Discussion on Key Control Points and Common Problems of Molecular Diagnostic Reagents in the Process of Design and Development / 中国医疗器械杂志

Design and development process of molecular diagnostic reagents is critical to quality management system of in vitro diagnostic reagent. Based on the technical characteristics of molecular diagnostic reagents, the study analyzed the concerned key control points and common problems in the process of design and development from the view of registration quality management system. It aimed at offering technical guidance on design and development process of molecular reagents and registration quality management system to enterprises, thus improving the product development efficiency, optimizing the quality management system, and increasing the efficiency and quality of registration and declaration.

Analysis on the Quality Status of in Vitro Diagnostic Reagents for National Medical Device Supervision and Inspection in 2020 / 中国医疗器械杂志

OBJECTIVE@#This paper puts forward suggestions on the development of in vitro diagnostic reagents and supervision measures for the post-marketing products, so as to further improve the quality of in vitro diagnostic reagents and ensure the safety use of medical device.@*METHODS@#This paper summarizes the quality of in vitro diagnostic reagents and analyzes the causes of the problems, according to the results of the national medical device supervision and inspection in 2020.@*RESULTS@#The overall quality of in vitro diagnostic reagents for national medical device supervision and inspection in 2020 is stable and the unqualified detection rate is 1.6%. However, there are some problems. For example, the management of raw materials is unscientific, the faultiness in the preparation of reference materials, the understanding of standards is unthorough, and the management of instructions is unimportance.@*CONCLUSIONS@#It is suggested that manufacturers of in vitro diagnostic reagents should improve the binding force of the quality management system, strengthen the awareness of risk management, attach importance to communicate with regulatory authorities, study standards sufficiently and strengthen the management of instructions. It is also suggested that the regulatory authorities should strengthen supervision and inspection, and further complete the evaluation guidance and standard publicity and implementation.

Analysis of Cut Off Value or Reference Interval of / 中国医疗器械杂志

The cut off value or reference interval is significant in clinical testing and diagnosis. If there is no scientific and reasonable cut off value or reference interval for

Relationship between Reference Interval Establishment and Clinical Evaluation in Quantitative / 中国医疗器械杂志

Reference interval study and clinical evaluation are crucial supportive researches to demonstrate the intended use of quantitative

Summary of Statistical Methods Commonly Used in Clinical Evaluation of / 中国医疗器械杂志

Referring to relevant normative documents, we summarized the commonly used statistical methods in clinical evaluation of

Analysis of the Development Status of Clinical Pharmacogenomics Based on External Quality Assessment from 2014 to 2019 in China / 中国药房

OBJECTIVE：To provide reference for promoting individualized medication in clinic. METHODS ：Information on external quality assessment （EQA）projects and approved kits for the guidance of chemical drug use were collected from the websites of National Center for Clinical Laboratories （NCCL） and National Medical Products Administration （NMPA） as of December 31，2019. The number of laboratories participating in each evaluation project was count. Taking EQA projects of clopidogrel and warfarin drug metabolism gene polymorphism detection as examples ，who was with the highest participation rate ， the methods and reagent kits of each laboratory were analyzed so as to analyze the current status of the clinical pharmacogenomics （PGx）in China. RESULTS ：The number of PGx genetic test EQA projects conducted by NCCL increased from 3（2014）to 9 （2019）. The total number of participating laboratories was 926 in 2018，and 1 249 in 2019. The number of laboratories of warfarin and clopidogrel drug metabolism gene polymorphism detection increased from 57 to 300.5 for warfarin and from 124 to 374.5 for clopidogrel. The more widely used methods were fluorescent PCR and PCR-chip hybridization. The number of reagent kits currently approved by NMPA was 7 for warfarin and 15 for clopidogrel ，respectively. But some of the laboratories participating in EQA used self-prepared reagents yet. CONCLUSIONS ：The clinical PGx is in its infancy ，and the awareness of laboratories about EQA is improving；the main method was fluorescence PCR ，but the use of self-made reagents in laboratories is still common ，regulations concerning the approval ，use and supervision still need to be further improved.

Expression and immune recognition of polypeptides derived from Hepatitis C virus structural proteins

Background: Hepatitis C virus (HCV) is characterized by a high degree of nucleotide sequence variability between genotypes. This variability extends to functional and immunological determinants. Serological tests using antigenic segments derived from the HCV polyprotein have been used for the diagnosis of HCV infection. However, available diagnostic Kits do not necessarily take type variability into consideration and are not optimized for HCV genotype 4a (HCV4a), the predominant genotype in Egypt. Aim: The aim of this study was to express some HCV4a-derived polypeptides in order to identify those with immunodiagnostic utility. Materials and Methods: Six sequential/overlapping genomic segments encoding 100–266 amino acid peptides from the core (peptide 1), envelope 1 (E1; peptide 2), envelope 2 (E2; peptides 4, 5, and 6), and E1/E2 (peptide 3) regions of the HCV4apolyprotein were selected for in vitro expression as glutathione S-transferase-fusion proteins. The immunoreactivity of the expressed peptides was evaluated against sera from HCV-infected/uninfected individuals using dot blot, western blot, and enzyme-linked immunosorbent assay. Results: The expressed polypeptides were recognized by HCV-infected sera from 20 patients, while showing no immunoreactivity toward uninfected serum. Peptide 1 derived from the core protein was found to be the most immunoreactive. Conclusion: Expressed polypeptides hold good potential for use in the development of improved HCV immunodiagnostics.

Study on Risk Assessment Model of in Diagnostic Reagent Adverse Events Based on BP Neural Network / 中国医疗器械杂志

OBJECTIVE@#To modify the monitoring process and means of adverse events diagnostic reagents,improve the quantity and quality of adverse events reported ,and reduce the workload of regulatory authorities,eventually ensure the safety and effectiveness of diagnostic reagents.@*METHODS@#The pre-filtering risk assessment system based on BP neural network was used to evaluate the adverse events of diagnostic reagents.According to the evaluation results,the administrative supervision departments took corresponding countermeasures.@*RESULTS@#The BP neural network learned the historical data,and the risk evaluation results of the adverse events were basically consistent with the expert group.@*CONCLUSIONS@#BP neural network can be used to evaluate the risk of adverse events and achieve risk signal aggregation of adverse events.

Discussion on Regulatory Risk of in Vitro Diagnostic Reagents in Use / 中国医疗器械杂志

According to the information of the supervision and inspection of in vitro diagnostic reagents for clinical use, this article analyzed the compliance issues and discussed the methods to solve the problems, to urge medical institutions to reduce the regulatory risk of in vitro diagnostic reagents in use.

The management and application of cold-chain for in vitro diagnostic reagent / 中国医学装备

Objective: To carry out effective management for the cold-chain temperature of in vitro diagnostic reagent so as to provide safe and credible inspection basis for clinical diagnosis and treatment. Methods: The remote control and alarm platform of cold storage and refrigerator were applied to achieve acceptance for temperature control of in vitro diagnostic reagent, and achieve acceptance for temperature and achieve differentiation management for unqualified product. These methods could ensure controllability of temperature for the reagent with requirements of cold-chain. Results: Through the management of cold-chain of in vitro diagnostic reagents, hospital has achieved effective supervising for them, and hospital has concrete record for these reagents in the entire medical process, and all of them were traceability. Therefore, it provide effective guarantee for clinical safety. Conclusion: The support of informatization technique and implementation of management system of hospital can ensure the cold-chain management of entire process is not out of control, and enhance the stability and accuracy of clinical test results and effective guarantee the safety of diagnosis and treatment for hospital.

Reacción en cadena de la polimerasa en tiempo real para la cuantificación del ADN del virus de la hepatitis B / Real-time polymerase chain reaction assay for Hepatitis B virus DNA quantification

Introducción: los niveles de ADN viral en muestras de suero son un marcador útil para monitorear la progresión de la enfermedad y la respuesta al tratamiento en pacientes con hepatitis B crónica; de ahí que se comercialicen estuches diagnósticos para esta función, con la desventaja de ser costosos. Objetivos: desarrollar y evaluar el desempeño analítico de un sistema de reacción en cadena de la polimerasa en tiempo real para la cuantificación del ADN del virus de la hepatitis B. Métodos: se utilizaron cebadores que amplifican un fragmento del gen C y sonda de hidrólisis en el equipo LightCycler 1.5. Se construyó una curva estándar y se evaluó su eficiencia. Se utilizaron 272 muestras de suero para ensayos de especificidad analítica y clínica, especificidad y exactitud genotípica, coeficientes de variación intraensayo e interensayo, comparación con un estuche comercial y con la reacción en cadena de la polimerasa cualitativa para el virus de la hepatitis B. Resultados: la curva estándar mostró excelente correlación lineal (r= -1) y valores muy bajos de error a lo largo de varias magnitudes de concentración de ADN diana. La especificidad analítica y clínica fue de 100 %, en tanto que al evaluar la especificidad y exactitud genotípica, se obtuvo que las diferencias entre los Log10 del valor obtenido y el de referencia eran inferiores a 0,5 Log10. El límite de detección por análisis de Probit se estimó en 16,41 UI/µL con un rango dinámico de cuantificación de hasta 10(8) UI/mL. El sistema mostró bajos coeficientes de variación intraensayo (0,16 a 1,45 %) e interensayo (0,9 a 2,62 %). La comparación con el estuche comercial artus HBV LC PCR kit mostró una correlación de r= 0,964 y r²= 0,929; con la reacción en cadena de la polimerasa cualitativa se confirmó la mayor sensibilidad y ventajas de la reacción en cadena de la polimerasa en tiempo real. Conclusiones: el ensayo cumple con los requisitos para la cuantificación del ADN del virus de la hepatitis B, que demuestra ser específico, sensible y reproducible. Su aplicación permitirá un mejor diagnóstico y seguimiento de los pacientes con hepatitis B crónica en Cuba.

Introduction: viral DNA levels in serum samples are a useful marker to monitor the disease progression and the treatment response in patients with chronic hepatitis B. Commercial kits for this purpose are available, but they are considerably expensive. Objectives: to evaluate the analytical performance of a real-time polymerase chain reaction (RT-PCR) assay for Hepatitis B virus DNA quantification. Methods: specific primers to the gene C and TaqMan chemistry in a LightCycler 1.5 equipment was used. A standard curve was made and evaluated. Two hundred and seventy-two serum samples were used to assess the clinical and analytical specificity, the genotypic accuracy and specificity, the intra-assay and interassay coefficients of variation and the comparison with a commercial assay and with the qualitative PCR. Results: the standard curve showed a strong linear correlation (r= -1) and low error values in the tested target DNA concentration. Analytical and clinical specificities were 100 %. Genotype accuracy and specificity showed that the differences between the results obtained by RT-PCR assay and those of the reference assay were less than 0.5 Log10. The 95% HBV DNA detection end-point assessed by Probit analysis was 16.41 IU/µL with a dynamic range of quantification of 10(8) IU/mL. Intra-assay and interassay coefficients of variation ranged from 0.16 to 1.45 % and 0.9 to 2.62 % respectively. The RT-PCR assay correlated well with those from a commercial assay (r= 0.964 and r²= 0.929) and with the HBV qualitative PCR, thus confirming its better sensitivity and advantages. Conclusions: the RT-PCR assay is well suited to monitoring HBV DNA levels showing to be sensitive, specific and reproducible. Its application in the clinical practice ensures a better diagnosis and management of patients with chronic hepatitis B in Cuba.

Establishment of quality control system for domestic hepatitis C diagnostic reagents / 中华检验医学杂志

Objective To evaluate the quality of domestic hepatitis C diagnostic reagents objectively,and to build up the quality control systems for assessment of hepatitis Cdiagnostic reagents.Methods4080 serum samples from blood donors were collected and detected with EIA kits.146anti-HCV positive and negative samples were selected and tested repeatedly by two different imported ( Murex and Ortho) and domestic anti-HCV EIA kits(InTec,ZHONGSHAN BIO-TECH,WANTAI and KHB),then confirmed by CHIRON RIBA HCV 3.0 and PCR qualitative reagents.The samples were tested by nucleic acid quantitative assay and the RNA positive samples were detected by genotyping reagents.ResultsThe quality control systems of diagnostic reagents of anti-HCV and HCV RNA were constructed.Each quality control system was consisted of 50 samples,including 20 anti-HCV/HCV RNA positive,20 anti-HCV/HCV RNA negative and 10 diluted specimens for sensitivity evaluation.The positive samples with dominant HCV genotypes in China contained strong,moderate and weak positive samples.The negative samples involved those S/CO value ( signal-to-cutoff ratios ) close to threshold.Conclusion The quality control systems established in this study are suitable for assessment of the new and improved domestic hepatitis C diagnostic reagents.

Evaluation of four domestic and three imported fourth-generation HIV diagnostic reagents / 中华微生物学和免疫学杂志

Objective To evaluate the quality of four domestic and three imported fourth-generation HIV diagnostic reagents.Methods The specificity and sensitivity of these assays were analyzed when testing HIV negative samples and HIV-1 RNA positive samples.The relative seroconversion sensitivity index was analyzed when testing BBI seroconversion panels.Results The sensitivity of seven 4th-generation assays were 100％ (95％ CI:99.86％-100％ ),and one sample at the window period of HIV-1 infection were detected as positive.Of the seven assays,one imported assay exhibited the relative largeδ + value (1.0892),and the small δ+ value were found on the remaining six assays (0.0836-0.3003 ).For the samples negative for HIV antibody,varying degrees of false positives were observed on the seven assays ( specificity:97.80％ -99.60％,δ- value:-1.3803 to -0.4778).When testing the BBI seroconversion panels,the relative seroconversion sensitivity index of domestic assays were -0.500-0,however,which of imported assays were -0.600 and -0.700.Conclusion The seven reagents exhibited high sensitivity and specificity.The 4th generation HIV assays can be used as blood screening reagents to find the samples at window period of HIV-1 infection,thus indicating the certain meaning in reducing the transmission risk of HIV-1 for fourth-generation HIV diagnostic reagents.However,the better efficiency to detect HIV-1 early infection was observed on the imported assays than on the domestic assays.

Comparative evaluation of eight third generation and four fourth generation anti-HIV diagnostic reagents / 中华微生物学和免疫学杂志

Objective To evaluate the differences between the third and the fourth generations of anti-HIV assays,and different kits within the same generation.Methods A total of 989 HIV-negative samples,185 samples positive for HIV-1 RNA.1st-generation international references of HIV antibodies and samples from 9 sets of BBI seroconversion panels were detected by 8 kits of the third generation and 4 kits of the fourth.Results The fourth generation kits can detect HIV infection earlier than the third generation kits.However,the detected days of HIV infection with different kits of the fourth generation were different whilst no significant difierences were found with difierent kits of the third generation.Furthermore,the capacity of detecting samples with different genotypes for different reagents was different,especially the capacity of domestic reagents on detecting HIV-1 O group and HIV-2 samples was relatively weak.Conclusion These data provided information to improve the quality of anti-HIV diagnostic reagents further.