个阳性结果视为有意义时，灵敏度和特异性分别为80%和77.8%。如果需要多个样本呈阳性，则特异性提高到100%，尽管灵敏度降至50%。AsperGenius检测具有良好的临床性能，但未观察到血浆检测预期的改善，这可能是由于样本储存导致靶标降解所致。需要进行前瞻性检测以确定该检测方法的临床实用性，特别是对于唑类耐药疾病的诊断。
