RESUMEN
【Objective】 To evaluate the performance and clinical application of a high-throughput nucleic acid blood screening detection system for SARS-CoV-2, so as to provide basis and technical means for its application in detection of plasma from recovered COVID-19 patients. 【Methods】 The SARS-CoV-2 nucleic acid was detected by real-time fluorescence quantitative PCR, and the sensitivity, precision, anti-interference and other parameters were evaluated. Blood donor samples collected during COVID-19 epidemic period were screened using the detection system to evaluate its applicability. 【Results】 The detection limits of gene N and ORF 1ab were 3.98 copies/mL and 9.38 copies/mL, respectively. The CV of high and low concentration samples were both less than 5%. Hemoglobin at 500 mg/dL and triglyceride at 3g/dL had little effect on the results. The detection system can effectively prevent carryover, thus avoiding false positive results. The SARS-CoV-2 nucleic acid blood screening was carried out in a total of 39 306 blood samples, and all samples were negative. 【Conclusion】 The established method can meet the needs of SARS-CoV-2 nucleic acid screening therefore ensure the safe application of plasma from recovered COVID-19 patients.
RESUMEN
BACKGROUND: A range of well characterized materials are needed for validating the performance of hepatitis B surface antigen (HBsAg) immunoassays. These materials are purchased currently from overseas manufacturers at a high cost and with limited quantity. This study was conducted to establish an HBsAg low titer performance panel for use as a national standard for validation of HBsAg immunoassays in Korea. METHODS: 476 plasma units reactive on blood donor screening were collected HBsAg was tested using 3 enzyme immunoassays (EIA) and 1 chemiluminescence immunoassay (CIA). Units reactive on the CIA assay or on 2 or more immunoassays were subjected to hepatitis B virus (HBV) DNA quantification, HBV genotyping and subtyping. Units reactive on HBV DNA quantification were confirmed for HBsAg by neutralization. Candidates for the panel were subjected to a collaborative study performed at 7 laboratories using 7 immunoassays. RESULTS: Eleven HBsAg positive units were selected for the low titer performance panel based on HBsAg immunoassay, HBV DNA quantification, HBV genotyping and subtyping results. The range of the HBsAg concentration of the panel members was 0.05~1.28 IU/mL. Two HBsAg negative units were also included as negative controls. CONCLUSION: As a result of this study, a low titer performance panel [KFDA standard (08/028); HBsAg low titer performance panel (BTRL HBV/LP)] for validation of HBsAg immunoassays has been established as a Korean national standard. Use of this panel will improve performance assessment of HBsAg immunoassays. Because the performance of immunoassays cannot be assessed properly with a limited number of panels, continuous efforts are needed to develop a range of performance panels.