BACKGROUND: The XN-series (Sysmex, Japan) is the new hematology analyzer from Sysmex, with new channels to improve the accuracy of differential leukocyte count and platelet count in the low cell count range. We evaluated the analytical performance and low white blood cell (WBC) mode of the XN-2000. METHODS: Precision, linearity, and carryover were evaluated for the analyzer. We analyzed the accordance of complete blood count (CBC), reticulocyte count, and differential leukocyte count between the XN-2000 and XE-2100 (Sysmex), using 200 samples from normal controls and patients. For 80 samples with a WBC count <1.5x10(9) cells/L, the low WBC mode was evaluated by comparing the automated count with a manual differential count as the reference. RESULTS: The coefficients of variation of precision were <5% for most CBC parameters and <10% for differential leukocyte count. All results obtained with the XN-2000 showed good correlation with those obtained with the XE-2100. The correlation coefficients (r) were >0.9800 for all CBC parameters except mean corpuscular hemoglobin concentration, mean platelet volume, and platelet distribution width, and >0.9900 for differential leukocyte count except monocytes and basophils. The low WBC mode provided accurate counts for neutrophils and lymphocytes, with r>0.9300 for samples with a WBC count of 0.1-1.5x10(9) cells/L. CONCLUSIONS: The XN-2000 showed good analytical performance and correlation with the existing model, the XE-2100. The XN-2000 provided accurate results for differential leukocyte count in samples with a WBC count of 0.1-1.5x10(9) cells/L, and reduced manual slide reviews.
Basophils ; Blood Cell Count ; Blood Platelets ; Cell Count ; Erythrocyte Indices ; Hematology* ; Humans ; Leukocyte Count* ; Leukocytes ; Lymphocytes ; Mean Platelet Volume ; Monocytes ; Neutrophils ; Platelet Count ; Reticulocyte Count

BACKGROUND: Platelet clumping is a common cause of erroneous platelet counts by automated blood cell counter. The most commonly employed solution to this problem is to redraw the specimen into a different anticoagulant. However, this is unpleasant for the patient and not rapid for reporting of the corrected platelet count. Mixing of blood with a vortex mixer was evaluated as a method to disaggregate platelet clumps in blood and thus obtain accurate platelet counts. METHODS: Whole blood samples coated with ethylenediaminetetraacetic acid (EDTA) from 28 patients with platelet clumping and 20 controls without platelet clumping from July to September 2002 were mixed for 30 seconds with a vortex mixer. Platelet counts, blood smears, erythrocyte counts, Hgb, MCV and total leukocyte counts were evaluated before and after mixing. RESULTS: Vortex mixing of blood samples with platelet clumps caused an increased platelet count in 96% (27/28) and a decreased total leukocyte count in 68% (19/28). The mean platelet and total leukocyte counts of 28 blood samples before mixing were 155.0+/-89.6 (x10(3)/microL) and 12.9+/-5.5 (x10(3)/microL) and after mixing they were 249.2+/-116.2 (x10(3)/microL) and 12.0+/-5.4 (x10(3)/microL). Total erythrocyte counts, Hgb, MCV were not significantly affected by vortex mixing. Further, vortex mixing of 20 control samples had no consistent effect on each items. CONCLUSIONS: Vortex mixing of blood samples is a simple, rapid method without re-sampling in correction of erroneous platelet count induced by platelet clumps.
Blood Cell Count ; Blood Platelets ; Edetic Acid ; Erythrocyte Count ; Humans ; Leukocyte Count ; Platelet Count*

Two trials were conducted with proficiency tests for complete blood cell count (CBC) and blood cell morphology as part of the 2018 Routine Hematology Program of the Korean Association of External Quality Assessment Service. Three different control samples were sent for CBC testing and two blood cell morphology pictures were posted on the laboratory website during each trial. The mean response rates of the 1,719 participating laboratories were 97.4% and 37.2% for CBC and blood cell morphology, respectively. The distribution of equipment for CBC testing was comparable to that of the previous year. The coefficient of variation (CV) ranges were determined as 3.5%–4.1%, 1.9%–2.7%, 1.4%–2.8%, 4.5%–5.3%, and 5.4%–6.9% for white blood cell counts, red blood cell counts, hemoglobin, hematocrit, and platelet counts, respectively. The concordance rate ranged from 83.0% to 97.5% in blood cell morphology tests. We observed a continuous increase in the number of participating laboratories and a trend towards a decrease in the CVs of platelet counts compared to those in 2016. Values of the other assessed parameters were similar to those of the previous year.
Blood Cell Count ; Blood Cells ; Erythrocyte Count ; Hematocrit ; Hematology ; Laboratory Proficiency Testing ; Leukocyte Count ; Platelet Count

Four trials of external quality assessment in diagnostic hematology were performed in 2004 with about 440 participating laboratories in Korea. We performed quality assessment for white blood cell count, hemoglobin, red blood cell count, platelet count, white cell differential count, red blood cell morphology and coagulation test. The response rate was more than 96%. The coefficients of variation in hemoglobin and RBC number was stable but variable in platelet number and WBC number according to measuring cell counts. Blood coagulation study was performed twice. Test results show wide variation according to measuring machine and reagents.
Blood Coagulation ; Cell Count ; Equidae* ; Erythrocyte Count ; Erythrocytes ; Hematology* ; Indicators and Reagents ; Korea* ; Leukocyte Count ; Platelet Count

Under the Routine Hematology Program of Korean Association of External Quality Assessment Service, proficiency tests for complete blood count (CBC) and blood cell morphology were performed during 2016. We conducted two trials, and sent three level control materials for CBC testing and posted two cell morphology pictures on the website for each trial. Of 1,455 laboratories, the mean response rates for CBC and blood cell morphology were 96.3% and 40.4%, respectively. The distribution of equipment for CBC test was similar to that of previous year. The coefficient of variations for white blood cell counts, red blood cell counts, hemoglobin, hematocrit, and platelet counts, were 3.8%–4.5%, 1.9%–2.3%, 1.4%–2.8%, 4.8%–5.8%, and 6.2%–9.4%, respectively. More than 80% of the blood cell morphology tests were concordant in all trials. In 2016, the number of participating laboratories increased, and the performance was similar to that of the previous year.
Blood Cell Count ; Blood Cells ; Erythrocyte Count ; Hematocrit ; Hematology* ; Korea* ; Laboratory Proficiency Testing ; Leukocyte Count ; Platelet Count

Under the Routine Hematology Program of the Korean Association of External Quality Assessment Service, complete blood count (CBC) and blood cell morphology proficiency tests were performed during 2017. We conducted two trials, sent three control materials for CBC testing, and posted two cell morphology pictures on the website for each trial. Of 1,646 laboratories, the mean response rates for CBC and blood cell morphology were 96.7% and 42.0%, respectively. The distribution of equipment for CBC testing was similar to that of the previous year. The coefficient of variations for white blood cell counts, red blood cell counts, hemoglobin, hematocrit, and platelet counts were 3.7%–4.7%, 2.2%–2.4%, 1.5%–3.0%, 5.4%–6.0%, and 7.2%–10.2%, respectively. More than 80% of the blood cell morphology tests were concordant among all of the trials, except for the HHI-17-03 trial. In 2017, the number of participating laboratories increased, and the performance was similar to that of the previous year.
Blood Cell Count ; Blood Cells ; Erythrocyte Count ; Hematocrit ; Hematology* ; Korea* ; Laboratory Proficiency Testing ; Leukocyte Count ; Platelet Count

Four trials of external quality assessment in diagnostic hematology were performed in 2009 with average 946 participating laboratories in Korea. We performed quality assessment for white blood cell count, hemoglobin, hematocrit, red blood cell count, platelet count, blood cell morphology, prothrombin time and activated partial thromboplastin time. The response rate was more than 98.2%. The coefficients of variation in hemoglobin, hematocrit and RBC count were stable but variable in platelet count and WBC count according to measuring cell counters. Test results of blood cell morphology showed variation among various cell morphologies.
Blood Cells ; Cell Count ; Erythrocyte Count ; Hematocrit ; Hematology ; Hemoglobins ; Korea ; Leukocyte Count ; Partial Thromboplastin Time ; Platelet Count ; Prothrombin Time

Four trials of external quality assessment in diagnostic hematology were performed in 2007 with average 722 participating laboratories in Korea. We performed quality assessment for white blood cell count, hemoglobin, hematocrit, red blood cell count, platelet count, blood cell morphology, prothrombin time and activated partial thromboplastin time. The response rate was more than 95.2%. The coefficients of variation in hemoglobin, hematocrit and RBC were stable but variable in platelet count and WBC count according to measuring cell counters. Test results of blood cell morphology showed variation among various cell morphologies.
Blood Cells ; Cell Count ; Erythrocyte Count ; Hematocrit ; Hematology ; Hemoglobins ; Korea ; Leukocyte Count ; Partial Thromboplastin Time ; Platelet Count ; Prothrombin Time

Four trials of external quality assessment in diagnostic hematology were performed in 2007 with average 722 participating laboratories in Korea. We performed quality assessment for white blood cell count, hemoglobin, hematocrit, red blood cell count, platelet count, blood cell morphology, prothrombin time and activated partial thromboplastin time. The response rate was more than 95.2%. The coefficients of variation in hemoglobin, hematocrit and RBC were stable but variable in platelet count and WBC count according to measuring cell counters. Test results of blood cell morphology showed variation among various cell morphologies.
Blood Cells ; Cell Count ; Erythrocyte Count ; Hematocrit ; Hematology ; Hemoglobins ; Korea ; Leukocyte Count ; Partial Thromboplastin Time ; Platelet Count ; Prothrombin Time

Four trials of external quality assessment in diagnostic hematology were performed in 2008 with average 822 participating laboratories in Korea. We performed quality assessment for white blood cell count, hemoglobin, hematocrit, red blood cell count, platelet count, blood cell morphology, prothrombin time and activated partial thromboplastin time. The response rate was more than 96.5%. The coefficients of variation in hemoglobin, hematocrit and RBC was stable but variable in platelet count and WBC count according to measuring cell count. Test results of blood cell morphology showed variation among various cell morphologies.
Blood Cells ; Cell Count ; Erythrocyte Count ; Hematocrit ; Hematology ; Hemoglobins ; Korea ; Leukocyte Count ; Partial Thromboplastin Time ; Platelet Count ; Prothrombin Time