Division of Transfusion Medicine and Diagnostic Development, Department of Haematology, University of Cambridge, Cambridge Blood Centre, Long Road, Cambridge, UK.
J Viral Hepat. 2011 Feb;18(2):91-101. doi: 10.1111/j.1365-2893.2010.01282.x.
Malaysia is a medium endemic country for hepatitis B virus (HBV) infection but little is known about HBV strains circulating in Malaysian blood donors. Viral load, HBsAg concentrations and nested PCR products from 84 HBV surface antigen (HBsAg) positive samples were analysed in detail. Median viral load was 3050 IU/mL and median HBsAg 1150 IU/mL. Fifty-six full genome, 20 pre-S/S, 1 S gene and six basic core promoter/precore-only sequences were obtained. Genotypes B and C were present at a ratio of 2:1, and two genotype D samples were obtained, both from donors of Indian background. Phylogenetically, genotype B was more diverse with subgenotypes B2-5, B7 and B8 present, while most genotype C strains were from subgenotype C1. Genotypes B and C were equally frequent in ethnic Malays, but 80% of strains from Chinese were genotype B. HBsAg concentrations were higher in genotype C than in genotype B, in Chinese than Malays and in donors under the age of 30. HBV vaccine escape substitutions (P120S/T, I126N and G145G) were present in six strains. In the large surface protein, immuno-inactive regions were more mutated than CD8 epitopes and the major hydrophilic region. Strains of genotype B or from ethnic Malays had higher genetic diversity than strains of genotype C or from Chinese donors. Hence HBV strains circulating in Malaysia are phylogenetically diverse reflecting the ethnic mix of its population. Ethnic Malays carry lower HBsAg levels and higher genetic diversity of the surface antigen, possibly resulting in more effective immune control of the infection.
马来西亚是乙型肝炎病毒 (HBV) 中度流行的国家，但对于在马来西亚献血者中循环的 HBV 株知之甚少。详细分析了 84 份 HBV 表面抗原 (HBsAg) 阳性样本的病毒载量、HBsAg 浓度和巢式 PCR 产物。中位病毒载量为 3050IU/mL，中位 HBsAg 为 1150IU/mL。获得了 56 个全基因组、20 个前 S/S、1 个 S 基因和 6 个基本核心启动子/前核心仅序列。基因型 B 和 C 的比例为 2:1，还获得了 2 个基因型 D 样本，均来自印度裔背景的献血者。从系统发生学上看，基因型 B 更为多样化，存在 B2-5、B7 和 B8 亚基因型，而大多数基因型 C 株来自 C1 亚基因型。马来裔人群中基因型 B 和 C 的频率相等，但 80%的中国人群基因型 B 株。基因型 C 的 HBsAg 浓度高于基因型 B，中国人群高于马来人群，年龄在 30 岁以下的献血者高于年龄在 30 岁以上的献血者。有 6 株存在 HBV 疫苗逃逸突变 (P120S/T、I126N 和 G145G)。在大表面蛋白中，免疫非活性区域的突变多于 CD8 表位和主要亲水区域。基因型 B 或马来裔人群的株比基因型 C 或中国人群的株具有更高的遗传多样性。因此，在马来西亚循环的 HBV 株具有系统发生多样性，反映了其人口的种族构成。马来裔人群携带的 HBsAg 水平较低，表面抗原的遗传多样性较高，可能导致对感染的更有效免疫控制。
