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Objective:The allowable total error ( TEa),allowable imprecision ( CV)and allowable bias( Bias)were recommended for 34 routine chemistry analytes in China. Methods:According to the performance specification setting mode newly determined at the Milan conference in Italy,the performance specification was derived based on components biological variation (BV)and current state of the art mode. The data(including EQA data and IQC data)of laboratories participating in the routine chemistry and lipids and lipoproteins EQA activities of the national center for clinical laboratories from 2019 to 2021 was collected through clinet-EQA. For the analytes with biological variation(BV)data,compared the'percentage difference′ of EQA data and the'in-control coefficient of variation of the month′ of IQC data of each research analyte with the three levels evaluation criteria derived based on BV,and calculated the percentage difference passing rate and CV passing rate of all batches in each year. When the passing rate reaches 80%,the performance specifications of this level met the requirements of the recommended performance specifications of the analyte. For the analytes without BV data or analytes whose performance specifications at three levels derived based on BV could not be used as recommended standards,the recommended performance specifications are derived based on the current state of the art. After obtaining the recommended TEa and allowable CV for each analyte,used the formula | Bias|≤ TEa-z? CV to derive the recommended allowable bias. Results:The results of TEa ( CV)% recommended by 34 analytes are as follows:K4.7(2),Na4(1.5),Cl4(1.4),Ca5(2),P9.6(3.9),Glu6.4(2.5),Urea8(3),UA12(4.1),Cre11(3.3),TP5(2),Alb5.2(2.4),TC8.6(2.7),TG13.5(5),HDL-C16.5(4.3),LDL-C20.5(6.2),ApoAⅠ16(5.3),ApoB 17.1(5.5),Lp(a) 24.1(10.4),TBil 12.4(5),DBil 20(7.3),ALT16(5),AST13.5(4.8),ALP17.5(4.8),AMY13.1(3.3),CK11.3(3.8),LDH11(3.9),CHE13.4(5.3),LIP20(6.9),Fe13.3(5.2),Mg14(4.5),Cu17.9(6.8),Zn15.1(6.4),γ-GGT10(3.3),α-HBDH18(5.8).The formula | Bias|≤ TEa-z? CV is used to derive the allowable bias of 34 analytes. Conclusions:For 34 clinical routine chemistry quantitative analytes,the allowable total error,allowable imprecision and allowable bias that meet the current state of the art of Chinese laboratories are recommended.
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Objective:To investigate the molecular mechanism of proliferation-inhibiting effect of icaritin on hepatoma cells via regulating miRNA-329 (miR-329) and miRNA-1236 (miR-1236).Methods:Hepatoma cell line HepG2 was treated with icaritin at different concentrations (2.5, 5.0, 10.0, 20.0, 40.0 μmol/L), and the control group only added dimethyl sulfoxide (DMSO). The half inhibitory concentration ( IC50) of icaritin on HepG2 cells and cell proliferation rate were detected by CCK-8 after cultured for 36 h. HepG2 cells were treated with 400 μg/L alpha fetoprotein (AFP). After cultured for 0, 12, 24, 36, 48 and 60 h, the effect of AFP on the proliferation of HepG2 cells was detected by CCK-8 method. AFP-3'UTR reporter plasmid pmirGLO-AFP-3'UTR plasmid was constructed, pmirGLO blank vector plasmid, pmirGLO-AFP-3'UTR plasmid, miR-329 or miR-1236 mimics or inhibitors, control plasmid of mimics (NC), control plasmid of inhibitors (INC) were respectively co-transfected with HepG2 cells, and the effect of miR-329 and miR-1236 on the luciferase activity was detected by dual-luciferase reporter assay after cultured for 24 h. Western blot and real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) were used to detect the effects of icaritin on the expressions of AFP, miR-329 and miR-1236 in HepG2 cells. HepG2 cells were respectively transfected with mimics and inhibitors of miR-329 and miR-1236 to detect the effects of miR-329 and miR-1236 on the expression of AFP. Results:The cell proliferation rates of 2.5, 5.0, 10.0, 20.0, 40.0 μmol/L icaritin group and control group were (80.4±2.3)%, (73.2±1.6)%, (51.7±3.3)%, (38.2±4.6)%, (29.5±4.3)%, and (94.0±2.9)%, respectively, and the difference was statistically significant ( F = 75.65, P < 0.01); the differences in the proliferation rate of HepG2 cells between different concentrations of icaritin group and control group were statistically significant (all P < 0.01). The IC50 of icaritin on HepG2 cells was 10 μmol/L. The relative expressions of AFP mRNA in 2.5, 5.0, 10.0, 20.0, 40.0 μmol/L icaritin group and control group were 0.83±0.06, 0.69±0.02, 0.53±0.07, 0.45±0.01, 0.33±0.07, and 1.00±0.01, respectively, and the difference was statistically significant ( F = 42.67, P < 0.01); the differences in the relative expressions of AFP mRNA between different concentrations of icaritin group and control group were statistically significant (all P < 0.01). HepG2 cells were treated by 400 μg /L AFP for 0, 12, 24, 36, 48 and 60 h, and the cell proliferation rates were (102±5)%, (138±13)%, (186±24)%, (260±12)%, (311±15)%, and (348±25)%, respectively, and the difference was statistically significant ( F = 27.483, P < 0.01); the differences in the cell proliferation rate between different time of AFP treatment and 0 h were statistically significant (all P < 0.01). Compared with the control group, different concentrations of icaritin can promote the expression of miR-329 and miR-1236 (all P < 0.01). After co-transfection of miR-329 and miR-1236 mimics and AFP-3'UTR, the luciferase activity decreased by about 40%; after co-transfection of miR-329 and miR-1236 inhibitors and AFP-3'UTR, the luciferase activity increased about 1.5 times. Both miR-329 and miR-1236 can reduce the expression levels of AFP protein and mRNA (both P < 0.05). Conclusion:Icaritin can promote the binding of miR-219, miR-1236 and AFP-3'UTR by promoting the expression of miR-329 and miR-1236, inhibit the stability and translation activity of AFP mRNA, inhibit the expression of AFP, and thus inhibit the proliferation of hepatoma cells in vitro.
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Background@#Using commutable external quality assessment (EQA) materials is important for monitoring successful harmonization efforts. We assessed the commutability of four human serum pool (HSP) preparations to identify candidate EQA materials for alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity measurement. @*Methods@#One set each of 85 clinical samples (CSs) was collected for ALT and AST activity measurement. The 15 candidate EQA materials included four types of HSP preparations (A to D): materials A, C, and D contained human original recombinant (HOR) aminotransferases; materials B was mixed leftover samples. The CSs and 15 candidate EQA materials were analyzed using seven routine assays, and the ln-transformed results were analyzed in 21 assay pairs. Commutability was assessed using Deming regression, with a 95% prediction interval (CLSI approach) and the difference in bias with an error component model (International Federation of Clinical Chemistry and Laboratory Medicine [IFCC] approach). @*Results@#For ALT, all materials were commutable for 14–21 assay pairs according to the CLSI and IFCC approaches. For AST, B01-03 showed commutability for 14-21 assay pairs, and C01-03 and D01-03 showed commutability for no less than 10 assay pairs according to the two approaches. A01-06 were commutable for 9-16 assay pairs according to the CLSI approach, but for 6-9 assay pairs according to the IFCC approach. @*Conclusions@#Mixed leftover samples showed desirable commutability characteristics as candidate EQA materials for routine aminotransferase activity measurements. Human serum bases supplemented with HOR were commutable for most routine ALT activity measurements.
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Objective@#The aim of this study is to evaluate the commutability of 16 processed materials for 17-hydroxyprogesterone by using 2 commutability assessment approaches.@*Methods@#52 serum specimens were collected in Clinical Laboratory Department of Beijing Hospital from February 2018 to June 2019. According to the report of the Clinical and Laboratory Standards Institute (EP14-A3) document and the recommendations of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) working group on commutabilityassessment, serum 17-hydroxyprogesterone isotope diluent chromatogram tandem mass spectrometry (ID-LC/MS/MS) was used for comparison. Three clinical routine analysis systems (1 radioimmunoassay, 2 LC/MS analysis methods) were used to determine the concentration of 17-hydroxyprogesterone in 52 human serum samples and 16 processed materialsfor commutabilityassessment.@*Results@#Combined with the results of the two commutability assessment, all accuracy verification materials and national steroid hormone standards showed good commutability in the LC/MS analysis system, and 6/9 EQA materials showed commutability in the three routine analysis systems.All materials showed good commutability in the LC/MS analysis system of bias difference method.@*Conclusions@#The two kinds of commutability assessment results are different. Bias difference method has more clinical value, but it has certain application limitations. The use of fresh frozen human serum as a quality assessment materialfor serum 17-hydroxyprogesterone is meets the commutability requirement.
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Objective:To establish a candidate reference method for simultaneous determination of whole blood iron and copper based on ICP-MS technology.Methods:Cobalt (Co) was chosen as the internal standard, and was added gravimetrically into the standard solution and the whole blood sample. The whole blood sample was digested by electric heating plate and diluted. The isotopic ratios of 57Fe/ 59Co and 63Cu/ 59Co were measured by ICP-MS in the isotopic analysis mode. The precision, standard recovery and accuracy of the method were verified by measuring EQA materials and certified standard materials, and the performance of the method was further evaluated by method comparison. Results:The detection limit of iron is 0.136 mg/kg and the limit of quantification was 0.454 mg/kg in this method. The detection limit of copper in whole blood was 0.008 mg/kg and the limit of quantification was 0.027 mg/kg. The standard curve of copper ranges from 0.83-3.33 mg/kg, iron ranges from 167-667 mg/kg. The calibration curve of iron and copper was good linearity ( R 2>0.999 90). The precision of the method did well. The total CV range was 0.42%-0.68% for iron and 0.14%-0.94% for copper. The spike recoveries were all around 100%, the range of iron: 99.69%-100.07%; copper: 99.26%-100.51%. The correlation between this method and the existing clinical mass spectrometry methods was good. Conclusions:A candidate reference ICP-MS method for simultaneous determination of whole blood Fe and Cu was established. This is a simple and rapid method with good precision and spike recovery compared to the traditional one.
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Objective:To evaluate the performance of aldosterone testing in China through the External Quality Assessment (EQA) and improve the testing quality of aldosterone.Methods:Two kinds of EQA program for aldosterone were carried out in China, one of which is Routine EQA and the other is Trueness verification scheme. Lyophilized sera with 5 concentration levels were used as quality control of Routine EQA. The results were grouped according to the instrument. Target values and the coefficient of variation ( CV) were calculated in each group. Trueness verification scheme was verified by using frozen human sera of 3 concentration levels determined by the reference method, and the bias of each instrument group from the target value was calculated. Results:272 laboratories submitted the testing results, and 91.6% of laboratories used chemiluminescence method. The maximum CV was obtained by radioimmunoassay and liquid chromatography mass spectrometry, and the robust CVs were 14.6%-33.4% and 43.5%-53.9%, respectively. For chemiluminescence methods, the robust group CV was less than 10%. The results of the Trueness verification scheme showed that liquid chromatography mass spectrometry method was the most accurate method, with biases of -7.9%, 8.9% and -0.7% for the three quality controls. Diasorin system had the more accurate results deviated from the target by 58.7%, 7.9% and -2.1%, respectively. The results of other chemiluminescence methods were negatively correlated with the sample concentration, and one of them with a bias of 479%. Conclusions:The accuracy and comparability of aldosterone among laboratories in China are not satisfactory. Reagent manufacturers and laboratories should pay more attention to EQA, with the aldosterone results traceable to SI unit, and improve the test quality of aldosterone.
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Objective:The aim of this study is to evaluate the commutability of 16 processed materials for 17-hydroxyprogesterone by using 2 commutability assessment approaches.Methods:52 serum specimens were collected in Clinical Laboratory Department of Beijing Hospital from February 2018 to June 2019. According to the report of the Clinical and Laboratory Standards Institute (EP14-A3) document and the recommendations of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) working group on commutabilityassessment, serum 17-hydroxyprogesterone isotope diluent chromatogram tandem mass spectrometry (ID-LC/MS/MS) was used for comparison. Three clinical routine analysis systems (1 radioimmunoassay, 2 LC/MS analysis methods) were used to determine the concentration of 17-hydroxyprogesterone in 52 human serum samples and 16 processed materialsfor commutabilityassessment.Results:Combined with the results of the two commutability assessment, all accuracy verification materials and national steroid hormone standards showed good commutability in the LC/MS analysis system, and 6/9 EQA materials showed commutability in the three routine analysis systems.All materials showed good commutability in the LC/MS analysis system of bias difference method.Conclusions:The two kinds of commutability assessment results are different. Bias difference method has more clinical value, but it has certain application limitations. The use of fresh frozen human serum as a quality assessment materialfor serum 17-hydroxyprogesterone is meets the commutability requirement.
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Objective:To investigate the molecular mechanism of alpha-fetoprotein (AFP) inhibiting cisplatin-induced apoptosis of hepatocellular carcinoma cells.Methods:HepG2 (AFP positive) and QSG-7701 (AFP negative), two common hepatocyte carcinoma cell lines were selected. The expression of AFP was knockdown in HepG2 cells with RNA interference method and AFP expression plasmid was transfected in QSG-7701 cells. After the cells were cultured for 12, 24, 36 and 48 hours, the cell proliferation was detected by cell counting kit-8 (CCK-8) assay. After HepG2 and QSG-7701 cell lines were interfered or overexpressed AFP protein for 24 h, respectively, apoptotic inducer cisplatin (CDDP) was added. The effect of AFP on apoptosis induced by CDDP in hepatocellular carcinoma cells was determined by flow cytometry. The interaction between AFP and transcription factor retinoic acid receptor (RAR) was examined by protein coimmun oprecipitation (CoIP) technique. The effect of AFP expression level on the expression of DNA damage inducible transcript 1 ( DDIT1), and the effects of AFP and DDIT1 on apoptosis of hepatocellular carcinoma cells were tested by chromatin immunoprecipitation (ChIP) assay and Western blotting. T test was performed for statistical analysis. Results:The results of CCK-8 test showed that after plasmid transfected for 12, 24, 36 and 48 hours, the relative proliferation rates of QSG-7701 cells overexpressed AFP increased by 28.7%±2.7%, 49.8%±6.1%, 65.8%±3.0% and 79.3%±2.0%, respectively; however the relative proliferation rates of HepG2 cells after AFP knockdown decreased by 16.5%±6.1%, 28.5%±5.7%, 42.5%±1.7% and 57.6%±3.8%, respectively, when compared with the control group, and the differences were statistically significant ( t=3.978, 4.357, 3.461, 3.636, 2.858, 2.446, 3.233 and 4.492, all P<0.05). The results of flow cytometry indicated that after AFP overexpression for 24 and 48 hours, the apoptosis rate of QSG-7701 cells decreased by 46.3%±2.9% and 47.7%±7.4%, respectively, compared with cisplatin induced cells; however after AFP knockdown for 24 and 48 hours, the apoptosis rate of HepG2 cells increased by 86.7%±4.0% and 31.6%±10.5%, respectively, compared with cisplatin induced cells, and the differences were statistically significant ( t=3.543, 3.893, 2.336 and 2.561, all P<0.05). The results of CoIP experiment showed that AFP could interact with RAR. After AFP knockout in HepG2 cells, after nucleoprotein extracted, RAR entering the nucleus increased as compared with the control group. However, after overexpression of AFP in QSG-7701 cells, RAR entering the nucleus decreased compared with the control group. The results of ChIP experiments showed that AFP could regulate the expression of DDIT1. The expression of DDIT1 in AFP knockdown HepG2 cells was higher than that of control group, however the expression of DDIT1 in AFP overexpressed HepG2 cells was lower than that of control group. Compared with the control group, the apoptosis rate of HepG2 and QSG-7701 cells increased by 53.1%±4.0% and 73.3%±6.4% respectively after transfecting with DDIT1, and the differences were statistically significant ( t=3.462, 3.012, P=0.009, 0.017). In QSG-7701 cells, after AFP overexpression, the apoptosis rates decreased by 46.6%±4.8% compared with cisplatin added alone. After overexpression of AFP, cisplatin added and overexpression of DDIT1, the apoptosis rate increased by 43.6%±2.7% as compared with that of overexpression of AFP and cisplatin added, and the differences were statistically significant ( t=2.833 and 2.545, P=0.018 and 0.029). In HepG2 cells, after AFP knockdown the apoptosis rate increased by 73.3%±6.1% compared with cisplatin added alone; and after AFP knockdown, cisplatin added and DDIT1 knockdown the apoptosis rate decreased by 32.7%±3.7% as compared with AFP knockdown and cisplatin added, and the differences were statistically significant ( t=2.497 and 2.773, P=0.032 and 0.020). Conclusions:AFP can inhibit the expression of its downstream gene DDIT1 by interacting with the transcription factor RAR, which not only promotes the proliferation of hepatocellular carcinoma cells but also enhances the anti-apoptosis ability of hepatocellular carcinoma cells and weakens cisplatin induced apoptosis in hepatocellular carcinoma cells.
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The laboratory medicine is aimed to support clinical decisions and patient health by providing accurate results. The internal statistical quality control (SQC) can help laboratories detecting the instability of the analytical system and preventing laboratories from reporting the patient results with medically important errors, so it is essential to ensure the quality of testing results and patient safety. The traditional methods of designing SQC strategy are based on the probability of error detection (Ped) and the probability of false rejection (Pfr). With the introduction of risk management concepts, the design of SQC strategy began to be based on the patient risk parameter [MaxE(Nuf)] proposed by Parvin, which means the maximum increase in the number of unacceptable patient results reported compared to the in-control condition during the existence of an undetected out-of control error condition. MaxE(Nuf) is related to the SQC frequency and patient risk, which is very essential for optimizing the SQC frequency and designing a risk-based SQC strategy.
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The laboratory medicine is aimed to support clinical decisions and patient health by providing accurate results. The internal statistical quality control (SQC) can help laboratories detecting the instability of the analytical system and preventing laboratories from reporting the patient results with medically important errors, so it is essential to ensure the quality of testing results and patient safety. The traditional methods of designing SQC strategy are based on the probability of error detection (Ped) and the probability of false rejection (Pfr). With the introduction of risk management concepts, the design of SQC strategy began to be based on the patient risk parameter [MaxE(Nuf)] proposed by Parvin, which means the maximum increase in the number of unacceptable patient results reported compared to the in-control condition during the existence of an undetected out-of control error condition. MaxE(Nuf) is related to the SQC frequency and patient risk, which is very essential for optimizing the SQC frequency and designing a risk-based SQC strategy.
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Objective Accurate measurement of aldosterone is critical in the diagnosis of primary aldosteronism. We compared the harmonization of three assays including isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) and two chemiluminescence immunoassays (CLIAs:system A and system B) for the aldosterone measurement. Methods A total of 45 plasma samples, 4 quality control materials, 5 lyophilized bovine serums, and 3 fresh frozen human serum pools were measured by three assays respectively. Based on CLSI EP15-A3 rule, the precision was assessed by coefficient of variance. Deming regression and Bland&Altman plots was performed for method comparison, and correlation coefficient was calculated for concordance (CCC). Results All three methods met the performance criteria based on desirable biological variation for precision (<7.35％). System A showed a relevantly good correlation and comparability with ID-LC/MS/MS (R2=0.985, CCC=0.967), while System B showed relevantly bad correlations and comparability with both System A (R2=0.538, CCC=0.605) and ID-LC/MS/MS (R2=0.547, CCC=0.528).. However, the average relevant bias of two CLIAs exceeded the bias requirement derived from biological variation (18.60％). Conclusion Significant differences were found in the measurement of plasma aldosterone using ID-LC-MS/MS and two CLIAs, which urges the establishment of traceability hierarchy and improvement of reagents' specificity for standardization of aldosterone measurement in clinical settings.
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Objective To evaluate the comparability and consistency of two kinds of triglycerides reference methods, one of which is the isotope dilution liquid chromatography-mass spectrometry (LC/MS) in the Cholesterol Reference Method Laboratory Network (CRMLN), the other isthehigh-performance liquid chromatography (HPLC) method for triglyceride detection in China. Methods 52 fresh frozen sera with triglycerides levels among 0.45-4.52 mmol/L were determined by LC/MS and HPLC. After evaluation the precision and accuracy of the two methods,a series of analyses were conducted including plotting to scatter plots and deviation graphs, testing outliers, selecting the best fitting regression models and calculating the regression equations and parameters, and so on. The expected deviation at the level of medical decision of triglycerides and the 95％confidence range were statistically analyzed.Results For HPLC method, the CV of instrument measurement was 0.29％(0％-1.16％), the total CV of samples measurement was 0.54％(0.04％-1.28％), and the average bias of the reference materials was 0.22％(-0.43％-0.68％). ForLC/MSmethod,the CV of instrument measurement was 0.55％(0％-1.68％),the total CV of samples measurement was 0.79％(0％-1.93％), and the average bias of the NIST reference materials was 0.09％(-0.73％-1.29％). No outlier was found from the scatter plots and the statistical analysis and the linear regression was fitted to analyze the results of the two methods. The linear regression parameters of two methods for 52 fresh frozen human sera were as follows:the slope was 0.9988,the standard error of slope was 0.0035, the intercept was 0.0037mmol/L, the standard error of intercept was 0.0030 mmol/L, the standard error of Y-estimate was 0.0236 mmol/L,and the correlation coefficient was 0.9997. Compared with the LC/MS method,the absolute deviation of fresh sera by HPLC method was-0.001 mmol/L (-0.070-0.056 mmol/L), with a relative deviation of 0.13％ (-2.01-2.83％). T-test showed no statistically significant difference between the two methods. The expected deviations at the triglycerides medicine decision level were within the 95％confidence range,and the expected deviations were far less than the allowable error. Conclusions The HPLC method of triglyceridesdetetion has good consistency and comparability with LC/MS method as one of the reference methods of CRMLN. Because of the advantages of HPLC method such as low cost, simplicity,less technical need,and better precision,HPLC method is expected to play an important role in the process of standardization and traceability of serum triglycerides.
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Objective To investigate the 15 quality indicators at medical institutions in China , and to explore the model of quality specifications .Methods Online questionnaires were sent to 8029 clinical laboratories ,with the results analyzed by SPSS 20 .The 25th percentile ,50th percentile ,and 75th percentile of the distribution ,according to the level of the hospital ,were regarded as the optimum , appropriate and minimum quality specifications for each quality indicator ,respectively .Results As shown in the median ,sigma values of most indicators were greater than 3 .The defect percentages of test uncovered by internal quality control (IQC)and test uncovered by inter-laboratory comparison were 47.46％ and 85.73％ ,respectively ,both too poor to calculate the sigma values. The turnaround time (TAT )differed greatly among the subjects.The longest time of pre-examination TAt and Intra-laboratory TAT were clinical immunity. The minimum quality specifications for the quality indicators were from 3σ to 6σ.Conclusions Laboratories should strengthen their IQc and inter-laboratory comparison with continuing education training to realize the continuous quality improvement .
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Objective To investigate the reasons of unacceptable external quality assessment results for hemoglobin A1c (HbA1c), and improve quality level.Methods At the end of February 2017, five samples of HbA1c for external quality assessment (EQA) were sent to participated laboratories by post.After testing and reporting results by laboratories , the EQA organizer made statistical analysis and sent results back to laboratories.Meanwhile , messages would be sent to participants those had unacceptable EQA results . Investigating reasons of unacceptable results in 2017 through the EQA System based on web , which was developed by National Central for Clinical Laboratories , calculating the failure rate , analyzing the concrete reasons and combining EQA failure rates with current coefficient of variation .Results The EQA failure rate on HbA1c was 11.2％and reporting rates of reasons for failures was 70.4％(126/179).In the reasons for unacceptable results , technological (27.8％,35/126) and equipment's defects (26.2％,33/126) were the main reason categories , while malfunction ( 12.7％, 16/126 ) and methods defection ( 10.3％, 13/126 ) were the main reason subclass .The unexplainable results after survey account for 8.7％( 11/126 ) .In the group for coefficient of variation ( CV ) over 2％, the percentage of laboratories that had five samples get acceptable results was higher than that of group for CV less than 2％,and the percentage of laboratories that had at most four samples get acceptable results was lower than that of group for CV less than 2％.Conclusions The result of the reasons of unacceptable external quality assessment results for HbA 1c is generally satisfactory.The laboratory, manufacturer and EQA organizers should find and solve the working problems by analyzing EQA data , to improve the testing quality.
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Objective To investigate the status of blood specimen acceptability for clinical chemistry tests in routine medical laboratories of China. Methods The questionnaires were assigned to the laboratories which participated in the routine chemistry exter-nal quality assessment (EQA) programs proposed by National Health Commission for Clinical Laboratory. The questionnaires included general information of participants and information about unacceptable blood specimens. Participants were required to record all the in-formation concerning unacceptable blood specimen received from 1stto 31stJuly, 2017. The data from each laboratory were reported and collected via special online system.Results A total of 866 valid questionnaires were collected.Of 15 981 752 specimens received dur-ing the data collection period unqualified 122 00 specimens were rejected with overall rejection rate of 0.076%. The main reasons for unacceptable specimens were hemolysis (33.98%), insufficient specimen quantity (10.78%) and chylemia/lipemia (10.62%). The rejected specimens were related to the original laboratories, types of container and specimen, transportation manner and operating staff of blood collection. Conclusion Certain problems existed in the receiving and management system for unqualified blood specimen in our country and remaining to be perfected. The clinical laboratories should pay more attention for pre-examination stage, including routinely monitoring unacceptable specimens, analyzing related data at the most possible granular levels, identifying the main problem and taking effective measures.
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Objective To investigate the implementation of professional standards for reference intervals in routine biochemistry laboratories.Methods The relevant data of reference intervals from different laboratories including upper and lower limits,sources of reference intervals,verification and grouping rules,etc was submitted by using the software of interval quality assessment (EQA) via WEB application.The background monitor saved all the data as Microsoft Excel 2007 documents.The implementation of reference intervals of professional standards for decreed 18 routine biochemical tests was analyzed.Results The proportion of laboratories in which the reference intervals were derived from professional standards increased largely in 2016 compared with those in 2014.The data of 2016 showed that the reference intervals derived from professional standards were verified in 58.9％ to 67.5％ of laboratories before they were used in clinical diagnosis.The grouping rules for reference intervals in most laboratories (59.1％ to 83.3％) were in accordance with professional standards,except for individual items,including urea (43.4％),creatinine (40.1％) and alkaline phosphatase (35.8％).There were significant differences for the upper and lower limits of the most items between the laboratories using professional standards and those without using professional standards (P ＜ 0.05),except for some items,including lower limit value of kalium,upper limit of phosphorus,upper limit of amylase,upper limit of aspartate aminotransferase and lower limit of ferrum.There was no significant difference in most items between the the upper and lower limits of the reference intervals in the laboratories using professional standards and the reference intervals defined by professional standards,except for individual items,including upper limit of total protein,lower and upper limit of creatine kinase,upper limit of urea and upper limit of creatinine (P ＜ 0.05).Conclusion The implementation of reference intervals from professional standards in most routine biochemistry laboratories could not be satisfactory.Only a small part of laboratories used the professional standards,and the reference intervals of professional standards,were not verified before use in quite a part of laboratories.
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Objective To understand the current status of the measurement quality of serum Cystatin C (CysC) in China.Methods The external quality assessment (EQA) data in 2017 were collected from the network platform of National Center for Clinical Laboratories.The EQA data were classified into 8 groups according to different types of diagnostic reagents,each of which was employed by at least 18 users.The robust mean value and robust coefficients of variation (CV) were calculated according to ISO 13528 document in each group.The robust mean value was set as the target value.The total error derived from biological variation was used as the fine (3.8％),moderate (7.6％) and weak (11.4％) criteria in evaluating the pass rates,respectively.The reagents which were employed by more than 50 users were classified into subgroups named as " reagent-analyzer" group according to the used analyzer.The median values and differentials between maximum and minimum value were calculated for each reagent-analyzer subgroup.Results A total number of 710 laboratories submitted their results of CysC measurement during 2017.The fine,moderate and weak pass rates according to the setting criteria were 25.9％ (184/710),55.5 ％ (394/710) and 75.2％ (534/710),respectively.The variations of CysC measurement results of among different reagent-analyzer groups ranged from 1.62％ to 12.27％.Conclusion The quality of CysC measurement of should be improved with nationwide attention.
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Objective To evaluate the consistency and comparability of two kinds of cholesterol reference methods listed in the Joint Committee for Traceability in Laboratory Medicine(JCTLM).Methods 52 fresh frozen sera with cholesterol concentrations among 3 -10 mmol/L were tested by isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS)and high performance liquid chromatography(HPLC).The precision and accuracy of the two methods were calculated,and then a series of analysis were conducted including plotting scatter plots and deviation graphs,testing outliers,selecting the best fitting regression models and calculating the regression equations and parameters,and so on.The results of the two methods were statistically analyzed to estimate the expected deviation at the level of medical decision of cholesterol and the 95% confidence range.Results For HPLC method,the CV of instrument measurement was 0.22%(0 -0.49%),the total CV of samples measurement was 0.36%(0.02% -0.83%),and the average bias of the reference materials was 0.37%(-1.31%-0.14%).For ID-LC/MS/MS method,the CV of instrument measurement was 0.50%(0 -1.51%),the total CV of samples measurement was 0.55%(0.03%-1.17%),and the average bias of the reference materials was 0.24%(-0.53%-0.14%).No outliers were found from the scatter plots and the statistical analysis and the linear regression were fitted to analyze the results of the two methods.The linear regression parameters of two methods for 52 fresh frozen human sera were as follows:the slope was 0.989 5,the standard error of slope was 0.003 4,the intercept was 0.063 4 mmol/L,the standard error of intercept was 0.019 9 mmol/L,the standard error of Y-estimate was 0.034 8 mmol/L,and the correlation coefficient was 0.999 7.Compared with the ID-LC/MS/MS method,the absolute deviation of fresh sera by HPLC method was 0.000 mmol/L (-0.083-0.076 mmol/L),with a relative deviation of 0.07%(-1.22-1.24%).T-test results showed no statistically significant difference between the two methods.The expected deviations at the cholesterol medicine decision level were within the range 95% confidence range,and the expected deviations were far less than the allowable error.Conclusions The HPLC method of cholesterol has good consistency and comparability with ID/MS method using the primary measurement principle.Because of more advantages of HPLC method such as less cost,more simple,requirement,and better precision,HPLC method is expected to play an important role in the process of standardization and traceability of serum cholesterol.
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Before performing patient testing with commercial microbial test systems,each laboratory must verify that it can obtain performance specifications comparable to those of the manufacturer.This includes trueness,precision (reproducibility),and reportable range of test results,and verifying that the manufacturer's reference ranges are appropriate for the laboratory's patient population.American Clinical and Laboratory Standards Institute has set up a committeeto develop a verification process and a quality assurance program for commercial microbial identification system and antimicrobial susceptibility testing system,in order to provide recommendations for US Food and Drug Administration (FDA).This guidance is applicable to instrument systems widely used in clinical laboratories and can also be used for manual testing of microbiological identification and antimicrobial susceptibility testing.The aim of this article is to provide advice for the microbial identification system and antimicrobial susceptibility testing system verification process,based on principles of microbiological identification and antimicrobial susceptibility and CLSI M52 guideline.
ABSTRACT
In clinical laboratory medicine,measurement uncertainty (MU) is a fixed property of testing results in the measuring system.As an important part of ISO 15189,it is necessary for clinical laboratories to determine MU during the period of validation and verification for each measurement procedure and to review MU over time.Now,testing reports provided by clinical laboratories usually do not offer MU,but some clinical laboratories have already estimated MU in their routine work.Estimation andmonitoring of MU can help clinical laboratories offering more accurate results and provide objective tools for clinicians used in result intcrpretatinn.Generally,result interpretation can be achieved by the result comparison with three main comparators,including a previous result from the same patient,a population reference interval and a clinical decision point.The means of true value and the components contributing to the estimation of MU are both different when the com parison is conducted between testing results and different comparators,so the optimum estimation method of MU is accordingly different,which will subsequently affect the MU value and the determination of clinical decisions.Obviously,depending on the actual clinical uses,laboratories can choose appropriate comparators to the result interpretation and the determination of optimum estimation method of MU.For different clinical uses (diagnosis or monitoring) of the same mearurands,the adoption of different estimation methods should be used to acq uire reasonable MU.By interpreting the concept,characteristics,estimation,and uses of MU,as well as explaining how three main comparison methods of results exploit their own traceable chain to get MU,this paper intends to help clinical laboratories get further understanding of the importancc of MU and provide guidance for the MU estimation in routine work.