PathWest Laboratory Medicine WA, Department of Clinical Microbiology, Fiona Stanley Hospital, Murdoch, WA, Australia.
PathWest Laboratory Medicine WA, Department of Clinical Microbiology, Fiona Stanley Hospital, Murdoch, WA, Australia; Department of Infectious Diseases, Fiona Stanley Fremantle Hospital Group, Murdoch, WA, Australia.
Pathology. 2021 Dec;53(7):896-901. doi: 10.1016/j.pathol.2021.03.006. Epub 2021 Jul 1.
We studied a Pneumocystis jirovecii quantitative polymerase chain reaction (qPCR) for distinguishing P. jirovecii disease from colonisation. Eighty-two respiratory samples from 65 patients with qPCR results were analysed against a gold standard clinical diagnosis of Pneumocystis pneumonia. High inter-assay reproducibility using recombinant and clinical material was observed. Contemporaneous samples from the same patient displayed high variability (median difference 2.6 log copies/mL, IQR 2.1-3.1 log copies/mL). Despite this, area under the receiver operator characteristic curve was 0.8. An optimum cut-off of 2.8 log copies/mL (equivalent to C of 34.0 cycles) had 59% sensitivity and 92% specificity. The median P. jirovecii load was 7.3 log copies/mL in HIV patients compared to 2.6 log copies/mL in non-HIV patients. Specificity was 100% in non-HIV patients with qPCR of >3.8 log copies/mL. qPCR was useful for distinguishing P. jirovecii disease from colonisation. A quantitative standard, standardisation of definitions and methods are required to improve the generalisability of results.
我们研究了一种用于区分肺孢子菌病与定植的肺孢子菌定量聚合酶链反应（qPCR）。对 65 名患者的 82 份呼吸道样本进行 qPCR 结果分析，以金标准临床诊断为肺孢子菌肺炎。使用重组和临床材料观察到高的组内可重复性。同一患者的同期样本显示出高度的可变性（中位数差异为 2.6 log 拷贝/mL，IQR 2.1-3.1 log 拷贝/mL）。尽管如此，接受者操作特征曲线下的面积仍为 0.8。最佳截断值为 2.8 log 拷贝/mL（相当于 C 为 34.0 个循环），具有 59%的敏感性和 92%的特异性。HIV 患者的肺孢子菌负荷中位数为 7.3 log 拷贝/mL，而非 HIV 患者为 2.6 log 拷贝/mL。qPCR >3.8 log 拷贝/mL 的非 HIV 患者的特异性为 100%。qPCR 可用于区分肺孢子菌病与定植。需要定量标准、定义和方法的标准化，以提高结果的通用性。
