Performance evaluation of some domestically produced biochemical reagents / 中华检验医学杂志

Objective:To evaluation the performance of a total of 40 clinical biochemical reagents from three domestic manufacturers and two foreign manufacturers, and evaluate their clinical application value.Methods:The Beckman AU5400 automatic biochemical analyzer was used to verify the performance of 40 kinds of commonly used clinical biochemical reagents from three domestic manufacturers of Sichuan Maccura, Ningbo Medical System, and Shanghai Fosun Long March, and two foreign imported manufacturers of Roche and Japan′s Hitachi. The analysis samples were selected from the serum of patients who underwent clinical testing in Nanjing Drum Tower Hospital hospital from December 2021 to June 2022. Refer to China′s national health industry standards, China′s national pharmaceutical industry standards, the US Clinical Laboratory Standards Institute (CLSI) for the performance evaluation standards of in vitro diagnostic reagents, and the methods recommended in the relevant regulations of China′s State Food and Drug Administration on the management of in vitro diagnostic reagents. The precision, linear range, open bottle stability, interchangeability of calibrators and accuracy from different batches of 40 reagents were evaluated and validated. Simple linear regression analysis was used for linear regression, and P<0.05 indicated that the regression was statistically significant. Results:The overall precisions of 40 reagents were fine, except for one domestic reagent with low-level intra-batch coefficient of variation ( CV) exceeding the range declared in the specification. The intra-and inter-batch CVs of the remaining reagents were all smaller than those declared in their respective specifications. The linear ranges of domestic reagents and imported ones have achieved the linear ranges declared by each manufacturer. There were no statistical differences on the measurements between the reagents from open bottle of 30 days and the corresponding new ones for 40 reagents( P>0.05). The test values of domestic reagents and imported reagents after exchange of different batches of calibrators were within the ranges declared by each manufacturer. Both domestic reagents and imported reagents have passed the accuracy verification. Conclusions:The performance index of 27 biochemical detection indicators of the three domestic manufacturers are basically consistent with those of imported reagents, meeting the requirements of clinical biochemical laboratories. However, the bottle opening stability and anti-interference performance of some detection reagents needs to be improved.

La trazabilidad en las mediciones del laboratorio clínico: impacto en la calidad y seguridad del paciente / Traceability in clinical laboratory measurements: impact on quality and patient safety

Las mediciones confiables, trazables metrológicamente y comparables proporcionan la base racional para la evaluación de la calidad de un resultado y el fortalecimiento de las redes de laboratorios clínicos, lo cual permite mejorar la calidad de atención y la seguridad del paciente. En este documento se revisan los principios básicos que deben seguirse para garantizar la trazabilidad de las mediciones del laboratorio clínico, las ventajas de utilizar métodos trazables, el impacto de no hacerlo, y se discuten las principales limitaciones para relacionar las mediciones con los estándares de medición de referencia apropiados

Reliable, metrologically traceable, and comparable measurements provide the rationale for evaluating the quality of a result and strengthening clinical laboratory networks, thereby improving quality of care and patient safety. This document reviews the basic principles that must be followed to ensure the traceability of clinical laboratory results, the advantages of using traceable methods, the impact of not doing so, and the main limitations in relating measurements to appropriate reference standards

Comparison and analysis of the detection performance of six new coronavirus nucleic acid detection reagents / 重庆医学

Objective To compare and analyse the detection performance of different 2019-new coronavirus (2019-nCoV) nucleic acid detection kits, in order to provide references for laboratory. Methods Six kinds of domestic reagents (A—F reagent) were selected for parallel detection of a series of samples from one patient in this hospital whose 2019-nCoV nucleic acid result was confirmed weakly positive. The samples were taken at three different times, the RNAs were extracted and amplified, and two parallel tests were performed each time by use of these six kits. The detection performance was compared according to the results of each kit. Results The three parallel test results (ORF1ab and N gene) of C and F reagents were positive, the results of D reagent showed the N gene was not detected, and the results of A, B, E reagents showed the ORF1ab gene was not detected sometimes. The reproducibility of in-batch detections by C reagent was the best, and the CT values of F reagents (N and ORF1ab), E reagents (ORF1ab) and A reagents (ORF1ab) showed changes in trend. Conclusion There are differences in the detection ability of six 2019-nCoV nucleic acid detection reagents for weakly positive samples, and the accuracy, sensitivity and reproducibility of some reagents are not good. There is an urgent need to further optimize and improve their performance in order to better meet the needs of large-scale screening.

Usefulness of Carbohydrate Antigen 19-9 Test in Healthy People and Necessity of Medical Follow-up in Individuals with Elevated Carbohydrate Antigen 19-9 Level / 가정의학회지

BACKGROUND: Carbohydrate antigen 19-9 (CA 19-9) is a tumor marker whose level is elevated in many types of cancers and other benign conditions. CA 19-9 levels are frequently found to be elevated in individuals during general health examinations. This study aimed to investigate the clinical characteristics of such individuals and to determine the need for medical follow-up. METHODS: We investigated individuals who underwent a health inspection, including a serum CA 19-9 test, at our center. Their CA 19-9 levels, age, sex, body mass index (BMI), and personal and past histories were investigated. Additionally, subgroup analyses were performed for those who underwent follow-up study for the elevated CA 19-9 levels. RESULTS: Of 58,498 subjects, 581 (1.0%) had elevated CA 19-9 levels. Multivariate analyses revealed that older age, female sex, lower BMI, and diabetes were independent predisposing factors for elevated CA 19-9 level. A subgroup analysis revealed that the causative conditions were identified in 129 of 351 subjects (36.8%). Among them, the causative conditions in 31 subjects (8.8%, including four cases of cancer and 15 of benign tumors) were not detected at the initial check-up and were found during the follow-up period. CONCLUSION: The use of CA 19-9 as a marker for cancer in healthy individuals is inappropriate. However, medical follow-up in individuals with elevated CA 19-9 levels may be useful because some causative diseases may be detected during follow-up.

Evaluation of a novel small dense low-density lipoprotein cholesterol kit and investigate the clinical value in the population of coronary heart disease / 中华检验医学杂志

Objective To evaluate the performance of serum small dense low-density lipoprotein cholesterol(sdLDL-C) kit using enzymic method and investigate the clinical value in coronary heart disease (CHD).Methods According to the standard of Clinical and Laboratory Standards Institute (CLSI),evaluae the precision,linearity ranges,reportable range and accuracy of sdLDL-C kit.The 683 patients with coronary heart disease (CHD,423 men and 260 women,age 35-79 years) who were diagnosed at the people's hospital of Peking university from October 2015 to October 2016 were divided into two groups.The treated group include 571 patients(CHD1,342 men and 229 women,age 40-79 years) which taking lipidlowering drugs and the other include 112 cases (CHD2,81 men and 31 women,age 35-70 years)without Lipid-lowing treatment.Besides,the Control group contains 472 healthy persons (274 men and 198 women,age 41-75 years),were collected from the people's hospital of Peking university between April and August 2016.The liver function,renal function,blood glucose and blood lipid in CHD group(CHD1,CHD2) and healthy control group were detected.The new enzyme assay kit was used for the determination of sdLDL-C.The data of normal distribution were compared by independent t test between the two groups.The Mann-Whitney U nonparametric test was used for comparison between two groups.Results The precision of sdLDL-C kit examination was in compliance with manufacturer'statement.The linearity was good in 0.11-2.42 mmol/L(Y =1.008 9X + 0.024 8,R2 =0.998 2),the scope of the report is 0.11-4.84 mmol/L.The level of sdLDL-C in CHD group was significantly higher than that in healthy control group,it has a statistical significance[0.824 (0.443) mmol/L,0.609 (0.361) mmol/L;Z =-5.603,P ＜ 0.001].The level of sdLDL-C in (CHD 1) was lower than (CHD 2) [0.761 (0.479) mmol/L,0.888(0.426) mmol/L;Z=-2.304,P＜ 0.021].After additional adjustment for various tradition cardiovascular risk factor,including ages,sex,CHO,TG,Hs-CRP,Lp(a),and GLU,the highest quartile of sdLDL-C comparison to the bottom quartile,the OR was 3.02,(95％ CI,1.15-9.05) for CHD.Conclusions Experiment data demonstrated that sdLDL-C kit using enzymic method has good performance in the precision,linearity ranges,reportable range and accuracy,sdLDL-C serum level was significantly higher in CHD group.

Serum small dense low-density lipoprotein cholesterol and performance evaluation of commercial detection kits and its relationship with the severity of coronary heart disease / 中华检验医学杂志

Objective To evaluate the performance of serum small dense low-density lipoprotein cholesterol(sdLDL-C)kit using enzymic method and evaluate the relationship with the severity of coronary heart disease.Methods Performance verification methodology. The analytical performance consisted of accuracy, precision and linearity of serum sdLDL-C kit using enzymic method was assessed. One hundred and twenty healthy persons were recruited to establish serum sdLDL-C reference interval. Two hundred and twelve patients underwent coronary angiography were enrolled in the study.Among them 110 cases were positive for coronary angiography, where as 102 cases were negative. We examined serum levels of sdLDL-C in 110 patients with positive angiography, 102 patients with negative angiography and 120 healthy volunteers. Positive group was classfied into severe group(Gensini score>30) and mild group (Gensini score≤30).Results The accuracy and precision of sdLDL-C examination were in compliance with manufacturer′s statement and there was a good linear correlation(Y=0.9937X-0.1063,R2=0.99) in range of 0.06-2.45 mmol/L. The reference interval of sdLDL-C was 0.15-0.97 mmol/L and without gender and age specificity. The level of sdLDL-C was higher in positive angiography group than in negative angiography group and healthy control group(P<0.01). The level of sdLDL-C was higher in severe group than in mild group(P<0.05). Binary stepwise regression analysis demonstrated that sdLDL-C was independently associated with the severity of coronary heart disease(OR=3.101,P<0.05).ConclusionsExperiment data demonstrated that serum sdLDL-C kit using enzymic method has good performance in the accuracy, precision and linearity. SdLDL-C that plays an important role in the occurrence and progression of coronary heart disease, is an independent important risk of the severity of coronary heart disease.

Evaluation of three commercially-available chikungunya virus immunoglobulin G immunoassays / Evaluación de tres inmunoensayos comercializados de inmunoglobulina G para el diagnóstico del virus del chikungunya

ABSTRACT The emergence of chikungunya virus in the Americas means the affected population is at risk of developing severe, chronic, rheumatologic disease, even months after acute infection. Accurate diagnostic methods for past infections are essential for differential diagnosis and consequence management. This study evaluated three commercially-available chikungunya Immunoglobulin G immunoassays by comparing them to an in-house Enzyme-Linked ImmunoSorbent Assay conducted by the Centers for Disease Control and Prevention (Atlanta, Georgia, United States). Results showed sensitivity and specificity values ranging from 92.8% - 100% and 81.8% - 90.9%, respectively, with a significant number of false-positives ranging from 12.5% - 22%. These findings demonstrate the importance of evaluating commercial kits, especially regarding emerging infectious diseases whose medium and long-term impact on the population is unclear.(AU)

RESUMEN Como consecuencia de la aparición del virus del chikungunya en las Américas, la población afectada corre el riesgo de padecer reumatismos crónicos graves, aun meses después de la infección aguda. Es fundamental contar con métodos precisos para diagnosticar los antecedentes de la infección a fin de elaborar un diagnóstico diferencial y abordar las manifestaciones de la fase crónica. Se han estudiado tres inmunoensayos comercializados de detección de inmunoglobulinas G para el diagnóstico del chikungunya, comparándolos con el enzimoinmunoanálisis de adsorción (ELISA) propio. Los resultados señalan valores de sensibilidad del 92,8% al 100% y de especificidad del 81,8% al 90,9%, así como un número significativo de falsos positivos, de entre el 12,5% y el 22%.(AU)

Rapid laboratory identification of Mycobacterium abscessus / 中华检验医学杂志

Objective To identify Mycobacterium abscessus rapidly with HAIN molecular assay genotype kit、gene chip and hsp65 gene sequencing,and to assess the clinical value of these three methods.Methods 13 clinical non-tuberculous Mycobacterium (NTM) of in-patient samples were collected from January2014 to January 2015,in the Department of Clinical Laboratory,Yinzhou People's Hospital,and meanwhile,these strains were identified with HAIN molecular assay genotype Mycobacterium kit and gene chip respectively.The hsp65 gene sequencing was used as the standard method to be compared with HAIN and gene chip.Results The results of HAIN kit and hsp65 gene sequencing showed that all the 13 strains were subspecies Mycobacterium abscessus,while that of gene chip showed that these strains were Mycobacteriumchelonae complex strains,and the subtypescould not be identified.Conclusion These results obtained from the HAIN molecular assay genotype mycobacterium system are in agreement with those obtained from the hsp65 gene sequencing,whereas the HAIN kit method is easier to use.

Evaluation of a novel fully automated real-time PCR assay for hepatitis B virus DNA quantification / 中华检验医学杂志

Objective To evaluate the analytical performance of a novel HBV DNA assay based on automated DNA extraction and real-time fluorescence quantitative PCR .Methods Analytic verification studies.Accuracy and lower limit of detection were assessed by determining a panel of HBV standard plasma of WHO.HBV standard plasma (genotype A, B, C and D) at 6 different concentrations were measured 18 times to evaluate precision and reproducibility .Pseudo-viral particles at high HBV DNA concentration were serially diluted to assess linear range .One hundred and forty-four clinical specimens were quantified for HBV DNA so as to evaluate the correlation between the new test and COBAS ? system. Results Quantification of HBV standard plasma showed acceptable accuracy , with each deviation between observed and expected values within ±0.35 lg IU/ml (-0.17-0.32 lg IU/ml).Intra-assay coefficients of variation ( CV) for genotype A , B, C and D were 3.87% -6.32%, 0.45% -14.68%, 0.16% -8.36% and 0.64%-13.01%respectively, and the inter-assay CV were 5.67%-9.69%, 1.28%-15.68%, 0.36%-9.05%and 1.69%-13.65%, separately.Linearity assessment exhibited an excellent dynamic range of linear quantification from 20 to 1.0 ×1010 IU/ml ( r =0.998, P <0.001 ) .And the satisfactory results obtained at 3 levels of HBV DNA concentration (10, 20, 50 IU/ml, respectively) confirmed the claimed lower limit of detection with 5/5 detectable rate at 20 IU/ml.Furthermore, good correspondence was observed between the new HBV DNA assay and the COBAS ? system with 100% ( 144/144 ) qualitative coincidence and significant correlation based on 104 positive data ( r=0.984, P<0.000 1).Conclusions The novel fully-automated real-time PCR assay displayed good analytical and clinical performance for highly sensitive detection of HBV DNA.It was well suited for monitoring antiviral responses as well as drug resistance according to current clinical practice guidelines for the management of chronic HBV infection .

The system setting for diagnostic reagents of polymerase chain reaction nucleic acid amplification / 中华检验医学杂志

Diagnostic reagents of polymerase chain reaction ( PCR ) nucleic acid amplification is growing more and more important in the field of clinical diagnosis along with the development of the PCR technology.During to the complexity of the detection target and the clinical requirements for measuring linearity, accuracy, specificity, subtype detection, precision, limit of detection/quantification and interfering substance , the diagnostic reagents of nucleic acid amplification have a very strict control system . In order to ensure the quality of the experimental data of quantitative PCR , there have been standards such as The Minimum Information for Publication of Quantitative Real-Time PCR Experiments ( MIQE) , aiming to putting forward specific requirements for sample processing , experimental designing , system setting and quality control.But in the clinical application of nucleic acid amplification products , lots of requirements are not clear for the PCR system setup .This article discussed the requirements of PCR system setting , quality control system and Methodology of nucleic acid extraction and purification , aiming to promote the related design and the establishment of the standards of relevant .

Trueness evaluation of 13 routine measurements for serum uric acid / 中华检验医学杂志

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 ( CV0.998, 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.

Development of a Forensic Multiplex Amplification STR Kit for 15 Autosomal STR Loci and 10 Y-STR Loci / 法医学杂志

Objective To establisha multiplex STR genotyping m ethod for autosom al STR and Y-STR loci in forensic biological practice. Methods W idely used autosom al STR loci and Y-STR loci w ere se-lected. A set of PC R prim ers w as designed, and a 5-dye fluorescent labeled STR multiplex PC R reagent kit w as developed. Results A kit w as developed w hich can sim ultaneously detect 15 autosom al STR loci, 10 Y-STR loci, and an Amelogenin. Conclusion The 15 autosom al STR plus 10 Y-STR kit in com bination w ith capillary electrophoresis m ethod w as used to STR genotyping w ith accurate and reli-able results. The new one-step testing kit can potentially be w idely used in forensic cases and D N A databank in the future.

Evaluation and selection of indirect ELISA and sandwich ELISA kits for anti -HCV detection / 临床肝胆病杂志

Objective To compare the sensitivity and specificity between indirect enzyme -linked immunosorbent assay (ELISA)and double -antibody sandwich ELISA kits produced in China and to select the best ELISA kit.Methods Samples for evaluation included 60 serum plates and 40 serum samples positive or weakly positive for antibody to hepatitis C virus (anti -HCV)which were confirmed by re-combinant immunoblot assay.These samples were tested with a sandwich ELISA kit and three indirect ELISA kits,all of which were pro-duced in China.Comparison between ELISA kits was made by paired chi -square test;comparison of false negative rate was made by R × C contingency table test.Results The sensitivities of three indirect ELISA kits and a sandwich ELISA kit were 90.2%,78.0%,95.1%, and 97.6%,respectively,and the specificities were 78.1%,72.6%,94.1%,and 100%,respectively.The sandwich ELISA kit had a 4-8 times higher sensitivity than indirect ELISA kits.The R ×C contingency table test revealed significant differences in false negative rate between ELISA kits and combinations of ELISA kits (χ2 =29.898,P <0.05).Conclusion Sandwich ELISA kit has higher sensitivity and specificity than indirect ELISA kits.Combined use of sandwich ELISA and indirect ELISA kits can significantly reduce the false negative rate and effectively prevent missed anti -HCV detection.

A novel molecular point-of-care testing detection technology for infectious pathogens：GeneXpert / 中华检验医学杂志

GeneXpert is an advanced molecular biological detection system developed in recent years, it integrates and automates the sample preparation , nucleic acid purification, gene amplification, results report of the fluorescent quantitative PCR process.As, an accurate, rapid, biosafe technology , GeneXpert has become one of the novel molecular POCT detection technology platforms for diagnosis of infectious pathogens and especially declared it a major milestone for global TB diagnosis .This paper introduces the detection principle , clinical application in the detection of infectious pathogens , limitation and prospect of GeneXpert.

The evaluation of dot immunogold filtration method in detection of serum SAA and its clinical value of diagnosing the infectious diseases of children / 中华检验医学杂志

Objective The purpose of this study was to assess the analysis capabilities of the dot immunogold filtration method on detecting serum amyloid A ( SAA ) protein in blood.It also aimed to research the clinical value of SAA in diagnosing the infectious diseases of children .Methods ( 1 ) The performance evaluation including the accuracy , within-run precision, inter assay variations , the linear and the distraction-analysis of SAA-SPOT was estimated following the EP file; From March to July in 2014, children from five 3A Grade hospitals in Guangdong Province were enrolled into this observational study.Data including white blood WBC count , CRP and SAA were obtained.(2) From March to July in 2014, children from five 3A Grade hospitals in Guangdong Province were enrolled randomly into this observational study.This study used a cross-sectional survey research method , and 386 children with bacterial infection and 219 children with virus infection were as the research object.The general , clinical diagnosis , treatment information as well as the data of blood SAA , C-reactive protein ( CRP ) and white blood cell ( WBC ) of children were collected.Data were analyzed by variance , independent t test, ROC curve analysis and stepwise regression statistics method.Results ( 1 ) The average recovery rate is 103.74 %.Coefficient of variation (CV) for 10 mg/L,100 mg/L within-run assays were 8.77%, 3.61% and between-run assays were 9.01%, 3.74%;the inter-day CV were 9.07%, 4.03%respectively;the linear range was 5 mg/L-200 mg/L, hemoglobin(5 g/L),serum bilirubin(800 μmol/L),triglyceride(TG, 22 mmol/L), and had no interference in SAA detection.When compared to the BNPRO quantitate system of SIEMENS , the coefficient of association of detection of SAA by SAA-SPOT was R2 =0.96.( 2 ) Compared with control group , the serum SAA of infection group ( bacterial infection group , t =13.05, P=0.001;virus infection group t =7.68, P=0.001) and SAA/CRP ratio (bacterial infection group t=2.29, P=0.023;virus infection group t=3.32, P=0.01) were significantly increased.(3) The serum CRP and SAA rose similarly in bacterial infection, while in viral infection, only SAA increased significantly , CRP had no apparent change.In combination with CRP and WBC , SAA had the better diagnostic efficiency apparently.Conclusions As a POCT detection project , analysis capabilities of the SAA assayed by domestic SAA-SPOT can meet the requirements of clinical test.Combined with CRP , WBC and SAA can improve the efficiency in the diagnosing of infectious disease especially in the virus infection.As a new biomarker of infections , SAA is useful for the early auxiliary diagnosis and differential diagnosis of childhood infection.

Clinical scheme design of in vitro tumor diagnostic reagents / 中华检验医学杂志

Cancer is a serious threat to human health with high morbidity and high mortality , using vitro tumor diagnostic reagents can improve the level of diagnosis and treatment.In order to develop the value of in vitro tumor diagnostic reagents in clinical use , this article would analyze “in vitro diagnostic reagents technical guidelines for clinical research” ,“in vitro diagnostic reagents registration” and other laws and regulations ,as well as the development of research in domestic and foreign.To discuss the clinical scheme design and development trend of in vitro tumor diagnostic reagents.

Application of orthogonal design in the development of Echinococcosis ELISA kit and its evaluation / 中华检验医学杂志

Objective To select the optimum conditions of Echinococcosis ELISA kit and kit preparation by using orthogonal experiments,then to test their detection performance.Methods Taking the absorbance of the samples as the indicator,orthogonal experiments of three factors four levels were taken to optimize the conditions of hydatid disease detection ELISA kit.Through L16 (43)orthogonal experiments,the concentration of the antigen(A),the dilution multiple of the sample (B) and the dilution multiple of the enzyme labeled antigen (C) were studied.The specimen were provided by The First Affiliated Hospital of Xinjiang Medical University specimen library collected between March 2011 and June 2013,including 36 sera confirmed alveolar Echinococcus by the gold standard,56 sera confirmed Echinococcus granulosus disease by the gold standard and 72 sera as the control group(including healthy people,cirrhosis,hepatitis,etc).Detecting sensitivity and specificity were compared using F test for statistical analysis.Results Orthogonal design showed the size proportion of three factors of echinococcosis ELISA kit:antibody dilution ＞ sample dilution ＞ antigen coating concentration.The optimal preparation conditions were A1 B2 C4,that was,the concentration of antigen was 1 mg/L,sample dilution of 1∶ 100,dilution of secondary antibody of 1∶160 000.Through the 3-factor and 4-level orthogonal design using F-test analysis,the fact of the concentration of the kit antigen(A),F =1.181,P =0.393; the fact of the dilution multiple of the sample (B),F =2.544,P =0.152,the fact of enzyme labeled antigen dilution (C) F =2.544,P =0.039.The sensitivity of the kit to Echinococcus granulosus disease and alveolar Echinococcus were 83％ (30/36),and 91％ (51/56),respectively; the specificity was 91％ (29/32) and 83％ (33/40); the misdiagnosis rate of 17％ (6/36) and 9％ (5/56) ; the misdiagnosis rate 9％ (3/32) and 18％ (7/40) ; positive likelihood ratio 8.86％ (83/9) and 5.20％ (91/18) ; negative likelihood ratio of 0.18％ (17/91) and 0.11％ (9/83).Conclusion Orthogonal design is a good method that can find out optimal conditions of preparation for Echinococcosis ELISA kit and improve the test performance.

Technical requirements of the pathogen-specific IgM qualitative detection reagents / 中华检验医学杂志

To offer the guidance of the registration application of in vitro diagnostic (IVD) reagents,the technical requirements for registration of the pathogen-specific Immunoglobulin M (IgM) qualitative test reagents were discussed.The application paperwork including the evaluation of analytical performance was analyzed based on the the legal requirement from the China Food and Drug Administration (CFDA)and the experience of the IVD registration.

Establishment of first national standard of Cystatin C / 中华检验医学杂志

Objective To establish the first national standard of Cystatin C.Methods The candidate standard was prepared from human recombinant Cystatin C,diluted and dispensed aseptically.Homogeneity and stability study were carried out on the automated biochemical analyzer.The target value was assigned by six laboratories using widely recognized immumoassay under strict conditions,and traceable to ERM-DA471.Commutabilities of the candidate standard and its saline dilutions were evaluated according to EP14-Evaluation of Matrix Effects.Excel 2007 was used to analyze the results.Results The preparation had good immunological activity and was proved to be homogeneous and stable (6 months sealed at 2-8 ℃,30 days sealed at room temperature and 37 ℃,30 days open-vial at 2-8 ℃).The assigned value of the preparation was (4.47 ± 0.25) mg/L (coverage factor k =2).The candidate standard and/or its saline dilutions have commutability on the 10 evaluated systems.Conclusion The preparation meets the requirements of national secondary standard and could be used in quality control and evaluation of Cystatin C assays in China.

A comparative study on the clinical performance of three fourth generation HIV diagnostic reagents / 中华检验医学杂志

Objective To compare the performance of fourth generation HIV antigen/antibody combined detection reagents for HIV early infection samples,international HIV seroconversion panel samples and routine clinical screening samples.Methods Thirty seven early HIV infected samples from the followup gays in Shen Yang between 2009 and 2011,66 seroconversion panel samples from BBI company (U.S.A),NABI company(U.S.A) and NIBSC company(U.K) and 703 routine HIV screening samples in the first hospital of China medical university in October 2010 were collected.All kinds of samples were tested by three diagnostic reagents based on chemiluminescence assay (CLIA),electrochemiluminescence assay (ECLIA) and enzyme-linked immunosorbent assay (ELISA) respectively.The detection sensitivity and specificity of these assays were analyzed.Results For 59 early infected and seroconversion samples,the sensitivities of both ECLIA and CLIA reagent were 96.61％ (95％ CI 91.5％-100.0％),higher than that of the ELISA kit (95％ CI 75.0％-92.9％) (x2 =5.341,P ＜ 0.05),which is 83.93％ ; Comparison among the three reagents for different subtypes of the antibody seroconversion samples showed that ECLIA had the highest sensitivity while CLIA was the lowest ; Detection sensitivity of the three reagents for the P24 antigen is CLIA ＞ ECLIA ＞ ELISA; With detection of 703 clinical routine screening samples,the specificities of three reagents were 100％ (CLIA),99.86％ (ECLIA) and 99.71％ (ELISA) respectively.Conclusions For the sensitivity of the fourth HIV diagnostic reagents CLIA and ECLIA are better than ELISA.The former two reagents are more suitable for identifying earlier HIV infection in clinic.