Serum HBV RNA as a possible marker of HBV replication in the liver during nucleot(s)ide analogue therapy

Selective detection of HBV pre-genomic RNA in chronic hepatitis B patients using a novel RT-PCR assay

In chronic hepatitis B (CHB) patients, quantification of HBV pgRNA in plasma has the potential to provide information on disease prognosis and liver injury or histopathology. However, current methods for detecting HBV pgRNA present technical difficulties due to the co-existence of HBV DNA in plasma samples. We have successfully established a novel one-step RT-PCR assay that allows selective quantification of HBV pgRNA. Two cohorts of participants were recruited for assay validation, including treatment-naïve patients with CHB and HBeAg-positive CHB patients who were treated with Tenofovir and monitored for 6 months to assess the predictive value of baseline HBV RNA for HBeAg seroclearance. Statistical analysis was performed using MedCalc version 20.019 software. The novel selective one-step RT-PCR assay for detecting HBV pgRNA was validated with a limit of detection of 100 copies/mL. The assay was able to selectively measure HBV pgRNA even in the presence of excess HBV rcDNA. In treatment-naïve CHB patients, HBV pgRNA levels were significantly lower than HBV DNA concentration. Serum HBV DNA levels and HBeAg status were positively associated with HBV pgRNA. Baseline serum HBV pgRNA levels were found to be strong predictors of HBeAg seroclearance after 6 months of Tenofovir treatment. The study presents a novel RT-PCR assay that allows accurate measurement of plasma HBV pgRNA in chronic hepatitis B patients, even in the presence of excess HBV DNA. The assay is highly selective and represents a significant advancement with potential for further breakthroughs in understanding the clinical significance of HBV pgRNA.

Change of Cytokines in Chronic Hepatitis B Patients and HBeAg are Positively Correlated with HBV RNA, Based on Real-world Study

BACKGROUND AND AIMS

The natural course of chronic hepatitis B virus (HBV) infection is widely studied; however, follow-up studies of the same patients are scanty. Here, we studied the dynamic changes of serum HBV RNA and cytokines in hepatitis B virus e antigen (HBeAg)-positive patients treated with entecavir (ETV) to explore the relationship between the HBV serum viral nucleic acids and host immunity.

METHODS

Thirty-three chronic hepatitis B patients who are HBeAg-positive, with high virus load (HBV DNA >20,000 IU/mL), and received standard nucleos(t)ide analogue (NA) antiviral therapy (ETV) for more than 48 weeks were included. The serum levels of HBV nucleic acids and selected cytokines were measured at 0, 12, 24, and 48 weeks respectively.

RESULTS

Serum HBV RNA could still be detected while serum HBV DNA had fallen below the detection limit in patients treated with ETV. There was a strong positive correlation between HBV RNA and HBeAg, with a concomitant decrease in the secretion of cytokines from type 1 helper T (Th1)/type 2 helper T (Th2)/interleukin (IL)-17 producing T (Th17) cells. IL-4 and IL-10 were the main cytokines negatively associated with serum HBV RNA.

CONCLUSIONS

HBeAg can be used to reflect the load of HBV RNA indirectly, because serum HBV RNA has not been widely used in clinical practice. Meanwhile, serum IL-4 and IL-10 might be explored in combination with HBV RNA in guiding future clinical antiviral therapy.

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.

What is new on HBsAg and other diagnostic markers in HBV infection?

Challenges in the management of chronic hepatitis B virus (HBV) infection involve the prediction of the natural course to identify patients who require antiviral therapy and the prediction of functional cure as ultimate goal of antiviral therapy. HBV DNA as marker for viral replication is important but not sufficient for an adequate management of patients with chronic HBV infection. Data on the quantification of additional HBV marker such as hepatitis B surface antigen (HBsAg), hepatitis B core-related antigen (HBcrAg) and hepatitis B virus RNA (HBV RNA) have accumulated in recent years. Here we review the current evidence how to use these markers and discuss open issues that require additional research.