Application And Quality Control Of Nucleic Acid Detected Technology In Primary Blood Stations

Background:In order to reduce the incidence of transfusion-transmitted diseases,the virus of blood samples have been carefully detected by blood collection and supply agencies around the world.Studies have found that the technology of serological enzyme-linked immunosorbent assay(ELISA)detection is insufficient as a basic method for blood screening with a risk of missed detection.The technology of nucleic acid amplification(Nucleic acid amplification testing,NAT)play as a supplement to this method in more countries to ensure the safety of blood products.In comparison with serological testing,NAT testing is characterized by high sensitivity,high quality requirements for specimens,susceptibility to pollution,strict requirements for laboratory environment,personnel operations and facilities,and high cost of testing.Therefore,it is particularly important to strengthen laboratory quality control.Objectives:The technology of nucleic acid detection has been introduced in the“Blood Station Technical Operation Regulations”by the Ministry of Health in 2015.This study aims to explore the role of the nucleic acid detected technology played in monitoring in grassroots blood stations and the measures to achieve quantification of laboratory NAT quality monitoring.Methods:(1)From XX city blood station center from January 1,2013 to December 31,2018,163,782 blood samples of unpaid blood donors were collected,and the blood samples were subjected to test of alanine aminotransaminase,hepatitis B surface antigen(HBs Ag),anti-hepatitis C antibody(HCV-Ab),HIV antibody(HIV-Ab),anti-Treponema pallidum antibody(TP-Ab)by using the rate method and the two-agent enzyme-linked immunoassay method.During the period of January 1,2016-December 31,2018,77721 blood donor specimens that were negative for the two-agent ELISA test were used.Using Shanghai Haoyuan or American Roche detection system,8 blood samples and 6blood samples were collected,and the blood samples were mixed.Nucleic acid extraction,viral nucleic acid amplification and detection are carried out in three stages of NAT mixed sample detection.Negative mixed test is regarded as negative result,and mixed test is positive for split test,and the split result is the final result.Each batch of test set a negative control,a positive control and an indoor quality control product.This study collects the above test data,and applies the chi-square(χ2)test method in SPSS software to compare the NAT positive rate,positive split rate,and the difference in NAT positive rate between different domestic and imported nucleic acid detection systems.Statistical analysis of related quality indicators such as positive rate of nucleic acid mixed test,effective resolution rate,and inefficiency of results.(2)The Questionnaire of Quality Control Management in XX Central Blood Station Blood Screening Laboratory was used in this study.The investigation of quality control of blood screening experiment in the blood station were recorded and the existing problems were found by listening to the introduction,on-site inspection of laboratory equipment and implementation,related archive records,and verbal inquiries.Results:(1)Among the 163,782 unpaid blood donor blood samples collected from XX City Center Blood Station from January 1,2013 to December 31,2018,5269 were positive for ALT(3.22%).255were positive for anti-HIV antibodies by ELISA dual-reagent detection(0.16%),829 were positive for TP-Ab(0.51%),373 were positive for HCV-Ab(0.23%),and 1199 were positive for HBs Ag positives(0.73%).From 2013 to 2018,the overall positive rates of ALT,HIV-Ab,TP-Ab,HCV-Ab,and HBs Ag showed a downward trend.The positive rates of ALT,HIV-Ab,TP-Ab,HCV-Ab,and HBs Ag in the three years after the application of NAT experiment were significantly lower than those in the three years before the application of nucleic acid experiment.(χ~2=296.512,47.014,25.218,77.564,41.098,P<0.05).The results suggested that the preliminary blood screening test is more standardized and stricter after the application of nucleic acid testing project,which increases the threshold for blood donors to enter the blood collection system and helps to reduce the consumption of resources for unqualified blood tests.(2)From January 2016 to December 2018,77,721 specimens were tested for for HBV-DNA,HIV-RNA,and HCV-RNA by two detected systems of Shanghai Haoyuan and American Roche in blood station.A total of 112 specimens were detected with positive results.62 were detected by NAT tests in Shanghai Haoyuan detection system with the positive rate of 0.17%(62/36563).50 were detected by American Roche detection system with the positive rate of 0.12%(50/41158).Meanwhile,the positive rate of NAT was no significant difference between these two detection systems(χ~2=3.111,P>0.05).Moreover,the NAT positive rate of Shanghai Haoyuan detection system were significantly different among three years(χ~2=7.889,P<0.05);the NAT positive rate of American Roche detection system were significantly different among three years(χ~2=1.226,P>0.05).These results suggest that the detection of HBV-DNA,HIV-RNA,and HCV-RNA were no significantly different between Shanghai Haoyuan and American Roche detection systems.The detected system of American Roche is more stable than Shanghai Haoyuan.(3)From January 2016 to December 2018,the positive rate of mixed test of Shanghai Haoyuan and American Roche detection system was 1.93%(107/5556)and 0.85%(68/7961),respectively.The difference was statistically significant(χ~2=24.409,P<0.05)byχ~2 test;the effective resolution rate of American Roche detection system was 73.53%(50/68)which was higher than that of Shanghai Haoyuan detection system 57.01%(61/107),and the difference was statistically significant(χ~2=4.892,P<0.05).The ineffectiveness rate of Shanghai Haoyuan detection system was 0.14%.There was no significant difference in the ineffectiveness rate of Shanghai Haoyuan detection system in the past three years(χ~2=0.032,P﹥0.05).The reason for the ineffectiveness was the ineffectiveness of internal reference(IC)in blood nucleic acid screening.The ineffectiveness rate of American Roche detection system was 0.19%.The ineffectiveness was caused by the batch of Constantine quality control serum.After changing the quality control serum,the number of invalid pools of nucleic acid test results is 0,and the invalid rate is 0.00%.It is suggested that the occurrence of invalid results is in random.It is necessary to keep close monitoring of the invalid results of nucleic acids,so that the detection system and the detection process can run stably and reliably.(4)“Questionnaire on quality control management of blood screening laboratory in XX city center blood station”results that a relatively comprehensive nucleic acid laboratory operating procedure and laboratory quality management system has been developed and performed by the blood station.The main problem is suitable monitoring indicators for quantitative quality monitoring and trend analysis of the NAT process were not selected for the laboratory’s quality.Conclusion:Nucleic acid amplification technology has high sensitivity and can play as a supplementary test for ELISA detection of virus-negative blood samples,which can improve blood quality and reduce the incidence of transfusion-transmitted diseases.NAT American technology is applied to blood donation blood screening,which improves the initial screening rigorousness,reduces the workload of screening experiments before nucleic acid testing and decreased the consumption of blood testing resources.The NAT detection results were no significantly different between the domestic and imported detection systems.The imported detection systems were more more stable than the domestic detection systems.The suitable quality monitoring indicators need selected,a quantitative quality monitoring and trend analysis system need established and performed for the NAT process,to ensure the higher safety of blood products.