A multi-center study on evaluation of leukocyte differential performance by an artificial intelligence-based Digital Cell Morphology Analyzer / 中华检验医学杂志

Objective:To evaluate the performance of an artificial intelligent (AI)-based automated digital cell morphology analyzer (hereinafter referred as AI morphology analyzer) in detecting peripheral white blood cells (WBCs).Methods:A multi-center study. 1. A total of 3010 venous blood samples were collected from 11 tertiary hospitals nationwide, and 14 types of WBCs were analyzed with the AI morphology analyzers. The pre-classification results were compared with the post-classification results reviewed by senior morphological experts in evaluate the accuracy, sensitivity, specificity, and agreement of the AI morphology analyzers on the WBC pre-classification. 2. 400 blood samples (no less than 50% of the samples with abnormal WBCs after pre-classification and manual review) were selected from 3 010 samples, and the morphologists conducted manual microscopic examinations to differentiate different types of WBCs. The correlation between the post-classification and the manual microscopic examination results was analyzed. 3. Blood samples of patients diagnosed with lymphoma, acute lymphoblastic leukemia, acute myeloid leukemia, myelodysplastic syndrome, or myeloproliferative neoplasms were selected from the 3 010 blood samples. The performance of the AI morphology analyzers in these five hematological malignancies was evaluated by comparing the pre-classification and post-classification results. Cohen′s kappa test was used to analyze the consistency of WBC pre-classification and expert audit results, and Passing-Bablock regression analysis was used for comparison test, and accuracy, sensitivity, specificity, and agreement were calculated according to the formula.Results:1. AI morphology analyzers can pre-classify 14 types of WBCs and nucleated red blood cells. Compared with the post-classification results reviewed by senior morphological experts, the pre-classification accuracy of total WBCs reached 97.97%, of which the pre-classification accuracies of normal WBCs and abnormal WBCs were more than 96% and 87%, respectively. 2. The post-classification results reviewed by senior morphological experts correlated well with the manual differential results for all types of WBCs and nucleated red blood cells (neutrophils, lymphocytes, monocytes, eosinophils, basophils, immature granulocytes, blast cells, nucleated erythrocytes and malignant cells r>0.90 respectively, reactive lymphocytes r=0.85). With reference, the positive smear of abnormal cell types defined by The International Consensus Group for Hematology, the AI morphology analyzer has the similar screening ability for abnormal WBC samples as the manual microscopic examination. 3. For the blood samples with malignant hematologic diseases, the AI morphology analyzers showed accuracies higher than 84% on blast cells pre-classification, and the sensitivities were higher than 94%. In acute myeloid leukemia, the sensitivity of abnormal promyelocytes pre-classification exceeded 95%. Conclusion:The AI morphology analyzer showed high pre-classification accuracies and sensitivities on all types of leukocytes in peripheral blood when comparing with the post-classification results reviewed by experts. The post-classification results also showed a good correlation with the manual differential results. The AI morphology analyzer provides an efficient adjunctive white blood cell detection method for screening malignant hematological diseases.

A potential therapeutic target: platelet glycosylation / 中华检验医学杂志

Platelet surface is rich in glycocalyx. It has been found that platelet glycosylation plays an important role in the physiological hemostasis mechanism, regulating the interaction between platelets and receptor proteins, and dynamically reshaping the surface glycosylation through its own glucose metabolism system. Platelet glycosylation also participates in platelet aging and clearance, and regulates platelet counts. Meanwhile, abnormal platelet glycosylation is closely related to primary immune thrombocytopenia, coronary heart disease and other related diseases, being a potential therapeutic target.

Standardization and normalization of flow cytometry / 中华检验医学杂志

Flow cytometry has been widely used in clinical practice. Due to the powerful user-defined function of flow cytometry, different instrument settings among manufacturers and lack of standard materials, the comparability of results needs to be improved and flow cytometry is facing the great challenge of normalization and standardization. In this paper, the recent progress of normalization and standardization about flow cytometry was discussed form the aspects of standardizing operation protocol, including specimen and centrifugation, standardizingantibody selection and panel combination and ensuring instrument and data analysis consistency.

To standardize the detection of cerebrospinal fluid in hematological malignancy by multiparameter flow cytometry / 中华检验医学杂志

Central nervous system (CNS) involvement is a serious complication of hematological malignancies. At present, the gold standard to detect CNS involvement is cerebrospinal fluid (CSF) cytology, but it has low sensitivity. The multiparameter flow cytometry (MFC) shows higher sensitivity than CSF cytology. The occult central nervous system involvement with negative conventional cytology but positive MFC result is the same as dominant central nervous system involvement, which is associated with a high risk of recurrence of hematological tumors. However, due to the particularity of cerebrospinal fluid specimens--less number of cells, low activity, and more interfering cells, the application of MFC for detection of cerebrospinal fluid is limited. Therefore, there is an urgent need to standardize the MFC detection of CSF for hematological tumors, including defining specimen transportation, antibody selection and cut-off value, standardizing data analysis and strengthening employee training, which will greatly improve the role of MFC in the diagnosis of CNS with hematological malignancies.

Application of high-throughput sequencing in the diagnosis of inherited bleeding and thrombotic disorders / 中华检验医学杂志

Inherited bleeding and thrombotic disorders (BTD) are a group of heterogeneous diseases related to the coagulation system, platelet function and fibrinolytic system. In addition to the common BTD, it is difficult to diagnose such patients by routine laboratory tests, and special laboratory tests are often required to confirm the diagnosis. Therefore, the diagnosis and treatment of patients may be delayed, or even life-threatening. With the increasing use of high-throughput sequencing (HTS) technology in clinical practice, the diagnosis and differential diagnosis of BTD have made great progress.

The application of three statistical methods for reference intervals establishment of coagulation assays during pregnancy / 中华检验医学杂志

Objective:To compare the practical value of three statistical methods in establishing reference intervals by the indirect method.Methods:This is a methodological evaluation study. The data of coagulation parameters were obtained from laboratory information system, which were from pregnant women who had done prenatal examination in Peking University First Hospital from January 2017 to December 2019. The test results from 32 401 pregnant women were collected. Those healthy pregnant women were divided into three groups: early pregnancy group(n=11 151), middle pregnancy group(n=4 872) and late pregnancy group(n=16 378). Statistical analysis was performed for the result of PT, APTT, FIB, TT, D-D and FDP, and the necessity of stratification based on age in different periods of pregnancy was analyzed. Stratification based on age was necessary in three pregnancy groups for PT and APTT, in late pregnancy group for FIB and TT, and in early pregnancy group for D-D. The reference intervals of coagulation parameters were calculated by three statistical methods: non-parametric method, Hoffmann method and Q-Q plot method. Forty-two healthy pregnant women from October 2019 to January 2020 were enrolled as reference individuals for the validation of the reference intervals.The proportions of test results outside the reference intervals in the reference population calculated and compared.Results:The levels of the six coagulation assays vary significantly during the three periods of pregnancy, stratification based on age was necessary in three pregnancy groups for PT and APTT, in late pregnancy group for FIB and TT, and in early pregnancy group for D-D. If the number of test results was large, non-parametric and Hoffmann method provided more similar results, while the reference intervals calculated with Q-Q plot method was slightly wider than Hoffmann method. If the number of test results was small, reference intervals calculated with Hoffmann and Q-Q plot method were more reliable. For pregnant women during early pregnancy under the age of 35, the reference intervals of PT, APTT, FIB and TT calculated by this method were (10.44-13.11)s, (25.29-35.88)s, (2.61-4.64)g/L and (11.53-15.58)s.Conclusion:When establishing the reference interval, stratification according to pregnancy period and age was needed. Hoffmann method can be used as an alternative to the direct method.

Discussion on the role of case design in PBL teaching in laboratory diagnostics / 中华医学教育探索杂志

Objective:To investigate the role and influencing factors of case design in PBL teaching.Methods:Thirty-two six-year-program undergraduates from the Department of Medicine of Peking University in batch 2014 and batch 2015 were selected as the subjects. PBL teaching was used in the practice class of experimental diagnostics. The feedback effects of four times PBL courses were analyzed by collecting questionnaires for teachers, students, and supervisors. The data obtained from the five-point questionnaire and the question-and-answer questionnaire were analyzed by one-way ANOVA and statistics respectively. Then the problems in case preparation process are discussed and the experience of case design is summarized. SPSS 13.0 was used in this study.Results:The 5-point questionnaire showed that the average score of anemia PBL course was the highest among students' self-evaluation and mutual evaluation of teachers and students (4.84 points, 4.79 points), with statistical significance compared with other courses ( P<0.05). The question-and-answer questionnaire survey showed that 93.75% of the students generally agreed with the teaching model of anemia cases; 78.13% and 59.38% of the students believed that it was difficult to set up cases of infection and coagulation, which affected the classroom effect; and 50% of the supervisors thinked that the students' level should be taken into account in case design and oral expression should be avoided. Conclusion:Case design is the key to PBL teaching. Summarizing the experience of case design can lay a good foundation for the establishment of PBL teaching database.

Study on molecular pathogenesis for a case of Glanzmann′s thrombasthenia / 临床检验杂志

Objective@#To investigate the molecular pathogenesis for a patient with Glanzmann thrombasthenia (GT). @*Methods@#The peripheral blood of a patient with Glanzmann′s thrombasthenia was collected, and the genetic mutations were detected by gene sequencing technology. The mutant plasmids were prepared by PCR site-directed mutagenesis and transfected into CHO-K1 cells of Chinese hamster ovary to construct in vitro eukaryotic expression system. The expressions of αⅡb and β3 protein subunits in CHO-K1 cells were detected by western blot. The expression levels of αⅡb and β3 in cellular membrane and cytoplasm of CHO-K1 cells were detected by flow cytometry. The expression and distribution of αⅡb and β3 in CHO-K1 cells were observed by immunofluorescent labeling under microscope. @*Results@#This patient was diagnosed with type Ⅱ GT. Gene sequencing revealed two mutations in ITGB3 gene which has not been reported in the literature. ITGB3 c.1495 T＞C missense mutation resulted in replacement of cysteine no.499 by arginine (p.C499R). ITGB3 c.1728 delC code shift mutation resulted in a change in the amino acid synthesis initiated by the β3 protein subunit serine no.577 and terminated by the 92nd amino acid following these changes. The results of western blotting showed that the synthesis and expression of primary structures of αⅡb and β3 were detectable in the lysates of mutant CHO-K1 cells. The results of flow cytometry showed that no expression of β3 on the surface and intracellular of mutant CHO-K1 cells was observed. Under fluorescence microscopy no distribution of β3 protein subunit was displayed in mutant CHO-K1 cells. @*Conclusion@#The mutation of ITGB3 c.1728 del C or ITGB3 c.1495 T＞C should be relevant to the cause of GT in this patient. The mutation of ITGB3 c.1728 del C and ITGB3 c.1495 T＞C seems not to affect the formation of the primary structure of β3 protein subunit, but did affect the formation of its high-level structure.

Mutational analysis of 3 Glanzmann's thrombasthenia pedigrees / 中华检验医学杂志

Objective To explore the molecular pathogenesis of 3 Glanzmann's thrombasthenia pedigree by using bioinformatics software and provide evidence for in vitro experiments. Methods The genetic analysis of 3 pedigree diagnosed as Glanzmann's thrombasthenia was carried out. Clustalx-2.1 win software was used to analyze the conservatism of mutant sites in homologous sequences. Bioinformatics software such as PolyPhen-2, PROVEAN, SIFT and Mutationtaster was used to analyze the biological effect of mutation. SPDBV software constructed the molecular structure model of mutant protein and evaluated the influence of mutation on protein structure. Results The "new mutations" found in 3 Glanzmann's thrombasthenia pedigree were ITGA2B:c. 814G>C (p. Val272Leu), ITGA2B:c. 432G>A (p. Trp144Ter) and ACTN1:c. 2458A>G (p. Ile820Val). All three mutations were highly conserved among homologous species. Mutationtaster software showed that 3 new mutations were likely pathogenic. PolyPhen-2 and PROVEAN software showed ITGA2B p.Val272Leu and ACTN1 p.Ile820Val were benign and SIFT software showed that ITGA2B p. Val272Leu were likely pathogenic, while ACTN1 p. Ile820Val is benign. The result of SPDBV software showed that the Val272 of ITGA2B was transformed to Leu, neutralizing all the original hydrogen bond. The Trp144 of ITGA2B is transformed to Ter, resulting in the truncated proteins with only 113 amino acid residues. All these mutations affected the molecular structure of GPⅡb, resulting in a decrease ofGPⅡb/Ⅲa expression. When the Ile820 of ACTN1 is transformed to Val, onlyretained the hydrogen bond of Ile820 and Asp822, neutralized the rest hydrogen bond, whichaffected the molecular structure and protein function of ACTN1. Conclusion The mutations of ITGA2B:c.814G>C (p.VAL272LEU), ITGA2B:c.432G>A (p.Trp144Ter) and ACTN1:c.2458A>G (p.Ile820Val) are pathogenic.

A multi-center research on the establishment and validation of autoverification rules for blood analysis / 中华检验医学杂志

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)

Monitoring of antiplatelet therapy and changes of mean platelet volume after percutaneous coronary intervention in the patients with coronary heart disease / 临床检验杂志

Objective To compare the consistency of thrombelastography (TEG) and light transmittance aggregometry (LTA) in monitoring the antiplatelet therapy of the patients with coronary heart disease (CHD) after percutaneous coronary intervention (PCI),and observe the changes of mean platelet volume (MPV) of the patients treated with aspirin and clopidogrel after PCI.Methods A total of 177 patients undergoing PCI and the treatment of aspirin and clopidogrel in Peking University First Hospital during March 2014 and May 2015 were enrolled in the study.Their adenosine diphosphate (ADP) or arachidonic acid (AA) induced platelet inhibition rates determined by TEG,MPV before and after antiplatelet therapy,and the maximum platelet aggregation rates measured by LTA from 99 patients were retrospectively analyzed.Results There was no any correlation between the maximum aggregation rates measured by LTA and the platelet inhibition rates determined by TEG regardless of using ADP or AA as agonist (all P ＞ 0.05).The detection rates of clopidogrel hyporesponsiveness determined by LTA and TEG were 30.3％ and 45.5％,respectively,while those of aspirin hyporesponsiveness were 19.2％ and 31.3％,respectively.The detection rate of hyporesponsiveness determined by LTA was significant lower than that by TEG (P ＜ 0.05).The MPVs after antiplatelet therapy were significant lower than that before treatment (all P ＜ 0.01) regardless of clopidogrel hyporesponsive or sensitive and aspirin hyporesponsive or sensitive.The MPVs in clopidogrel hyporesponsive group before and after treatment were significantly lower than that in clopidogrel sensitive group (all P ＜ 0.05).The PLT counts in clopidogrel or aspirin hyporesponsive groups after treatment were significantly higher than that before treatment (all P ＜ 0.05).Conclusion There is poor correlation between LTA and TEG.It should be noted that the incidence rate of antiplatelet drug hyporesponsiveness is high in clinical practice.The MPVs of the patients significantly decrease after antiplatelet therapy.The patients with a significant increase of PLT after antiplatelet therapy are more likely to become drug hyporesponsiveness,while the patients with lower MPV are more likely to have clopidogrel hyporesponsiveness.

Advances in laboratory monitoring of direct oral anticoagulants / 中华检验医学杂志

Direct oral anticoagulants,include direct thrombin inhibitor and direct factor Xa inhibitor.As the pharmacokinetics and pharmacodynamics of these drugs are known,their plasma concentration is not food-effective,and theoretically it is not necessary to monitor routinely.However, clinical practice in recent years has shown that anticoagulant effect of DOACs is required to evaluate in patients with thrombosis, major bleeding, emergency surgery, hepatic/renal dysfunction and other special situations.Recent studies have shown that routine coagulation assays such as activated partial thromboplastin time(APTT) and thrombin time(TT) can be used as laboratory screening tests for direct thrombin inhibitor dabigatran and prothrombin time(PT) can be used as laboratory screening test for direct factor Xa inhibitor rivaroxaban.DOAC′s quantitative measurements include dilute thrombin time(dTT),hemoclot thrombin inhibitor (HTI),ecarin clotting time (ECT) and ecarin chromogenic assay (ECA) for direct thrombin inhibitor and anti-FXa assay(rivaroxaban calibration) for rivaroxaban.Laboratories should establish their own monitoring range when performing these assays.

Evaluation of point-of-care testing for D-dimer in elderly patients / 中华急诊医学杂志

Objective To evaluate the clinical performance of AQT90 FLEX,a novel time-resolved fluorescence based point-of-care test (POCT) for quantification of D-dimer in elderly patients.Methods The method from Quantitative D-dimer assay (WS/T 477-2015) for testing equipment performance was used as a reference to evaluate the clinical performance of AQT90 FLEX.The correlation was compared between testing results of D-dimer using the AQT90 immune-assay analyzer and those using the ACL TOP coagulation analyzer.Results At high concentration of D-dimer,the within-run precision coefficient of variation (CV)was 2.619％,and at low concentration of D-dimer,the within-run precision CV was 2.767％.The pollution-carrying rate was 0.12％.The measured data from AQT90 and ACL TOP had a correlation coefficient of r =0.9491 (P ＜ 0.01).The equation of the line of best fit for D-dimer with which all AQT90 results can be adapted to the ACL TOP was:AQT90 =2.52 ACL TOP + 0.15.The number from the equation was slightly greater in female than that in male,and it was also increased in elderly.Conclusions The AQT90 FLEX had rational precision and linearity in determination of concentration.There was a high agreement between the testing results from AQT90 and those from ACL TOP.It was recommended to use a slope of 2.52 and an intercept of 0.15 to adjust the D-dimer values of the ACL TOP to the AQT90 FLEX assay systems.POCT for D-dimer by AQT90 FLEX raises feasibility for use in elderly patients.

Application of white blood cell differential in peripheral blood by flow cytometry / 中华检验医学杂志

Manual microscopic differential of white blood cell has been challenged by multiparameter flow cytometry,using monoclonal antibodies to define the different leukocyte types.Compared with manual differential,flow cytometry method is more sensitive,specific,objective and has good repeatability.Recent studies demonstrated flow cytometric differential correlates well with manual microscopic method and has good clinical performance for blast and immature granulocyte.Meanwhile more leukocyte populations can be identified with flow cytometric method,such as lymphocyte subset and CD 16 + monocyte,thus helping in monitoring blast in acute leukemia,B lymphocyte proliferative disorder differential diagnosis and minimal residual disease.With the development and improvement of flow cytometric differential,it might be a candidate reference method of leukocyte differential,gradually applied in the routine work.

Method establishment of minimal residual disease in B lineage acute lymphoblastic leukemia by 8- color flow cytometric detection / 中华检验医学杂志

Objective To establish and evaluate the new method of 8-color flow cytometry (8c-FCM) with two tube detecting bone marrow minimal residual disease (MRD) in B lineage acute lymphoblastic leukemia (B-ALL).MethodsThe MRD cells were analyzed by using two combinations of 8c-FCM antibody panels,gating with CD19/Side scatter(SSC),CD45/CD10 and CD34(or cTdT).Nalm-6 cell of B-ALL was mixed into normal marrow cells,with proportion of 10.00％,1.00％,0.10％,0.01％and 0.005％,and recovery test and reproducibility test were carried with 8c-FCM established to value its accuracy and precision of.Fluorescence intensity was detected on different time points after marked Nalm-6 by antibodies to evaluate the fluorescent stability of the antibodies.The immunophenotyping was analyzed in 39 bone marrow specimens,including 9 cases of normal control,9 cases of B-ALL primary or recurrent,21 cases of complete remission (CR) after chemotherapy or bone marrow transplantation ( BMT),to evaluate the detection of normal B lymphocyte lineage,leukemia cells of B-ALL,MRD cells of B-ALL using the 8c-FCM and compare it with 4c-FCM in being.ResultsThe method of two tube 8c-FCM with main antibodies of CD19,CD45 and CD10 to detect MRD of B-ALL was founded; CV ＜ 2.5％,average recovery rate was 95.81％,when the actual percent of Nalm-6 mixed into normal bone marrow≥0.10％,and the percent of Nalm-6 detected and actual was linear dependent ( r =0.99,P ＜ 0.05 ) ranged from 10.00％ - 0.01 ％,when 106 cells were acquired ; the sensitivity of the method established could reach 0.01％.The fluorescent intensity decreased along with the time after Nalm-6 cell marked,but less than 10％ in 24 hours.Using the antibody combinations and analyze strategy,the immunophenotye of B lymphocyte in normal bone marrow presented four sequential stages:Stage Ⅰ CD45low/CD10stro/CD20 -/CD38stro/CD34 + or cTdT +,Stage ⅡCD45 +/CD10 + / CD20 -/CD38stro/CD34+ or cTdT +,Stage Ⅲ CD45 +/CD10 +/CD20 -/CD38stro/CD34 -or cTdT-,Stage Ⅳ CD45stro/CD10 -/CD20 +/CD38low/CD34or cTdT.Antigen expressions of leukeamic cells of B-ALL primary or recurrent were different compared with control team; there were 5 cases with MRD positive in CR team,and the main antigen expression was consistent with the results from 4c-FCM.The range of the percent of MRD cells was 0.02％ - 5.42％ of the 5 cases of MRD positive.ConclusionsThe new method of two tube 8c-FCM established shows good reproducibility and high accuracy,and can identify normal B lymphocyte populations in bone marrow and regenerated B-precursors in CR cases with MRD cells;compared with 4c-FCM,the new method of two tube 8c-FCM with the fewer specimen is faster and efficient to diagnose MRD of B-ALL.

A new platelet activated-release test for monitoring aspirin response / 中华检验医学杂志

Objective To establish a new method for monitoring aspirin response by platelet activated-release experiment.Methods The platelets in whole blood were activated by ARA,and the MPC was measured by hematology analyzer.Blood samples were drawn from five healthy volunteers for measuring MPC,LTAARA and platelet membrane CD62P expression.Blood samples were mixed thoroughly right after venipuncture. The concentration of ARA (0,0. 5,1.0,1.5,5.0 and 10. 0 mmol/L) and the time for platelet activation (5,10,20,30,40,50,60,70,80 and 90 min in 37℃ water bathe) were optimized to evaluate the stability (0,1,2 and 3 h after venipuncture) and reproducibility (MPC, LTAARA and platelet membrane CD62p were measured ten times and the CV was calculated). Platelets were mixed with acetylsalicylic acid at different concentrations in vitro in order to verify the validity for monitoring aspirin response. The percentage of CD62p positive platelets after activated by ARA was measured using flow cytometer with CD61-PerCP and CD62p-PE antibodies. The correlation between MPC and CD62P was determined. 100 patients without taking or stop taking aspirin more than 7 days and 93 patients who took aspirin at least 7 days were enrolled. Duplicate measurements of platelet function were performed using the change of MPC (ARA 0. 5 mmol/L) and LTA (ARA 0. 5 mmol/L) among two patient groups to evaluate the accuracy of the new method. Results Platelcts were completely activated by ARA at final concentration of 0. 5 mmol/L. MPC negatively correlated with platelet membrane CD62p(r=-0. 755,P<0. O1 ). MPC was stable for 30 minutes in 37 ℃ water bathe after ARA activation. The result of MPC was consistent at room temperature within 3 hours after blood collection. This method had good reproducibility. CV in batch using fresh whole blood was 1.35% and CV between batches using commercial control whole blood were 0. 71% and 0. 74%. With the concentration of acetylsalicylic acid increased (0-6. 95 μmol/L), MPC increased as CD62P decreased, which showed negative correlation (r=-0. 765 ,P <0. 01 ). The difference of MPC before and after ARA activation (ΔMPC) and MPC variance ratio of the group taking aspirin were ( 8. 2±8. 6) g/L and ( 3.4±3.6) %, and they were (37.4±10. 3 ) g/L and ( 15.7±4.0) % in control group, respectively.ΔMPC and MPC variance ratio showed significant difference between the two groups ( t=21. 522, 22. 409, all P < 0. 01 ). Area under the ROC curve for MPC variance ratio was 0. 992 with sensitivity of 96. 8% and specificity of 99.0% for monitoring the aspirin response using the cut-off of 8. 7%. MPC variance ratio had good correlation with LTAARA (r = 0. 720, P < 0. O1 ). Conclusions A new method for monitoring aspirin response by platelet activated-release experiment is established. It may replace LTAARA for routine clinical examination.

"Leukocyte differential count in peripheral blood ""with"" single tube/ten colors""flow cytometry" / 中华检验医学杂志

Objective To explore the values of potential clinical application ofsingle tube/ten colorsflow cytometry for leukocyte differential count in peripheral blood.Methods Utilizing multiple monoclonal antibody combinations and the vavious logical gating strategies,the single tube/12 antibodies with no-wash method for the leukocyte differential count in peripheral blood were determined by using 10 colors flow cytometry.Leukocyte differentials of 142 peripheral blood samples were determined by both Beckman-Coulter LH750 hematology analyzer and 10 colors flow cytometry.The results were then compared to standard microscopic examination as a reference method.The clinical diagnostic efficiency ofsingle tube/10 colorsflow cytometry was calculated.The correlations between standard microscopic cytology,single tube/10 colorsflow cytometry and the hematology analyzer were determined.In addition,the clinical diagnosis efficiency for blast counts ofsingle tube/10 colorswere compared to the results determined by BD FACS Calibur flow cytometer.Results The leukocyte differentials were correlated well between the single tube/10 colorsflow cytometry and standard microscopic cytology(r>0.700,P<0.01) except for basophils.The correlations with neutrophilic granulocytes,lymphocytes,immature granulocytes and blasts were superior(r=0.972,0.951,0.801,0.912,respectively,P<0.01).When 1% was selected as the cut-off point for immature granulocytes determined by standard microscopic cytology,the sensitivity and the specificity ofsingle tube/10 colorsflow cytometry were 92%(57/62) and 79% (63/80),respectively.When 0.5% was selected as the cut-off point for blasts detected by standard microscopic cytology,the sensitivity and the specificity were 99% (67/68) and 92% (68/74).Using the immunophenotyping results from BD FACS Calibur as a standard,the sensitivity for detecting blasts bysingle tube/10 colOrsflow cytometry was 100% (40/40),the specificity was 91% (10/11),the positive predictive value was 98% (40/41),the negative predictive value was 100% (10/10) and the accuracy was 98% (50/51).Conclusions Thesingle tube/10 colorsflow cytometry has a excellent correlation with the standard microscopic cytology when applied on leukocyte differential count in peripheral blood.It may potentially use as a subsequent method for verification of abnormal results of complete blood cell count in the future.

Alteration of platelet membrane glycoprotein Ⅵ in patients with type 2 diabetes mellitus and its clinical significance / 中华检验医学杂志

Objeetive To explore change of platelet glycoproteins Ⅵ(GPⅥ)in patients with type 2 diabetes mellitus and its clinical significance.Methods The surface expression of platelet glycoprotein Ⅵ was determined by flow cytometry in 56 patients with type 2 diabetes mellitus and 61 normal individuals.Plasma GP Ⅵ concentration was measured by ELISA in 30 patients with type 2 diabetes mellitus.Platelet surface CD62P was analyzed by flow cytometry and HbA1c was determined in Datients with type 2 diabetes mellitus.Results The geometric mean fluorescence of platelet surface GPⅥ in Datients with type 2 diabetes mellitus was 93.66±35.24,which was significantly enhanced compared with normal subjects (62.83±24.2)(t=-4.927,P＜0.05).Nine patients were positive in plasma GPⅥ among 30 Datients with type 2 diabetes mellitus.Plasma GP Ⅵ concentrations in 9 positive patients were conversely correlated with platelet surface GPⅥ expression(r=-0.633,P＜0.05).However,there was no correlation between platelet Surface CD62P and plasma HbA1c concentrations, and the correlation coemcient is -0.333 and -0.417,respectively(P＞0.05).There was no correlation between platelet surface GP Ⅵ expression with C062P and HbA1c in patients with type 2 diabetes mellitus and the conrrelation coefficient is -0.009 and -0.217,respectively(P＞0.05).Conclusions GPⅥ expression on platelet surface is elevated in Datients with type 2 diabetes mellitus and the determination of platelet surface GPⅥ and plasma GPⅥ concennlation may helP to prognosticate the risk of thrombotic events and may play an important role in evaluating platelet activation in patients with type 2 diabetes mellitus.

Prognostic relevance of immunophenotyping in 131 patients with acute myeloid leukemia / 中华检验医学杂志

Objective To investigate the correlation of prognosis with the immunophenotype in acute myeloid leukemia(AML)patients.Methods Immunophenotyping was performed in 131 patients with AML by mtdtieolor flow cytometry.Correlation of immunophenotype with other laboratory parameters such as initial white blood cell count(WBC),platelet count(PLT),hemoglobin(Hb),and the complete remission(CR)ratio was analyzed.Results In these AML patients,myeloid antigens CDl3,CD33 and myeloperoxidase(MPO)were more highly expressed than other antigens.Expression of CD34 and HLA-DR were lower in acute promyelocytic leukemia(M3)subtype.The expression of lymphocyte antigen CD19 and CD7 were the highest.CD7 expression was associated with age(t=-2.27,P＜0.05).CD14 was associated with initial WBC(Z=-2.284,P＜0.05).The overall CR ratio was 56.5%among all patients.CD34positive patients had a significantly lower CR rato(45.1%),compared with the CD34 negative patients whose CR ratio was 75.6%(x2=11.524,P=0.001).The CR ratio was significantly lower in cases expressing both CD34 and HLA-DR(74 patients with CR rate 41.9%)than in cases expressing only CD34 or HLA-DR(38 patients with CR rate 78.9%)and both negative(19 patients with CR rate 68.4%)(Z=-3.492,P＜0.01).However,other antigens,including CD7,CD19,CD13,CD33,CD38,CD15,CD64,CD14 and MPO had no significant association with CR ratio.Logistic regression analysis showed that age(60 years or older),initial WBC(more than 50 x 109/L),PLT(more than 30 x 109/L),Hb(less than 60g/L)and CD34 were independent adverse factors for achieving CR.Conclusions In AML patients,age,initial WBC,PLT,Hb and CD34 are associated with CR ratio.Detection of immunophenotype may help to estimate prognosis of patients with AML and guide the treatment of AML.

Flow cytometric immnno-bead array assay for detection of platelet-specific autoantibodies / 中华检验医学杂志

Objective To establish a new flow cytometric immuno-bead array assay (FCIBA)to detect several platelet-specific autoantibodies simultaneously in a single serum sample.Methods A series of beads of different red fluorescent intensity were used for coating with different anti-platelet membrane protein monoclonal antibodies(anti-GP Ⅱb/a,anti-GP Ⅰ a/Ⅱ a,anti-GP Ⅳ,anti-GP Ⅰ b/Ⅸ and anti-HLAABC)to detect five platelet-specific autoantibodies in serum. The beads captured platelet antigenautoantiboay complex.Subsequently,different platelet-specific autoantibodies in a patient serum can be detected simultaneously by the flow cytometry.In addition,we evaluated the new FCIBA,and compared its results with modified antigen capture ELISA method(MACE).The new FCIBA was used to detect five platelet-specific autoantibodies in serums of autoimmune thrombocytopenic purpura(AITP)and nonautoimmune thromboeytopenic purpura patients.Results The new FCIBA can be used to detect five plateletspecific autoantibodies simultaneously(Anti-GP Ⅱ b/Ⅲ a,Anti-GP Ⅰ a/Ⅱ a,Anti-GP Ⅳ,Anti-GP Ⅰ b/Ⅸand Anti-HLA-ABC).The coefficient of variation(CV)of intra-repetition are 4.82%,6.09%,5.04%,5.73%and 5.30%,respectively.The dilution test results are in good logarithm linearity which are 0.997 2,0.996 6,0.998 8,0.996 5 and 0.998 2,respectively. The resuhs of the new FCIBA are highly correlated with those with MACE method,and the coefficient correlation were 0.928 9,0.922 4,0.889 4,0.910 0 and 0.913 4,respectively(P＜0.01).51.69%samples of AITP patients show positive for platelet-specific autoantibodies as detected by the new FCIBA.Among the AITP patients,the positivity of specific autoantibodies for anti-GPⅡb/ Ⅲ a,anti-GP Ⅰ a/Ⅱ a,anti-GP Ⅳ,anti-GP Ⅰb/Ⅸ and anti-HLA-ABC were 40.82%,24.45%,19.39%,32.65%and 17.35%.Among the 40 non-autoimmune thrombocytopenic purpura patients,none of platelet-specific autoantibodies in serum samples can be detected.Conclusion A new FCIBA is established successfully to detect five platelet-specific autoantibodies coefficient correlation.