Application of combined nucleic acid test with serologic test in blood screening for voluntary blood donors in Weifang City of Shandong Province

Abstract

Objective To explore the combined application of nucleic acid test and serologic test in blood screening for voluntary blood donors in Weifang City of Shandong Province. Methods From June to December 2016, a total of 55 852 voluntary blood donors in Weifang Blood Centre were selected as study subjects. Enzyme-linked immunosorbent assay (ELISA) was used to perform serologic tests on plasma specimens from all voluntary blood donors. ELISA tests included HBsAg, anti-hepatitis C virus (HCV), anti-human immunodeficiency virus (HIV), anti-Treponema pallidum (TP) and alanine aminotransferases (ALT). For the plasma specimens with negative results of ELISA test, the nucleic acid amplification technology (NAT) was used to detect the viral nucleic acid by viral nucleic acid detection system of Kehua Bio-engineering Co., Ltd of Shanghai and viral nucleic acid detection system of Novartis Diagnostics of Switzerland. NAT tests included HBV DNA, HCV RNA and HIV RNA. For the plasma specimens with HBsAg negative of ELISA test and HBV DNA positive of NAT split test and identification test, the five viral markers test of hepatitis B virus (HBV) were performed, which included HBsAg, HBsAb, HBeAg, HBeAb and HBcAb test. And according to the results of five viral markers of HBV, the HBV infection of voluntary blood donors were presumed. χ2 test was used to compare positive detection rates of nucleic acid in plasma specimens of Kehua viral nucleic acid detection system and Novartis viral nucleic acid detection system. The continuous correction χ2 test was used to compare the effective split rate of Kehua viral nucleic acid detection system and the positive detection rate of identification test for HBV DNA, HCV RNA and HIV RNA in plasma specimens of Novartisc viral nucleic acid detection system. Results ① In 55 852 plasma specimens from voluntary blood donors, 1 962 plasma specimens were positive for ELISA test. In 53 890 plasma specimens with negative ELISA results, 19 (0.035%, 19/53 890) plasma specimens were positive for NAT test. ② There were 53 890 plasma specimens were performed NAT test in this study. Among them, the positive detection rate of nucleic acid in plasma specimens of Kehua viral nucleic acid detection system was 0.014% (4/28 199), the positive detection rate of nucleic acid in plasma specimens of Novartis viral nucleic acid detection system was 0.058% (15/25 691). There was a statistically difference between the positive detection rate of Kehua viral nucleic acid detection system and that of Novartis viral nucleic acid detection system (χ2=7.50, P<0.05). ③ The effective split rate of Kehua viral nucleic acid detection system was 44.4% (4/9). The positive detection rate of identification test for HBV DNA, HCV RNA and HIV RNA in plasma specimens of Novartisc viral nucleic acid detection system was 50.0% (15/30). There was a statistically difference between the effective split rate and identification test positive detection rate (χ2=0.03, P=0.87). ④ There were 18 voluntary blood donors who were negative for HBsAg of ELISA test and positive for HBV DNA of NAT test. There were 5 serologic infection patterns in these 18 voluntary blood donors, including occult HBV infection accounted for 88.9% (16/18), and suspectedwindow periodHBV infection accounted for 11.1% (2/18). Conclusions There is a certain risk of missed detection of ELISA serologic tests in blood screening for voluntary blood donors. NAT test is an effective supplement to ELISA. The mixed sample test reduces the positive detection rate of the viral nucleic acid, by reducing the sensitivity of NAT test. The risk of transmitting HBV through blood transfusion needs to be highly vigilant for the blood collection and supply institution in Weifang City. Nucleic acid test as a supplemental method for serological test can further reduce the risk of transmitting HBV through blood transfusion, and ensures blood safety. Key words: Blood safety; Nucleic acid amplification techniques; Serologic tests; Enzyme-linked immunosorbent assay; Blood donors; Blood screening