广东省河源地区献血人群隐匿性乙型肝炎病毒感染的血清学及分子生物学特征分析

Analysis of Serological and Molecular Characterization of Occult Hepatitis B Virus Infection among Blood Donors in Heyuan,Guangdong

目的了解河源地区献血人群隐匿性乙型肝炎病毒感染(occult hepatitis B virus infection,OBI)的情况,分析其血清学及分子生物学特征。方法采用酶联免疫吸附法(enzyme-linked immunosorbent assay,ELISA)和核酸检测(nucleic acid testing,NAT)方法筛查河源地区2016年1月~2018年5月44596人份无偿献血标本。对HBsAg-/HBV DNA+标本进一步采用电化学发光法进行乙肝病毒血清标志物定性,HBsAg及抗-HBs定量检测;大容量提取HBsAg-/HBV DNA+血浆标本病毒核酸,采用巢式PCR扩增BCP和S区基因序列,对S片段阳性产物进行基因分型,同时应用实时荧光定量PCR(quantitative PCR,qPCR)测定病毒载量。结果共确认69例HBsAg-/HBV DNA+标本,其中OBI 68例,OBI检出率为0.15%(1∶656)。OBI检出率男性高于女性,高年龄组高于低年龄组,初次献血者高于重复献血者,河源籍高于非河源籍,差异均具有统计学意义(χ2=4.371,28.403,5.157和7.378,P=0.037,0.000,0.023和0.007)。病毒载量测定10例不可定量,其余58例病毒载量范围为1.08~1383.93 IU/ml(中位数34.38 IU/ml);不同血清学模式病毒载量分布差异有统计学意义(U=333.000,P=0.008)。43例可分型的OBI标本中,B基因型41例(95.3%),C基因型2例(4.7%)。结论河源地区献血人群OBI检出率相对较高,以B基因型为主。应选用灵敏度更高的单人份核酸检测系统以进一步提高OBI标本的检出率,降低经输血传播HBV风险。

Objective To understand the status of occult Hepatitis B virus infection(OBI)among blood donors in Heyuan and analyze its serological and molecular characteristics.Methods Enzyme-linked immunosorbent assay(ELISA)and nucleic acid testing(NAT)were used to screen the samples of 44596 voluntary blood donors in Heyuan from January 2016 to May 2018.The samples of HBsAg-/HBV DNA+were further tested for qualitative Hepatitis B virus serum markers,quantitative HBsAg and anti-HBs by electrochemical luminescence method.HBsAg-/HBV DNA+plasma was extracted in large capacity for viral nucleic acid,the gene sequences of BCP and S region were amplified by nested PCR,the positive products of S fragment were genotyped,and the viral load was determined by real-time fluorescent quantitative PCR(qPCR).Results 69 cases were confirmed with HBsAg-/HBV DNA+,of 68 cases with OBI,OBI detection rate was 0.15%(1∶656).OBI detection rate was higher in men than in women,the high age group blood donors was higher than the low age group,the first time blood donors was higher than the repeated blood donors,and the blood donors of Heyuan cadastral was higher than the non Heyuan cadastral,the differences were statistically significant(χ2=4.371,28.403,5.157 and 7.378,P=0.037,0.000,0.023 and 0.007).The viral load of the 58 cases ranged from 1.08 to 1383.93 IU/ml(median 34.38 IU/ml),the other 10 cases were undetectable.The distribution of viral load in different serological models was statistically significant(U=333.000,P=0.008).Of the 43 samples of classifiable OBIs,41(95.3%)were of B genotype and 2(4.7%)were of C genotype.Conclusion The OBI detection rate of blood donors was relatively high in Heyuan,B genotype was dominant.Individual-donation nucleic acid detection system with higher sensitivity should be used to further improve the detection rate of OBI specimens and reduce the risk of HBV transmission through blood transfusion.