2. HBsAg+ candidate blood donors HBV genotypes Number Origin(s) A1 43 S. Africa A2 72 Poland B 126 Hong Kong Malaysia Taiwan Thailand C 90 Hong Kong Malaysia Taiwan Thailand D 465 Egypt Iran Poland S. Africa Turkey Tunisia E 184 Guinea HBsAg quantification: Architect HBsAg, Abbott Lab. (0.05 IU/ml or 0.28 ng/ml) HBV DNA quantification: in-house real-time QPCR assay (<20 IU/ml)

4. Relationship between HBsAg and HBV DNA levels C 1 2 3 4 5 6 246810 HBV DNA (log IU/ml) HBsAg (log IU/ml) R2=0.31 D 1 2 3 4 5 6 HBsAg (log IU/ml) 246810 HBV DNA (log IU/ml) R2=0.17 E 1 2 3 4 5 6 HBsAg (log IU/ml) 246810 HBV DNA (log IU/ml) R2=0.22 A1 1 2 3 4 5 HBsAg (log IU/ml) 246810 HBV DNA (log IU/ml) R2=0.02 A2 1 2 3 4 5 HBsAg (log IU/ml) 246810 HBV DNA (log IU/ml) R2=0.08 12 B 1 2 3 4 5 HBsAg (log IU/ml) 246810 HBV DNA (log IU/ml) R2=0.39 6 n=43 n=72 n=126 n=90 n=465n=184

5. HBsAg / HBV DNA ratio 0 20 40 60 A2 1>1<11 A1 0 10 20 30 >1<11 0 10 20 >1<11 B 0 10 25 1>1<1 C 0 10 20 30 >1<11 D 0 10 20 30 1>1<1 E Ratio Frequency (%) n=43n=72 n=126n=90 n=465 n=184

7. HBsAg / HBV DNA ratio according to ethnic groups

8. Conclusions HBsAg range is between 10 2 and 10 6 IU/ml for genotypes A, C and E. Significantly lower values are seen in genotypes B and D. A1, B and D have lower median DNA than genotypes A2, C and E No correlation between plasma levels of HBsAg and viral load irrespective of genotype Very low HBsAg (3.7%) or DNA (6.2%) levels are observed in genotype D Within genotype B infection HBsAg and DNA levels are significantly higher in Chinese than Malays

9. Acknowledgements B Meldal P Garmiri D Belkhiri Dept Haematology University of Cambridge, UK B Foglieni Dept of Transfusion Medicine and Hematology, Lecco, Italy K Lin, HKRCBTS, Hong Kong T Sakul, NRCBTS, Bangkok, Thailand M Vermeulen, SANBTS, Durban, SA E Brojer, NIHTM, Warsaw, Poland A Loua, CNTS, Conakry, Guinea H Bon, NBTS, Kuala Lumpur, Malaysia K Boukef, NBTS, Tunis, Tunisia O Arslan, Ankara, Turkey H Zadeh, IBTO, Teheran, Iran M El Ekiaby, Cairo, Egypt Supported by ISBT Foundation NHSB&T, England Novartis