Development of an Automated Malaria Discriminant Factor Using VCS Technology

Briggs, Carol; Costa, Anabela Da; Tech, Nat Dip Med; Freeman, Lyn; Aucamp, Ilse; Ngubeni, Busisiwe; Machin, Samuel J.

doi:10.1309/0pl3c674m39d6gen

Cited by 47 publications

(39 citation statements)

References 26 publications

(29 reference statements)

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“…21 Three prototypes of analyzers have been evaluated for malaria diagnosis. The Cell-Dyn analyzers detect monocyte-coded depolarizing events corresponding to hemozoin-laden macrophages 8 with a maximum sensitivity and specificity of 97% 22 and 98%, 23 respectively.…”

Section: Discussionmentioning

confidence: 99%

“…For the Coulter analyzers, a malaria discriminant factor that uses monocyte and lymphocyte DC measurements has a maximum sensitivity and specificity of 98% and 96.9%, respectively. 4,21 More recently, using the XE-2100 analyzer, two case series in South Korea, one with 16 and one with 3 P. vivax -infected patients, described pseudoeosinophilia and abnormal granulocyte-coded events in the DIFF scatterplot in approximately 38% of samples. 9,10 In 2008, Huh and others 5 in South Korea compared these two findings against thick-film malaria diagnosis in 144 samples of P. vivax -infected patients and in 319 samples from febrile patients, reporting a sensitivity of 69.4% and a specificity of 100%.…”

Section: Discussionmentioning

confidence: 99%

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Design of Malaria Diagnostic Criteria for the Sysmex XE-2100 Hematology Analyzer

Campuzano-Zuluaga¹,

Álvarez-Sánchez²,

Escobar-Gallo³

et al. 2010

The American Society of Tropical Medicine and Hygiene

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Hygiene INTRODUCTIONEarly detection of malaria in patients not suspected of having the disease is a potential novel application for modern hematology analyzers like the Sysmex XE-2100 (Sysmex Corporation, Kobe, Kansai, Japan). A prompt and accurate diagnosis is critical to reduce adverse outcomes associated with malaria, including death. 1 In endemic regions, malaria is a prime diagnostic concern in febrile patients, and expert thickfilm evaluation is usually available.2 However, the accuracy of microscopic malaria diagnosis in less experienced centers or in non-endemic regions may be lower, and health personnel is less likely to consider the disease, leading to delayed diagnoses.1 Automated full blood counts (FBC) are usually performed in patients with febrile illnesses, providing a unique opportunity to guide a timely parasitological malaria diagnosis.Hematology analyzers evaluated for malaria detection include the Cell-Dyn (Abbott Diagnostics, Santa Clara, CA), 3 the GEN.S and LH-750 (Beckman Coulter, Miami, FL), 4 and the XE-2100 and XS-1000 i (Sysmex Corporation, Kobe, Kansai, Japan). 5,6 The Sysmex XE-2100 is an automated hematology analyzer that uses flow cytometry, direct current (DC) impedanciometry, and radiofrequency conductance (RF) to detect and measure blood corpuscular elements.7 Flow cytometry may detect malaria parasites or parasite debris such as free hemozoin or hemozoin-laden macrophages as reported for Cell-Dyn instruments.8 For the Sysmex XE-2100, two case series reported a gap between the manual and automated eosinophil counts (pseudoeosinophilia) and abnormal granulocyte-coded events in the DIFF scatterplot used for white blood cell (WBC) separation based on fluorescence versus side-scatter signals in samples from Plasmodium vivaxinfected patients.9, 10 Later, Huh and others 5 found that the two previously reported abnormalities, compared with thick film, had a sensitivity of 69.4% and a specificity of 100% for P. vivax diagnosis. These findings suggest the potential clinical utility of malaria detection by the XE-2100. Ideally, to improve the clinical impact of this detection method, it should be an automated process relying on the analyzer's quantitative data and expressed as a "malaria alarm" that could motivate the microscopic search for malaria.The primary aim of this study was to develop, validate, and test the accuracy of one observer-dependent (OD) and two non-observer-dependent (N-OD) diagnostic prediction models for P. vivax and P. falciparum malaria. The approach for developing the OD models was similar to previous studies using the XE-2100 for malaria diagnosis 5 with the inclusion of other clinical and scatterplot variables not previously investigated. The N-OD models were developed to obtain a framework for an automated malaria-detection algorithm for the XE-2100. Secondary aims were to determine the occurrence of pseudoeosinophilia and to explore a possible cause for the XE-2100 FBC malaria-related abnormalities. MATERIALS AND METHODSStudy population. Blood samples were col...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Design of Malaria Diagnostic Criteria for the Sysmex XE-2100 Hematology Analyzer

Campuzano-Zuluaga¹,

Álvarez-Sánchez²,

Escobar-Gallo³

et al. 2010

The American Society of Tropical Medicine and Hygiene

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show abstract

“…The second method also used a Cell-Dyn � 3500, and analyzed depolarized laser light (DLL) to detect malaria infection, with an overall sensitivity of 72% and specificity of 96% [82]. The third technique used a Beckman Coulter ACC to detect increases in activated monocytes by volume, conductivity, and scatter (VCS), with 98% sensitivity and 94% specificity [83]. Although promising, none of the 3 techniques is routinely available in the clinical laboratory; further studies are required to improve and validate the instrument and its software.…”

Section: Automated Blood Cell Counters (Acc)mentioning

confidence: 99%

Malaria Diagnosis: A Brief Review

et al. 2009

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Malaria is a major cause of death in tropical and sub-tropical countries, killing each year over 1 million people globally; 90% of fatalities occur in African children. Although effective ways to manage malaria now exist, the number of malaria cases is still increasing, due to several factors. In this emergency situation, prompt and effective diagnostic methods are essential for the management and control of malaria. Traditional methods for diagnosing malaria remain problematic; therefore, new technologies have been developed and introduced to overcome the limitations. This review details the currently available diagnostic methods for malaria.

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“…13 Some work on the changes in VCS parameters has been undertaken in patients with acute malaria. In a study conducted by Briggs et al, 14 response to malarial infection was shown to cause an increased monocyte count and production of large activated monocytes detectable by the VCS technology. We also observed a significant increase in the mean MV as well as in their relative quantity in malarial infection.…”

mentioning

confidence: 99%

“…This could be attributed to racial and, possibly, environmental differences in the two populations studied. Also, the values put forth in the study by Briggs et al 14 are of a single patient of falciparum malaria. It is not a scientific comparison, nonetheless, it gives an insight into the alteration of VCS parameters in malaria, given the paucity of literature on the subject.…”

mentioning

confidence: 99%

Quantitative and volume, conductivity and scatter changes in leucocytes of patients with acute undifferentiated febrile illness: a pilot study: Table 1.

Kalra

Ahmad

Shrivastava

et al. 2016

Trans R Soc Trop Med Hyg

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Background: A single diagnostic test for acute undifferentiated febrile illnesses (AUFI) is elusive. This pilot study was undertaken on the premise that leucocytes, being the main cells of defence, undergo quantitative, structural and functional changes in AUFI. We evaluated the potential of volume, conductivity and scatter (VCS) parameters of leucocytes, generated with the haemogram report by the Coulter auto-analyzer, in differentiating the common etiologies of AUFI. Methods:The haematological and VCS data obtained from 800 controls and 200 cases of AUFI (50 cases each of acute malaria, dengue, scrub typhus and enteric fever) were retrieved for analysis.Results: The cases and controls differed significantly with respect to relative numbers and the VCS parameters of neutrophils, lymphocytes and monocytes (p<0.05). The neutrophil and lymphocyte were significantly voluminous in acute malaria and scrub typhus as compared to dengue and enteric fevers (p<0.05). Enteric fever significantly enhanced the conductivity of neutrophils as compared to other subgroups while lymphocyte conductivity significantly differed from dengue and scrub typhus. Lymphocyte and neutrophil scatter values in malaria and scrub typhus were comparable but differed significantly from that in enteric fever.Conclusions: Etiology-specific changes occur in leucocytes, both in numbers and their VCS properties, which can be identified without additional cost.

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Development of an Automated Malaria Discriminant Factor Using VCS Technology

Cited by 47 publications

References 26 publications

Design of Malaria Diagnostic Criteria for the Sysmex XE-2100 Hematology Analyzer

Design of Malaria Diagnostic Criteria for the Sysmex XE-2100 Hematology Analyzer

Malaria Diagnosis: A Brief Review

Quantitative and volume, conductivity and scatter changes in leucocytes of patients with acute undifferentiated febrile illness: a pilot study: Table 1.

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