Nucleic acid amplification technology for hepatitis B virus, and its role in blood donation screening in blood banks

OBJECTIVE: To investigate the performance of hepatitis B virus polymerase chain reaction (HBV PCR) using one of the commercial methods used around the world to screen for HBV in some blood donors where other conventional serological assays have limitations to detect the virus.

METHODS: This study was designed to use Amplicor AmpliScreen for HBV testing to detect the presence of the HBV DNA in the specimens tested by COBAS AmpliPrep^™ system using a modified manufacture protocol COBAS AmpliPrep of total nucleic acid isolation (TNAI) kit. All serological tests were carried out on the donors' samples to detect the hepatitis B surface antigen (HBsAg), Australian antibody anti-HBs (AUSAB) and hepatitis B core antigen (HBcAg) in the 2 periods of the study. The first period was started in February 2005 and the second period was started in April 2007. Both periods were continued for 2 months after beginning in the molecular pathology laboratory, Al-Hada Armed Forces Hospital, Taif, Kingdom of Saudi Arabia. The 600 donors' data were then studied and analyzed.

RESULTS: Five nucleic acid amplification test (NAT-HBV) positives were found out of 600. There were 3 positive for HBcAb and negative for HBsAg, 2 had reading with <100 mIU/mL anti-HBs (AUSAB), and one had >100 mIU/mL AUSAB readings.

CONCLUSION: Our results show that there is a possibility to have “occult” HBV infection in some donors that cannot be detected by the HBsAg routine serological assays. Moreover, the study can be useful to formulate a new deferral policy based on the implementation of NAT-HBV for blood screening.