RESUMO
OBJECTIVES: To avoid further transmission of hepatitis B virus (HBV) infection, blood is tested for hepatitis B surface antigen (HBsAg) before transfusion. However, post-transfusion hepatitis B has been detected in clinics after transfusion of HBsAg-negative blood. The study presented here was undertaken to assess if HBsAg-negative blood is free from HBV or not. METHODS: Sera were collected from 398 blood donors who were negative for HBsAg. Out of 398 blood samples, antibody to hepatitis B core antigen (ant-HBc) was detected in 82 sera samples. HBV DNA was evaluated in HBsAg-negative, anti-HBc-positive sera. HBsAg, hepatitis B e antigen (HBeAg), antibody to HBeAg (anti-HBe), and anti-HBc in the sera were measured by an enzyme-linked immunosorbent assay (ELISA). HBV DNA was quantified by a real time polymerase chain reaction (PCR). RESULTS: Out of 82 HBsAg-negative, anti-HBc-positive sera samples, HBV DNA were detected in the sera of 7 voluntary blood donors. Out of these 7 subjects, all were negative for HBeAg. The levels of ALT were more than 30 IU/L in 6 of 7 HBVDNA-positive subjects and it was above upper limit of normal (>42 IU/ml) in one subject. CONCLUSIONS: The present recommendation about blood transfusion of HBsAg-negative blood system is not capable of blocking HBV transmission to blood recipients. Although advanced countries have adopted nucleic acid testing (NAT) for preventing HBV transmission, developing countries may apply anti-HBc testing and ALT estimation before blood transmission.
