Hepatitis B NAT virus-positive blood donors in the early and late stages of HBV infection: analyses of the window period and kinetics of HBV DNA
Article first published online: 17 FEB 2005
Volume 88, Issue 2, pages 77–86, February 2005
How to Cite
Yoshikawa, A., Gotanda, Y., Itabashi, M., Minegishi, K., Kanemitsu, K., Nishioka, K. and the Japanese Red Cross NAT Screening Research Group (2005), Hepatitis B NAT virus-positive blood donors in the early and late stages of HBV infection: analyses of the window period and kinetics of HBV DNA. Vox Sanguinis, 88: 77–86. doi: 10.1111/j.1423-0410.2005.00602.x
- Issue published online: 17 FEB 2005
- Article first published online: 17 FEB 2005
- Received: 5 May 2004, revised 25 October 2004, accepted 7 November 2004
- half-life of HBV;
- HBV DNA doubling time;
- HBV DNA kinetics;
- HBV genotypes;
- HBV mutations;
- window period
Background and Objectives The Japanese Red Cross (JRC) carries out nucleic acid amplification testing (NAT) for hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus-1 (HIV-1) by using a multiplex (MPX) reagent. Screening is undertaken on serologically negative units. In this study we characterized HBV NAT-positive donations individually and analysed the window period and kinetics of HBV DNA, during acute infection, in follow-up studies.
Materials and Methods Two hundred and seventy-seven HBV DNA-positive donations have been identified in Japan since the introduction of NAT screening of 50-donation minipools. The viral loads and genotypes of these HBV DNA-positive donations were characterized. The doubling time and half-life of HBV was estimated from the data of 123 follow-up donors. The sensitivity of the NAT system (based on 50-donation minipools) was compared with the sensitivities of the enzyme immunoassay (EIA) and the chemiluminescence immunoassay (CLIA). Samples that were CLIA negative, but with > 104 copies/ml of HBV DNA, were analysed by sequencing the hepatitis B surface antigen (HBsAg) region.
Results Out of 277 HBV NAT-positive samples, 125 (45%) were found to have an increasing viral load and 45 (16%) a decreasing viral load. Forty per cent of HBV NAT-positive samples with an increasing viral load, and 33% of those with a decreasing viral load, were negative when tested by using the CLIA. No mutations related to escape mutants were found in the samples that were CLIA negative but with HBV DNA loads of > 104 copies/ml. The median HBV doubling time was 2·6 days (n = 93, 1·3–15·2 days) and the half-life was 1·6 days (n = 55, 0·9–6·3 days). Some kinetic difference was observed between genotypes A and B.
Conclusions HBV NAT screening detected HBV DNA in both early (the so-called serological window period) and late stages of acute HBV infection.