酶免检测双试剂反应性核酸初筛无反应性献血者核酸重复检测结果分析OA

Objective To investigate the impact of current laboratory testing models and screening strategies on blood safety by analyzing repeat nucleic acid testing(NAT)results obtained from blood donors who had dual-reactive enzyme-linked immunosorbent assay(ELISA)results but were initially nonreactive by NAT.Methods Samples from blood donors with dual-reactive ELISA results and initially nonreactive NAT results collected at Dalian Blood Center from 2017 to 2025 were included.Repeated testing was performed using two NAT systems:transcription-mediated amplification(TMA)and polymerase chain reaction(PCR).The results were analyzed in terms of the frequency of reactive NAT results and the tes-ting strategies,including minipool and individual donation testing.Results A total of 199 samples with dual-reactive ELISA results and initially nonreactive NAT results were included,comprising 66 HBsAg-reactive samples,130 anti-HCV-reactive samples,and 3 HIV Ag/Ab-reactive samples.Among the HBsAg-reactive samples,57(57/66,86.4%)showed at least one reactive NAT result upon repeated testing,and 49 showed two or more repeat reactive results.Anti-HBc was re-active in 64 samples(64/66,97.0%)and nonreactive in 2 samples(2/66,3.0%);both anti-HBc-nonreactive samples remained nonreactive in repeated NAT.No stable repeat nucleic acid reactivity was observed in anti-HCV-or HIV Ag/Ab-reactive samples.The TMA system detected 50 reactive samples(50/66,75.8%)through three combined assays plus one discriminatory assay,whereas the PCR system detected 51 reactive samples(51/66,77.3%)through four rounds of indi-vidual-donation testing.Fortyfour samples were reactive on both systems,6 were reactive only on the TMA system,and 7 were reactive only on the PCR system.Conclusion Among blood donors with dual-reactive ELISA results and initially non-reactive NAT results,HBsAg-reactive samples contain a high proportion of low viral load HBV-related cases,with intermit-tent and probabilistic nucleic acid detectability.Both testing frequency and detection strategy significantly affect the detec-tion of low viral load samples.These findings highlight the importance of recognizing the detection characteristics of low viral load HBV-related samples in order to optimize blood screening strategies and improve blood safety.