Rehan Madeeha, Khalid Attika, Nasreen Fariha
Dr. Madeeha Rehan, Associate Professor, Department of Pathology, Foundation University Medical College, Fauji Foundation Hospital Rawalpindi, Pakistan.
Dr. Attika Khalid, Assistant Professor, Department of Pathology, Foundation University Medical College, Fauji Foundation Hospital Rawalpindi, Pakistan.
Pak J Med Sci. 2022 Mar-Apr;38(3Part-I):687-691. doi: 10.12669/pjms.38.3.4702.
BACKGROUND & OBJECTIVE: Undiagnosed malarial infectionis associated with significant mortality and morbidity. Laboratory investigations leading to rapid, accurate and timely diagnosis of malaria is still a challenge. This study was done to assess the utility of abnormal White blood cell differential fluorescence (WDF) scattergram for diagnosis of malaria. Our aim was to study the utility of WDF scattergram for early detection of malarial parasite.
All EDTA anti-coagulated blood samples received in laboratory during a period from Dec 2019 to May 2020 were analyzed on anautomated hematology analyzer, Sysmex XN 1000. All abnormal WDF scattergrams pertaining to plasmodium specie were critically evaluated and recorded. Review of Leishman-stained peripheral smears as well as immune-chromatographic assay by rapid test devices (RTD) was done. Accordingly, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detection of malaria by abnormal scattergram were calculated.
Out of total 1, 26,000of samples analyzed, abnormal WDF scattergrams were detected in 96 cases. Amongst these, 95.8% (92) were positive for MP on Leishman-stained peripheral smear as well as on ICT with a p-value of 0.05. WDF scattergram abnormalities typical of malaria showed a sensitivity of 80% and specificity of 93.26%. Positive predictive value of 95.8% whereas negative predictive value of 99.9% was detected. Significant findings of hemolysis, platelet clumps, nucleated RBCS (NRBCs) and RBC agglutination were noted in cases (n=4) with abnormal WDF scattergram negative for malaria on peripheral smear.
Interpretation of abnormal WDF scattergram not only increases the early detection rate for malarial parasite but isa strong indicator for presence of hemolysis, RBC agglutination, platelet clumps and leucoerythroblastic blood picture as well.
未确诊的疟疾感染与显著的死亡率和发病率相关。实现快速、准确且及时的疟疾诊断的实验室检测仍是一项挑战。本研究旨在评估异常白细胞分类荧光（WDF）散点图在疟疾诊断中的效用。我们的目的是研究WDF散点图在早期检测疟原虫方面的效用。
对2019年12月至2020年5月期间实验室收到的所有乙二胺四乙酸（EDTA）抗凝血液样本，使用Sysmex XN 1000全自动血液分析仪进行分析。对所有与疟原虫种类相关的异常WDF散点图进行严格评估并记录。同时对利什曼染色外周血涂片以及快速检测设备（RTD）的免疫层析法检测结果进行复查。据此，计算异常散点图检测疟疾的灵敏度、特异度、阳性预测值（PPV）和阴性预测值（NPV）。
在总共分析的126,000份样本中，检测到96例异常WDF散点图。其中，95.8%（92例）在利什曼染色外周血涂片以及免疫层析检测中疟原虫呈阳性，p值为0.05。典型的疟疾WDF散点图异常显示灵敏度为80%，特异度为93.26%。阳性预测值为95.8%，而阴性预测值为99.9%。在外周血涂片上疟疾WDF散点图异常阴性的病例（n = 4）中，发现了溶血、血小板聚集、有核红细胞（NRBCs）和红细胞凝集的显著表现。
异常WDF散点图的解读不仅提高了疟原虫的早期检测率，也是溶血、红细胞凝集、血小板聚集和白红系血液图像存在的有力指标。
