无偿献血人群中HCV/OBI共感染者的分子流行病学特征

Molecular epidemiological characteristics of HCV/OBI co-infected blood donors

目的了解无偿献血人群丙型肝炎病毒(HCV)感染者中隐匿性乙肝感染(OBI)率,为进一步阐明HCV/OBI的作用机制提供科学依据。方法采用盖立复PROCLEIX TIGRIS、罗氏cobas s 201和罗氏E601等仪器对2011年1月—2015年7月广州无偿献血者中的933(人)份HCV感染者标本做HBV DNA和抗-HBc检测,比较HCV单纯感染者和HCV/OBI共感染者之间性别、年龄、民族和转氨酶的差异;巢式PCR扩增HCV/OBI共感染者HCV C区和S区,并构建进化树和基因分型,荧光定量PCR检测HCV和HBV的病毒载量;另外,随机选取同期本地HCV 6a基因型的44名单纯HCV感染者和16名HCV/HBV共感染者最为对照组,通过巢式PCR扩增各组HCV C区,并对3组对象的HCV核心蛋白氨基酸序列做比对分析。结果本组HCV感染的献血者标本中,有6(人)份HBV DNA和抗-HBc阳性,亦即OBI感染率为6.43‰(6/933);该6份HCV/OBI共感染标本的HCV基因型中6a占83.3%(5/6)、1b占16.7%(1/6),HCV病毒载量(log_(10)IU/mL)为3.8—5.7(5.0±0.69)。HCV单纯感染者和HCV/OBI共感染者的性别、年龄、民族、籍贯和ALT均无明显差异(P>0.05)。HCV单纯感染者、HCV/HBV共感染者和HCV/OBI共感染者HCV核心蛋白序列氨基酸变异数分别为0.8±1.3 vs 0.7±1.5 vs 0.4±0.5(P>0.05),没有在HCV/OBI共感染者中发现一致性的结构或突变规律。结论广州地区无偿献血人群HCV感染者中的OBI阳性率较高。

Objective To investigate the prevalence of occult hepatitis B infection(OBI) among blood donors with chronic hepatitis C virus(HCV) infection in China, and provide a scientific basis for further clarifying the mechanism of HCV/OBI. Methods HBV DNA and anti-HBc were detected in 933 samples of HCV infected volunteer blood donors in Guangzhou from January 2011 to July 2015 using PROCLEIX TIGRIS, Roche Cobas s 201 and Roche E601. The differences of gender, age, nationality and ALT between the HCV-monoinfected and HCV/OBI co-infected blood donors were statistically analyzed. HCV C region and HBV S region were amplified by nested polymerase chain reaction(PCR). The evolutionary tree was constructed for genotyping, and the viral loads of HCV and HBV were detected by real time polymerase chain reaction(RT-PCR). In addition, 44 local HCV-monoinfected patients with HCV 6a genotype and 16 local HCV/HBV co-infected patients were randomly selected as the control group. The HCV C region of each group was amplified by nested PCR,and the amino acid sequences of HCV core protein in the three groups was compared and analyzed.Results Among 933 HCV-infected samples, 6 were HBV DNA and anti-HBc positive, and the OBI infection rate was 6.43(6/933) among HCV-infected blood donors. Among 6 HCV/OBI co-infected individuals, HCV genotype 6a accounted for 83.3%(5/6) and 1b accounted for 16.7%(1/6). HCV viral load(log10 IU/mL) ranged from 3.8 to 5.7, with the mean value of 5.0±0.69. There was no significant differences in gender, age, nationality, native place and ALT between HCV-monoinfected group and HCV/OBI co-infected group(P>0.05). The amino acid variability of HCV core protein sequence in HCV-monoinfected group, HCV/HBV co-infected group and HCV/OBI co-infected group were 0.8±1.3,0.7 ±1.5 and 0.4±0.5, respectively(P>0.05). No consistent structure or mutation pattern was found in HCV/OBI co-infection group.Conclusion There is a higher positive rate of OBI among the volunteer blood donors in Guangzhou, and the proportion of HCV 6 a genotype in the co-infection of HCV/OBI was significantly higher than that of type 1b.