Characterization of Occult Hepatitis B virus Infection from Blood Donors in China

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http://jcm.asm.org/cgi/content/abstract/JCM.00145-11v1

Clin. Microbiol. doi:10.1128/JCM.00145-11

Copyright © 2011, American Society for Microbiology and/or the Listed

Authors/Institutions. .

Characterization of Occult Hepatitis B virus Infection from Blood Donors in

China

Xin Zheng, Xianlin Ye, Ling Zhang, Wenjing Wang, Lifang Shuai, Anqi Wang,

Jinfeng Zeng, Candotti, Jean-Pierre Allain*, and Chengyao Li*

Department of Transfusion Medicine, Southern Medical University, Guangzhou,

China; Shenzhen Blood Centre, Shenzhen, China; Guangzhou Military Centre of

Disease Control, Guangzhou, China; National Health Service Blood & Transplant,

Cambridge Blood Centre, Cambridge, England; Department of Hematology, University

of Cambridge, Cambridge, UK

* To whom correspondence should be addressed. Email: jpa1000@....

Prevalence and characteristics of occult hepatitis B virus infection (OBI) of

genotypes B and C prevalent in China have not been extensively explored.

Characterization of OBIs from Chinese blood donors was based on clinical,

serological, follow-up testing and sequence analyses. Twenty-eight samples from

165,371 HBsAg negative plasmas were confirmed HBsAg-/DNA+, of which 22 were

classified as OBIs and six as window period infections. OBI yield was 1:7,517 in

blood donors, whose ages ranged between 20 and 45 years (median 28). OBI donors

had normal ALT levels and low viral loads ranging between un-quantifiable and

178 IU/ml (median 14 IU/ml). Sequences from 21 BCP/PC, five whole genomes and

two additional pre-S/S from OBIs were compared to genotypes B and C HBsAg+

reference strains. 86% (6/7) OBIs were genotype C. Deletions, insertions, stop

codons and substitutions were detected in 15/21 (71%) core regulatory elements

of OBIs. Critical mutations were found in core of 5/5 OBIs in parallel with

random substitutions in pre-S/S proteins from 6/7 (86%) OBIs. Critical mutations

in core regulatory elements and core proteins might affect OBI genotype B and C

strain replication. Few S protein substitutions suggest a minor role of the host

immune defences in OBI occurrence.