Study On Reduction Of The Residual Risk Of Transfusion-transmitted Diseases By NAT Detection In Donor-blood Screening

ObjectivesThe purpose of this study is to evaluate the necessity and feasibility of nucleic acid amplification technique (NAT) detection in donor-blood screening for reducing the residual risk of transfusion-transmitted diseases and to provide a data for the national health administration in formulating strategy of donor-blood screening.MethodsThe actual processes of donor blood collection were simulated and the conditions for blood storage including different storage time, storage temperature and different degree of hemolysis were designed to evaluate the effects of the above 3 factors on the sensitivity of NAT detection and to study the feasibility of NAT detection in screening donor blood which was collected under the existing conventional process. To study the necessity of NAT detection in the donor-blood screening, NAT detection for HBV DNA,HCV RNA and HIV RNA was used in the donor-blood samples in which HBsAg, Anti-HCV and Anti-HIV were all tested to be negative by ELISA technique. The NAT detection-positive samples were then detected by nucleic acid quantitation and by electrochemiluminescence for "two pairs and semi"-markers of hepatitis B, respectively, to analyze the infection status of HBV, HCV and HIV, and to evaluate the residual risk of existing strategy for donor-blood screening in Dongguan City, Guangdong, China.Results 31 NAT positive samples were found among the 40018 ELISA-negative donor-blood samples, the positive rate was 0.07%.26 of the 31 NAT-positive samples were further tested by NAT-quantitative detection while the other 5 samples were excluded because of insufficient sample volume.17 of the 26 NAT-positive samples were positive in NAT-quantitation for HBV DNA and the other 9 samples were negative. All of the 26 NAT-positive samples were negative in NAT-quantitation for HCV and HIV. The residual risk was 1/2354～1/1291, and the experimental specificity of NAT detection was 99.97%. The storage condition of 4℃within 72 hours for plasma samples has no significant effect on the sensitivity of NAT detection, while the moderate and severe hemolytic blood samples were all false RNA-negative by NAT detection, Therefore the hemolytic blood samples are unsuitable for NAT detection in blood screening.ConclusionsIn the existing strategy for donor-blood screening, there are still definite residual risk of transfusion-transmitted diseases, especially hepatitis B. In order to further reduce the residual risk, the NAT detection is necessary and feasible to be used in the donor blood screening.Therefore we suggest strongly that the Blood centers or Blood stations should take NAT detection as early as possible into the donor-blood screening procedures so as to provide datum for the national health administration to formulate a safer strategy for donor-blood screening.