Objective To assess system deviation of HbA1c measurement in clinical laboratories in China by the national trueness verification project.Methods Bias assessing research.Two lots samples of human whole blood pools with different HbA1c concentration levels were prepared and sent to laboratories by dry ice package.Laboratories were asked to measure these samples in 5 repeats per set in three consecutive Wednesday separately,results were reported through Web-based software.Meanwhile the IFCC reference measurement procedure was applied to assign HbA1c reference values for the two lots samples.The following information or data were analyzed:measurement systems,intra-lab CVs and inter-lab robust CVs of all laboratories,inter-lab robust CVs and bias based on peer groups,et.al.The criterion of bias was set at ± 4.5％.Results 106 of 120 laboratories submitted results,including 88 using high performance liquid chromatography method,13 using immune turbidimetry method and 5 using enzymatic methods the intra-lab CVs of lot 201311 ranged from 0 to 4.6％,with median of 1.1％,while for lot 201312 the intra-lab precision ranged from CV0 to CV4.5％,with median of CV0.9％.The inter-lab robust CVs of 201311 and 201312 with single determinations were 5.6％ and 6.1％ and inter-lab robust CVs of 201311 and 201312 of each lab's average results were 5.9％ and 5.6％ respectively.The inter-lab CVs of group BIO-RAD,TOSOH,ARKRAY and PRIMUS at two level were less than 5％.For all laboratories,the percents of pass of 201311 and 201312 were 61/106(57.5％) and 56/106(52.8％) respectively.The pass ratio of each group on two lots were as follows:of group BIO-RAD were both 19/45 (42.2％),of group TOSOH were 85％ (17/20) and 75％ (15/20),of group ARKRAY were 71.4％ (10/14) and 50％ (7/14),of group PRIMUS were 6/8,5/8; of group immune turbidimetric method were both 46.2％ (6/13) and of group enzymatic were both 3/5.Conclusions There were improvement for the performance of trueness of HbA1c measurement in domestic laboratories,while some of them should be addressed.Academic,research institutions,EQA organizer,manufacturers and clinical laboratories should work together to achieve the standardization of HbA1c measurement.

Objective To study the applicability of a new analytical specification defined in WS/T 403-2012 in the external quality assessment schemes and the external comparision of internal quality control .Methods It was a quality management method study.Total error allowable criterions listed in WS/T 403-2012 and GB/T 20470-2006 were selected to assess the results of 23 analytes in the 1st challenge of 2013 routine chemistry external quality assessment.The acceptable rate of 23 analytes were calculated with the two specifications.Criterions of imprecision derived from the two standards were applied to assess the coefficient of variation with internal quality control data.Results With the specification based on WS/T 403-2012, the ratio of laboratories that all five samples were passed in the 1st challenge for 23 analytes ranged from 55.5%to 94.7%.The ratio of laboratories with 80%or more samples passed in 2013 EQA ranged from 73.9%to 98.5%.While ratios of two kinds described above evaluated based on GB /T 20470-2006 ranged from 63.0%to 99.2%, and from 90.0% to 99.7%, respectively.The acceptable rate of CV according to the two criterions ranged from 55.5% to 94.7% and 63.0% to 99.2%, respectively.Conclusions As evaluation criterions of external quality assessment allowable total error and internal quality control imprecision in routine chemistry , the specification in WS/T 403-2012 can be used to assess the analytical performance of clinical laboratory more objectively and comprehensively.It can help laboratories to identify the latent problems for further quality improvement.

Objective To evaluate the difference of Doumas′method and 15 commercial serum total protein ( TP ) methods based on EP9-A3.Methods Serum panels were quantified for TP with Doumas′method and measured in parallel with 15 commercial methods.The linear regression analyses were performed, followed by calculating relative deviation and 95%CI between commercial method and Doumas′method at three different medical decision levels (45 g/L, 60 g/L, 80 g/L).We also calculated relative deviation, 95% limit of agreement ( LoA ) and 95% CI based on classical and improved Bland-Altman method at three different medical decision levels.If both the relative deviation and 95%CI were within 5%, we conside red the commercial serum total protein method was comparable to Doumas′method.Results (1) All assays presented high correlation ( r>0.975, P<0.001) with the Doumas′method.All assays showed that the relative deviations and 95%CIs were within the biological total error goal (5%) at medical decision levels based on regression analysis.(2) Based on classical and improved Bland-Altman method, fourteen of 15 commercial methods showed that the relative deviations and 95%CIs were within +/-5%. Conclusions All commercial assays are comparable to Doumas′method at medical deviation levels.There is no difference between regression analysis and Bland-Altman method for comparison study.

We analyzed the genetic characteristics of coxsackievirus A4 (CV-A4) based on the entire VP1 coding region. Samples were isolated from patients with acute flaccid paralysis (AFP) in Shaanxi, China from 2006 to 2010. We wished to ascertain the predominant genotype and the relationship between CV-A4 infection and AFP. Sixty-eight non-polio enteroviruses were inoculated onto RD cells (to increase the virus titer) and molecular typing was undertaken. The entire VP1 coding region was amplified. Percentage of CV-A4 was 10.3% (7/68). Analyses of genetic identify and creation of phylogenetic trees revealed that CV-A4 could be classified into A, B and C genotypes. Seven CV-A4 strains from Shaanxi and other CV-A4 strains from China formed an independent evolution lineage located in group 4 and belonged to the C2 sub-genotype. These data suggested that CV-A4 strains of sub-genotype C2 were the predominant genotypes in China. These strains co-evolved and co-circulated with those from other provinces in China, so continued monitoring of CV-A4 (by clinical and genetic surveillance) should be enhanced.
China ; Enterovirus A, Human ; classification ; genetics ; isolation & purification ; Enterovirus Infections ; virology ; Genotype ; Humans ; Paralysis ; virology ; Phylogeny ; Viral Proteins ; genetics

Objective To develop a candidate reference method for the measurement of creatinine in human serum based on isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS). Methods An isotopically labeled internal standard [<'2>H<,3>] creatinine was added to the serum sample and equilibrated with the endogenous creatinine. The samples were treated with anhydrous ethanol to remove proteins by precipitation. After being washed with chloroform for further clean-up, the samples were analyzed by LC/MS/MS. Serum creatinine was quantified by a bracketing calibration. Results The within-run, between-run and total coefficients of variation ranged from 0.52% to 0.61%, 0.11% to 0.59% and 0.61% to 0.83%, and the averages were 0.57%, 0.43% and 0.73%, respectively. The analytical recoveries ranged from 99.09% to 101.13% with an average of 100.3%.The results of analyzing the certified reference material SRM 909b (Level Ⅰ and Ⅱ) and SRM 967b showed biases of less than 0.4%. Conclusions An ID-LC/MS/MS method for measuring serum creatinine has been developed. The method is highly precise and accurate and may be used as a candidate reference method for serum creatinine measurements.

Objective To evaluate the analytical quality of different analytical systems in measuring seven kinds of sero-enzymes consisting of Alanine Aminotransferase(ALT), Aspartate Aminotransferase (AST),γ-Glutamyltransferase(GGT), Lactate Dehydrogenase(LDH), Creatine Kinase(CK), α-Amylase (AMY) and Alkaline Phosphatase(ALP).Methods Data from 2013 routine chemistry external quality assessment (EQA) and Enzymes Trueness Verification(ETV) were collected.1 450 and 165 participating laboratories were selected respectively for investigation.Analytical systems of participating laboratories were classified into 6 kinds,i.e.imported matching system(AI), domestic matching system(AH), systems consisting of imported reagents and corresponding calibrators(BI), systems consisting of domestic reagents and corresponding calibrators ( BH ) , unmatched systems using imported calibrators ( CI ) and unmatched systems using domestic calibrators ( CH ) .Total error, bias and coefficient of variation within laboratories ( CVI) were calculated from the data of 2013EQA and ETV The proportion of laboratories meeting the desirable and the optimal criteria derived from biology variation were analyzedby EXCEL2010 with coincidence rate (CR) above 85% as evaluation criterion.Results The AI and CI occupied more than 70%among six systems, CH occupied approximate 15% and the other systems were less than 10%.The
range of the average of ETV′s total errors , EQA′s total errors, absolute value of bias and CVI of seven kinds of sero-enzymes were 6.2%-27.8%, 4.0%-7.0%, 4.2%-25.1% and 3.6%-4.6% respectively. Accuracy, bias and within-laboratory imprecision were judged by CR of ETV′s total errors, ETV′s bias, CVI and EQA′s total errors respectively and comparability between different systems was evaluated.It turned out that the results of analytical systems of enzymes except ALP were comparable, the accuracy of systems of enzymes except AMY, ALP and GGT, LDH of AI, the within-laboratory imprecision of enzymes except LDH, AMY, ALP and AST of AI, CH could meet the desirable criteria.The bias of all systems of seven kinds of sero-enzymes were undesirable.Conclusions The analytical quality of routine testing of seven kinds of sero-enzymes could fulfill the clinical requirement generally in China.

Objective Preparation of aqueous reference materials for cholesterol and glycerol.Methods Study on reference materials.The certified reference materials GBW09203b and GBW09149 were weighed accurately and dissolved into 20% of methyl cyclodextrin aqueous solution to prepare six kinds of candidate reference materials of cholesterol and glycerol according to the concentration.The materials were tested for homogeneity and stability using routine methods.The reference methods of isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS) were used to determine the concentration of cholesterol and glycerol to evaluate the accuracy of the certified values.Meanwhile, the blank verification test was carried out.The expanded uncertainty was the combination of standard uncertainty of measurement, unhomogeneity and instability.Results It showed that the six candidate reference materials were homogeneous and stable for at least 1 year at-70 ℃ and-20 ℃.The certified values (reference value ± expanded uncertainty,mmol/L) were as follows,for cholesterol:0.65±0.01,1.31 ±0.01,2.57±0.02,5.21±0.06,7.71±0.08,10.24±0.06;for glycerol:0.29±0.01,0.58±0.01,1.22±0.02,2.24±0.02,3.46±0.04,4.52 ±0.04.The results of reference methods were consistent with the certified values.Blank validation tests showed that the concentration of the analytes would not be affected by the reagent and the blank matrix.Conclusions Certified reference materials for cholesterol and glycerol in aqueous solution have been prepared successfully.These materials are homogeneous and stable, and the certified values are reliable.Therefore the materials have been approved to be the Certificate Reference Materials of GBW 09823, GBW 09824, GBW 09825, GBW09826, GBW09827 and GBW 09828.

Objective To develop a candidate reference method for the measurement of serum glucose based on isotope dilution liquid chromatography tandem mass spectrometry(ID-LC/MS/MS)Methods An internal standard [~(13)C_6]glucose was added to serum samples and equilibrated with endogenous glucose.Serum proteins were removed by a precipitation with anhydrous ethanol.Serum glucose and the internal standard were then reacted with 1-phenyl-3-methyl-5-pyrazolone and the formed derivatives were analyzed by liquid chromatography tandem mass spectrometry with multiple reaction monitoring(MRM).The method was calibrated with bracketing calibrators and serum glucose concentrations were calculated by comparing the peak area ratios of samples with that of the calibrators.Results The within-run,between-run and total coefficients of variation averaged 0.36%,0.47%and 0.61%,respectively.The analytical recoveries ranged from 99.0% to 100.9%.Results of analyzing the certified reference material SRM 965a showed an average biases of-0.20%.Conclusions An ID-LC/MS/MS method for measuring serum glucose has been developed.The method is highly precise and accurate and may be used as a candidate reference method.

Objective To evaluate the trueness of 13 routine measurements for serum uric acid and the role of reference method in improving harmonization and trueness among routine measurement systems. Methods The research is related to the reagent evaluation.Usingisotope dilution liquid chromatography tandem mass spectrometry ( ID-LC/MS/MS) method as the comparison method, Wako, Sekisui, DiaSys, Maker,Dirui,Leadman,BSBE,Biosina,Mindray,MedicalSystem,LongMarch,and Kehua 13 kinds of uric acid kits were chosen as the evaluation methods with Hitachi 7170A as the analyzer.serum uric acid in 40 fresh frozen serawere collected from clinical laboratory of Beijing hospital in 2014,coveringboth physiological and pathological status ( 80 -940 μmol/L ) .19 kinds of prepared materials and the 40 fronzen sera were measuredby comparison method and evaluation methods and linear regression analysis was made for the results.The performance of evaluation methods was revealed and recalibration was performed on every evaluation methodby the linear regression equation.The variation of percent bias(%) of the uric acid values in 19 preparation materials was compared.Results All test methods demonstrated good precision ( CV<1.75) and good correlation (R2 >0.998, P<0.01) with the comparison method when measuring uric acid values in 40 fresh frozen sera The meanpercent bias was 0.17% ( -3.06% -7.31%).After recalibration, 4 of 19 samples with no matrix effect values percent bias reduced and met the demands of quality ( <4.8%) induced from biological variation.Conclusion All test methods demonstrated good trueness and their calibration traceability was verified.Recalibration using reference method or standard reference materials contributes to harmonization among methods.

Objective:To investigate the effect of conventional coronary CT angiography (CCTA) bolus injection of contrast agent on the diameter and angle of the left main coronary artery (LMA) bifurcation area, and to provide a basis for the application of CCTA to accurately measure the coronary artery.Methods:In Cangzhou Central Hospital of Hebei Province from January to December 2020, the clinical data of 54 patients with suspected coronary heart disease who underwent coronary artery calcification score (CACS) and CCTA with conventional bolus injection of contrast agent were retrospectively analyzed. Two physicians measured middle lumen diameter of LMA (d1), proximal lumen diameter of left anterior descending (LAD) (d2), proximal lumen diameter of left circumflex (LCX) (d3) and bifurcation angle between LAD and LCX (∠1). The consistency of 2 physicians was compared, and the results of CACS and CCTA were compared.Results:The consistency analysis result showed that only d3 measured by CCTA had a moderate consistency (intra-group correlation coefficient = 0.717), and the remaining indexes were in good agreement (intra-group correlation coefficient >0.75). There were no statistical differences in indexes measured results between CACS and CCTA ( P>0.05). According to the degree of left coronary artery stenosis, 54 patients were divided into 2 groups: LMA and branches normal or stenosis degree < 50% group (25 cases) and LMA and branches 1 or more branches stenosis degree≥50% group (29 cases). There were no statistical differences in indexes measured results between CACS and CCTA in patients with different disease severity ( P>0.05). Conclusions:In the CCTA examination, the conventional bolus injection of contrast agent does not affect the diameter and angle of the lumen of the LMA bifurcation area of the coronary artery.