Explore The Standardization Of 12 Conventional Biochemical Project Measurement Results

ObjectiveUsing the reference measurement system and fresh frozen serum to eval uation the accuracy of the 12 conventional biochemical project of 21 clin ical laboratories in Guangzhou, in order to make sure the traceability of the measurement result can meet the clinical need. Values are assigned t o the fresh frozen serum with reference method, which used to calibration the routine systems, after calibration, whether the standardization and consistency of the measurement results.Methods1、Fresh frozen serum samples were validated the homogeneity and stab ility.2、Two reference laboratory established international standard refere nce method for alanine aminotransferase (ALT), Aspartate Aminotransferase (AST), and alkaline phosphatase (ALP) and gamma pancreatic acyl transfe rase (GGT), Urea (Urea), uric acid (UA), creatinine (CR), lactate dehydro genase (LDH), amylase (AMY), Creatine Kinase (CK), total Bilirubin (TBIL) and Glucose (GLU) in accordance with the IFCC recommendation, reference target values assigned with the mean of 2 laboratory measurement results3、5 different concentrations of fresh frozen serum and 5 different co ncentrations of lyophilized samples were distributed to 21 participating laboratories, and calculate the mean values of all the laboratory measure ments.To evaluate the accuracy of conventional detection system of 21 pa rticipating laboratories.4、For GGT project of fresh frozen serum shows that the bias is great er than lyophilized samples, therefore, we select one of the obvious lab for evaluation of the effect of matrix.5、14 different concentrations of fresh frozen serum samples and 9 fr esh frozen serum calibrator were received from the National Center for C1 inical Laboratories, to explore the accuracy of the measurement result of 12 biochemical projects before and after the calibration. Target value o f these fresh frozen serum samples from five reference laboratories. Avera ge assignment. The measurement results of 21 laboratories were compared wi th the reference target value, respectively, and calculate the bias.Results1, The homogeneity and stability test found 12 projects of five diffe rent concentrations of five fresh frozen serum specimens P values of the measurement results were greater than 0.05, shows that no statistical sig nificance among samples, In addition, the uncertainty of the homogeneity of samples is less than uncertainty of the corresponding method repeatabi lity measurement, shows that the uniformity of the preparation of fresh f rozen serum is very well.In stability experiments, in addition to the con centration of CK Project 4, all samples of the rest of the item in the ob servation period of 20 months did not appear obvious fluctuation.2、Most projects (76.92%) show that the concentration of correlation, namely smaller with the increase of concentration of bias, but except for CK. Cr and LDH project, when it is beyond the scope of reference values. This rule then disappeared, for fresh frozen serum, calculating the relat ive bias between the reference target value and the mean value of all par ticipating laboratories.the obvious change of the relative bias has ALP (13.17%-10.95%), GGT (6.23%～4.31%), TBIL (6.23%～0.89%) and AMY (10. 47%～6.63%); For lyophilized samples, Larger projects are ALT (4.06%～4. 06%), AST (10.96%～6.43%), ALP (8.55%～8.55%), CK (3.79%～3.79%), Urea (5.77%～5.77%), TBIL (14.24%～14.24%), Cr (3.20%～10.12%), LDH (5.76% ～5.76%), AMY (2.40%～2.40%). GGT (6.23%～4.31%), TBIL (6.23%～0.89%) and AMY (10.47%～6.63%);for GGT project, No matter use fresh frozen seru m samples or use producing samples, the laboratory satisfactory ratio of u sing the reference target value is less than the laboratory satisfactory ratio of the mean of participating laboratories, For producing samples, th e deviation between the two kinds of target value is larger than fresh fr ozen serum samples, and more projects involved. Furthermore, biological va riation rules were stricter than 1/2 CLIA’88 criteria in our study, mainl y manifested in the following projects:the AST, ALP, UA, GLU, LDH, AMY a nd Cr.3、Matrix study found that the results of Lyophilized samples fall ou tside the 95% prediction interval, and then the samples were considered t o have matrix effect in this laboratory。4、For the concentration 1 of sample, the laboratory satisfactory rat e of some project was less than 80%, for example, Using 1/2CLIA’88 judgm ent criteria, the satisfaction rate of ALT project was only 33.33% and th e satisfaction rate of TBIL project was just 47.62%, With biological vari ation as the judgment criteria, the satisfaction rate of the AST, ALP, CR, AMY, GLU and TBIL was 14.19%,38.10%,38.10%,42.86%,47.62% and 38.10%, r espectively. After calibration, the relative bias of the laboratories has been greatly reduced, the purpose of satisfactory rate was higher than 80 %, and even for some projects, which satisfaction rate completely accords with the requirement, such as GGT.After calibration, however, there was s till the bias of some items of some laboratory larger than the bias of be fore calibration, for example, LDH project has seven laboratory, GLU proj ect has eight laboratories and ALT project has four laboratories. For conc entration 2 of sample, before calibration, Using CLIA 88’judgment criter ia, no laboratory satisfaction rate was lower than 80% of the projects. Us ing biological variation criterion, laboratory satisfaction rate was lowe r than 80% of the project had the AST (28.57%), ALP (23.81%), AMY (47.62 %), Cr (47.62%) (33.33%), TP, LDH (38.10%) and GLU (19.05%). After calibra tion, the satisfaction rate was all higher than 80%, there was even seve ral projects that all conform to the requirements, such as GGT, AMY and L DH.But after calibration, there was still the relative bias of some items increases, such as ALT project has five laboratories. TBIL project has e ight laboratories and UA has seven laboratories.Conclusion1、The accurate and comparable of the test results has always been th e focus of attention for the clinical laboratory. The accuracy of the meas urement results needs to be further improved.2、Using fresh frozen serum and reference target value can be better than using the mean of laboratory and lyophilized samples to evaluate the accuracy of the results.3、The use of fresh frozen serum as a calibrator, to some extent, can improve the diversified situation of the measurement results for the same analyte among different examination system. So as to realize the standard ization of clinical measurement results...