Department of Laboratory Sciences and Infectious Diseases, A. Gemelli University Hospital Foundation IRCCS, 00168 Rome, Italy.
Department of Life Science and Public Health, Catholic University of the Sacred Heart, 00168 Rome, Italy.
Int J Mol Sci. 2024 Oct 29;25(21):11632. doi: 10.3390/ijms252111632.
We developed a flow cytometry (FC) assay enabling the rapid and accurate identification of bacterial and viral infections using whole blood samples. The streamlined flow cytometry assay is designed to be user-friendly, making it accessible even for operators with limited experience in FC techniques. The key components of the assay focus on the expression levels of specific surface markers-CD64 on polymorphonuclear neutrophils (PMN) as a marker for bacterial infection, and CD169 on monocytes (MO) for viral infection. The strong performance indicated by an area under the receiver operating characteristic (ROC) curve of 0.94 for both PMN CD64 positive predictive value (PPV) 97.96% and negative predictive value (NPV) 76.67%, and MO CD169 PPV 82.6% and NPV 86.9%, highlight the assay's robustness in differentiating between bacterial and viral infections accurately. The FC assay includes the assessment of immune system status through HLA-DR and IL-1R2 modulation in MO, providing a useful insight into the patients' immune response. The significant increase in the frequency of MO exhibiting reduced HLA-DR expression and elevated IL-1R2 levels in infected patients (compared to healthy controls) underscores the potential of these markers as indicators of infection severity. Although the overall correlation between HLA-DR and IL-1R2 expression levels was not significant across all patients, there was a trend in patients with more severe disease suggesting that these markers may have the potential to assist in stratifying patient risk. The present FC assay has the potential to become routine in the clinical microbiology laboratory community and to be helpful in guiding clinical decision making.
我们开发了一种流式细胞术（FC）检测方法，能够使用全血样本快速准确地识别细菌和病毒感染。这种简化的流式细胞术检测方法设计为用户友好型，即使是对 FC 技术经验有限的操作人员也易于使用。该检测方法的关键组件集中在特定表面标志物的表达水平上，中性粒细胞（PMN）上的 CD64 作为细菌感染的标志物，单核细胞（MO）上的 CD169 作为病毒感染的标志物。曲线下面积（ROC）为 0.94 的强烈性能表明 PMN CD64 阳性预测值（PPV）为 97.96%，阴性预测值（NPV）为 76.67%，MO CD169 PPV 为 82.6%，NPV 为 86.9%，这突出了该检测方法在准确区分细菌和病毒感染方面的稳健性。FC 检测方法包括通过 MO 中 HLA-DR 和 IL-1R2 调节来评估免疫系统状态，为患者的免疫反应提供了有用的见解。与健康对照组相比，感染患者中 MO 上 HLA-DR 表达降低和 IL-1R2 水平升高的频率显著增加，这突出了这些标志物作为感染严重程度指标的潜力。尽管所有患者的 HLA-DR 和 IL-1R2 表达水平之间的总体相关性没有统计学意义，但在疾病更严重的患者中存在趋势，表明这些标志物可能有潜力帮助分层患者风险。目前的 FC 检测方法有可能成为临床微生物学实验室社区的常规检测方法，并有助于指导临床决策。
