Laras Andreas, Koskinas John, Dimou Evangelini, Kostamena Ageliki, Hadziyannis Stephanos J
Hepatitis Research Laboratory, Athens University School of Medicine, and Henry Dunant Hospital, Athens, Greece.
Hepatology. 2006 Sep;44(3):694-702. doi: 10.1002/hep.21299.
Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is responsible for viral persistence in the natural course of chronic HBV infection and during prolonged antiviral therapy and serves as the template for the production of HBV pregenomic RNA (pgRNA), the primary step in HBV replication. In this study, we have developed and applied sensitive and specific quantitative real-time polymerase chain reaction (PCR) assays for the measurement of intrahepatic concentration, pgRNA production, and replicative activity of cccDNA in liver biopsy samples from 34 non-treated patients with chronic hepatitis B (CHB); 12 hepatitis B e antigen (HBeAg)(+) and 22 HBeAg(-). Median copy number for cccDNA was 1.5 per cell and for pgRNA significantly higher, 6.5 copies per cell, with a good correlation between cccDNA and pgRNA levels in all samples. In HBeAg(-) patients, median values of cccDNA and pgRNA levels were 10-fold and 200-fold lower than in HBeAg(+), respectively, reflecting the differences in viral activity and clinical characteristics of the two groups. Furthermore, the replicative activity of intrahepatic cccDNA was significantly lower in HBeAg(-) patients harboring mutant HBV strains than in HBeAg(+) patients: median 3.5 versus 101 pgRNA copies per cccDNA molecule. In conclusion, the levels of both HBV cccDNA, a marker of HBV persistence, and pgRNA, an indicator of viral replication, in the liver of chronically infected patients correlate with viral activity and the phase of HBV infection. The combined measurement of cccDNA and pgRNA levels provides valuable information on the presence and replicative activity of intrahepatic HBV cccDNA.
乙型肝炎病毒(HBV)共价闭合环状DNA(cccDNA)在慢性HBV感染的自然病程以及长期抗病毒治疗期间导致病毒持续存在,并作为产生HBV前基因组RNA(pgRNA)的模板,这是HBV复制的首要步骤。在本研究中,我们开发并应用了灵敏且特异的定量实时聚合酶链反应(PCR)检测方法,以测定34例未经治疗的慢性乙型肝炎(CHB)患者肝活检样本中肝内cccDNA浓度、pgRNA产生情况及复制活性;其中12例为乙肝e抗原(HBeAg)阳性,22例为HBeAg阴性。cccDNA的中位拷贝数为每个细胞1.5个,而pgRNA的中位拷贝数显著更高,为每个细胞6.5个拷贝,所有样本中cccDNA和pgRNA水平之间具有良好的相关性。在HBeAg阴性患者中,cccDNA和pgRNA水平的中位值分别比HBeAg阳性患者低10倍和200倍,这反映了两组患者病毒活性和临床特征的差异。此外,携带突变HBV毒株的HBeAg阴性患者肝内cccDNA的复制活性显著低于HBeAg阳性患者:每cccDNA分子的pgRNA拷贝数中位数分别为3.5和101。总之,慢性感染患者肝脏中HBV cccDNA(HBV持续存在的标志物)和pgRNA(病毒复制指标)的水平均与病毒活性及HBV感染阶段相关。联合检测cccDNA和pgRNA水平可为肝内HBV cccDNA的存在及复制活性提供有价值的信息。