Wednesday, 27 February 2019

The Evolution of HIV Testing Continues


HIV testing is a key component of HIV prevention. It is this critical clinical encounter that serves as the starting point for diagnosing and treating persons who are infected and delivering preventive services to those who are uninfected. Because HIV testing is so important to prevention strategies for controlling the HIV epidemic in the United States, we read with great interest the article by Hurt and colleagues1 in this issue, which provides an excellent overview of the current options available for HIV testing in clinical, nonclinical, and research settings. Their update highlights recent changes to nomenclature, updated data—particularly on the window period of HIV tests—and updates to the laboratory algorithm for diagnosis of HIV infection, at a time when this information is changing rapidly.
Hurt et al. refer to changes in the “official nomenclature” of HIV tests. Although the Centers for Disease Control and Prevention (CDC) does not determine official nomenclature for HIV test types, the CDC Division of HIV/AIDS Prevention has recently made changes to Web sites and other documents that refer to the different types of HIV tests. As discussed at the 2016 HIV Diagnostics Conference, the term “generations” began to appear in the literature shortly after HIV tests that used recombinant peptides instead of viral lysate antigens (the “2nd generation”) were developed. However, the “official” nomenclature likely gained traction when Owen et al. published an article including a discussion of generations, and CDC and others largely adopted the term for use in presentations, Web pages, and other documents. Indeed, a complete description of test generations appears in both the updated Clinical & Laboratory Standards Institute standards and the CDC/Association of Public Health Laboratories (APHL) guidelines for the laboratory diagnosis of HIV infection. However, as new HIV tests continued to become available, the lines between generations began to blur. In the 2008 article, the term generation was reserved for laboratory-based, instrumented immunoassays. As Hurt et al. reviewed, single-use, point-of-care rapid tests use different technology and probably should be considered separately. Nevertheless, both test manufacturers and authors evaluating these tests began to use the term generations to describe rapid tests. Originally, the generations described incremental improvements in test sensitivity and specificity. However, some of the newer tests within the same generation have different sensitivity for early infection. These differences can largely be explained by other aspects of test design, for example, whether they are lateral flow or immunconcentrating rapid tests, reagents used for detection of analytes, or the volume of sample required to perform the test. In addition, there are also IgG-sensitive rapid tests that differentiate HIV-1 from HIV-2, and new tests that differentiate p24-antigen detection from antibody detection, but have the same sensitivity during early infection as tests that report only one signal as “reactive for p24-antigen and/or HIV antibody. As a result, in the article documenting seroconversion sensitivity on plasma specimens that Hurt et al. referenced,
 tests were described in terms of the analytes they can detect and the types of technology (instrumented, laboratory-based, vs. single-use, rapid) that they use to do so. These changes have been implemented in CDC Web pages and documents contained therein. In particular, the advantages/disadvantages of Food and Drug Administration–approved HIV tests guide may be particularly useful for clinicians and others who need to understand differences in characteristics of the tests available in the United States.
Source: Sexually Transmitted Diseases




Get to know more research studies come and join

2nd World Congress on HIV AIDS STD and STI

Theme : Addressing the Recent Advancement in HIV Preventions and Care
After the magnificent success of World Congress on HIV AIDS STD and STI which was held in Valencia, Spain during April 23-25, 2018, we are proudly announcing the 2nd World Congress on HIV AIDS STD and STI during September 09-10, 2019 at Bangkok, Thailand.
HIV AIDS Congress 2019 is the best platform for interdisciplinary researchers, practitioners, academics, research scientists, students and healthcare industrialists to meet, share, discuss and exchange the most recent relevant experiences in their practices. This would centre on presentations and discussions on research oriented results on all aspects of HIV and AIDS. Consequently, it will provide the necessary platform to both transfer and exchange relevant knowledge in the field of HIV and AIDS.
Do not miss the best Keynote lectures, Plenary talks, Workshops, and Networking tour.
We cordially invite you all to take part in HIV AIDS Congress 2019!

Friday, 15 February 2019

Focus on resistance to HIV offers insight into how to fight the virus


Of the 40 million people around the world infected with HIV, less than one per cent have immune systems strong enough to suppress the virus for extended periods of time. These special immune systems are known as "elite controllers." But how do they actually fight HIV? Canadian scientists think they've found an important clue.
Working in collaboration with a team from the Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), researchers at the Laboratory of Antiviral Immunity of Université du Québec à Trois-Rivières (UQTR) have found that genetic mutations affecting the capsid, the structure surrounding the HIV genome, make it possible for a protein called TRIM5α to trigger the immune system of elite controllers.
This discovery, recently published in PLOS Pathogens, sheds light on the role that TRIM5α plays in the human body. In elite controllers, the protein sets off a mechanism that protects against HIV-1, the type of HIV responsible for the global pandemic. "In most infected individuals, TRIM5α's triggering ability is so weak that it has no effect on the virus, but in elite controllers, TRIM5α seems to play a role in naturally inhibiting HIV-1," said lead author Natacha Mérindol, a postdoctoral researcher at the UQTR lab.
There is no vaccine or cure for HIV-1. That's why it's important to understand why the virus is naturally inhibited in elite controllers, said Mérindol, who works under the direction of UQTR medical biology professor Lionel Berthoux, head of the lab, and Dr.Cécile Tremblay, a professor at Université de Montréal's Faculty of Medicine and a clinical researcher at CRCHUM.
"Our HIV-positive patients played an essential role in making this research possible and we would like to thank them for their incredible generosity and availability," said Tremblay, a microbiologist and infectious disease specialist at the CHUM. "It's an important study that could advance research on HIV vaccines."

Source: University of Montreal