hbv screening further improvement of blood safety based on the knowledge deduced from the results on...
TRANSCRIPT
HBV screening
Further improvement of blood safety
based on the knowledge deduced from the resultson analysis of the donor’s sera positive for HBV DNA by NAT
as well as the results of experimental HBV infection to Chimpanzees
Hiroshi YOSHIZAWA1 MD
Junko TANAKA 1 PhD
Keiko KATAYAMA1 MD
Hisao YUGI 2 PhD
Tetsushi TOMOGURI 3 PhD
1. Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
2. Division of NAT, Japanese Red Cross Association,Tokyo, Japan
3. Primate Center, Sanwa Kagak, Ltd., Kumamoto, Japan
● Importance of HBV DNA Testing
● Natural Course of Persistent HBV infection- typical/ or classical pattern of HBV carrier state -
● Natural Course of Acute HBV Infectionclinically : anamnestic infectionvirologically : (atypical) HBV carrier state
● Characteristics of Acute HBV InfectionLate phase of Infection
● Relationship between quantity of HBV DNA and titer of anti HBc
● Detection of HBsAg by highly sensitive immunoassay method (PRISM) in 268 early phase of HBV infected blood donors : both negative for HBsAg (by R-PHA method) and anti HBc ( by CLIA method)
● Experimental HBV infection using model animal (Chimpanzees)
● Results of the experiment- 10 copies of HBV DNA can transmit HBV to Chimpanzees -
● Doubling time and log time of HBV DNA in the peripheral blood of HBV (genotype A, early phase) infected Chimpanzees
● Characteristics of Acute HBV InfectionEarly phase of Infection
Importance of HBV DNA testing for Blood Safety
For late stage of HBV infectionStrategy should be different in hyper-endemic area and l
ow-endemic area of HBV infection.
For early stage of HBV infectionGenerally saying, it is almost impossible to achieve 10
0% of blood safety by HBV DNA testing solely both in hyper-endemic area and low-endemic area.
Other strategy such as social edecation to donors should be considered.
conclusion