The Usefulness of Blast Flags on the Sysmex XE-5000 Is Questionable
ABSTRACT Hematology analyzers generate suspect flags that involve microscopic reviews to confirm the presence of pathologic cells. This study investigated the reliability of the blast flag in a side-by-side evaluation of 3 Sysmex XE-5000 instruments (Sysmex, Kobe, Japan). The repeatability of the Q values reported by each instrument for 10 replicates of the same blood samples was low (intraclass correlation coefficient [ICC] values, 0.62-0.74). The reproducibility of the Q values obtained by analyzing 408 samples on all 3 instruments was reasonable (ICC value, 0.85). In addition, a systematic difference was observed among the instruments in the level of reported Q values. With cutoff commonly being 100, the observed reproducibility of the blast flagging among the instruments was evaluated as poor (κ = 0.73). Based on the observed low performances, we question the usefulness of the Q value as a predictor of blasts and whether a blast flag reported by the XE-5000 is sufficient as a criterion for performing a microscopic review.
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ABSTRACT: Abstract Background: The rate of auto-validation is dependent on the ability of the laboratory information system (LIS) to integrate historical data, on the frequency and methods for identifying analyzer errors, and on the criteria for reflex testing, including the need for peripheral smear review. The rate of auto-validation in outpatient laboratories, however, is unclear. Methods: We examined 45,925 consecutive complete blood count (CBC) test results (1 January, 2014-31 January, 2014) from patients aged 50±24 years. The LIS auto-validates all samples according to set criteria. Technicians validated test results when previous CBC test results were required to determine: 1) the need for peripheral slide review and/or sample rerun or 2) the need for reflex testing to detect autoimmune hemolytic anemia or β-thalassemia minor. Results: The auto-validation rates were 97.6% after rejecting results requiring validation to determine the need for a peripheral smear review and/or sample rerun. This decreased to 92.9% after including reflex testing to determine the reasons for normocytic and microcytic anemia. We estimated that auto-validation decreased the workload by 7.7-11.6 h per 3000 test results. Conclusions: We conclude that very high auto-validation rates are possible in outpatient general laboratories, leading to conformity in the validation process and a considerable estimated savings in technician time. Further studies are needed in other settings.Clinical Chemistry and Laboratory Medicine 08/2014; 53(2). DOI:10.1515/cclm-2014-0572 · 2.96 Impact Factor
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ABSTRACT: Objectives: The Sysmex XE-5000 instruments (Sysmex, Kobe, Japan) count immature granulocytes (IGs) and use the "Imm Gran? "flag to signal unreliable results. This study investigated the usefidness of the "Imm Gran?" flag and the analytical and diagnostic performance of the IG measurements in a side-by-side evaluation. Methods: In total, 408 samples were analyzed on three XE-5000 instruments. The IG count and the "Imm Gran?" flag reports from all three instruments were used for reproducibility studies. The diagnostic performance of the automated IGs and the "Imm Gran?" flag were studied by comparing the XE-5000 results with the results of the manual differential. Results: The reproducibility of the "Imm Gran?" flagging between instruments was poor (tc, 0.75-0.80). The most significant contributor to the report of the "Imm Gran?" flag was bands, and the flag played a minor role in detecting blasts. The interinstrument reproducibility of the IG counts was high (intraclass correlation, 0.99). The IG count reported by XE-5000s was higher than the manual IG count (36%-550) and the difference and the variability tended to increase with increasing levels of IGs. Conclusions: The "Imm Gran?" flag has a poor analytical quality and gives no substantial information on the presence of blasts in the sample. We therefore suggest reporting the automated IG count without initial microscopic slide reviewAmerican Journal of Clinical Pathology 10/2014; 142(4):553-60. DOI:10.1309/AJCP4V4EXYFFOELL · 3.01 Impact Factor
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ABSTRACT: The usefulness of the CytoDiff flow cytometric system (Beckman Coulter, USA) has been studied in various conditions, but its performance including rapidity in detecting and counting blasts, the most significant abnormal cells in the peripheral blood, has not been well evaluated. The objective of this study was to evaluate the performance of the CytoDiff differential counting method in challenging samples with blasts. In total, 815 blood samples were analyzed. Samples flagged as "blasts" or "variant lymphocytes" and showing <10% blasts by manual counts were included. In total, 322 samples showed blasts on manual counts, ranging from 0.5% to 99%. The CytoDiff method was performed by flow cytometry (FC500; Beckman Coulter, USA) with a pre-mixed CytoDiff reagent and analyzing software (CytoDiff CXP 2.0; Beckman Coulter). The average time required to analyze 20 samples was approximately 60 min for manual counts, and the hands-on time for the CytoDiff method was 15 min. The correlation between the CytoDiff and manual counts was good (r>0.8) for neutrophils and lymphocytes but poor (r<0.8) for other cells. When the cutoff value of the CytoDiff blast count was set at 1%, the sensitivity was 94.4% (95% CI; 91.2-96.6) and specificity was 91.9% (95% CI; 89.0-94.1). The positive predictive value was 88.4% (95% CI; 84.4-91.5) (304/344 cases) and negative predictive value was 96.2% (95% CI; 93.9-97.7) (453/471 cases). The CytoDiff blast counts correlated well to the manual counts (r=0.9223). The CytoDiff method is a specific, sensitive, and rapid method for counting blasts. A cutoff value of 1% of at least 1 type of blast is recommended for positive CytoDiff blast counts.Annals of Laboratory Medicine 01/2015; 35(1):28-34. DOI:10.3343/alm.2015.35.1.28 · 1.48 Impact Factor