Mutations in surface and polymerase gene of chronic hepatitis B patients with coexisting HBsAg and anti-HBs

AIM： To investigate the clinical significance and presence of mutations in the surface （S） and overlapping polymerase gene of hepatitis B patients with coexisting HBsAg and anti-HBs. METHODS： Twenty-three patients with chronic hepatitis B were studied. Of the 23 patients, i i were both positive for hepatitis B virus （HBV） surface antigen （HBsAg） and antibody to HBV surface antigen （anti-HBs）, 12 were negative for anti-HBs while positive for HBsAg. DNA was extracted from 200 μL serum of the patients. Nucleotide of the surface and overlapping polymerase gene from HBV-infected patients was amplified by PCR, and the PCR products were sequenced. RESULTS： Forty-one mutations were found within the surface gene protein of HBV in 15 patients （10 with coexisting HBsAg and anti-HBs）. Six （14.6%） out of 41 mutations were located at ＂α＂ determinant region in 5 patients （4 positive for HBsAg and anti-HBs）. Eleven mutations （26.8%） occurred in the downstream or upstream of ＂α＂ determinant region. Lamivudine （LMV）- selected mutations were found in three patients who developed anti-HBs, which occurred in amino acid positions （196, 198, 199） of the surface protein and in YMDD motif （M204I/V） of the polymerase protein simultaneously. Presence of these mutations did not relate to changes in ALT and HBV DNA levels.CONCLUSION： Besides mutations in the ＂α＂ determinant region, mutations at downstream or upstream of the ＂α＂ determinant region may contribute to the development of anti-HBs. These mutations do not block the replicating competency of HBV in the presence of high titer of anti-HBs.

瞄准：与共存的 HBsAg 和 anti-HBs 在表面(S) 和肝炎 B 病人的重叠聚合酶基因调查变化的临床的意义和存在。方法：有长期的肝炎 B 的 23 个病人被学习。23 个病人， 11 为肝炎 B (HBV ) 表面抗原(HBsAg ) 和抗体两个都是积极的到 HBV 表面抗原(anti-HBs ) ， 12 为 anti-HBs 是否定的当时为 HBsAg 积极。DNA 从病人的 200 muL 浆液被提取。从感染 HBV 的病人的表面和重叠聚合酶基因的核苷酸被 PCR 放大，并且 PCR 产品被定序。结果：41 个变化在 15 个病人在 HBV 的表面基因蛋白质以内被发现(10 与共存的 HBsAg 和 anti-HBs ) 。(14.6%) 六从 41 个变化被定位在“高山哈”在 5 个病人的决定因素区域(4 为 HBsAg 和 anti-HBs 积极) 。十一个变化(26.8%) 发生了在下游或在上游“高山哈”决定因素区域。选择变化在开发了 anti-HBs 的三个病人被发现的 Lamivudine (LMV ) 发生在氨基酸位置， 196， 198， 199 ) 表面蛋白质并且在聚合酶蛋白质的 YMDD 主题(M204I/V ) 同时。这些变化的存在没在中高音和 HBV DNA 层次联系到变化。结论：除变化在以外“高山哈”决定因素区域，变化在下游或在上游“高山哈”决定因素区域可以贡献 anti-HBs 的发展。这些变化不面对 anti-HBs 的高 titer 堵住 HBV 的复制才能。