Distribution of mutations of HBV in Chinese blood donors from five blood centers in different regions of China

Objective To study the mutations in important regions of HBV( PreS,MHR,polymerase region and PreC / BCP) in Chinese blood donors. To analyze the geographic and demographic distribution of these mutations and it's relationship with the genotype,subgenotype and the serological characteristics of HBV. Methods A total of 245 blood samples were selected randomly from HBsAg positive blood donors of 5 geographically diverse blood centers in China. The PreS / S region,S region and PreC / BCP region were amplified was amplified and sequenced. The amino acid sequences of the S region were aligned and the mutations related to the failure of immunization and HBsAg detection were determined. The amino acid sequences of the polymerase region were aligned and the mutations related to drug resistence were determined. The nucleotidesequences of PreS region and PreC / BCP region were aligned and the mutations related to HCC were determined. The SPSS 11. 0 software was used to analyze the distribution of mutations. Comparisons between groups were analyzed by chi-square test or Fisher's exact test for categorical variables and by Student's t-test for quantitative variables. P-values below 0. 05 were considered significant. Results Mutations were present in 39( 17. 1%) of 228 samples in the major hydrophilic region( MHR) of the S region while the prevalence was higher in genotype B than in genotype C( 23. 1% vs 4. 0%). Mutations in PreS region were found in 28( 28 /200,14. 0%) samples including deletions,T31C,and T53C mutations. Few deletions( 5 /200,2. 5%) in PreS region were detected in blood donors infected HBV and no deletions specific to genotype D was detected. The prevalence of mutations in PreS region was significantly higher in genotype C than in genotype B( 26. 0% vs 5. 2%,P 0. 001) and higher in subgenotype C2 than in B2( 42. 5% vs 3. 8%). Mutations in PreC / BCP region were found in 68 samples( 29. 8%,68 /228). More A1762T / G1764A mutations were found in C than B genotype( 34. 0% vs 4. 48%) while the opposite was observed for G1896A mutation( 26. 9% vs 8. 0%,P's 0. 01). The prevalence of HBeAg was significantly lower in samples with mutations in PreC / BCP region than that in the samples with no mutation( 11. 8% vs 26. 7%,P = 0. 02). Mutations in polymerase region were found in 14 samples( 7. 0%,14 /200),most of which were related to resistance to Adefovir and Lamivudine. Conclusion The prevalence of mutations in MHR of HBV infected by Chinese blood donors was lower than the mutation rate reported by other countries. However,the mutation rate in MHR was higher than in other regions in our study. The occurrence of MHR mutants in HBV-infected blood donors and the potential failure to detect some of them in collected units poses a threat to transfusion safety. HCC related mutations were found less in PreS region but more in PreC / BCP region in blood donors. The prevalence of mutations in PreS region and A1762T / G1764A mutations was higher in genotype C than in genotype B while the opposite is the case for G1896A mutations. The drug resistance mutations were found in HBV infected by Chinese blood donors.