ABSTRACT
【Objective】 To explore the HBV infection of initially reactive but discriminatory test non-reactive (NAT suspicious) samples of voluntary blood donors after PANTHER individual nucleic acid testing (ID-NAT) in Tianjin. 【Methods】 From January to August 2021, after routine testing and PANTHER ID-NAT, a total of 66 HBsAg-NAT reactive but discriminatory test non-reactive samples(referred to as NAT suspicious samples) were tested from 69 362 blood samples. Among which, 23 samples were selected by simple random sampling method and enriched by ultra-high speed centrifugation. HBV DNA was detected by supersensitive fluorescence quantification PCR (qPCR)and ID-NAT, and electrochemiluminescence was supplemented for two and half pairs of hepatitis B detection. 【Results】 Among 23 suspicious NAT samples, 14 were confirmed HBV DNA positive by serological and molecular biological tests, and the anti-HBc positive rate of HBV infected individuals was 92.8%. 92.8% (13/14) of the infected individuals were occult hepatitis B virus infection(OBI). A total of 10 samples were detected for viral load by qPCR, of which 5 were quantifiable, with viral load of (11~464) IU/mL and a median of 15.4 IU/mL. 【Conclusion】 60% of the NAT suspicious samples were detected as HBV DNA positive. Anti-HBc testing can exclude most OBI undetectable by NAT, and the sensitivity of NAT should be improved to ensure the safety of blood transfusion.
ABSTRACT
【Objective】 To compare the detection performance of Cobas s201, a minipool(MP) nucleic acid test(NAT) system, and Panther, a individual donation(ID) NAT system, in blood donor screening. 【Methods】 NAT was conducted on 126 359 blood samples, and initially reactive (IR) samples were either discriminated or resolved by ID testing.The non-discriminated reactive (NDR) samples implicated in Panther sysytem were subjected to ID-NAT by Cobas s201. Some non-repeatable reactivet(NRR) and repeatable reactive (RR) samples implicated in Cobas s201 system were subjected to ID-NAT by Panther. 【Results】 61 MP-IR cases were implicated in a total of 85 128 samples that detected by Cobas 201, and 29(0.34‰) were RR after resolved by ID testing. 74(1.79‰)IR samples were implicated in 41 231 samples that detected by Panther, and 22 (29.73%) were DR-HBV after discriminatory test. Among the NDR 28 samples detected by Panther multiplex system, 7 were positive by Cobas s201 single sample (PP1) whereas non-reactive in simulated MPs of six by Cobas 201.In 28 RR samples resolved by Cobas 201, 24 positive and 4 negative samples were retested by Panther. Among the 11 samples presenting inconsistent retest results by Panther and Cobas 201, 10 were anti-HBc positive, carrying low viral load HBV. 【Conclusion】 The NAT-yield by Panther was significantly higher than that by Cobas s201. Some samples with negative discriminatory results were OBI, and it is necessary to further track and verify the unidentified samples. Cobas s201 is more suitable for a wide array of MP-NAT testing while Panther sample loading, which is flexible and easy to operate, is more suitable for ID-NAT with medium sample size.
ABSTRACT
Introduction: Nucleic acid testing (NAT) is the latest approved method for detection of transfusion transmitted infections. With higher prevalence of infections in window period and occult infections, blood safety can be compromised when testing is done using only serological techniques. With this background this study had been taken up to compare the results of serological test with NAT. Material and methods: Voluntary blood donations were screened for hepatitis B, hepatitis C and human immunodeficiency virus using ELISA. All samples were sent for ID-NAT and results of both methods were compared, analyzed individually. Results: A total of 11,393 blood units were collected during the study period. ELISA test results. showed 176 (1.54%) positivity for these transfusion transmitted infections (TTIs) in total. Among them, 133 (75.56%) was HBV, 22 (12.5%) was HCV and 21 (11.93%) was HIV as shown by ELISA. ID- NAT test results showed 174 (1.52%) positive in total. As analyzed by individual test results, 37 (0.32%) of total blood samples showed positivity in NAT which showed negative results in ELISA. Also 38 (0.33%) of total blood samples (HBV = 27, HCV = 08, HIV = 03) which showed positivity in ELISA were negative in NAT. Conclusion: ID-NAT is definitely a useful screening method for HBV, HCV, HIV. It clarifies infections in window period, occult infections and false seroreactive cases.