Recombinant HBV Surface Antigen (subtype ay)

Background Post-transfusion hepatitis B virus (PTHB) infection is still a public health problem in the world. In many developed countries, nucleic acid testing (NAT) for detection of Hepatitis B Virus (HBV)-DNA has been implemented to enhance blood donation safety. In Libya, however, the testing for HBV infection is limited to the detection of HBV surface antigen (HBsAg) only. Objectives To determine the frequency of anti-Hepatitis B core antibody (HBc) and HBV-DNA in HBsAg-negative, anti-HBc-positive blood donors in the main Central Blood Bank Units (CBBUs) in eastern Libya. Methods One thousand blood samples were obtained from healthy blood donors at the five main CBBUs in eastern Libya. The samples were screened for HBsAg and anti-HBc. Real-time polymerase chain reaction (PCR) was carried out to detect HBV-DNA in all anti-HBc-positive samples. Results A total of 94 (9.4%) donors were positive for anti-HBc. Of the 94 anti-HBc-positive samples, 9 samples (9.5%) tested positive for HBV-DNA by real-time PCR. Conclusion The rate of anti-HBc among blood donors in this study (9.4%) was similar to that reported from other regions in the country. In the absence of advanced tests for the detection of HBV infection in blood donors, such as NAT, anti-HBc should be routinely tested for, at least for first-time donors.

Background: Hepatitis B surface antigen (HBsAg) remains the main viral marker for screening and monitoring hepatitis B virus (HBV) infection. The quantification limit of most current HBsAg assays is around 0.05 IU/mL. The Lumipulse-G-HBsAg-Quant assay (Fujirebio) claims to obtain a tenfold improvement in sensitivity. This study aimed to assess the performance of this assay in detecting low HBsAg levels in clinical samples. Methods: Three panels of stored frozen samples were selected on the basis of HBV-DNA and HBsAg values obtained previously with routine techniques. Panels 1 (n=13) and 2 (n=52) consisted of DNA-positive/HBsAg-negative samples from individuals in the window period and with occult HBV infection respectively. Panel 3 comprised 23 samples with low or discrepant HBsAg screening results. All these samples were tested retrospectively with the DiaSorin and Fujirebio HBsAg assays. Results: Sixteen out of 65 samples (25 %), initially screened HBsAg negative, were reactive only with the Fujirebio assay (median value= 0.015 IU/mL; IQR= 0.012): three (23 %) samples from panel 1 and 13 (25 %) from panel 2. Thirteen of these 16 (81 %) had HBsAg values below 0.03 IU/mL with the DiaSorin assay. In panel 3, 22 (96 %) samples were quantified successfully with the Fujirebio assay (median: 0.32 IU/mL; IQR: 1.20) and 19 (83 %) with the DiaSorin assay (median: 0.31 IU/mL; IQR: 0.65). Concentrations obtained with the two assays showed good correlations (r=0.893, Spearman). Conclusions: HBsAg assays with enhanced analytical sensitivity could improve HBV serological profile interpretation with possible consequences on clinical management of infected patients, and on blood transfusion safety.