Abstract:
Pneumocystis jirovecii 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 Pneumocystis jirovecii analyte-specific reagent (ASR) in a laboratory-developed test (LDT) for the direct detection of P. jirovecii DNA without prior nucleic acid extraction. Respiratory samples (n = 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 Pneumocystis ASR accurately detects P. jirovecii DNA and demonstrates improved sensitivity compared to the IFA method.
OBJECTIVE: 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.
摘要:
肺孢子虫肺炎(PJP)是一种严重的,有时是致命的感染,发生在免疫功能低下的个体中。高危患者包括由于人类免疫缺陷病毒感染和移植受者而导致CD4计数低的患者。PJP的发病率正在增加,需要快速检测PJP才能有效靶向治疗并改善患者预后。常用的方法是免疫荧光测定(IFA),有局限性,包括人工成本,灵敏度低,和专家解释的要求。这项研究评估了DiaSorin分子肺孢子虫jirovecii分析物特异性试剂(ASR)在实验室开发的测试(LDT)中的性能,用于直接检测P.jiroveciiDNA,而无需事先提取核酸。包括来自111名患者的先前通过IFA测试的呼吸样品(n=135)。使用内部IFA和参考实验室PJPPCR的复合标准,使用DiaSorinASR的LDT的正一致性百分比为97.8%(90/92)。负百分比一致性为97.7%(42/43)。测定的检测下限在支气管肺泡灌洗液中确定为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。没有观察到交叉反应性。我们的研究表明,与IFA方法相比,DiaSorin肺孢子菌ASR可以准确检测P.jiroveciiDNA,并显示出更高的灵敏度。
目的:我们的研究与以前发表的其他关于DiaSorin分析物特异性试剂(ASR)的研究相比是独特的,因为我们专注于常用的微生物诊断方法(免疫荧光测定),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DiaSorinASR作为单重测定的协议,这将允许其他用户评估ASR在他们的实验室临床使用。