隐匿性乙型肝炎病毒感染血液透析患者的分子特性及转归

Molecular characteristic and prognosis of occult hepatitis B virus infection in maintenance hemodialysis patients

目的:探讨维持性血液透析(MHD)合并隐匿性乙型肝炎病毒感染(OBI)患者的转归、HBV基因型及S区域“a”抗原决定簇突变情况等病毒分子特性。方法:对7例MHD合并OBI患者随访2年。利用ELISA、荧光定量聚合酶链反应(real⁃time PCR)对OBI患者2年前后的乙型肝炎病毒(HBV)标志物及HBV⁃DNA进行检测对比,了解其转归情况。同时对HBV⁃DNA检测阳性者进行巢式PCR扩增HBV S基因,测序分析以了解HBV的基因型及“a”抗原决定簇突变情况。结果:(1)7例MHD合并OBI患者随访2年,2例死亡,5例患者HBV标志物与2年前相比无变化。3例HBsAg-/HBsAb+/HBcAb+患者未检出HBV⁃DNA,2例单独HBcAb+患者则检出HBV⁃DNA(<20 IU/mL);(2)将2例单独HBcAb+OBI患者HBV S区域进行测序,序列结果分析显示为B型HBV;并将其“a”抗原决定簇的氨基酸序列与B型HBV的进行比对分析,一例患者未发现突变,另一例患者存在Q129R,T131N,M133S,F134L,D144E突变,其中Q129R及M133S突变为首次发现。结论:本中心MHD患者的OBI以血清学阳性为主,主要为B型HBV。首次发现“a”抗原决定簇的Q129R及M133S突变。单独HBcAb+OBI患者的HBV⁃DNA呈持续阳性,提示应重视对MHD患者单独HBcAb+患者的HBV⁃DNA筛查。

Objective:To assess the molecular characteristic and prognosis of occult hepatitis B infection(OBI)in maintenance hemodialysis(MHD)patients in Sichuan Province of China.Methodology:A 2⁃year follow⁃up study of 7 MHD patients with OBI were conducted.Serum samples were collected for ELISA assay to test serological markers of HBV infection,and real⁃time PCR assay to identify presence of HBV⁃DNA,and nested PCR plus sequencing analysis to investigate genotype of HBV and gene mutations of S gene.Results:After 2⁃years of followed,2 fo the 7 MHD⁃OBI patients were unfortunately died.Serum amples from 3 patients that were HBsAg-/HBsAb+/HBcAb+before,were not able to detect HBV⁃DNA again.The other 2 were still positive of HBV⁃DNA(<20 IU/ml).By nested PCR and sequencing analysis,it′s found that these two patients were genotype B.Further amino acid analysis revealed that patient No􀆰2 did not carry any amino acid mutation in“a”determinant.However,patient No􀆰6 was found to have mutations of Q129R,T131N,M133S,F134L and D144E,which were localized at“a”determinant of HBsAg.The Q129R and M133S mutations were first reported.Conclusion:Our study reveals that prevalence of OBI in MHD patients were still positive in serological markers.The major genotype is B.We first demonstrate mutations of Q129R and M133S in“a”determinant of HBsAg.These findings indicate the importance of HBV⁃DNA examination in MHD patients.