Treatment News : Drug Resistance Testing Is Effective Even With Low Virus Levels

POZ - Health, Life and HIV
Subscribe to:
POZ magazine
Newsletters
Join POZ: Facebook MySpace Twitter Pinterest
Tumblr Google+ Flickr MySpace
POZ Personals
Sign In / Join
Username:
Password:

Back to home » Treatment News » March 2010

Most Popular Links
Most Popular Lessons

The HIV Life Cycle

Shingles

Herpes Simplex Virus

Syphilis & Neurosyphilis

Treatments for Opportunistic Infections (OIs)

What is AIDS & HIV?

Hepatitis & HIV

20 Years Ago In POZ


More Treatment News

Click here for more news

Have news about HIV? Send press releases, news tips and other announcements to news@poz.com.


emailprint

March 30, 2010

Drug Resistance Testing Is Effective Even With Low Virus Levels

Testing for HIV drug resistance in people taking antiretroviral (ARV) treatment is both effective and useful even when a person’s viral load is low, according to a study published online March 29 in The Journal of Infectious Diseases.

It is standard practice for HIV care providers to test a person for drug resistance when ARV therapy either fails to reduce virus fully or when virus levels return after being undetectable. Unfortunately, genotypic HIV resistance tests have proved to be less accurate when a person’s viral load is less than 1,000 copies. This makes it difficult to determine which drugs a person ought to switch to if his or her viral load is low.

It is possible for resistance testing labs to tweak the standard tests so that they are better able to detect resistant virus in people with low virus levels. Data indicate this practice is occurring more frequently now than in the past. It is not a standardized practice, however, given a paucity of research indicating whether modified genotypic testing is sensitive enough to yield conclusive results.

Hoping to answer this question, a team in London led by Nicola Mackie, MD, from the Imperial College Healthcare National Health Service Trust, examined the results of 7,861 HIV resistance tests—1,001 of which involved samples with viral loads below 1,000 copies—collected from 3,791 people.

Several major resistance mutations, including those conferring high-level resistance to protease inhibitors, non-nucleoside analogues and some of the nucleoside analogues, were as likely to be detected at viral loads below 1,000 copies as they were to be detected at viral loads above this level. Though there was a higher frequency of mutations conferring resistance to the thymidine family of nucleoside analogues—zidovudine (found in Retrovir, Combivir and Trizivir) and stavudine (found in Zerit)—at viral loads higher than 1,000, Mackie’s group said this should be expected, given that thymidine analogue mutations tend to accumulate with prolonged treatment failure.

“Although data do not yet exist regarding the utility of HIV‐1 genotyping at low viral load in terms of clinical outcomes, guidelines exist that recommend prompt switching among patients with detectable viremia,” the authors write. “The use of HIV‐1 genotypic resistance testing among patients with low viral loads may be helpful in clinical practice to allow a timely and optimized therapeutic change and may improve outcomes.”

Search: resistance testing, low viral loads, genotypic testing, Nicola Mackie, thymidine analogue, Zerit, stavudine, Retrovir, Combivir, Trizivir, zidovudine


Scroll down to comment on this story.



Name:

(will display; 2-50 characters)

Email:

(will NOT display)

City:

(will display; optional)

Comment (500 characters left):

(Note: The POZ team reviews all comments before they are posted. Please do not include either ":" or "@" in your comment. The opinions expressed by people providing comments are theirs alone. They do not necessarily reflect the opinions of Smart + Strong, which is not responsible for the accuracy of any of the information supplied by people providing comments.)

Comments require captcha.
Please enter this number for verification:

| Posting Rules



Show comments (0 total)

 
[Go to top]


Facebook Twitter Google+ MySpace YouTube Tumblr Flickr Instagram
Quick Links
Current Issue

HIV Testing
Safer Sex
Find a Date
Newly Diagnosed
HIV 101
Disclosing Your Status
Starting Treatment
Help Paying for Meds
Search for the Cure
POZ Stories
POZ Opinion
POZ Exclusives
Read the Blogs
Visit the Forums
Job Listings
Events Calendar
POZ on Twitter

Ask POZ Pharmacist

Talk to Us
Poll
Are you buying holiday gifts that raise HIV/AIDS awareness?
Yes
No

Survey
Smoke Signals

more surveys
Contact Us
We welcome your comments!
[ about Smart + Strong | about POZ | POZ advisory board | partner links | advertising policy | advertise/contact us | site map]
© 2014 Smart + Strong. All Rights Reserved. Terms of use and Your privacy.
Smart + Strong® is a registered trademark of CDM Publishing, LLC.