Raimondo G, Campo S, Smedile V, Rodinò G, Sardo M A, Brancatelli S, Villari D, Pernice M, Longo G, Squadrito G
Dipartimento di Medicina Interna, Università di Messina, Italy.
J Hepatol. 1991;13 Suppl 4:S74-7. doi: 10.1016/0168-8278(91)90029-b.
We analyzed hepatitis B virus (HBV) genomes obtained from serum samples and liver biopsy specimen of a chronic HBsAg/anti-HBe carrier with hepatocellular carcinoma (HCC). Before the liver biopsy, performed at the time of HCC diagnosis, the patient had been followed for 2 years; the serum samples collected in that period resulted negative for HBV-DNA dot blot hybridization. The hepatic DNA was at first examined by Southern blot, but no HBV sequence was detected. Polymerase chain reaction (PCR) amplification revealed the presence of HBV genomes in DNA extracted from the liver tissue and from two serum samples collected, respectively, 1 and 2 years before the biopsy. Direct sequence of the amplified preC/C and preS regions showed that the viral populations present in serum and liver were identical and that they had a 34 nucleotide deletion in the preS2 region, while the preC region presented two mutations each introducing a translational stop codon, one at the carboxy terminal end and the other at the second codon of the region, both able to prevent HBeAg expression. These results identify a new HBV variant which was selected during a chronic infection, and had very low levels of replication as shown by its detection only after PCR amplification.
我们分析了一名慢性乙肝表面抗原/乙肝e抗体携带者合并肝细胞癌（HCC）的血清样本和肝活检标本中获得的乙肝病毒（HBV）基因组。在肝癌诊断时进行肝活检之前，该患者已被随访2年；在此期间收集的血清样本经乙肝病毒DNA斑点杂交检测为阴性。起初通过Southern印迹法检测肝DNA，但未检测到HBV序列。聚合酶链反应（PCR）扩增显示，从肝组织以及活检前1年和2年分别采集的两份血清样本中提取的DNA中存在HBV基因组。对扩增的前C/C区和前S区进行直接测序表明，血清和肝脏中存在的病毒群体是相同的，并且它们在前S2区有一个34个核苷酸的缺失，而前C区有两个突变，每个突变都引入了一个翻译终止密码子，一个在该区域的羧基末端，另一个在该区域的第二个密码子处，两者都能够阻止HBeAg的表达。这些结果鉴定出一种新的HBV变异体，它是在慢性感染期间被选择出来的，并且如仅在PCR扩增后才检测到所示，其复制水平非常低。
