What is the more suitable for early detection of low abundant lamivudine-resistant mutants?

Jan 16, 2008

Lamivudine is an effective antiviral agent for treatment of patients with chronic hepatitis B and advanced liver diseases. However, long-term lamivudine monotherapy leads to the emergence of lamivudine-resistant hepatitis B virus (HBV) mutants in some patients chronically infected with HBV. Sensitive methods for early detection of lamivudine-resistant mutants will help physicians make clinical decisions in treating patients with HBV infection.

To date, many assays have been used for detection of lamivudine-resistant mutants in patients with Hepatitis B. Differences in sensitivity, specificity, cost, and time required, exist in these methods. Real-time PCR is able to quantitatively detect a small portion of resistant mutants in HBV populations and ligase detection reaction (LDR) is a newly developed method for detection of low abundant mutants in the background of wild-type HBV. However, there are no studies which have compared the clinical performance of the two methods.

A research article to be published on January 7 in the World Journal of Gastroenterology (volume 14, issue 1) addresses this question. It compared LDR and real-time PCR for detection of low abundant YMDD mutations in mixed plasmids and serum samples from 52 lamivudine treated patients. Time required and reagent cost for both assays were evaluated. The research was conducted carefully by an experienced team of investigators.

The article suggested both methods are sensitive and inexpensive for detection of YMDD mutation; but LDR is more sensitive than real-time PCR. The results obtained with both methods were completely concordant in all serum samples. LDR was able to detect as low as 0.01% (100 copies/mL) of YIDD plasmid, while real-time PCR only detected 0.1% (1000 copies/mL) of YIDD plasmid in the background of YMDD plasmid. In addition, the cost of LDR is slightly lower than that of real-time PCR.

However, real-time PCR is much more rapid and requires less manual work than LDR. The total assay time for LDR and real-time PCR was 4.5 and 2.5 h, respectively. Another advantage of the real-time PCR method is it is able to calculate the ratio of mutants to total virus in samples. This will be useful in clinical studies on the dynamics of resistant mutants during lamivudine therapy.

Source: World Journal of Gastroenterology

Explore further: Second bird flu case confirmed in Canada

add to favorites email to friend print save as pdf

Related Stories

The latest fashion: Graphene edges can be tailor-made

13 hours ago

Theoretical physicists at Rice University are living on the edge as they study the astounding properties of graphene. In a new study, they figure out how researchers can fracture graphene nanoribbons to get ...

Infrared imaging technique operates at high temperatures

13 hours ago

From aerial surveillance to cancer detection, mid-wavelength infrared (MWIR) radiation has a wide range of applications. And as the uses for high-sensitivity, high-resolution imaging continue to expand, MWIR sources are becoming ...

Recommended for you

Second bird flu case confirmed in Canada

8 hours ago

The husband of a Canadian who was diagnosed earlier this week with bird flu after returning from a trip to China has also tested positive for the virus, health officials said Friday.

What exactly is coronavirus?

14 hours ago

The conflicts in Syria and Iraq are straining public health systems and public health efforts meant to prevent and detect the spread of infectious diseases. This is generating a "perfect storm" of conditions for outbreaks. Among the infections raising concern is Middle East Respiratory Syndrome, caused by a type of coronavirus, which emerged in 2012. ...

Scientists find Ebola virus is mutating

15 hours ago

(Medical Xpress)—Researchers working at Institut Pasteur in France have found that the Ebola virus is mutating "a lot" causing concern in the African countries where the virus has killed over eight thous ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.