Improving diagnosis and management of chronic hepatitis B

Chinese researchers have created a new and powerful laboratory tool that may improve the diagnosis and treatment of hepatitis B virus (HBV) infection, simultaneously assessing several indicators important for optimal patient management.

Typically spread through contact with infected blood or bodily fluids, HBV can be prevented by vaccines that offer almost total protection against HBV infection. Yet according to the World Health Organization, 257 million individuals were living with and 887,000 died from HBV infection in 2015, usually as a result of cirrhosis (loss of liver cells and irreversible scarring of the liver) or liver cancer. In 2016, only about 10.5% of individuals infected with HBV were aware of their status, only a fraction of whom were receiving treatment.

Now, scientists have developed highly sensitive co-amplification at lower denaturation temperature PCR (COLD-PCR) coupled with probe-based fluorescence melting curve analysis (FMCA) for precision diagnosis of chronic hepatitis B (CHB) patients. Described in The Journal of Molecular Diagnostics, the novel tool is said to be simple, stable, convenient, practical and inexpensive, and may be used routinely in the average hospital laboratory.

“Guidelines have confirmed that dynamic monitoring of HBV DNA, genotypes and reverse transcriptase (RT) mutant DNA is of great importance to assess infection status, predict disease progression and judge treatment efficacy in HBV-infected patients,” explained lead investigator Dr Qishui Ou, from Fujian Medical University. “We believe COLD-PCR/FMCA provides a powerful laboratory tool for precise diagnosis and treatment of HBV-infected patients.”

Although a number of molecular methods have been developed for measuring these parameters, many are limited by poor sensitivity or inability to detect more than one mutation at a time. Others are too cumbersome or expensive for clinical use. As explained by Dr Ou, “Our goal was to establish a more practical and inexpensive method with high sensitivity to detect genotype and RT mutations while detecting HBV DNA.”

Moreover, COLD-PCR/FMCA can detect HBV mutations at much lower concentrations than other techniques such as PCR/FMCA or PCR Sanger sequencing (1% vs 10% vs 20%, respectively). This new technique can also distinguish different phases of HBV infection according to the proportion and type of mutations as well as by detecting HBV DNA.

The researchers also report that the genotype and mutation detected by COLD-PCR/FMCA may predict whether a patient will respond to antiviral therapy. Analysis of serum samples from 41 patients with CHB who were receiving entecavir revealed that the drug was most effective for patients with genotype B and those with a lower percentage of RT mutations at baseline or week 4.

“Until now there have not been high-throughput approaches to detect HBV DNA, genotype and RT mutations simultaneously. Therefore, it is necessary to establish a more practical and inexpensive method with high sensitivity to detect genotype and RT mutations while detecting HBV DNA. COLD-PCR/FMCA has that potential,” Dr Ou said.

Image credit: ©stock.adobe.com/au/Kateryna_Kon

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