Automated Detection of Malaria-Associated Pseudoeosinophilia and Abnormal WBC Scattergram by the Sysmex XE-2100 Hematology Analyzer: A Clinical Study with 1,801 Patients and Real-Time Quantitative PCR Analysis in Vivax Malaria-Endemic Area

Abstract

Abstract. Recently, the XE-2100 hematology analyzer was investigated in a rather small patient group; pseudoeosinophilia or abnormal white blood cell (WBC) scattergrams reported by this instrument were considered as significantly valuable diagnostic parameters in detecting vivax malaria. This study was conducted not only to assess the usefulness of pseudoeosinophilia or abnormal WBC scattergram in vivax malaria-endemic areas with large patient groups ( N = 1,801) but also to investigate the correlation of parasitemia and platelet count with pseudoeosinophilia and abnormal WBC scattergrams. Of the 1,801 analyzed patients, 413 (22.9%) were found to have malaria by Wright-Giemsa stained blood smears. Overall, either pseudoeosinophilia or abnormal WBC scattergram was detected in 191 of 413 malaria patients and 4 of 1,388 patients without malaria (sensitivity = 46.2%, specificity = 99.7%). We suggest that clinical hematology laboratories using the XE-2100 analyzer should be aware of such specific parameters, even with the absence of a clinical request.

Abnormal scattergrams and cell population data generated by fully automated hematological analyzers: New tools for screening malaria infection?

“…3,4 Notwithstanding the widespread availability of specific external quality assessment programs (EQAs), the low incidence of new diagnoses in Western countries does not allow to maintain a satisfactory degree of expertise for identifying Malaria parasites with microscopic revision of blood smears, so that screening techniques for a targeted microscopic review may be necessary for enabling an early and accurate diagnosis of this infection, especially in nonendemic countries. 3 Recent evidence attests that the latest generation of hematological analyzers may be a valid support for the screening of patients with suspected Malaria, [5][6][7][8][9][10][11][12][13][14][15] although the diagnostic sensitivity and specificity of abnormal findings were found to be strictly dependent on the instrumentation, the parasitic index, and the stage of Plasmodium maturation. The most suggestive findings that have been described so far include abnormalities of leukocyte differential scattergram and reticulocyte (RET) count, which may indicate the presence of parasites at various stages of maturation (i.e.…”

“…trophozoites, schizos, and gametocytes). [5][6][7][8][9][10][11][12][13][14][15] The new hematological analyzer Sysmex XN-module (Sysmex Co., Kobe, Japan) enumerates and classifies blood cells, RET, immature leukocytes (White Precursors Cell; WPC), and platelets (PLT) with a combination of optical fluorescence technique (PLT-F), flow cytometry, and laser-optical recognition. The XN-module also provides a variety of innovative cell population data (CPD) parameters, which can be helpful for improving leukocyte differential count and for the more accurate identification of abnormal cells.…”

“…Therefore, identification and validation of putative laboratory hallmarks, such as specific anomalies generated by fully automated hematological analyzers in blood samples containing Malaria parasites, should be seen as an extremely valuable perspective for allowing rapid and accurate screening or diagnosing [6][7][8][9][10][11][12][13][14]. Notably, even in healthcare facilities using point of care (POC) analyzers and no…”

Automated haematology analysis to diagnose malaria

“…Later, two studies in a malaria-endemic region in South Korea evaluated pseudoeosinophilia (>5% difference between the automated and manual eosinophil count) and DIFF scatter-plot abnormalities for P. vivax diagnosis against thick film [54], or against thick film and real-time polymerase chain reaction (RT-PCR) [55] (Table 4). In the first study by Huh and colleagues [54], pseudoeosinophilia and abnormal DIFF scatter-plot alone yielded sensitivities of 39% and 52%, respectively, with no change in specificity.…”

The Correlation of Spurious Eosinophilia in Automated Hematological Analyzer Sysmex Xs-800i with Plasmodium Infection Diagnosis

“…[19] Spurious eosinophilia detected in malaria patients is also a fair indicator of the degree of parasitemia as indicated by Jong, et al [20] The sensitivity and specificity of spurious eosinophilia as a marker of Plasmodium infection in the present study were 61.5% and 100%, respectively. Lower sensitivity and comparable specificity were obtained in study by Jong-Ha, et al [20] with sensitivity and specificity of 39.0% and 99.7%, respectively.…”