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Objective:To evaluate the performance of the automated digital cell morphology instrument in detecting platelet (PLT) clumps.Methods:A total of 4271 blood samples whose PLT reached the reviewing rules of thrombocytopenia were selected from inpatients having blood analysis in Xijing Hospital from January 1 st to June 30 th, 2019, including 2 200 males and 2 071 females,with a median age of (35±7.03) years old. The smears for these cases were made, stained by Wright-Giemsa, and examined to capture PLT clumps by digital cell morphology system and manual microscope separately. The digital cell analysis system (hereinafter referred to as the instrument method) as an evaluation method and the microscope method as a reference method were used to calculate the positive rate of platelet clump detection and evaluate the comparison of two methods and bias assessments. The chi-square test was used to compare counting data rates. Results:Among 4, 271 samples reaching the reviewing rule of thrombocytopenia, 128 cases with platelet clumps were detected by manual microscope(initial) with a positive detection rate of 96.24%, and a total 133 of cases with PLT clumps were detected by microscope (initial+reconfirmation) with a positive detection rate of 100 %. Meanwhile, 129 cases with platelet clumps were detected by instrument method with a positive detection rate of 96.9%. There was no significant difference in terms of positive rate of PLT clumps detection between the instrumental method and the microscope method (initial) ( χ2 =0.115, P=0.73); the positive rate of clumps detection by the instrumental method was lower than microscope method (initial+reconfirmation), and the difference was statistically significant (χ 2 =4.061, P=0.04). For instrument method, the positive rate of PLT clumps detection by simultaneous observation of RBC analysis interface+PLT aggregation interface+WBC analysis interface was higher than only observation of PLT aggregation interface, and the difference was statistically significant (χ 2 =5.090, P=0.02). The average error of the deviation of PLT counting results before and after correction of the cases with PLT plumps missed by instrument method was significantly higher than microscope method (initial), and the difference was statistically significant (χ 2 =56.26, P<0.001). Conclusion:The automated digital cell morphology system has a good consistency with manual microscope(initial) in terms of the sensitivity of platelet clumps detection and can be used as a supplementary method for detecting platelet aggregation.
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Objective@#To establish a set of rules for autoverification of blood analysis, in order to provide a way to validate autoverification rules for different analytical systems, which can ensure the accuracy of test results as well as shorten turnaround time (TAT) of test reports.@*Methods@#A total of 34 629 EDTA-K2 anticoagulated blood samples were collected from multicenter cooperative units including the First Hospital of Jinlin University during January 2017 to November 2017. These samples included: 3 478 cases in Autoverification Establishment Group, including 288 cases for Delta check rules; 5 362 cases in Autoverification Validation Group, including 2 494 cases for Delta check; 25 789 cases in Clinical Application Trial Group. All these samples were analyzed for blood routine tests using Sysmex XN series automatic blood analyzers.Blood smears, staining and microscopic examination were done for each sample; then the clinical information, instrument parameters, test results and microscopic results were summarized; screening and determination of autoverification conditions including parameters and cutoff values were done using statistical analysis. The autoverification rules were input into Sysmex Laboman software and undergone stage Ⅰ validation using simulated data, and stage Ⅱ validation for post-analytical samples successively. True negative, false negative, true positive, false positive, autoverification pass rate and passing accuracy were calculated. Autoverification rules were applied to autoverification blood routine results and missed detection rates were validated, and also data of autoverification pass rate and TAT were obtained.@*Results@#(1)The selected autoverification conditions and cutoff values included 43 rules involving WBC, RBC, PLT, Delta check and abnormal characteristics. (2)Validation of 3 190 cases in Autoverification Establishment Group showed the false negative rate was 1.94%(62/3 190)(P<0.001), autoverification pass rate was 76.74%, passing accuracy was 97.47%; Validation of 2 868 cases in Autoverification Validation Group, the false negative rate was 3.38%(97/2 868)(P=0.002), autoverification pass rate was 42.26%, passing accuracy was 92.00%; Validation of Delta check on 288 cases in Autoverification Establishment Group and 2 494 cases in Autoverification Validation Group showed the false negative rates were respectively 1.39% and 2.61%(P<0.001). (3)Three hospitals adopted these rules of autoverification for 25 789 blood routine samples, and found that the average TAT of blood routine test reports were shortened by 24min, 32min and 7min respectively, the rate of samples reported within 30min were elevated by 33%, 53% and 7%. The autoverification pass rates were 72%-74%.@*Conclusions@#The application of this set of 43 autoverification rules in blood sample analysis can ensure test quality while shortenTAT and improve work efficiency. It is worth pointing out that for the same analytical systems in this research, validation is necessary before application of this set of rules, and periodic validation is required during application to make necessary adjustment; for different analytical systems, as this research provide a way to establish autoverification rules for blood routine tests.Clinical labs may establish their own suitable autoverification rules on the basis of technological parameters. (Chin J Lab Med, 2018, 41: 601-607)
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Objective To analyze the cause of platelet aggregation in blood specimens ,so as to provide basis for reducing platelet aggregation ,and avoiding false positive of platelet count ,false report ,misdiagnosis and mistreatment .Methods The blood speci-mens which platelet was below 80 × 109 /L ,below 125 × 109 /L with histogram hinted platelet aggregation ,were smeared ,stained with Wright-Giemsa ,and observed by microscope for platelet morphological changes .The data between each groups were calculated and analyzed by statistical software SPSS version 18 .0 .Results A total of 184 cases of ethylenediaminetetraacetic acid dependent pseudothrombocytopenia(EDTA-PTCP) were found ,accounted for 0 .444 ‰ totally ,including 0 .244 ‰ of out-patients (101 cases) , 0 .159 ‰ of hospitalized patients (66 cases) ,and 0 .041 ‰ of health examination personnel (17 cases) .3 cases of multi-dependent pseudothrombocytopenia and 25 cases of pseudo platelet aggregation were found ,and accounted for 0 .007 ‰ and 0 .060 ‰ respec-tively .Conclusion The discovery of platelet aggregation which caused mainly by EDTA-PTCP ,still relies on microscopy ,and pseu-do platelet aggregation comes mainly from sampling ,so it needs to strengthen the skills training .
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Objective To evaluate the performance of XE‐5000 automated blood cell analyser for detecting nucleated red blood cell (NRBC) in peripheral blood and investigate its clinical application value .Methods The intra‐assay imprecision ,carryover rate , and linear range of the analyser were evaluated .The absolute NRBC count and percentage of NRBC of 137 blood specimens (NRBC‐positive according to the DIFF channel of the analyser) were determined in the NRBC channel of the analyser ,and the percentage of NRBC of these blood specimens were determined by using microscope method as well .Differences between the two methods were analysed by using SPSS18 .0 statistic software .Results The intra‐assay imprecision of the analyser for detecting absolute NRBC count in specimens with high ,moderate ,and low Q‐flag values were 2 .10% ,3 .26% and 11 .62% ,respectively ,and the imprecision for detecting percentage of NRBC were 3 .79% ,5 .80% and 13 .33% ,respectively .The carryover rates of the analyser for detecting absolute NRBC count and percentage of NRBC were 0 .51% and 0 .26% ,respectively .At the range of (0~18)× 109/L ,the absolute NRBC count detected by using the analyser showed good linearity :Y=1 .048 6X+0 .189 6(r=0 .999 1) .There were no statistically significant differences between the analyser and microscope for detecting percentage of NRBC(P=0 .716) ,and showed good corre‐lation:Y=1 .150 2X+0 .626 1(r=0 .967 0) .Conclusion The XE‐5000 automated blood cell analyser could completely replace the traditional microscope for clinically classifying and counting NRBCs .