Evaluation of reverse transcription-polymerase chain reaction and simultaneous amplification and testing for quantitative detection of serum hepatitis B virus RNA

BACKGROUND

Chronic hepatitis B virus (HBV) infection is one of the common infectious diseases in the world. HBV covalently closed circular DNA (cccDNA) is the initial template of HBV replication, which can exist in human hepatocytes for a long time and is difficult to be completely removed. It has been shown that HBV RNA can directly respond to the levels and transcriptional activity of cccDNA in hepatocytes and can be used as a surrogate marker of cccDNA transcriptional activity. At present, the detection techniques used for quantitative HBV RNA mainly include reverse transcription quantitative polymerase chain reaction (RT-qPCR) and simultaneous amplification and testing (SAT).

METHODS

In this study, we verified the performance of the SAT method for detecting HBV RNA and the clinical effectiveness of SAT and RT-qPCR, and compared the correlation and consistency of the two detection methods for HBV RNA detection.

RESULTS

The results showed that the limit of detection for HBV RNA by SAT method was 50 copies/mL, with a linear range of 1 × 102-1 × 108 copies/mL. There was no difference in HBV RNA levels detected by the two methods. The correlation and consistency of the results were good, with the coefficient of determination of 0.7787 in HBeAg positive group and 0.8235 in HBeAg negative group.

CONCLUSIONS

Therefore, this study confirmed that the SAT method and RT-qPCR for detecting HBV RNA have good agreement, which are both reliable methods to detect HBV RNA and can replace each other.

Lower end of treatment HBsAg and HBcrAg were associated with HBsAg loss after nucleos(t)ide analog cessation

BACKGROUND

Since hepatitis B surface antigen (HBsAg) loss is rarely achieved with nucleos(t)ide analog (NA) treatment, most patients require life-long NA treatment. Previous studies have shown that some patients remain virologically responsive even after NA cessation. However, there is still controversy surrounding whether NA discontinuation increases the HBsAg loss rate. Therefore, this study aimed to assess the cumulative rate of HBsAg loss and identify the predictors of HBsAg loss after NA discontinuation.

METHODS

This multicenter prospective study included HBV e antigen (HBeAg)-positive patients without cirrhosis from 12 hospitals in China who met the inclusion criteria. The enrolled patients stopped NA and were followed up with clinical and laboratory assessments every 3 months for 24 months after NA cessation or until clinical relapse (CR) occurred.

RESULTS

Overall, 158 patients were classified into two groups. Group A included patients with HBsAg positivity at NA cessation (n = 139), and Group B included patients with HBsAg negativity at NA cessation (n = 19). In Group A, the 12-month and 24-month cumulative rates of HBsAg loss were4.3%and 9.4%, respectively. End of treatment (EOT) HBsAg (hazard ratio (HR) = 0.152, P < 0.001) and EOT hepatitis B core-related antigen (HBcrAg) (HR = 0.257, P = 0.001) were associated with HBsAg loss. The areas under the receiver operating characteristic curves for EOT HBsAg and HBcrAg levels were 0.952 (P < 0.001) and 0.765 (P < 0.001), respectively. Patients with EOT HBsAg ≤ 135 IU/mL (59.2% vs. 1.3%, P < 0.001) or HBcrAg ≤ 3.6 logU/mL (17% vs. 5.4%, P = 0.027) had a higher 24-month cumulative HBsAg loss rate. In Group B, none of the patients experienced virological relapse after NA cessation. Only 1 (5.3%) patient had HBsAg reversion.

CONCLUSIONS

EOT HBsAg ≤ 135 IU/mL or HBcrAg ≤ 3.6 logU/mL can be used to identify patients with a higher likelihood of HBsAg loss after NA cessation. Patients with HBsAg negativity after NA cessation have favorable clinical outcomes, and HBsAg loss was durable in most cases.

Association of serum hepatitis B virus RNA with hepatocellular carcinoma risk in chronic hepatitis B patients under nucleos(t)ide analogues therapy

BACKGROUND

Whether serum hepatitis B virus (HBV) RNA associates with hepatocellular carcinoma (HCC) development in chronic hepatitis B (CHB) patients has not been fully elucidated.

METHODS

We enrolled 2974 patients receiving nucleos(t)ide analogues (NAs) from a prospective, observational CHB cohort to investigate the effect of serum HBV RNA, measured at study entry (baseline), on HCC development, using Cox regression analyses.

RESULTS

During median follow-up of 4.4 years, 90 patients developed HCC. Patients with detectable baseline HBV RNA (n=2072) exhibited significantly higher HCC risk than those with undetectable level (5-year HCC incidence estimated by Kaplan-Meier method: 4.1% versus 1.8%, P=0.007; adjusted hazard ratio [aHR]=2.21, P=0.005). HBV RNA levels of 609-99,999 and ≥100,000 copies/ml were associated with incrementally increasing HCC risk (aHR=2.15 and 3.05, respectively; P for trend=0.003), compared to undetectable level (<609 copies/ml). Moreover, patients with single-detectable either HBV DNA or RNA and double-detectable DNA and RNA had 1.57- and 4.02-fold higher HCC risk respectively, than those with double undetectable DNA and RNA (P for trend=0.001).

CONCLUSION

High-level HBV RNA is associated with increased HCC risk in NAs-treated patients. Achieving undetectable HBV RNA may contribute to better clinical outcomes, indicating it could be a valuable endpoint of anti-HBV treatment.

Cross-sectional evaluation of circulating hepatitis B virus RNA and DNA: Different quasispecies?

BACKGROUND

Different forms of pregenomic and other hepatitis B virus (HBV) RNA have been detected in patients’ sera. These circulating HBV-RNAs may be useful for monitoring covalently closed circular DNA activity, and predicting hepatitis B e-antigen seroconversion or viral rebound after nucleos(t)ide analog cessation. Data on serum HBV-RNA quasispecies, however, is scarce. It is therefore important to develop methodologies to thoroughly analyze this quasispecies, ensuring the elimination of any residual HBV-DNA. Studying circulating HBV-RNA quasispecies may facilitate achieving functional cure of HBV infection.

AIM

To establish a next-generation sequencing (NGS) methodology for analyzing serum HBV-RNA and comparing it with DNA quasispecies.

METHODS

Thirteen untreated chronic hepatitis B patients, showing different HBV-genotypes and degrees of severity of liver disease were enrolled in the study and a serum sample with HBV-DNA > 5 Log₁₀ IU/mL and HBV-RNA > 4 Log₁₀ copies/mL was taken from each patient. HBV-RNA was treated with DNAse I to remove any residual DNA, and the region between nucleotides (nt) 1255-1611 was amplified using a 3-nested polymerase chain reaction protocol, and analyzed with NGS. Variability/conservation and complexity was compared between HBV-DNA and RNA quasispecies.

RESULTS

No HBV-DNA contamination was detected in cDNA samples from HBV-RNA quasispecies. HBV quasispecies complexity showed heterogeneous behavior among patients. The Rare Haplotype Load at 1% was greater in DNA than in RNA quasispecies, with no statistically significant differences (P = 0.1641). Regarding conservation, information content was equal in RNA and DNA quasispecies in most nt positions [218/357 (61.06%)]. In 102 of the remaining 139 (73.38%), HBV-RNA showed slightly higher variability. Sliding window analysis identified 4 hyper-conserved sequence fragments in each quasispecies, 3 of them coincided between the 2 quasispecies: nts 1258-1286, 1545-1573 and 1575-1604. The 2 hyper-variable sequence fragments also coincided: nts 1311-1344 and 1461-1485. Sequences between nts 1519-1543 and 1559-1587 were only hyper-conserved in HBV-DNA and RNA, respectively.

CONCLUSION

Our methodology allowed analyzing HBV-RNA quasispecies complexity and conservation without interference from HBV-DNA. Thanks to this, we have been able to compare both quasispecies in the present study.

Novel viral markers and the prediction of off-treatment relapse in chronic hepatitis B patients: A systematic review

BACKGROUND AND AIM

Hepatitis B core-related antigen (HBcrAg) and hepatitis B virus RNA (HBV RNA) are novel markers that reflect intrahepatic cccDNA and could be useful in the prediction of relapse after nucleos(t)ide analogues (NA) discontinuation. The aim of the study is to perform a systematic review on this issue.

METHODS

Medline/Pubmed database was searched using text terms related to HBcrAg, RNA, NAs, discontinuation, and relapse. Included studies were those that enrolled adult patients who had been on NAs for more than 6 months with available information on end-of-treatment (EOT) HBcrAg and/or HBV RNA and relapse rates.

RESULTS

Sixteen studies were included. Virological and clinical relapse rates ranged from 11% to 100% and 11% to 73%, respectively. Low or undetectable EOT HBcrAg levels were associated with low off-treatment relapse rates in most studies with area under the receiver operating characteristic curve (AUROC) of 0.69-0.70 for predicting virological relapse (VR) and 0.61-0.77 for predicting clinical relapse (CR). Undetectable EOT HBV RNA was associated with a lower risk of off-treatment relapse with AUROC of 0.65-0.76 for predicting VR and 0.66-0.73 for predicting CR. Combined EOT HBcrAg and HBV RNA performed better in predicting off-treatment relapse than either test alone with AUROC of 0.816-0.846 for predicting CR. None of the patients with double-negative HBV RNA and HBcrAg developed CR.

CONCLUSION

Combining HBcrAg with HBV RNA or HBsAg improved the discriminating abilities in the prediction of off-treatment relapse of each test. Patients with double-negative HBcrAg and HBV RNA at EOT had low risks of relapse and could be considered for NA discontinuation.

New Biomarkers of Chronic Hepatitis B

Chronic hepatitis B (CHB) infection leads to clinically heterogeneous disease outcomes. Different viral markers are utilized to monitor treatment effects and predict risk of complications in patients with CHB. Hepatitis B core-related antigen (HBcrAg) is a novel serum composite viral protein whose performance has been proven to be superior to that of existing viral markers. It showed good correlation with intrahepatic covalently closed-circular DNA. Its profile differs drastically in patients in different disease phases, and the level declines with antiviral therapies. HBcrAg may be helpful for predicting hepatocellular carcinoma development and hepatitis B virus (HBV) reactivation in immunosuppressed patients. Another emerging measurable serum marker, HBV RNA, exists in the form of pregenomic RNA-containing virions. Its profile differs between patients in different disease phases in a similar manner to that of HBcrAg. HBV RNA is present in serum at lower levels than HBV DNA in treatment-naïve patients by 1–2 logs. In contrast, its level is higher than HBV DNA in patients receiving nucleos(t)ide analogues (NAs). A significant decline in serum RNA was observed in patients receiving novel antiviral therapies, including core protein allosteric modulators and RIG-1/NOD2 agonists. Both HBcrAg and HBV RNA may be helpful for predicting off-therapy sustained virological control in patients who stop long-term NA treatment.

Serum hepatitis B virus RNA is a predictor of HBeAg seroconversion and virological response with entecavir treatment in chronic hepatitis B patients

BACKGROUND

Characteristics of alterations of serum hepatitis B virus (HBV) RNA in different chronic hepatitis B (CHB) patients still cannot be fully explained. Whether HBV RNA can predict HBeAg seroconversion is still controversial.

AIM

To investigate whether HBV RNA can predict virological response or HBeAg seroconversion during entecavir (ETV) treatment when HBV DNA is undetectable.

METHODS

The present study evaluated 61 individuals who were diagnosed and treated with long-term ETV monotherapy at the Department of Infectious Diseases of Peking University First Hospital (China) from September 2006 to December 2007. Finally, 30 treatment-naive individuals were included. Serum HBV RNA were extracted from 140 μL serum samples at two time points. Then they were reverse transcribed to cDNA with the HBV-specific primer. The product was quantified by real-time quantitative PCR (RT-PCR) using TAMARA probes. Statistical analyses were performed with IBM SPSS 20.0.

RESULTS

Level of serum HBV RNA at baseline was 4.15 ± 0.90 log₁₀ copies/mL. HBV RNA levels showed no significant difference between the virological response (VR) and partial VR (PVR) groups at baseline (P = 0.940). Serum HBV RNA significantly decreased among patients who achieved a VR during ETV therapy (P < 0.001). The levels of HBV RNA in both HBeAg-positive patients with seroconversion group and those with no seroconversion increased after 24 wk of treatment. Overall, HBV RNA significantly but mildly correlated to HBsAg (r = 0.265, P = 0.041), and HBV RNA was not correlated to HBV DNA (r = 0.242, P = 0.062). Furthermore, serum HBV RNA was an independent indicator for predicting HBeAg seroconversion and virological response. HBeAg seroconversion was more likely in CHB patients with HBV RNA levels below 4.12 log₁₀ copies/mL before treatment.

CONLUSION

The level of serum HBV RNA could predict HBeAg seroconversion and PVR during treatment. In the PVR group, the level of serum HBV RNA tends to be increasing.

Hepatitis B virus pathogenesis: Fresh insights into hepatitis B virus RNA

Hepatitis B virus (HBV) is still a worldwide health concern. While divergent factors are involved in its pathogenesis, it is now clear that HBV RNAs, principally templates for viral proteins and viral DNAs, have diverse biological functions involved in HBV pathogenesis. These functions include viral replication, hepatic fibrosis and hepatocarcinogenesis. Depending on the sequence similarities, HBV RNAs may act as sponges for host miRNAs and may deregulate miRNA functions, possibly leading to pathological consequences. Some parts of the HBV RNA molecule may function as viral-derived miRNA, which regulates viral replication. HBV DNA can integrate into the host genomic DNA and produce novel viral-host fusion RNA, which may have pathological functions. To date, elimination of HBV-derived covalently closed circular DNA has not been achieved. However, RNA transcription silencing may be an alternative practical approach to treat HBV-induced pathogenesis. A full understanding of HBV RNA transcription and the biological functions of HBV RNA may open a new avenue for the development of novel HBV therapeutics.