Researchers say their method can trace ancestry back 100,000 years and could lay groundwork for identifying new genetic markers for diseases that could be used in clinical laboratory tests
Cheaper, faster, and more accurate genomic sequencing technologies are deepening scientific knowledge of the human genome. Now, UK researchers at the University of Oxford have used this genomic data to create the largest-ever human family tree, enabling individuals to trace their ancestry back 100,000 years. And, they say, it could lead to new methods for predicting disease.
This new database also will enable genealogists and medical laboratory scientists to track when, where, and in what populations specific genetic mutations emerged that may be involved in different diseases and health conditions.
New Genetic Markers That Could Be Used for Clinical Laboratory Testing
As this happens, it may be possible to identify new diagnostic biomarkers and genetic indicators associated with specific health conditions that could be incorporated into clinical laboratory tests and precision medicine treatments for chronic diseases.
“We have basically built a huge family tree—a genealogy for all of humanity—that models as exactly as we can the history that generated all the genetic variation we find in humans today,” said Yan Wong, DPhil, an evolutionary geneticist at the Big Data Institute (BDI) at the University of Oxford, in a news release. “This genealogy allows us to see how every person’s genetic sequence relates to every other, along all the points of the genome.”
Researchers from University of Oxford’s BDI in London, in collaboration with scientists from the Broad Institute of MIT and Harvard; Harvard University, and University of Vienna, Austria, developed algorithms for combining different databases and scaling to accommodate millions of gene sequences from both ancient and modern genomes.
“Essentially, we are reconstructing the genomes of our ancestors and using them to form a series of linked evolutionary trees that we call a ‘tree sequence,’” said geneticist Anthony Wilder Wohns, PhD (above), in the Oxford news release. Wohns, a postdoctoral researcher in statistical and population genetics at the Broad Institute, led the study. “We can then estimate when and where these ancestors lived. The power of our approach is that it makes very few assumptions about the underlying data and can also include both modern and ancient DNA samples.” The study may result in new genetic biomarkers that lead to advances in clinical laboratory diagnostics for today’s diseases. (Photo copyright: Harvard School of Engineering and Applied Sciences.)
Tracking Genetic Markers of Disease
The BDI team overcame the major obstacle to tracing the origins of human genetic diversity when they developed algorithms to handle the massive amount of data created when combining genome sequences from many different databases. In total, they compiled the genomic sequences of 3,601 modern and eight high-coverage ancient people from 215 populations in eight datasets.
The ancient genomes included three Neanderthal genomes, a Denisovan genome, and a family of four people who lived in Siberia around 4,600 years ago.
The University of Oxford researchers noted in their news release that their method could be scaled to “accommodate millions of genome sequences.”
“This structure is a lossless and compact representation of 27 million ancestral haplotype fragments and 231 million ancestral lineages linking genomes from these datasets back in time. The tree sequence also benefits from the use of an additional 3,589 ancient samples compiled from more than 100 publications to constrain and date relationships,” the researchers wrote in their published study.
Wong believes his research team has laid the groundwork for the next generation of DNA sequencing.
“As the quality of genome sequences from modern and ancient DNA samples improves, the tree will become even more accurate and we will eventually be able to generate a single, unified map that explains the descent of all the human genetic variation we see today,” he said in the news release.
Developing New Clinical Laboratory Biomarkers for Modern Diagnostics
In a video illustrating the study’s findings, evolutionary geneticist Yan Wong, DPhil, a member of the BDI team, said, “If you wanted to know why some people have some sort of medical conditions, or are more predisposed to heart attacks or, for example, are more susceptible to coronavirus, then there’s a huge amount of that described by their ancestry because they’ve inherited their DNA from other people.”
Wohns agrees that the significance of their tree-recording methods extends beyond simply a better understanding of human evolution.
“[This study] could be particularly beneficial in medical genetics, in separating out true associations between genetic regions and diseases from spurious connections arising from our shared ancestral history,” he said.
The underlying methods developed by Wohns’ team could have widespread applications in medical research and lay the groundwork for identifying genetic predictors of disease risk, including future pandemics.
Clinical laboratory scientists will also note that those genetic indicators may become new biomarkers for clinical laboratory diagnostics for all sorts of diseases currently plaguing mankind.
MicroRNAs in urine could prove to be promising biomarkers in clinical laboratory tests designed to diagnose brain tumors regardless of the tumor’s size or malignancy, paving the way for early detection and treatment
Researchers at Nagoya University in Japan have developed a liquid biopsy test for brain cancer screening that, they claim, can identify brain tumors in patients with 100% sensitivity and 97% specificity, regardless of the tumor’s size or malignancy. Pathologists will be interested to learn that the research team developing this technology says it is simple and inexpensive enough to make it feasible for use in mass screening for brain tumors.
Neurologists, anatomic pathologists, and histopathologists know that brain tumors are one of the most challenging cancers to diagnose. This is partly due to the invasive nature of biopsying tissue in the brain. It’s also because—until recently—clinical laboratory tests based on liquid blood or urine biopsies were in the earliest stages of study and research and are still in development.
Thus, a non-invasive urine test with this level of accuracy that achieves clinical status would be a boon for the diagnosis of brain cancer.
Researchers at Japan’s Nagoya University believe they have developed just such a liquid biopsy test. In a recent study, they showed that microRNAs (tiny molecules of nucleic acid) in urine could be a promising biomarker for diagnosing brain tumors. Their novel microRNA-based liquid biopsy correctly identified 100% of patients with brain tumors.
Atsushi Natsume, MD, PhD (above), Associate Professor at Nagoya University, led the research team that created the simple, liquid biomarker urine test for central nervous system tumors that achieved 100% sensitivity and 97% specificity, regardless of the tumor’s size or malignancy. Such a non-invasive clinical laboratory test used clinically would be a boon to brain cancer diagnosis worldwide. (Photo copyright: Nagoya University.)
Well-fitted for Mass Screenings of Brain Cancer Patients
According to the National Cancer Institute (NCI), brain and other central nervous system (CNS) cancers represent 1.3% of all new cancer cases and have a five-year survival rate of only 32.6%.
In their published study, the Nagoya University scientists wrote, “There are no accurate mass screening methods for early detection of central nervous system (CNS) tumors. Recently, liquid biopsy has received a lot of attention for less-invasive cancer screening. Unlike other cancers, CNS tumors require efforts to find biomarkers due to the blood–brain barrier, which restricts molecular exchange between the parenchyma and blood.
“Additionally, because a satisfactory way to collect urinary biomarkers is lacking, urine-based liquid biopsy has not been fully investigated despite the fact that it has some advantages compared to blood or cerebrospinal fluid-based biopsy.
“Here, we have developed a mass-producible and sterilizable nanowire-based device that can extract urinary microRNAs efficiently. … Our findings demonstrate that urinary microRNAs extracted with the nanowire device offer a well-fitted strategy for mass screening of CNS tumors.”
The Nagoya University researchers focused on microRNA in urine as a biomarker for brain tumors because “urine can be collected easily without putting a burden on the human body,” said Atsushi Natsume, MD, PhD, Associate Professor in the Department of Neurosurgery at Nagoya University and a corresponding author of the study, in a news release.
A total of 119 urine and tumor samples were collected from patients admitted to 14 hospitals in Japan with CNS cancers between March 2017 and July 2020. The researchers used 100 urine samples from people without cancer to serve as a control for their test.
To extract the microRNA from the urine and acquire gene expression profiles, the research team designed an assembly-type microfluidic nanowire device using nanowire scaffolds containing 100 million zinc oxide nanowires. According to the scientists, the device can be sterilized and mass-produced, making it suitable for medical use. The instrument can extract a significantly greater variety and quantity of microRNAs from only a milliliter of urine compared to traditional methods, such as ultracentrifugation, the news release explained.
Simple Liquid-biopsy Test Could Save Thousands of Lives Each Year
While further studies and clinical trials will be necessary to affirm the noninvasive test’s accuracy, the Nagoya University researchers believe that, with the inclusion of additional technologies, a urine-based microRNA test could become a reliable biomarker for detecting brain tumors.
“In the future, by a combination of artificial intelligence and telemedicine, people will be able to know the presence of cancer, whereas doctors will be able to know the status of cancer patients just with a small amount of their daily urine,” Natsume said in the news release.
Biomarkers found in urine or blood samples that provide clinical laboratories with a simple, non-invasive procedure for early diagnosis of brain tumors could greatly increase the five-year survival rate for thousands of patients diagnosed with brain cancer each year. Such diagnostic technologies are also appropriate for hospitals and physicians interested in advancing patient-centered care.
Decision is part of UK effort to diagnose 75% of all cancers at stage I or stage II by 2028 and demonstrates to pathologists that the technology used in liquid biopsy tests is improving at a fast pace
Pathologists and medical laboratory scientists know that when it comes to liquid biopsy tests to detect cancer, there is plenty of both hope and hype. Nevertheless, following a successful pilot study at the Christie NHS Foundation Trust in Manchester, England, which ran from 2015-2021, the UK’s National Health Service (NHS) is pushing forward with the use of liquid biopsy tests for certain cancer patients, The Guardian reported.
NHS’ decision to roll out the widespread use of liquid biopsies—a screening tool used to search for cancer cells or pieces of DNA from tumor cells in a blood sample—across the UK is a hopeful sign that ongoing improvements in this diagnostic technology are reaching a point where it may be consistently reliable when used in clinical settings.
The national program provides personalized drug therapies based on the genetic markers found in the blood tests of cancer patients who have solid tumors and are otherwise out of treatment options. The liquid biopsy creates, in essence, a match-making service for patients and clinical trials.
Liquid Biopsy Genetic Testing for Cancer Patients
“The learnings from our original ‘Target’ study in Manchester were that genetic testing needs to be done on a large scale to identify rare genetic mutations and that broader access to medicines through clinical trials being undertaken across the country rather than just one site are required,” Matthew Krebs, PhD, Clinical Senior Lecturer in Experimental Cancer Medicine at the University of Manchester, told The Guardian.
Krebs, an honorary consultant in medical oncology at the Christie NHS Foundation Trust, led the Target National pilot study.
“This study will allow thousands of cancer patients in the UK to access genetic testing via a liquid biopsy. This will enable us to identify rare genetic mutations that in some patients could mean access to life-changing experimental medicines that can provide great treatment responses, where there are otherwise limited or no other treatment options available.”
Detecting cancers at earlier stages of disease—when treatment is more likely to result in improved survival—has become a strategic cancer planning priority in the UK, theBMJ noted.
“The NHS is committed to diagnosing 75% of all cancers at stage I or II by 2028, from around 50% currently,” the BMJ wrote. “Achieving such progress in less than a decade would be highly ambitious, even without disruption caused by the COVID-19 pandemic. In this context, considerable hope has been expressed that blood tests for circulating free DNA—sometimes known as liquid biopsy—could help achieve earlier detection of cancers.”
The Guardian noted that the UK’s initiative will use a liquid biopsy test made by Swiss-healthcare giant Roche.
“We can’t guarantee that we will find a fault in the genetic code of every cancer patient we recruit, or that if we do, there will be a suitable drug trial for them,” Matthew Krebs, PhD (above), lead scientist of the NHS’ Target National pilot study, told The Guardian. “However, as we learn more about the genetics of cancer in this study, it will help doctors and scientists develop new treatments to help people in the future. Ultimately, we hope liquid biopsy testing will be adopted into routine NHS care, but we need studies such as this to show the benefit of the test on a large scale and provide the evidence that patients can benefit from being matched to targeted medicines on the basis of the blood test.” (Photo copyright: Cancer Research UK Manchester Centre.)
In her article “The Promise of Liquid Biopsies for Cancer Diagnosis,” published in the American Journal of Managed Care (AJMC) Evidence-based Oncology, serial healthcare entrepreneur and faculty lecturer at Harvard Medical School Liz Kwo, MD, detailed the optimism surrounding the “revolutionary screening tool,” including its potential for:
identifying mechanisms of resistance to therapies,
measuring remaining disease after treatment,
assessing cancer relapse or resistance to treatment, and
eliminating risk surrounding traditional biopsies.
The AJMC article estimated the liquid biopsy market will be valued at $6 billion by 2030. However, Kwo also noted that clinical adoption of liquid biopsies in the US continues to face challenges.
Welch compared the investor hype surrounding liquid biopsies to that of the now-defunct blood testing company Theranos, which lured high-profile investors to pour millions into its unproven diagnostic technology.
“Effective cancer screening requires more than early detection. It also requires that starting therapy earlier helps people live to older ages than they would if they started treatment later,” he wrote. “If that doesn’t happen, liquid biopsies will only lead to people living longer with the knowledge they have a potentially incurable disease without extending their lives. These people would be subjected to cancer therapies and their toxicities earlier, but at a time when they would otherwise be experiencing no cancer-related signs or symptoms.”
And so, while there’s much excitement about the possibility of a minimally invasive way to detect cancer, anatomic pathology groups and clinical laboratories will have to wait and see if the hype and hope surrounding liquid biopsies is substantiated by further research.
Smaller cities and rural towns are finding the NWSS a useful early warning tool for tracking COVID-19 in their communities
In a move that mirrors similar programs around the world, the federal Centers for Disease Control and Prevention (CDC) now monitors sewage nationwide and records levels of SARS-CoV-2 in an effort to prevent new outbreaks of COVID-19 and spot any new variants of the coronavirus.
Advances in gene sequencing technologies are enabling the CDC’s National Wastewater Surveillance System (NWSS), and in many communities, clinical laboratories and health system laboratories have worked with local health authorities to test wastewater since onset of the pandemic.
“What started as a grassroots effort by academic researchers and wastewater utilities has quickly become a nationwide surveillance system with more than 34,000 samples collected representing approximately 53 million Americans,” noted epidemiologist Amy Kirby, PhD (above) during the telebriefing.
Kirby is a Senior Service Fellow in the Waterborne Disease Prevention Branch at the CDC.
“Currently, CDC is supporting 37 states, four cities, and two territories to help develop wastewater surveillance systems in their communities. More than 400 testing sites around the country have already begun their wastewater surveillance efforts,” she added.
“Estimates suggests between 40% and 80% of people with COVID-19 shed viral RNA in their feces, making wastewater and sewage an important opportunity for monitoring the spread of infection,” said epidemiologist Amy Kirby, PhD (above), a Senior Service Fellow in the Waterborne Disease Prevention Branch at the CDC. The NWSS’ findings could enable public health officials to better allocate mobile clinical laboratory testing and COVID-19 vaccination sites around the country. This would be especially beneficial in rural and underserved healthcare populations. (Photo copyright: Center for Global Safe Water, Sanitation, and Hygiene.)
Genetic Sequencing Enables Tracking of Virus and Bacteria
At the time of the telebriefing, the federal agency anticipated having an additional 250 sites online within a few weeks and even more sites added within the coming months. Many of the participating sites are sequencing the genes of their biological samples and reporting that data to the CDC.
“So, we’ve seen from very early days in the pandemic that rates of detection in wastewater correlate very well with other clinical indicators, like pace rates and hospitalization and test positivity,” Kirby stated. “That data continues to come in and it continues to be a very solid indicator of what’s going on in the community.”
Wastewater, also referred to as sewage, includes water from toilets, showers, and sinks that may contain human fecal matter and water from rain and industrial sources. To use the CDC’s wastewater surveillance system:
Wastewater is collected from a community area served by the surveillance system as it flows into a local water treatment plant.
Collected samples are sent to an environmental or public health laboratory where they are tested for SARS-CoV-2.
Health departments submit the testing data to the CDC through the online NWSS Data Collection and Integration for Public Health Event Response (DCIPHER) portal.
The DCIPHER system then analyzes the data and reports the results back to the health department for use in their COVID-19 response.
Beginning in February 2022, members of the public can view the results of collected data online through the CDC’s COVID Data Tracker.
Wastewater Sampling Is a ‘Critical Early Warning System’
According to the CDC NWSS website, there are many advantages to using wastewater surveillance in the fight against COVID-19, including:
Wastewater can capture the presence of the virus shed by people both with and without symptoms.
Health officials can determine if infections are increasing or decreasing within a certain monitoring site.
Wastewater surveillance does not depend on people having access to healthcare or the availability of COVID-19 testing.
It is possible to implement wastewater surveillance in many communities as nearly 80% of the US population are served by municipal wastewater collection systems.
“These built-in advantages can inform important public health decisions, such as where to allocate mobile testing and vaccination sites,” Kirby said. “Public health agencies have also used wastewater data to forecast changes in hospital utilization, providing additional time to mobilize resources and preparation for increasing cases.”
The wastewater sampling represents a critical early warning system for COVID-19 surges and variants, and the CDC hopes this type of sampling and research can be utilized in the future for other infectious diseases.
“Wastewater surveillance can be applicable to a wide variety of health concerns. And so, we are working to expand the National Wastewater Surveillance platform to use it for gathering data on other pathogens, and we expect that work to commence by the end of this year,” Kirby said. “Our targets include antibiotic resistance, foodborne infections like E. Coli, salmonella, norovirus, influenza, and the emerging fungal pathogen Candida Auris.”
Critical Surveillance Tool for Microbiology Laboratories
Independent of the nation’s network of public health laboratories, expansion of this program may give microbiology and clinical laboratories in smaller cities and rural towns an opportunity to test wastewater specimens in support of local wastewater monitoring programs.
As the CDC develops this surveillance network into a more formal program, microbiology labs may find it useful to learn which infectious diseases are showing up in their localities, often days or weeks before any patients test positive for the same infectious agents.
That would give pathologists and clinical laboratory leaders an early warning to be on the alert for positive test results of infectious diseases that wastewater monitoring has confirmed exist in the community.
At that reduced cost, clinical laboratories in developing countries with no access to WGS could have it as a critical tool in their fight against the spread of deadly bacteria and viruses
New research into a low-cost way to sequence bacterial genomes—for as little as $10—is predicted to give public health authorities in low- and middle-income countries (LMICs) a new tool with which to more quickly identify and control disease outbreaks.
This new approach offers an alternative to more expensive Whole genome sequencing (WGS) methodologies, which clinical laboratories in developed countries typically use to identify and track outbreaks of infectious diseases. And with SARS-CoV-2 variants resulting in increased COVID-19 infections, the ability to perform low-cost, rapid, and accurate WGS is becoming increasingly important.
But for many developing countries that need it the most, the cost of WGS has kept this critical technology out of reach.
Now, a global consortium of scientists has successfully established an efficient and inexpensive pipeline for the worldwide collection and sequencing of bacterial genomes. The large-scale sequencing method could potentially provide researchers in LIMCs with tools to sequence large numbers of bacterial and viral pathogens. This discovery also could strengthen research collaborations and help tackle future pandemics.
The team of scientists, led by researchers at the Earlham Institute and the University of Liverpool, both located in the UK, are confident their technology can be made accessible to clinical laboratories in LMICs around the globe.
“It has been 26 years since the first bacterial genome was sequenced, and it is now possible to sequence bacterial isolates at scale,” Neil Hall, PhD (above), director of the Earlham Institute and one of the authors of the study, told Genetic Engineering and Biotechnology News. “However, access to this game-changing technology for scientists in low- and middle-income countries has remained restricted. The need to ‘democratize’ the field of pathogen genomic analysis prompted us to develop a new strategy to sequence thousands of bacterial isolates with collaborators based in many economically challenged countries.” (Photo copyright: Earlham Institute.)
Streamlining Collection and Sequencing
The international team of scientists aimed their innovative WGS approach at streamlining the collection and sequencing of bacterial isolates (variants). The researchers collected more than 10,400 clinical and environmental bacterial isolates from several LMICs in less than a year. They optimized their sample logistics pipeline by transporting the bacterial isolates as thermolysates from other countries to the UK. Those isolates were sequenced using a low cost, low input automated method for rapid WGS. They then performed the gene library construction and DNA sequencing analysis for a total reagent cost of less than $10 per genome.
The scientists focused their research on Salmonella enterica, a pathogen that causes infections and deadly diseases in human populations. Non-typhoidal Salmonella (NTS) have been associated with enterocolitis, a zoonotic disease in humans linked to industrial food production.
Because the disease is common in humans, there have been more genome sequences generated for Salmonella than any other type of germ.
“In recent years, new lineages of NTS serovars Typhimurium and Enteritidis have been recognized as common causes of invasive bloodstream infections (iNTS disease), responsible for about 77,000 deaths per year worldwide,” the researchers wrote in their Gen Biology paper. “Approximately 80% of deaths due to iNTS disease occurs in sub-Saharan Africa, where iNTS disease has become endemic.”
Increasing Access to Genomics Technologies in Developing Countries
The research consortium 10,000 Salmonella Genomes Project (10KSG) led the large-scale WGS initiative. The alliance involves contributors from 25 institutions in 16 countries and was designed to generate information relevant to the epidemiology, drug resistance, and virulence factors of Salmonella using WGS techniques.
“One of the most significant challenges facing public health researchers in LMICs is access to state-of-the-art technology, Jay Hinton, PhD, Professor of Microbial Pathogenesis at the University of Liverpool and one of the paper’s authors, told Technology Networks. “For a combination of logistical and economic reasons, the regions associated with the greatest burden of severe bacterial disease have not benefited from widespread availability of WGS. The 10,000 Salmonella genomes project was designed to begin to address this inequality.”
The authors noted in their study that the costs associated with sequencing have remained high mostly due to sample transportation and library construction and the fact that there are only a few centers in the world that have the ability to handle large-scale bacterial genome projects.
“Limited funding resources led us to design a genomic approach that ensured accurate sample tracking and captured comprehensive metadata for individual bacterial isolates, while keeping costs to a minimum for the Consortium,” Hall told Genetic Engineering and Biotechnology News(GEN). “The pipeline streamlined the large-scale collection and sequencing of samples from LMICs.”
“The number of publicly available sequenced Salmonella genomes reached 350,000 in 2021 and are available from several online repositories,” he added. “However, limited genome-based surveillance of Salmonella infections has been done in LMICs, and the existing dataset did not accurately represent the Salmonella pathogens that are currently causing disease across the world.”
The $10 cost is designed to help healthcare systems in developing countries identify the specific genetic composition of infectious diseases. That’s the necessary first step for developing a diagnostic test that enables physicians to make an accurate diagnosis and initiate appropriate therapy.
“The adoption of large-scale genome sequencing and analysis of bacterial pathogens will be an enormous asset to public health and surveillance in LMI countries,” molecular microbiologist Blanca Perez Sepulveda, PhD, told GEN. Sepulveda is a postdoctoral Researcher at the University of Liverpool and one of the authors of the study.
Improvement in next-generation sequencing technology has reduced costs, shortened turnaround time (TAT), and improved accuracy of whole genome sequencing. Once this low-cost method for collecting and transporting bacterial sequences becomes widely available, clinical laboratories in developing countries may be able to adopt it for genome analysis of different strains and variants of bacteria and viruses.
Though the variant poses low risk thanks to modern HIV treatments, the scientists stress the importance of access to early clinical laboratory testing for at-risk individuals
With the global healthcare industry hyper focused on arrival of the next SARS-CoV-2 variant, pathologists and clinical laboratories may be relieved to learn that—though researchers in the Netherlands discovered a previously unknown “highly virulent” strain of HIV—the lead scientist of the study says there’s “no cause for alarm.”
In a news release, researchers at the University of Oxford Big Data Institute said the HIV variant got started in the Netherlands in the 1990s, spread quickly into the 2000s, and that prior to treatment, people with the new virulent subtype B (VB variant) had exceptionally high viral loads compared to people with other HIV variants.
Fortunately, the scientist also found that around 2010, thanks to antiretroviral drug therapy, the severe variant began to decline.
In an interview with NPR, Chris Wymant, PhD, the study’s lead author, said, “People with this variant have a viral load that is three to four times higher than usual for those with HIV. This characteristic means the virus progresses into serious illness twice as fast, and also makes it more contagious.”
Fortunately, he added, “Existing medications work very well to treat even very virulent variants like this one, cutting down on transmission and reducing the chance of developing severe illness.
“Nobody should be alarmed,” he continued. “It responds exactly as well to treatment as HIV normally does. There’s no need to develop special treatments for this variant.”
Wymant is senior researcher in statistical genetics and pathogen dynamics at the Big Data Institute (BDI).
Epidemiologist Chris Wymant, PhD (above), lead author of the Big Data Institute study at Oxford University, says today’s modern HIV antiretroviral drug therapies effectively treat for the “highly viral” HIV VB variant he and his team discovered. “Nobody should be alarmed,” he told NPR. “It responds exactly as well to treatment as HIV normally does.” Nevertheless, he stressed the importance of access to early clinical laboratory testing for at-risk individuals. (Photo copyright: Oxford Big Data Institute.)
In their published study, the BDI researchers reported that their analysis of genetic sequences of the VB variant suggested it “arose in the 1990s from de novo (of new) mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.
“By the time, they were diagnosed, these individuals were vulnerable to developing AIDS within two to three years. The virus lineage, which has apparently arisen de novo since around the millennium, shows extensive change across the genome affecting almost 300 amino acids, which makes it hard to discern the mechanism for elevated virulence,” the researchers noted.
The researchers analyzed a data set from the project BEEHIVE (Bridging the Epidemiology and Evolution of HIV in Europe and Uganda). They found 15 of 17 people positive for the VB variant residing in the Netherlands. That prompted them to focus on a cohort of more than 6,700 Dutch HIV positive people in the ATHENA (AIDS Therapy Evaluation in the Netherlands) cohort database, where they found 92 more individuals with the VB variant, bringing the total to 109.
According to a Medscape report on the study’s findings, people with the VB variant showed the following characteristics:
Double the rate of CD4-positive T-cell declines (indicator of immune system damage by HIV), compared to others with subtype-B strains.
Increased risk of infecting others with the virus based on transmissibility associated with variant branching.
Wymant says access to clinical laboratory testing is key to curtailing the number of people who contract the VB variant. “Getting people tested as soon as possible, getting them onto treatment as soon as possible, has helped reduce the numbers of this variant even though we didn’t know that it existed,” he told NPR.
The University of Oxford Big Data Institute study is another example of how constantly improving genome sequencing technology allows scientists to dig deeper into genetic material for insights that can advance the understanding of many diseases and health conditions.
