New Weapon for Monitoring Hepatitis B Virus: HBV-RNA Test

The prevalence of Hepatitis B Virus

Currently, Hepatitis B Virus (HBV) remains a significant risk factor threatening human health. HBV infection has a high incidence worldwide. Reports indicate that approximately 2 billion people globally have been infected with HBV, and about 257 million people have chronic hepatitis B infection. Among these, China is the country with the highest number of HBV infections, accounting for about one-third of the global total. Therefore, the prevention and treatment of Chronic Hepatitis B (CHB) remain a major public health issues globally.

Once HBV enters the human body, it easily forms a chronic persistent infection that is difficult to cure. The root cause lies in the covalently closed circular DNA (cccDNA) within the nucleus of liver cells, which is difficult to eliminate. Unfortunately, there are currently no effective drugs targeting cccDNA available for clinical use. The detection methods for cccDNA require liver biopsy, which is invasive and bears the risk of missed diagnosis. Thus it cannot be widely implemented. Therefore, the exploration of non-invasive alternative indicators that can reflect the levels and transcriptional activity of cccDNA within liver cells has led to the emergence of the HBV RNA test.

What is serum HBV RNA test?

Antiviral therapy is one of the most effective methods for treating HBV infection. Evaluating the effectiveness of antiviral therapy at different stages requires corresponding indicators. Traditional methods like "two-and-a-half pair" tests for HBV and HBV DNA play critical roles in determining hepatitis B infection and disease progression. However, they have certain limitations in evaluating and predicting seroconversion, antiviral efficacy, and prognosis.

Serum HBV RNA can better reflect the activity of cccDNA in liver tissue. If serum HBV RNA levels are detected before discontinuing medication, it can help predict the risk of relapse in patients. This helps identify patients who have achieved a virological response and can maintain this response after stopping the medication, thus enabling a safe discontinuation of the therapy.

Under the influence of antiviral drugs, when HBV DNA levels fall below the detection limit, the disappearance of serum HBV DNA only indicates that the virus's reverse transcription process is effectively inhibited and does not truly reflect the transcriptional activity state of cccDNA in liver cells. Stopping treatment at this time often leads to virological rebound and disease relapse in patients. However, serum HBV RNA levels are closely related to the incidence of virological rebound. Patients with undetectable HBV RNA have a significantly reduced risk of rebound. Therefore, HBV RNA holds significant biological importance for monitoring viral replication, resistance development, and therapeutic efficacy.