| Background:Viral load testing is an important indicator for monitoring the disease progression of HIV infected persons,evaluating the effect of antiviral treatment and adjusting treatment plans.At present,although many domestic laboratories have incorporated viral load testing into the work of HIV infection diagnosis and treatment monitoring,many laboratories have a relatively short period of work and lack of experience.In order to ensure the quality of viral load testing,we organized an inter-laboratory quality evaluation of HIV-1 viral load testing laboratories across China since 2005.As a control method of laboratory testing quality,inter-laboratory quality evaluation is important for improving the laboratory testing level by issuing standard quality control products,analyzing and summarizing the existing problems in the laboratory,and making the research results of the various experimental sites in the multi-center research comparable.For a long time,the laboratory testing of HIV-1 viral load in China has mainly relied on imported reagents such as Roche or Abbott,which are expensive and can only be used on supporting equipment,and difficult to meet the huge increase in the domestic demand for HIV-1 viral load testing.In recent years,with the continuous improvement of the automation,detection quality and performance of domestic HIV-1 viral load testing reagents,the gap between domestic and imported reagents has gradually narrowed,and some cities and regions have gradually begun to choose to use self-developed HIV-1 reagents.The HIV-1 viral load detection reagent has promoted the development of related reagents in China,However,many laboratories do not understand the detection performance of domestic reagents.As the demand for viral load testing is increasing year by year,it is urgent to evaluate the detection performance of newly marketed domestic viral load testing reagents.Objectives:1.Through the analysis of the HIV-1 viral load test results reported by the participating laboratories from 2005 to 2019,in order to clarify the influencing factors of the laboratory test results,and to improve Chinese HIV-1 viral load test experiments in a targeted manner laboratory testing level to ensure the quality of testing and provide data reference.2.Evaluate the detection effect and performance of the HIV-1 viral load test reagent developed by China,and provide data for disease control institutions and medical institutions to choose to use domestic HIV-1 viral load test reagents in their actual work.Methods:The first sectionThe viral load test results(copy/ml)submitted by the participating laboratories from 2005 to 2019 are converted into log10 logarithm,and then classified according to the test method and sample number,and the mean(M)and standard deviation(S)of the test results are calculated.According to the scoring criteria in the "Guidelines for HIV-1 Viral Load Determination and Quality Assurance",the assessment results of different laboratories participating in the inter-office quality evaluation work were obtained.Analyze the factors that may affect the laboratory assessment results through the chi-square test.The single factor analysis method is used to evaluate the influence of the types of testing reagents,the types of laboratory institutions,the economic conditions of the laboratory’s area and the administrative divisions on the stability of laboratory test results,and the statistically significant influencing factors of the single factor analysis are included in the multivariate Linear regression analysis model.Use Robust Coefficient of Variation(RCV)to evaluate the stability of the test results of different reagents.The Bland-Altman consistency analysis method and regression analysis method are used to evaluate the consistency and correlation of the test results of different reagents,and the two statistical methods commonly used in the evaluation of inter-room quality:quartile robust statistics and iterative robust statistics method for comparison.The second sectionThe original quality control materials provided by Rush University in the United States for external quality evaluation were serially diluted with healthy human plasma,and the linearity and precision of detection of domestic viral load detection reagent were analyzed.The correlation and consistency of the test results of the domestic reagents and the imported Roche Cobas Taqman viral load test reagent were compared with HIV-1 infected samples and negative samples.Results:The first section1.The number of HIV-1 viral load testing laboratories has been increased from 2005 to 2019.At the end of 2019,there were 267 laboratories in 31 provinces(autonomous regions and municipalities)with HIV-1 viral load testing capabilities.Sichuan,Guangxi,Henan,and Anhui provinces with a heavier AIDS burden have established county-level viral load testing laboratories.The participating institutions are mainly disease control institutions(69.66%)and hospitals(28.46%),military systems(1.12%),maternal and child health centers(0.37%)and third-party testing institutions(0.37%)are involved,but the number is relatively small.2.Since 2013,the unqualified rate of participating laboratories has always been maintained at a low level(1.94～4.63%).The laboratories are generally operating in a good state.There are still a few laboratories that fail to pass the evaluation.It is recommended that the laboratories equipment,internal management procedures,laboratory environment,testing personnel,reagents were five reasons for failure.The geographical distribution of participating laboratories is a factor that affects laboratory assessment results(P<0.05).3.The types of reagents and the number of years involved in the assessment are factors that affect the stability of laboratory test results(P<0.05).The stability of laboratory test results is better if the duration of the inter-laboratory quality evaluation is greater than or equal to 5 years.Other factors such as the type of laboratory institution and the economic status of the area where the laboratory is located have not been found to have an impact on the stability of the test results(P>0.05),suggesting that after training and assessment,basic laboratories can also carry out HIV-1 viral load testing work.4.Taqman,EasyQ,M2000 and domestic reagents are the four main detection reagents used in laboratories at present.M2000(RCV distribution range is 0.04%～7.49%),Taqman(RCV distribution range is 0.37%～15.86%)and other reagents based on real-time fluorescent PCR technology have good stability.The stability of the test results of domestic reagents is slightly worse(RCV distribution range is 1.01%～49.97%).Bland-Altman analysis results show that the test results obtained by different reagents have a high consistency,and the test results of more than 85%of the samples fall between the 95%upper and lower limits of the test consistency interval.Further regression analysis found that the test results obtained by different reagents can be converted to each other(P<0.05).5.There is no significant difference between the quartile method and the iterative robust statistical method in determining the detection target value,but the standard deviation obtained by the iterative robust statistical method is larger than that of the quartile method,which can better reflect the true variability of laboratory test results.The second section1.The intra-assay coefficient of variation of the test results of the domestic reagent for the quality control products of different concentrations is less than 5%,and the inter-assay coefficient of variation is less than 15%.The correlation coefficients R2 of domestic reagent on the test results of a series of fixed-value quality control products were 0.989.2.The correlation coefficients R2 between the domestic reagent and the imported Roche Cobas Taqman viral load detection reagent is 0.847.The overall correlation is relatively high,but the domestic reagent and imported reagents are related to the detection of low viral load samples.The P value of the regression equation is less than 0.05,indicating that the test results obtained by different reagents can be converted.3.The Kappa value of the domestic reagent and imported reagent were 0.99.When using 1000 copies/ml as the detection line,the coincidence rate of domestic reagent and imported reagents was 95.55%;when using 5000 copies/ml as the detection line,The coincidence rates of domestic reagent with imported reagents were 93.33%.Conclusions:The first sectionSince 2005,after 15 years of laboratory quality evaluation,the testing level of HIV-1 viral load testing laboratories in China has gradually improved.The types of test reagents and the number of years involved in the assessment are important reasons that affect the stability of laboratory test results.M2000,Taqman and other fully automated real-time PCR detection technologies have good inter-laboratory stability.In recent years,the use of domestic HIV-1 viral load testing reagents has been increasing year by year,but the stability of laboratory testing results needs to be further improved to achieve better testing performance.The test results obtained by different methods can be converted into each other using regression equations.The quartile method and the iterative robust statistical method are currently two statistical methods commonly used to process the inter-room quality evaluation data.Compared with the quartile method,the iterative robust statistical method can better reflect the laboratory test results,the conclusions obtained are more reliable.The second sectionThe domestic reagent has good detection linearity and precision.Compared with imported Roche Cobas Taqman viral load detection reagents,it has higher consistency and relevance.The overall detection performance is good.However,the domestic reagent still need to further improve the detection precision in the low viral load concentration range to achieve better detection performance. |
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