乙型肝炎表面抗原、抗体共阳性者的病毒基因组S区、基本核心启动子区和前C区变异分析

Variations of surface, basic core promoter and precore regions in genomes of hepatitis B virus from chronic hepatitis B virus infected patients with positive for both hepatitis B surface antigen and antibody

目的 探讨HBsAg和抗-HBs共阳性患者HBV基因组S区、基本核心启动子（BCP）区和前C区变异特点.方法 慢性HBV感染者62例,其中血清HBsAg和抗-HBs共阳性者27例,HBsAg单阳性者35例.对患者血清中的HBV基因组S区、BCP区和前C区序列进行PCR扩增和测序,并对其变异位点进行分析.组间均数比较采用t检验,样本率和变异率的比较采用卡方检验.结果 HBsAg和抗-HBs共阳性组27例患者HBV基因S区发生156个氨基酸变异,HBsAg单阳性组35例患者发生100个氨基酸变异,共阳性组氨基酸变异率显著高于单阳性组（2.56％比1.26％,x2=32.07,P＜0.05）.在主要亲水区a决定簇,尤其是第一个茎环内,氨基酸变异频率共阳性组明显高于单阳性组（4.76％比1.02％,x2=11.58,P＜0.05）.共阳性组患者HBV基因组BCP区A1762T/G1764A双突变发生率显著高于单阳性组（59.3％比28.6％,x2=5.895,P＜0.05）;前C区A1846T变异也高于单阳性组（40.7％比17.1％,x2=4.265,P＜0.05）.共阳性组患者BCP区和前C区A1762T/G1764A＋G1896A联合突变发生率也高于单阳性组（37.0％比14.3％,x2=4.302,P＜0.05）.结论 HBsAg和抗-HBs共阳性患者S区a决定簇变异率、BCP区及前C区与肝细胞癌发生相关位点变异发生率明显高于HBsAg单阳性患者.

Objective To analyze the variations of surface（S） region,basic core promoter （BCP） and precore （preC） regions in genomes of hepatitis B virus （HBV） from patients with coexistence of hepatitis B surface antigen （HBsAg） and hepatitis B surface antibody （anti-HBs）.Methods S region,BCP and preC regions in genomes of HBV were amplified and sequenced in 62 HBV-infected patients including 27 HBsAg-positive/anti-HBs-positive patients （double positive group） and 35 HBsAg-positive/ anti-HBs-negative patients （single positive group）.The sequencing results and amino acid variants in these regions were analyzed.Difference of means between groups was compared by t test.Sample rate and variation rate were compared by chi-square test.Results One hundred and fifty-six amino acids mutations within the S region were detected in 27 patients of double positive group and 100 mutations in 35 patients of single positive group.The mutation rate in double positive group was significantly higher than those in single positive （2.56% vs 1.26%,x2 =32.07,P〈0.05）.The amino acid variants in double positive group were much higher than those in single positive group within major hydrophilic region （MHR）,especially in the first loop area of a-determinant in S region （4.76 % vs 1.02 %,x2 =11.58,P〈0.05）.The mutation rate of A1762T/G1764A in BCP in double positive group was significantly higher than those in single positive group （59.3% vs 28.6%,x2 =5.895,P〈0.05）.The mutation rate of A1846T in preC region was higher in double positive group than those in single positive group （40.7% vs 17.1%,x2-4.265,P〈0.05）.The mutation rate of A1762T/G1764A＋G1896A in double positive group was also higher than that in single positive group （37.0% vs 14.3%,x2 =4.302,P〈0.05）.Conclusions The mutation rates of S region,especially in the first loop area within a-determinant,BCP and preC regions which are related with hepatocellular carcinoma development in HBsAg and anti-HBs double positive group are higher than those in HBsAg single positive group in chronic HBV infected patients.