Integration of hepatitis B virus DNA in chronically infected patients assessed by Alu‐PCR

Hepatitis B virus (HBV) infection is the main risk factor for hepatocellular carcinoma (HCC) worldwide. Integration of HBV DNA into the human genome has been found in >80% of HBV‐related HCC cases. Some studies have, however, found similar integration patterns in tumorous and nontumorous tissues. Thus, the role of integrations for the development of HCC as well as the rate of integration in different stages of infection remain unclear. The aim of this study was to investigate integrations in patients without HCC, representing different stages of chronic HBV (CHB) infection. Extracted DNA in liver biopsies from 74 patients (one with 2 available biopsies) with CHB infection was analyzed by Alu‐PCR. Amplicons were further analyzed by Sanger sequencing. Integration was detected in 39 biopsies (52%) as an amplicon containing both human and HBV sequences by Alu‐PCR with one primer targeting a region in the HBV genome. Integrations were found in patients representing the different stages of CHB infection. A majority of the HBV sequences were located upstream or downstream of nucleotide position 1820, which previously has been identified as a common breakpoint in the HBV genome in integrated sequences. Approximately 60% of the HBV integrations were found in noncoding regions of the human genome. Integrations of HBV DNA into the human genome is an event frequently found in mild phases of chronic hepatitis.     

Serum hepatitis B surface antigen is correlated with intrahepatic total HBV DNA and cccDNA in treatment‐naïve patients with chronic hepatitis B but not in patients with HBV related hepatocellular carcinoma

The aim of the study was to investigate correlations between intrahepatic hepatitis B virus total DNA, covalently closed circular DNA (cccDNA), and serum HBsAg in treatment‐naïve chronic hepatitis B and HBV related hepatocellular carcinoma (HCC). Liver tissues were taken from 42 HBV related HCC and 36 patients with chronic hepatitis B. A fraction of DNA extracted from liver tissue was digested with a plasmid‐safe ATP‐dependent DNase and used for HBV cccDNA detection. The remaining DNA was used for the detection of HBV total DNA and β‐globin, the latter of which is a housekeeping gene and quantified for normalization by real‐time PCR. Quantitation of serum HBsAg was performed by a chemiluminescence assay. Serum HBsAg had positive correlations with serum HBV DNA (r = 0.636, P < 0.001), intrahepatic HBV total DNA (r = 0.519, P = 0.001) and cccDNA (r = 0.733, P < 0.001) in 36 treatment‐naïve chronic hepatitis B, while HBsAg correlated poorly with DNA (r = 0.224, P = 0.210), intrahepatic total DNA and cccDNA in the tumor (r = 0.351, P = 0.031; r = 0.164, P = 0.324, respectively) and non‐tumor (r = 0.237, P = 0.152; r = 0.072, P = 0.667, respectively) liver tissues of 42 HCC. HBV cccDNA and total DNA were significantly higher in liver tissue from chronic hepatitis B than in tumor and non‐tumor of HCC (P < 0.001). Serum HBsAg and HBV DNA were also higher in chronic hepatitis B than in HCC (P < 0.001). It was concluded that levels of serum HBsAg and intrahepatic cccDNA and total DNA were significantly higher in chronic hepatitis B than in HCC, and significant correlations among them were observed in treatment‐naïve chronic hepatitis B but not in HCC. J. Med. Virol. 85:219–227, 2013. © 2012 Wiley Periodicals, Inc.     

Cellular chromosome DNA interferes with fluorescence quantitative real-time PCR detection of HBV DNA in culture medium

Fluorescence quantitative real-time PCR (FQ-PCR) is a recently developed technique increasingly used for clinical diagnosis by detection of hepatitis B virus (HBV) DNA in serum. FQ-PCR is also used in scientific research for detection of HBV DNA in cell culture. Understanding potential FQ-PCR interference factors can improve the accuracy of HBV DNA quantification in cell culture medium. HBV positive serum was diluted with culture medium to produce three test groups with HBV DNA levels of 5 x 10(7) copies/ml (high), 5 x 10(5) copies/ml (medium), and 5 x 10(3) copies/ml (low). Chromosome DNA was extracted from HepG2 cells and then added to high, medium, and low group samples at final concentrations of 0, 12.5, 25, 50, and 100 microg/ml. The samples were quantified by FQ-PCR and data were evaluated using statistical software. No marked changes were seen in the quantitative curves for high level HBV DNA samples when the samples were supplemented with 0-100 microg/ml of chromosome DNA. Interference was observed in medium level samples when 50 and 100 microg/ml of chromosome DNA was added. Interference was also observed in low level HBV DNA samples when the concentration of added chromosome DNA was greater than 25 microg/ml. The interference was eliminated when samples were digested by DNase I prior to PCR detection. In Conclusions, the presence of cellular chromosome DNA can interfere with the detection of HBV DNA by FQ-PCR. Removal of cellular chromosome DNA from culture media prior to FQ-PCR is necessary for reliable HBV DNA quantitative detection.     

Kinetics of HBV DNA and HBsAg in acute hepatitis B patients with and without coinfection by other hepatitis viruses

The kinetics of hepatitis B virus (HBV) and its surface antigen (HBsAg) during acute hepatitis has not yet been studied accurately in a representative number of patients. The influence of coinfecting hepatitis viruses during the acute phase of infection is not known. Three to four serum samples from 21 patients with acute HBV monoinfection and 27 with coinfection were taken at intervals of 6-10 days and analyzed for the number of HBV genome equivalents (ge) by real time polymerase chain reaction (PCR) and for HBsAg quantity using Laurell electrophoresis. Log HBV ge/ml decreased during the follow-up from 6.8 +/- 1.1 to 5.1 +/- 1.0 to 4.2 +/- 0.8 to 3.3 +/- 1.1 (mean +/- SD). The half-life times of HBV ge increased from 1.6 days at the beginning to 4 days at the end. HBsAg decreased much slower: from 38 to 23 to 12 to 3.8 microg/ml. Half-life time was around 8 days at the beginning and 5.7 days at the end, but 11 patients showed a rapid elimination of HBsAg and HBV DNA. Hepatitis C virus (HCV) coinfection did not change the kinetics of HBV ge and HBsAg significantly. A moderate but significant suppression of HBV ge levels was observed in hepatitis D virus (HDV) coinfected patients. HBsAg levels were, however, enhanced in this cohort. In conclusion, the data suggest that expression and elimination of HBV is in most patients with acute hepatitis B not altered by coinfecting hepatitis viruses. The initial decrease of HBV ge and HBsAg in serum appears to be caused by decay or non-specific removal in the absence of replacement.     

Correlation between HBV DNA detection by polymerase chain reaction and Pre-S1 antigenemia in symptomatic and asymptomatic hepatitis B virus infections

The presence of hepatitis B virus (HBV) genome in sera from 73 symptomatic and asymptomatic HBsAg carriers was studied by the polymerase chain reaction (PCR) with primers specific for the S and C regions. Pre-S proteins of the HBV envelope were detected in serum by a specific monoclonal antibody in a double immunoradiometric assay. Out of twenty-five symptomatic patients with chronic active hepatitis (14 with HBeAg and 11 with anti-HBe), all were positive for HBV DNA by PCR, while 14/14 HBeAg and 2/11 (18%) of the anti-HBe patients were positive by dot blot hybridization. All but one anti-HBe patient (96%) carried Pre-S1 proteins. Among the asymptomatic HBsAg carriers, HBV DNA was detected by PCR in 14/14 (100%) HBeAg positive patients and in 25/34 (73%) anti-HBe positive patients. Pre-S1 proteins were found, respectively, in 14/14 (100%) and 11/22 (50%) of the same cases tested in parallel. The 20 healthy blood donors devoid of HBV markers and with normal transaminases tested were found negative for HBV DNA using PCR. Out of 12 patients who recovered from acute hepatitis B, all were found negative by PCR analysis after a mean follow up of 1 year after seroconversion to anti-HBs. When serial samples from 2 patients (one with acute hepatitis B, the other with chronic hepatitis B) were tested for the presence of HBV DNA and of Pre-S1 proteins, both markers showed parallel development.(ABSTRACT TRUNCATED AT 250 WORDS)     

Detection of integrated hepatitis B virus DNA in hepatocellular carcinoma cell lines by nonradioactive in situ hybridization

A sensitive and specific nonradioactive in situ hybridization method capable of detecting single-copy integrated hepatitis B virus (HBV) DNA sequences in hepatocellular carcinoma (HCC) cell lines was developed. In situ hybridization of biotinylated HBV (adr, adw) DNA probes with nine different human HCC cell lines were carried out in 96-well microtiter plates. Integration was detected in HCC cell lines HCCM, Hep3B, huH-1, huH-4, and PLC/PRF/5. Detection of single-copy HBV DNA sequences was also achieved in Hep3B and huH-4. HCC cell lines HepG2, HUH-6, HUH-7, Mahlavu, and the non-HCC control MCF-7, gave clear negative results. These results show a 100% correlation with those obtained by Southern blot hybridization assay. The results demonstrate that nonradioactive detection of single-copy integrated HBV DNA sequences in HCC cell lines is possible by the method described, which has potential application for viral genome analysis requiring in situ hybridization.     

锁核酸结合分子信标技术检测乙型肝炎病毒DNA G1896A点突变研究

目的研究和评估乙型肝炎病毒（HBV）DNA G1896A点突变的实时荧光PCR检测方法。方法收集经测序验证HBV DNA G1896A未突变的野生型样本150例和已发生突变的突变型样本58例,在突变区域设计分子信标探针,点突变处进行锁核酸处理,利用荧光PCR方法检测HBV前C区G1896A点突变;再从临床标本中随机抽取18例、8例和19例荧光PCR结果分别显示为G1896A突变的标本、杂合的标本以及野生型的标本的PCR产物进行序列测定。结果突变型质粒和野生型质粒的检测灵敏度均可以达到100copies/ml;突变型探针检测高浓度的野生型质粒时无检测信号,野生型探针检测高浓度突变型质粒时无检测信号;突变型模板在总杂合模板中的比例达到5%时则都可以将突变型检测出来;序列测定的8例G1896A突变标本、6例杂合标本和19例野生型标本的PCR产物结果和荧光PCR检测结果完全吻合。结论实时荧光PCR检测方法可以快速、简便、准确地检测HBVDNAG1896A点突变,是检测点突变的重要方法,具有重要的临床应用价值。     

采用PCR微板核酸杂交-ELISA技术进行HBV DNA基因分型的研究

目的 采用PCR微板核酸杂交－ELISA技术对HBV DNA进行基因分型研究。方法 采用PCR、核酸杂交和酶联显色技术,首先将HBV DNA进行PCR扩增,并将扩增产物加入预先包被HBV通用探针的微孔板,再加入HBV各基因型显色探针,同时进行微板核酸夹心杂交－ELISA显色,对152例临床诊断为不同程度乙型肝炎患者血清中HBV DNA进行基因分型。结果 152例不同临床表面的肝炎患得血清中的HBV DNA的基因型大多集中在B、C和D这3种基因型,其所占比例分别为：B型28．29％（43／152）,C型（37．50％（57／152）、D硎型18．42％（28／152）;A型、E型、F占比例很少,各占有3．29％（5／152）。还存在一定比例的混合基因型,B、C、D三型不同组合的混合型共占10．53％（16／152）。结论 PCR微板核酸杂交－ELISA方法可以准确、快速、简便进行HBV基因分型,在探讨HBV的流行病学及观察各基因型毒力强弱及致病性大小方面有重要意义。     

Sequencing of human-viral DNA junctions in hepatocellular carcinoma from patients with HCV and occult HBV infection

DNA of free hepatitis B viruses (HBV) has been detected in the liver of patients infected with hepatitis C virus (HCV). It is unknown whether HBV DNA is integrated into such livers; if so, it may affect hepatocarcinogenesis. Hepatocellular carcinomas (HCCs) from 34 patients without HBV surface antigen (HBsAg) and with anti-HCV, and from 7 patients with HBsAg and without anti-HCV as controls, were examined, using the cassette-ligation-mediated polymerase chain reaction and primers based on HBV DNA sequence. In the controls, HBV DNA had been integrated into human DNA of all HCCs. On the basis of HBV DNA in tumor tissue, 23 of the 34 patients with anti-HCV had occult infection. Junctions between human DNA and HBV DNA were detected in 10 of the 34 patients without HBsAg and with anti-HCV. HBV DNA was integrated into chromosome 11q in 4 of the 10 HCCs with junctions. The DNA to either side of the human-viral junctions was sequenced. Clinically, the mean tumor size of these 10 HCCs was 39 mm; that of the 24 HCCs without integrated HBV was 25 mm. The surrounding tissue was cirrhotic in 2 of the 10 former HCCs and in 16 of the latter 24 HCCs. In conclusion, integrated HBV was detected in some patients with HCV infection; in these patients, the integrated DNA was associated with accelerated hepatocarcinogenesis.     

Serum antibodies to hepatitis C virus in Italian patients with hepatocellular carcinoma

Antibodies against hepatitis C virus (anti-HCV) were detected in 60.8% of 78 patients with hepatocellular carcinoma (HCC). Cirrhosis, present in most of the patients, as well as alcohol abuse, age, sex, and alpha-fetoprotein were equally distributed in the anti-HCV-positive and -negative groups. HBsAg positivity was significatively higher in negative anti-HCV group. By contrast, hepatitis B virus (HBV) antibodies were detected more frequently in positive anti-HCV patients than in the negative anti-HCV group. These data must be considered with caution because of the small number of HBsAg-positive patients. It is concluded that the high prevalence of anti-HCV in patients with HCC may suggest an etiological role of the hepatitis C virus, although in relationship to age, alcohol abuse and cirrhosis, the similarity in the two groups questions this hypothesis.     

DNA: DNA hybridization method for the diagnosis of hepatitis B infection

Hepatitis B viral (HBV) DNA was detected in a hepatoma cell line which produces hepatitis B surface antigen (HBsAg) and in patients with acute hepatitis B. The serum of one patient with acute hepatitis B was found to be infectious when injected i.v. into a chimpanzee up to a dilution of 10(-8). Hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) were detectable in the same serum sample by radioimmunoassay up to a dilution of 10(-5) and of 10(-3), respectively. Using DNA: DNA hybridization on nitrocellulose membranes, HBV DNA sequences were detectable up to 10(-8) dilution corresponding to the infectivity level. Based on this finding, it appears that DNA: DNA hybridization is the most sensitive method for detecting hepatitis B virus (HBV) infection. In situations with low virus levels it may be the only indicator of the presence of infectious hepatitis B virus. The use of a tritium-labelled probe makes the method economical and adaptable to hospital laboratories.     

Clinical significance of occult hepatitis B virus infection in chronic hepatitis C patients

Background/Aims

We investigated the frequency of occult hepatitis B virus (HBV) infection in anti-hepatitis C virus (HCV)-positive individuals and the effects of occult HBV infection on the severity of liver disease.

Methods

Seventy-one hepatitis B virus surface-antigen (HBsAg)-negative patients were divided according to their HBV serological status into groups A (anti-HBc positive, anti-HBs negative; n=18), B (anti-HBc positive, anti-HBs positive; n=34), and C (anti-HBc negative, anti-HBs positive/negative; n=19), and by anti-HCV positivity (anti-HCV positive; n=32 vs. anti-HCV negative; n=39). Liver biopsy samples were taken, and HBV DNA was quantified by real-time PCR.

Results

Intrahepatic HBV DNA was detected in 32.4% (23/71) of the entire cohort, and HBV DNA levels were invariably low in the different groups. Occult HBV infection was detected more frequently in the anti-HBc-positive patients. Intrahepatic HBV DNA was detected in 28.1% (9/32) of the anti-HCV-positive and 35.9% (14/39) of the anti-HCV-negative subjects. The HCV genotype did not affect the detection rate of intrahepatic HBV DNA. In anti-HCV-positive cases, occult HBV infection did not affect liver disease severity.

Conclusions

Low levels of intrahepatic HBV DNA were detected frequently in both HBsAg-negative and anti-HCV-positive cases. However, the frequency of occult HBV infection was not affected by the presence of hepatitis C, and occult HBV infection did not have a significant effect on the disease severity of hepatitis C.     

慢性乙型肝炎肝内HBV DNA和HBsAg的双标记定位研究

应用原位杂交和免疫组化PAP法双标记技术,结合病人乙型肝炎(乙肝)病毒血清学标志物检测结果,研究了31例慢性乙肝病人肝穿刺组织中乙型肝炎病毒DNA(HBV DNA)和HBsAg的分布及意义。结果显示,肝组织内检出HBV DNA 23例,HBsAg 26例,二者同时检出者21例。从同组病人肝组织内HBV DNA和HBsAg双标检测结果与其乙肝病毒血清学标志物检测结果的比较来看,肝组织内HBV DNA和HBsAg同时阳性很可能表明HBV正处于复制及表达的活动状态。     

Application strategies of serum HBV DNA detection in HBV infection patients: A retrospective study of 5611 specimens

The detection of hepatitis B virus (HBV) DNA plays a critical role in determining the level of viral replication in HBV-infected patients. However, how to select appropriate HBV DNA detection method, low-sensitivity (ls) and hypersensitivity (hs) remains unclear. In this study, hepatitis B surface antigen (HBsAg), hepatitis B e-antigen (HBeAg), alanine transaminase (ALT), aspartate transaminase (AST), and hs HBV DNA titers in serum of 5611 cases with suspected HBV infection were reviewed. Besides, the dynamic changes of HBV DNA and HBsAg in 85 chronic hepatitis B (CHB) patients receiving peginterferon α (PegIFNα) or entecavir (ETV) were observed. The results showed the positive rate of HBV DNA was 32.8%, of which low viral load (20 to 500 IU/mL) accounted for 51.8%. In the 5611 cases, when the HBsAg was less than 1000 IU/mL, the proportion of low viral load was 76.3%. Moreover, in patients receiving antiviral treatment, when HBsAg was less than 2000 IU/mL (PegIFNα) or HBsAg was less than 3500 IU/mL (ETV), the proportion of patients with low viral load was 79.5% or 78.0%, respectively. We developed a strategy of serum HBV DNA detection in HBV-infected patients. When HBsAg was negative, HBV DNA detection should be unnecessary. When HBsAg was 0.05 to 1000 IU/mL, hs HBV DNA should be detected in patients with abnormal level of ALT, AST, or HBeAg. While HBsAg was greater than or equal to 1000 IU/mL, ls HBV DNA was recommended. Moreover, the cutoff value of HBsAg increased during antiviral therapy of CHB patients. In conclusion, hs HBV DNA is of great value in HBV-infected patients with low viral load. HBV DNA detection methods should be selected reasonably according to the levels of HBsAg, HBeAg, ALT, and AST.     

原发性肝癌与乙型肝炎肝硬化HBV DNA水平、HBV基因型的比较研究

目的 比较原发性肝癌与乙型肝炎肝硬化患者的血清HBV DNA水平、HBV基因型差别。方法 对210例原发性肝癌（HCC）患者及220例乙型肝炎肝硬化（HBV LC）患者的血清HBVDNA水平及HBV基因型进行分析,比较病毒学和基因型差异。结果 210例HCC患者和220例HBV LC患者HBV DNA检测阳性率分别为84.3％（177/210）、94.5％（ 208/220）;HBV DNA定量为（5.06±1.01） log10拷贝/ml和（5.36±1.13）log10拷贝/ml,HBV LC患者均高于HCC患者（P＜0.01）;HCC组和HBV LC组均以C基因型为主,两组B,C基因型分布无明显差异。结论 HCC患者血清HBV DNA水平低于HBV LC患者。两组HBV基因型分布无明显差异,均以C基因型为多。     

Presence of HBV DNA in spermatozoa: a possible vertical transmission of HBV via the germ line

Using molecular hybridization we studied the presence and state of HBV DNA in sperm samples obtained from 17 patients with HBV infection (eight HBsAg chronic carrier, nine acute hepatitis B). Presence of HBV DNA was detected in three samples of seminal fluid from three patients with acute hepatitis. Restriction enzyme patterns of cellular DNA were consistent with presence of integrated HBV DNA sequences in spermatozoa from two of these three patients. The results indicate that HBV DNA may be present in the semen, at least during the acute phase of HBV infection. The presence of HBV DNA in seminal fluid confirms the possibility of venereal transmission. The presence of integrated sequences in spermatozoa suggests the possibility of true vertical transmission of HBV via the germ line.     

Significance of HBV DNA by PCR over serological markers of HBV in acute and chronic patients

A study was undertaken to determine Hepatitis B virus DNA (HBV DNA) by PCR in acute and chronic hepatitis B infection and to correlate it with serological markers. Three hundred and forty-five serum samples of patients from all over India were categorized into different groups according to their serological profile. HBV DNA was detected upon amplification in 166/263 patients in group A, 3/14 patients in group B, and 2/32 patients in group C, and was not detected in groups D and E. The presence of HBV DNA in 49 patients with non-replicative HBV disease, as defined by the absence of HBeAg, suggests low levels of viremia which is also supported by the abnormal liver function tests (LFTs) in these patients. In addition, HBV DNA was detected in small proportion of individuals with past HBV infection. This data suggests that, detection of HBV DNA by amplification technique serves as an important supplementary tool besides serology in a number of clinical settings, especially in determining low levels of viremia in patients with non-replicative HBV disease and chronic hepatitis, and also in a few patients with past HBV infection and who could be asymptomatic carriers of HBV infection.     

State of hepatitis B virus DNA in leucocytes of hepatitis B patients

Hepatitis B virus (HBV) DNA in leucocytes from 50 hepatitis patients with various patterns of HBV serological markers and serum HBV DNA and 13 normal controls were examined by Southern blot hybridization with 32P-labeled 3.2 Kb HBV DNA. A free form of HBV DNA was observed in leucocytes of 8 patients, 7 of whom were positive for serum HBeAg, and in 6 patients an integrated form of HBV DNA was identified. HBV DNA was not identified in leucocytes from 13 normal controls. The free form of HBV DNA in leucocytes existed as a heterogeneous smear from 2.0 to 3.2 Kb, similar to the pattern in liver and hepatocellular carcinoma cells but different from serum HBV DNA in which the 3.2 Kb band was absent. The banding pattern of the integrated form of HBV DNA in leucocytes varied among different patients. During preparation of white blood cells and purification of HBV DNA probes, it was important to remove plasma contamination and traces of pBR322, respectively. The presence of extrachromosomal DNA sequences partially homologous to pBR322 could cause false results. The presence of a free and integrated form of HBV DNA in leucocytes is important for explaining the biology of HBV, the harbouring and replication sites of extrahepatic origin, the mechanism of recurrent infection, and the rationale of the treatment of hepatitis B.