Real-Time Polymerase Chain Reaction-Based Detection and Quantification of Hepatitis B Virus DNA

Summary

Real-time polymerase chain reaction (PCR)-based detection and quantification of hepatitis B virus (HBV) DNA is a sensitive and accurate method for diagnosing and monitoring HBV infection. Here, we present a protocol for HBV DNA detection and the viral load measurement of a sample.

Abstract

Hepatitis B virus (HBV) is a significant cause of liver disease worldwide. It can lead to acute or chronic infections, making individuals highly susceptible to fatal cirrhosis and liver cancer. Accurate detection and quantification of HBV DNA in the blood are essential for diagnosing and monitoring HBV infection. The most common method for detecting HBV DNA is real-time PCR, which can be used to detect the virus and assess the viral load to monitor the response to antiviral therapy. Here, we describe a detailed protocol for the detection and quantification of HBV DNA in human serum or plasma using an IVD-marked real-time PCR-based kit. The kit uses primers and probes that target the highly conserved core region of the HBV genome and can accurately quantify all HBV genotypes (A, B, C, D, E, F, G, H, I, and J). The kit also includes an endogenous internal control to monitor possible PCR inhibition. This assay runs for 40 cycles, and its cutoff is 38 Ct. For the quantification of HBV DNA in clinical samples, a set of 5 quantification standards is provided with the kit. The standards contain known concentrations of HBV-specific DNA that are calibrated against the 4^th WHO International Standard for HBV DNA for the nucleic acid test (NIBSC code 10/266). The standards are used to validate the functionality of the HBV-specific DNA amplification and to generate a standard curve, allowing the quantification of HBV DNA in a sample. HBV DNA as low as 2.5 IU/mL was detected using the PCR kit. The high sensitivity and reproducibility of the kit make it a powerful tool in clinical laboratories, aiding healthcare professionals in effectively diagnosing and managing HBV infections.

Introduction

Hepatitis B virus (HBV) is a partially double-stranded DNA virus from the genus Orthohepadnavirus and the Hepadnaviridae family¹. It can trigger a chronic infection that persists throughout one's life, potentially leading to liver cirrhosis and hepatocellular carcinoma^2,3,4. According to the World Health Organization (WHO), an estimated population of 296 million people were living with chronic hepatitis B infection in 2019, and 1.5 million people were newly infected each year⁵.

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Protocol

This study did not involve any human participants or clinical samples. The only biological material used was the 4^th WHO International Standard for HBV DNA for nucleic acid test (NIBSC code 10/266). This standard is a publicly available reference material that does not contain any personal information or identifiable data. As such, no ethical approval was required for this study.

1. DNA Extraction

1. Extract the viral DNA from human serum or plasma sample. .......

Discussion

NIBSC code 10/266 has been assigned a unit of 9,55,000 IU/mL when reconstituted in 0.5 mL of nuclease-free water as per the supplier information²¹. This can be considered a high-load HBV positive sample. The HBV viral load determined by the viral load kit used in this study was 6,65,900 IU/mL (Figure 4). As the DNA extraction efficiency of any DNA extraction kit is not 100%, some DNA is often lost during the purification process. Although the viral load determined by .......

Materials

Name	Company	Catalog Number	Comments
4th WHO International Standard for hepatitis B virus DNA	NIBSC	NIBSC code: 10/266	The 4th WHO International Standard for hepatitis B virus (HBV) DNA, NIBSC code 10/266, is intended to be used for the calibration of secondary reference reagents used in HBV nucleic acid amplification techniques (NAT).
ABI real-time PCR machines	ThermoFisher Scientific	ABI 7500; QuantStudio 5	This is a real time PCR machine
HBV, HCV and HIV Multiplex 14/198	NIBSC	NIBSC code: 14/198	This is a very low positive triplex reagent for NAT assays containing hepatitis B (HBV), hepatitis C (HCV) and human immunodeficiency virus-1 (HIV-1)
QIAGEN real-time PCR machine	Qiagen	Rotor-Gene Q	This is a real time PCR machine
TRUPCR HBV Viral Load kit	Kilpest India Limited	3B294	This is a real time PCR based kit used in this study for the HBV DNA detection and viral load determination
TRUPCR Viral Nucleic Acid Extraction Kit	Kilpest India Limited	3B214	This is a DNA extraction kit used for the extraction of HBV viral DNA from NIBSC:10/266 and NIBSC:14/198