McLendon Clinical Laboratories, University of North Carolina Medical Center, Chapel Hill, North Carolina, USA.
Department of Pathology and Laboratory Medicine, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA.
J Clin Microbiol. 2024 Apr 10;62(4):e0004524. doi: 10.1128/jcm.00045-24. Epub 2024 Mar 13.
pneumonia (PJP) is a serious and sometimes fatal infection occurring in immunocompromised individuals. High-risk patients include those with low CD4 counts due to human immunodeficiency virus infection and transplant recipients. The incidence of PJP is increasing, and rapid detection of PJP is needed to effectively target treatment and improve patient outcomes. A common method used is an immunofluorescent assay (IFA), which has limitations, including labor costs, low sensitivity, and requirement for expert interpretation. This study evaluates the performance of the DiaSorin Molecular analyte-specific reagent (ASR) in a laboratory-developed test (LDT) for the direct detection of DNA without prior nucleic acid extraction. Respiratory samples ( = 135) previously tested by IFA from 111 patients were included. Using a composite standard of in-house IFA and reference lab PJP PCR, the percent positive agreement for the LDT using the DiaSorin ASR was 97.8% (90/92). The negative percent agreement was 97.7% (42/43). The lower limit of detection of the assay was determined to be 1,200 copies/mL in bronchoalveolar lavage fluid. Analytical specificity was assessed using cultures of oropharyngeal flora and common respiratory bacterial and fungal pathogens. No cross-reactivity was observed. Our study suggests that the DiaSorin ASR accurately detects DNA and demonstrates improved sensitivity compared to the IFA method.
Our study is unique compared to other previously published studies on the DiaSorin analyte-specific reagent (ASR) because we focused on microbiological diagnostic methods commonly used (immunofluorescent assay) as opposed to pathology findings or reference PCR. In addition, in our materials and methods, we describe the protocol for the use of the DiaSorin ASR as a singleplex assay, which will allow other users to evaluate the ASR for clinical use in their lab.
肺炎（PJP）是一种在免疫功能低下的个体中发生的严重且有时致命的感染。高危患者包括因人类免疫缺陷病毒感染而 CD4 计数低的患者和移植受者。PJP 的发病率正在增加，需要快速检测 PJP，以有效靶向治疗并改善患者预后。常用的方法是免疫荧光分析（IFA），但其存在局限性，包括劳动力成本高、灵敏度低和需要专家解释。本研究评估了 DiaSorin 分子分析物特异性试剂（ASR）在实验室开发的测试（LDT）中直接检测未经核酸提取的 DNA 的性能。共纳入了来自 111 名患者的先前通过 IFA 测试的呼吸样本（=135）。使用内部 IFA 和参考实验室 PJP PCR 的复合标准，使用 DiaSorin ASR 的 LDT 的阳性符合率为 97.8%（90/92）。阴性符合率为 97.7%（42/43）。该测定的检测下限确定为支气管肺泡灌洗液中的 1,200 拷贝/ml。使用口咽菌群和常见呼吸道细菌和真菌病原体的培养物评估分析特异性。未观察到交叉反应。我们的研究表明，DiaSorin ASR 可准确检测 DNA，与 IFA 方法相比，灵敏度有所提高。
与之前关于 DiaSorin 分析物特异性试剂（ASR）的其他已发表研究相比，我们的研究是独特的，因为我们专注于常用的微生物诊断方法（免疫荧光分析），而不是病理学发现或参考 PCR。此外，在我们的材料和方法中，我们描述了使用 DiaSorin ASR 作为单重测定的方案，这将允许其他用户在其实验室中评估 ASR 的临床用途。
