Evaluation of the coulter LH 750 haematology analyzer compared with flow cytometry as the reference method for WBC, platelet and nucleated RBC count

Evaluation of the WBC-differential flagging performances and accuracy of the HORIBA Yumizen H2500 cell counter in oncology patients from a single institution

INTRODUCTION

The Yumizen H2500 (YH2500) cell analyser was compared to the Pentra DX Nexus (both from HORIBA Medical) to evaluate the efficiency of the new YH2500 technology for the WBC-differential in samples from oncology patients with WBC-diff abnormalities.

MATERIAL AND METHODS

The 220 samples with slide review criteria on the Nexus were systematically analysed on the YH2500. The WBC-diff was compared to flow cytometry (FCM). The 100 additional samples with Monocyte/Neutrophil separation flags were evaluated. The flagging performance and the accuracy of the WBC-diff were analysed.

RESULTS

The YH2500 generated fewer flags than the Nexus (47.73% vs 66.64%; p < .0001), except for Monocyte/Neutrophil flag (15.5% vs. 2.7%; p < 0.0001). Overall performances were higher on the YH2500 (Sensitivity, 100 vs. 89.6%; Specificity 81.0% vs. 50.9%; PPV, 74.3% vs. 62.9%; NPV, 100% vs. 69.5%; Efficiency, 87.7% vs. 69.5%). YH2500 showed a statistically significant better correlation with FCM for the 6-part differential than the Nexus. On 134 samples with Monocyte/Neutrophil separation flag, it was shown that, in samples with less than 10% monocytes on the YH2500, the results of monocyte and neutrophil counts were comparable to the manual count, and that these samples did not need a slide review if no other main criterion for review was present.

CONCLUSION

The YH2500 demonstrated better performance characteristics than the previous cell counter, the Nexus. Its implementation in our laboratory routine work significantly improved the practice workflow, decreased the number of manual cell counts and increased the pertinence of slide review and reporting of the microscopic count.

Associations among sleep, hematologic profile, and aerobic and anerobic capacity of young swimmers: A complex network approach

Although the link between sleep and hematological parameters is well-described, it is unclear how this integration affects the swimmer’s performance. The parameters derived from the non-invasive critical velocity protocol have been extensively used to evaluate these athletes, especially the aerobic capacity (critical velocity—CV) and the anaerobic work capacity (AWC). Thus, this study applied the complex network model to verify the influence of sleep and hematological variables on the CV and AWC of young swimmers. Thirty-eight swimmers (male, n = 20; female, n = 18) completed five experimental evaluations. Initially, the athletes attended the laboratory facilities for venous blood collection, anthropometric measurements, and application of sleep questionnaires. Over the 4 subsequent days, athletes performed randomized maximal efforts on distances of 100, 200, 400, and 800-m. The aerobic and anerobic parameters were determined by linear function between distance vs. time, where CV relates to the slope of regression and AWC to y-intercept. Weighted but untargeted networks were generated based on significant (p < 0.05) correlations among variables regardless of the correlation coefficient. Betweenness and eigenvector metrics were used to highlight the more important nodes inside the complex network. Regardless of the centrality metric, basophils and red blood cells appeared as influential nodes in the networks with AWC or CV as targets. The role of other hematologic components was also revealed in these metrics, along with sleep total time. Overall, these results trigger new discussion on the influence of sleep and hematologic profile on the swimmer’s performance, and the relationships presented by this targeted complex network can be an important tool throughout the athlete’s development.

The flagging features of the Sysmex XN-10 analyser for detecting platelet clumps and the impacts of platelet clumps on complete blood count parameters

OBJECTIVES

Platelet clumps present in anticoagulant specimens may generate a falsely decreased platelet count and lead to an incorrect diagnosis. A clear understanding of the ability of a haematology analyser (HA) to detect platelet clumps is important for routine work in the clinical laboratory.

METHODS

Citrate-anticoagulated whole-blood samples were collected from various patients as a negative group. Adenosine diphosphate (ADP)-induced platelet aggregation was performed on those negative samples to mimic platelet-clump-containing (positive) samples. The 'platelet clumps' and 'platelet abnormal' flags generated by the Sysmex XN-10 instrument were used to assess the flagging performance of this HA and demonstrate its flagging features. The complete blood count (CBC) results of paired negative and positive samples were compared to evaluate the impact of platelet clumps on the CBC parameters.

RESULTS

A total of 187 samples were eligible for this study. The total accuracy, sensitivity, and specificity of the platelet clumps flag were 0.786, 0.626, and 0.947, respectively. The total accuracy, sensitivity, and specificity of the platelet abnormal flag were 0.631, 0.348, and 0.914, respectively. A separate assessment focusing on the positive samples with low platelet counts showed that the total sensitivities of the platelet clumps and platelet abnormal flags were 0.801 and 1.000, respectively. Platelet clumps may interfere with the leukocyte count and with platelet and erythrocyte indices.

CONCLUSIONS

Platelet clumps can influence not only platelet indices but also leukocyte and erythrocyte counts. The Sysmex XN-10 instrument is sensitive to positive samples with low platelet counts but insensitive to those with high platelet counts.

Nutritional Status of Pre-school Children and Determinant Factors of Autism: A Case-Control Study

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder triggered by several factors, including those of genetic and environmental nature. ASD can alter communication, behavior, and children's nutritional status, placing them at high risk for nutritional imbalances. Therefore, this study aims to assess preschool autistic children's nutritional status as compared to that of Typically Developing (TD) children of the same age. The study also revealed some of the ASD risk factors among the Jordanian population. It included 52 ASD and 51 TD children (3-6 years), and considered sociodemographic, obstetric, and nutritional factors of the two groups, stratified by gender. Nutritional status was evaluated through a comprehensive questionnaire, 3-day food record, and anthropometric and biochemical measurements. Differences between groups were identified using the chi-square and independent-sample t-test. The logistic regression model was used after the adjustment of confounders to detect an autistic child's determinants. The study showed little difference between ASD and TD children with respect to nutrients' intake inadequacy and biochemical-nutritional deficiencies, but did reveal gender-based differences. Autistic girls were at higher risk of inadequate carbohydrate intake, while autistic boys were at higher risk of inadequate vitamin E, vitamin K, and fluoride compared to TD children. More autistic children had been treated in neonatal care units after birth than had TD children. The regression analysis revealed that lower maternal education level (OR, 12.25; 95% CI, 1.18-126.91), vaginal delivery (OR, 0.273; 95% CI, 0.105-0.712), family history of autism (OR, 0.189; 95% CI, 0.059-0.612), and taking dietary supplements during pregnancy (OR, 4.665; 95% CI, 1.158-18.79) were all determinants of ASD in children. In conclusion, maternal nutrition, postnatal conditions, and nutritional status might be contributors to ASD in children. Pre-school children are at high risk for developing nutritional deficiencies. It is therefore important to maintain optimal nutritional status in pregnant patients, and in children after delivery and during early childhood. Future studies that investigate the role of nutrient deficiencies and nutritional interventions in ASD are necessary. Also required are studies that focus on gender differences in the prevalence of ASD, types and severity of symptoms, and ASD nutrition-related problems.

White blood cell counting at point-of-care testing: A review

White blood cells, which are also called leukocytes, are found in the immune system that are involved in protecting the body against infections and foreign invaders. Conventional methods of leukocyte analysis provide valuable and accurate information to medical specialists. Analyzing and diagnosing of a disease requires a combination of multiple biomarkers, in some cases, however, such as personal health care, this will occupy some medical resources and causes unnecessary consumption. Traditional method (such as flow cytometer) for WBC counting is time and labor consuming. Compared to gold standard (flow-based fraction/micropore filtration) or improved filtration methods for WBC counting, this is still a lengthy and time consuming process and can lead to membrane fouling due to the rapid accumulation of biological materials. Therefore, the analysis of WBC counts requires more compact and efficient equipment. The microfluidic technologies, powered by different field (force, thermal, acoustic, optical, magnetic) and other methods for leukocyte counting and analysis, are much cost-efficient and can be used in in-home or in resource-limited areas to achieve Point-of-Care (POC). In this review, we highlight the mainstream devices that have been commercialized and extensively employed for patients for WBC counting, Next, we present some recent development with regards to leucocyte counting (mainly microfluidic technologies) and comment on their relative merits. We aim to focus and discuss the possibility of achieving POC and help researchers to tackle individual challenges accordingly. Finally, we offer some technologies in addition to previous detection devices, such as image recognition technology and cloud computing, which we believe have great potential to further promote real-time detection and improve medical diagnosis.

Automated nucleated red blood cell count using the Mindray BC-6800 hematology analyzer

INTRODUCTION

In current laboratory practice, obtaining a nucleated red blood cell (NRBC) count by manual microscopy (MM) is a laborious and time-consuming process. Modern hematology analyzers based on different technologies and methods have variable accuracies when determining NRBC counts. The aim of this study was to compare NRBC counts acquired by an automated Mindray BC-6800 analyzer (BC-6800), a flow cytometry (FC) reference method, and traditional MM.

METHODS

A hundred EDTA samples with initial NRBC flags from the BC-6800 were included. FC was used as a reference method to correlate the NRBC count with BC-6800 and MM counts. In addition, the performance of the Mindray SC-120 analyzer for preparing automated blood films for manual NRBC counting was compared to that of manually prepared blood films.

RESULTS

The NRBC counts obtained with the BC-6800 and MM vs the reference method were highly correlated (r = .994 and .989, respectively). However, the BC-6800 showed a lower bias than MM when compared with FC (0.3 × 10⁹ /L and -6.0 × 10⁹ /L, respectively). NRBC counts obtained using the automated Mindray SC-120 films were comparable to manually prepared films.

CONCLUSION

The Mindray CAL8000 automated hematology system, which is composed of the BC-6800 and the SC-120, yields a precise NRBC count and can replace the traditional MM method for obtaining accurate and reproducible NRBC counts in high-value samples, such as patient monitoring samples used to determine the necessity of transfusion therapy in thalassemia patients. Moreover, this method offers several advantages, including a faster turnaround time, labor savings, and cost effectiveness.

Concomitant spuriously elevated white blood cell count, a previously underestimated phenomenon in EDTA-dependent pseudothrombocytopenia

The proportion and potential risk of concomitant spuriously elevated white blood cell count (SEWC) are underestimated in ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia (PTCP). The proportion, kinetics and prevention of SEWC remain poorly understood. A total of 25 patients with EDTA-dependent PTCP were enrolled in this study. With the hematology analyzer Coulter LH 750, we determined the time courses of WBC count, WBC differential and platelet count in EDTA- and sodium citrate-anticoagulated blood, respectively. Blood smears were prepared to inspect the presence of platelet clumps using light microscopy. The effect of automatic instrumental correction on the extent of SEWC was evaluated. The proportion of SEWC was 92% in EDTA-dependent PTCP and 73.9% of SEWCs were within the normal range. The development of SEWC was time-dependent, and neutrophils and lymphocytes were the main subpopulations involved in SEWC. A strong and significant correlation (r = 0.9937, p < 0.001) was found between the increased WBC count and the decreased platelet count. Both corrected and uncorrected WBC counts at 15 minutes or later after blood collection in EDTA were significantly higher than their basal counts, respectively, p < 0.05. Interestingly, in citrated blood, WBC counts after blood collection were not significantly different from its basal counts, p > 0.05. A high proportion of concomitant SEWCs, which are mainly within normal range, are present in patients with EDTA-dependent PTCP. Proper interpretation of SEWC is crucial to avoid clinic errors. SEWC develops in a time-dependent pattern, although the Coulter LH 750 only partly mitigates the extent of SEWC, sodium citrate is able to effectively prevent SEWC.

Comparison of automated platelet counts and potential effect on transfusion decisions in cancer patients

OBJECTIVES

To evaluate the accuracy of platelet counts from various hematology analyzers using a reference immunologic method.

METHODS

We tested 403 samples with platelet counts less than 50 × 10(9)/L with the Advia (Siemens, Tarrytown, NY), Sysmex (Mundelein, IL), and Abbott (Santa Clara, CA) analyzers.

RESULTS

All methods showed a positive bias, especially at less than 20 × 10(9)/L and less than 10 × 10(9)/L. Undertransfusion risk ranged from 9.1% to 43.3 % in the groups below 20 × 10(9)/L and below 10 × 10(9)/L, respectively. For patients with optical counts more than 10 × 10(9)/L and CD61 less than 10 × 10(9)/L, 64.5% were transfused within 24 hours of the reported count, while 35.5% were transfused in more than 24 hours, after a subsequent optical platelet count of 10 × 10(9)/L or less was reported.

CONCLUSIONS

Although optical and impedance methods were shown to be falsely increased in severely thrombocytopenic samples, further studies are needed to determine if more accurate methods would be clinically useful.

Enumeration of nucleated red blood cells with the ADVIA 2120 Hematology System: an International Multicenter Clinical Trial

The accurate, reproducible, and timely reporting of nucleated red blood cells (NRBC) is an important function of the clinical hematology laboratory. We used 960 samples from 5 worldwide sites to evaluate a new NRBC enumeration method for the ADVIA 2120 Hematology System. The method showed excellent correlation with microscopy (r = 0.93). Sensitivity and specificity for the presence of NRBC for all samples analyzed was 77.3% and 74.6%, respectively. Almost all false negative samples were at NRBC counts <or=10/100 white blood cells (WBC). All false negative samples and the vast majority of the false positive specimens would be identified in clinical practice by routine slide review of flagged results, using existing review criteria. The coefficient of variation of the method was <10% for NRBC counts >10/100 WBC. The NRBC method automatically corrects WBC counts and differential results for the presence of NRBC; the uncorrected counts are available to the user on the run screen. This method allows the enumeration of NRBC with the ADVIA 2120 Hematology System in CBC/DIFF sample mode without need for additional hardware, sample preparation, or reagents.

Evaluation of the monocyte counting by two automated haematology analysers compared with flow cytometry

The aim is to determine the monocyte count performance of the Bayer Diagnostics ADVIA120 and Coulter LH 750 automated haematology analysers and the results obtained by these two instruments were compared with those provided by Becton Dickinson FACScan flow cytometer using the combination of CD45/CD14 MoAb. Linearity and imprecision were also evaluated. The linearity of both instruments was good. Coulter LH 750 showed better precision (4.3%) than ADVIA 120 (9.0%) both within and between batch. A significant correlation (r = 0.973) was found between the LH 750 and the flow cytometry method, while a modest one was observed between the latter and the ADVIA 120 (r = 0.880). When comparing the percentage of monocytes by means of one-way anova and Tukey test, it was found that the LH 750 provided the closest results in comparison with flow cytometry, with no statistical difference between the means (mean difference MO% = 0.6); however the difference was statistically different between the ADVIA 120 and flow cytometry (mean difference MO% = -4.06). These data were confirmed by Altman-Bland and Deming regression analyses.

Automated detection of malaria by means of the haematology analyser CoulterR GEN.STM

The haematology analysers Coulter(R) GEN.S(TM) and LH(TM) give a set of data--'positional parameters'--which define each WBC population by mean of index values, the mean and the standard deviation (SD) of volume, conductivity and scatter, used to identify the WBC populations. These parameters were analysed in patients investigated for suspicion of malaria, in order to show a difference between malaria negative and malaria positive patients and to use it for malaria detection. The six parameters exhibiting a significant difference between the two groups were submitted to a ROC analysis, which showed both sensitivity >90% and specificity >60% for two parameters, lymphocyte and monocyte SDs of volumes. A discriminator combining the two parameters showed a sensitivity of 96.9% and a specificity of 82.5%. The cut off of the discriminative value was calculated. Because of the good stability and reproducibility of the parameters selected, the test can be used in order to detect patients having a high probability to be malaria positive and to pay particular attention to these blood smears. For more extensive diagnostic use, a standard control procedure of the positional parameters should be introduced.