在临床环境下使用希森美康 XN-30 分析仪评估自动疟疾诊断。

Evaluation of automated malaria diagnosis using the Sysmex XN-30 analyser in a clinical setting.

机构信息

Wits Research Institute for Malaria, Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg, South Africa.

Hematology Department, P. D. Hinduja National Hospital & Medical Research Centre, Mumbai, India.

出版信息

Malar J. 2019 Jan 22;18(1):15. doi: 10.1186/s12936-019-2655-8.

DOI:10.1186/s12936-019-2655-8

PMID:30670023

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6341646/

Abstract

BACKGROUND

Early and accurate diagnosis of malaria is a critical aspect of efforts to control the disease, and several diagnostic tools are available. Microscopic assessment of a peripheral blood smear enables direct visualization of parasites in infected red blood cells and is the clinical diagnostic gold standard. However, it is subjective and requires a high level of skill. Numerous indirect detection methods are in use, but are not ideal since surrogate markers of infection are measured. This study describes the first clinical performance evaluation of the automated Sysmex XN-30 analyser, which utilizes fluorescence flow cytometry to directly detect and quantitate parasite-infected red blood cells.

RESULTS

Residual EDTA blood samples from suspected malaria cases referred for routine diagnosis were analysed on the XN-30. Parasitaemia was reported as a percentage, as well as absolute numbers of infected red blood cells, and scattergrams provided a visual image of the parasitized red blood cell clusters. The results reported by the XN-30 correlated with microscopy and the analyser demonstrated 100% sensitivity and specificity. Measurements were reproducible and storage of samples at room temperature did not affect the parameters. Several Plasmodium species were detected, including Plasmodium falciparum, Plasmodium vivax and Plasmodium ovale. The XN-30 also identified the transmissible gametocytes as a separate cluster on the scattergrams. Abnormal red blood cell indices (low haemoglobin and raised reticulocyte counts), haemoglobinopathies and thrombocytopenia did not interfere with the detection of parasites. The XN-30 also generated a concurrent full blood count for each sample.

CONCLUSIONS

The novel technology of the Sysmex XN-30 provides a robust, rapid, automated and accurate platform for diagnosing malaria in a clinical setting. The objective enumeration of red blood cells infected with Plasmodium species makes it suitable for global use and allows monitoring of the parasite load once therapy has been initiated, thereby providing an early marker of drug resistance. The automated generation of a full blood count for each sample provides an opportunity for detecting unsuspected cases. Asymptomatic carriers can also be identified, which will be useful in blood transfusion centres, and will enable treatment of these individuals to prevent the spread of the disease.

摘要

背景

疟疾的早期准确诊断是控制该疾病努力的关键方面，有几种诊断工具可用。外周血涂片的显微镜评估可直接观察感染红细胞中的寄生虫，是临床诊断的金标准。然而，它是主观的，需要高水平的技能。目前有许多间接检测方法在使用，但并不理想，因为它们是通过测量感染的替代标志物来进行检测的。本研究描述了 Sysmex XN-30 分析仪的首次临床性能评估，该分析仪利用荧光流式细胞术直接检测和定量寄生虫感染的红细胞。

结果

从疑似疟疾病例中保留的 EDTA 血液样本，用于常规诊断，在 XN-30 上进行分析。寄生虫血症以百分比以及感染红细胞的绝对数量报告，并提供寄生虫感染红细胞簇的直观图像。XN-30 报告的结果与显微镜检查结果相关，并且该分析仪显示出 100％的敏感性和特异性。测量结果具有可重复性，并且在室温下储存样本不会影响参数。检测到几种疟原虫，包括恶性疟原虫、间日疟原虫和卵形疟原虫。XN-30 还可以在散点图上识别出可传播的配子体作为一个单独的簇。异常的红细胞指数（低血红蛋白和高网织红细胞计数）、血红蛋白病和血小板减少症不会干扰寄生虫的检测。XN-30 还为每个样本生成了同步的全血细胞计数。

结论

Sysmex XN-30 的新技术为在临床环境中诊断疟疾提供了一种强大、快速、自动化和准确的平台。对感染疟原虫的红细胞进行客观计数使其适合全球使用，并允许在启动治疗后监测寄生虫负荷，从而提供耐药性的早期标志物。为每个样本自动生成全血细胞计数为检测未被怀疑的病例提供了机会。还可以识别无症状携带者，这在输血中心将非常有用，并使这些人能够接受治疗，以防止疾病的传播。