Analysis and evaluation of hepatitis B test results of blood nucleic acid testing under different screening modes

Objective To evaluate the effectiveness of Roche Cobas s 201 in detecting HBV by analyzing its blood nucleic acid testing (NAT) results. Methods The results were grouped according to the enzyme-linked immunosorbent assay (ELISA) and NAT minipool test (MP), NAT individual test (ID) and repeated NAT ID test (rID), and categorized into 4 groups as ELISA+ /NAT(ID)+ , ELISA+ /NAT(rID)+ , ELISA-/NAT(ID)+ and ELISA-/NAT(rID)+ . The data were statistically analyzed to explore whether there was a difference in the detection of reactive results by repeated NAT, and the correlation between cycle threshold (Ct) and nucleic acid detection rate for NAT-reactive samples with different ELISA results. The true infection status of blood donors was further analyzed by supplementary tests, including NAT systems and chemiluminescence serological marker assays using other methodologies. Results A total of 1 691 groups of 766 293 blood donor samples were HBV NAT(MP)+ , of which 1 418 groups(83.86%) were detected with reactive results (1 418 HBV NAT+ , 7 090 NAT-), and there were still 273 groups (16.14%) that remained undetected after repeated testing[a total of 1 638 NAT-, Ct(MP): 39.49±3.62]. Of the HBV NAT+ , 881(62.13%) were ELISA+ /NAT(ID)+ , 19(1.34%) were ELISA+ /NAT(rID)+ , 451(31.81%) were ELISA-/NAT(ID)+ , and 67(4.72%) were ELISA-/NAT(rID)+ . For samples with different ELISA results, difference was found in the detection of HBV by repeated NAT (P<0.05). There was no difference in Ct(ID) values between groups ELISA+ /NAT(rID)+ and ELISA-/ NAT(ID)+ , and groups ELISA+ /NAT(rID)+ and ELISA-/ NAT(rID)+ (P>0.05), but there were significant differences between other groups compared pairwise (P<0.05). Supplementary tests were performed on 228 ELISA-/ NAT(MP)+ (ID)- samples, 56 (24.56%) were reactive by chemiluminescent detection of HBsAg+ and 7 (3.07%) by other NAT systems. Among the remaining 221 NAT- samples/donors (96.93%), 53 (23.98%) HBsAg+ donors were likely to have chronic infection, 40 (18.10%) anti-HBe+ and/or anti-HBc+ donors might have previous infections, and the remaining 128 (57.92%) donors who were non-reactive were NAT (MP) pseudo-reactive, with significant differences in anti-HBs levels \'between groups (P<0.05). Conclusion Repeated NAT has differential detection of donor samples with different reactivity categories or different serologic results, especially within a certain interval, and repeated NAT for ELISA- samples can significantly improve the detection rate. Ct values can assist in assessing the stability and accuracy of the NAT system. For ELISA-/NAT(MP)+ (ID)- donors, the combination of other highly sensitive assays can reduce the risk of viral residuals and safeguard clinical blood safety.