Aguilar Yudy A, Rueda Zulma Vanessa, Maya María Angélica, Vera Cristian, Rodiño Jenniffer, Muskus Carlos, Vélez Lázaro A
Grupo Investigador de Problemas en Enfermedades Infecciosas-GRIPE, Facultad de Medicina, Universidad de Antioquia, Medellín 050031, Colombia.
Facultad de Medicina, Universidad Pontificia Bolivariana, Medellín 050031, Colombia.
J Fungi (Basel). 2021 Dec 2;7(12):1036. doi: 10.3390/jof7121036.
Respiratory sample staining is a standard tool used to diagnose pneumonia (PjP). Although molecular tests are more sensitive, their interpretation can be difficult due to the potential of colonization. We aimed to validate a (Pj) real-time PCR (qPCR) assay in bronchoscopic bronchoalveolar lavage (BAL) and oropharyngeal washes (OW). We included 158 immunosuppressed patients with pneumonia, 35 lung cancer patients who underwent BAL, and 20 healthy individuals. We used a SYBR green qPCR assay to look for a 103 bp fragment of the Pj gene in BAL and OW. We calculated the qPCR cut-off as well as the analytical and diagnostic characteristics. The qPCR was positive in 67.8% of BAL samples from the immunocompromised patients. The established cut-off for discriminating between disease and colonization was Ct 24.53 for BAL samples. In the immunosuppressed group, qPCR detected all 25 microscopy-positive PjP cases, plus three additional cases. Pj colonization in the immunocompromised group was 66.2%, while in the cancer group, colonization rates were 48%. qPCR was ineffective at diagnosing PjP in the OW samples. This new qPCR allowed for reliable diagnosis of PjP, and differentiation between PjP disease and colonization in BAL of immunocompromised patients with pneumonia.
呼吸道样本染色是用于诊断肺孢子菌肺炎（PjP）的标准工具。尽管分子检测更为敏感，但由于存在定植的可能性，其结果解读可能存在困难。我们旨在验证支气管镜下支气管肺泡灌洗（BAL）和口咽冲洗液（OW）中肺孢子菌（Pj）的实时荧光定量聚合酶链反应（qPCR）检测方法。我们纳入了158例免疫抑制的肺炎患者、35例接受BAL的肺癌患者以及20名健康个体。我们使用SYBR Green qPCR检测方法在BAL和OW中寻找Pj基因的103 bp片段。我们计算了qPCR的临界值以及分析和诊断特征。免疫受损患者的BAL样本中，qPCR阳性率为67.8%。BAL样本中区分疾病和定植的既定临界值为Ct 24.53。在免疫抑制组中，qPCR检测出所有25例显微镜检查阳性的PjP病例，另外还有3例。免疫抑制组中Pj定植率为66.2%，而癌症组的定植率为48%。qPCR在诊断OW样本中的PjP时无效。这种新的qPCR方法能够可靠地诊断PjP，并区分免疫抑制的肺炎患者BAL中PjP疾病和定植情况。
