Research advances from the National Institutes of Health (NIH) Intramural Research Program (IRP) often make headlines. Read the news releases that describe our most recent findings:
Whether you’re shedding pounds with the help of effective new medicines, slimming down after weight loss surgery or cutting calories and adding exercise, there will come a day when the numbers on the scale stop going down, and you hit the dreaded weight loss plateau.
In a recent study, Kevin Hall, a researcher at the National Institutes of Health who specializes in measuring metabolism and weight change, looked at when weight loss typically stops depending on the method people were using todrop pounds. He broke down the plateau into mathematical models using data from high-quality clinical trials of different ways to lose weight to understand why people stop losing when they do. The study published Monday in the journal Obesity.
In a new analysis of genetic susceptibility to kidney cancer, an international team of researchers has identified 50 new areas across the genome that are associated with the risk of developing kidney cancer. These insights could one day be used to advance our understanding of the molecular basis of kidney cancer, inform screening efforts for those at highest risk, and identify new drug targets. The study was led by scientists at the National Cancer Institute (NCI), part of the National Institutes of Health (NIH).
A previous genome-wide association study (GWAS) of people of European ancestry identified 13 regions of the genome that are associated with kidney cancer risk. However, the study population was not diverse. To identify additional regions, researchers conducted a GWAS in participants of many different genetic ancestries that included 29,020 people with kidney cancer and 835,670 people without kidney cancer. Analysis of the data, which came from published studies, biobanks, and a new study, resulted in the identification of 50 new regions associated with the risk of developing kidney cancer, bringing the total number of such regions to 63.
Among the newly identified genetic variants were several associated with a risk of developing papillary renal cell carcinoma, the second most common subtype of renal cell carcinoma. Another variant, in the VHL gene, was common in individuals of African ancestry and was associated with an estimated three times higher risk of developing clear cell renal cell carcinoma, the most common type of kidney cancer.
One injected dose of an experimental malaria monoclonal antibody was 77% effective against malaria disease in children in Mali during the country’s six-month malaria season, according to the results of a mid-stage clinical trial. The trial assessed an investigational monoclonal antibody developed by scientists at the National Institutes of Health (NIH), and results appear in The New England Journal of Medicine.
“A long-acting monoclonal antibody delivered at a single health care visit that rapidly provides high-level protection against malaria in these vulnerable populations would fulfill an unmet public health need,” said Dr. Jeanne Marrazzo, director of the National Institute of Allergy and Infectious Diseases, part of NIH.
The clinical trial assessed two dose levels, with 19% of the 300mg-dose group and 28% of the 150mg-dose group developing symptomatic malaria, providing protective efficacy of 77% and 67% against symptomatic malaria, respectively. Among children who received placebo, 81% became infected with Plasmodium falciparum, and 59% had symptomatic malaria during the six-month study period. The authors note that the trial demonstrated for the first time that a single dose of a monoclonal antibody given by subcutaneous injection can provide high-level protection against malaria in children in an area of intense malaria transmission.
The experimental monoclonal antibody binds to and neutralizes 'sporozoites,' the form of the malaria parasite transmitted by mosquitoes that invades the liver to initiate infection.
NIH scientists find clinicians still rely often on older and toxic medicines
Despite Food and Drug Administration (FDA)-approval of seven next-generation antibiotics to fight infections caused by resistant “gram-negative” bacteria, clinicians frequently continue to treat antibiotic-resistant infections with older generic antibiotics considered to be less effective and less safe, according to a study by researchers at the National Institutes of Health’s (NIH) Clinical Center. Researchers examined the factors influencing doctors’ preference for newer antibiotics over traditional generic agents to shed light on the decision-making processes among clinicians when treating patients with challenging bloodstream infections caused by gram-negative bacteria and significant comorbidities.
The study revealed that at a considerable proportion of hospitals, particularly smaller facilities located in rural areas, staff were reluctant to adopt newer antibiotics. Researchers identified a large cost disparity between older and newer classes of antibiotics; the newer drugs can cost approximately six times more than the older medications, which could disincentivize prescribing.
Researchers also highlight that next-gen agents are prescribed more often at hospitals where lab results that show the medications are effective against a patient’s bacterial infection are reported to prescribers. Scientists suggest that earlier and more widespread availability of such lab testing might improve use. Additionally, authors recommend that future public health policies and economic strategies on further development and use of similar antibiotics should be designed to identify and overcome additional barriers.
Scanning electron micrograph of methicillin-resistant Staphylococcus aureus bacteria (red, round items) killing and escaping from a human white blood cell.
Proof-of-concept study analyzed a newer technology known as single-cell RNA sequencing
In a proof-of-concept study, researchers at the National Institutes of Health (NIH) have developed an artificial intelligence (AI) tool that uses data from individual cells inside tumors to predict whether a person’s cancer will respond to a specific drug. Researchers at the National Cancer Institute (NCI), part of NIH, published their work on April 18, 2024, in Nature Cancer, and suggest that such single-cell RNA sequencing data could one day be used to help doctors more precisely match cancer patients with drugs that will be effective for their cancer.
Current approaches to matching patients to drugs rely on bulk sequencing of tumor DNA and RNA, which takes an average of all the cells in a tumor sample. However, tumors contain more than one type of cell and in fact can have many different types of subpopulations of cells. Individual cells in these subpopulations are known as clones. Researchers believe these subpopulations of cells may respond differently to specific drugs, which could explain why some patients do not respond to certain drugs or develop resistance to them.
In contrast to bulk sequencing, a newer technology known as single-cell RNA sequencing provides much higher resolution data, down to the single-cell level. Using this approach to identify and target individual clones may lead to more lasting drug responses. However, single-cell gene expression data are much more costly to generate than bulk gene expression data and not yet widely available in clinical settings.
NIH scientists use artificial intelligence called ‘P-GAN’ to improve next-generation imaging of cells in the back of the eye
Researchers at the National Institutes of Health applied artificial intelligence (AI) to a technique that produces high-resolution images of cells in the eye. They report that with AI, imaging is 100 times faster and improves image contrast 3.5-fold. The advance, they say, will provide researchers with a better tool to evaluate age-related macular degeneration (AMD) and other retinal diseases.
“Artificial intelligence helps overcome a key limitation of imaging cells in the retina, which is time,” said Johnny Tam, Ph.D., who leads the Clinical and Translational Imaging Section at NIH's National Eye Institute.
Tam is developing a technology called adaptive optics (AO) to improve imaging devices based on optical coherence tomography (OCT). Like ultrasound, OCT is noninvasive, quick, painless, and standard equipment in most eye clinics.
NIH-supported clinical trial could lead to first effective treatment for ACDC disease
A drug used to treat certain bone diseases shows promise for slowing the progression of a rare, painful genetic condition that causes excessive calcium buildup in the arteries, known as arterial calcification due to deficiency of CD73 (ACDC). These results are from a first-in-human clinical trial supported by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health. The study, published in the journal Vascular Medicine, could lead to the first effective treatment for the rare disease.
ACDC, which has no known cure, often targets the arteries of the legs and can make walking painful and difficult. It can also affect the joints of the hands, causing pain and deformities. In severe cases, the condition can lead to potential limb loss. Symptoms of the disease often begin in the late teens and 20s. An extremely rare disease, it is believed to affect only about 20 people worldwide and has an estimated prevalence of less than 1 in 1 million. Previous studies have identified the gene for ACDC disease and the biochemical mechanism behind it. More recent studies by the NHLBI research team identified an existing drug, called etidronate, as a potential treatment for ACDC based on disease models in animals and human cells.
In the study, researchers evaluated the safety and effectiveness of etidronate in treating calcification of the arteries and impaired blood flow in the legs of seven people (four women and three men) with ACDC disease. Although few, they collectively represent about one-third of all the known cases in the world. Treatment consisted of taking the oral drug daily for 14 days every three months over a three-year period. The researchers measured calcium deposits using CT scans and tested blood flow using the ankle brachial index, a non-invasive tool, both at the start of the study and as a yearly follow-up after treatment.
A CT angiography scan of a person with ACDC disease showing abnormal calcification of the blood vessels in the legs and feet.
NIH-supported study also found Black people with depression used different language compared to white people to express their thoughts on Facebook
Researchers were able to predict depression severity for white people, but not for Black people using standard language-based computer models to analyze Facebook posts. Words and phrases associated with depression, such as first-person pronouns and negative emotion words, were around three times more predictive of depression severity for white people than for Black people. The study, published today in the Proceedings of the National Academy of Sciences, is co-authored by researchers at the University of Pennsylvania, Philadelphia, and the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health (NIH), which also funded the study.
While previous research has indicated that social media language could provide useful information as part of mental health assessments, the findings from this study point to potential limitations in generalizing this practice by highlighting key demographic differences in language used by people with depression. The results also highlight the importance of including diverse pools of data to ensure accuracy as machine learning models, an application of artificial intelligence (AI) language models, are developed.
“As society explores the use of AI and other technologies to help deliver much-needed mental health care, we must ensure no one is left behind or misrepresented,” said Nora Volkow, M.D., NIDA director. “More diverse datasets are essential to ensure that healthcare disparities are not perpetuated by AI and that these new technologies can help tailor more effective health care interventions.”
Treatment for rare childhood disease was well tolerated and slowed loss of motor function
An investigational gene therapy for a rare neurodegenerative disease that begins in early childhood, known as giant axonal neuropathy (GAN), was well tolerated and showed signs of therapeutic benefit in a clinical trial led by the National Institutes of Health (NIH). Currently, there is no treatment for GAN and the disease is usually fatal by 30 years of age. Fourteen children with GAN, ages 6 to 14 years, were treated with gene transfer therapy at the NIH Clinical Center and then followed for about six years to assess safety. Results of the early-stage clinical trial appear in the New England Journal of Medicine.
The gene therapy uses a modified virus to deliver functional copies of the defective GAN gene to nerve cells in the body. It is the first time a gene therapy has been administered directly into the spinal fluid, allowing it to target the motor and sensory neurons affected in GAN. At some dose levels, the treatment appeared to slow the rate of motor function decline. The findings also suggest regeneration of sensory nerves may be possible in some patients. The trial results are an early indication that the therapy may have favorable safety and tolerability and could help people with the rapidly progressive disease.
“One striking finding in the study was that the sensory nerves, which are affected earliest in GAN, started ‘waking up’ again in some of the patients,” said Carsten G. Bonnemann, M.D., senior author and chief of the Neuromuscular and Neurogenetic Disorders of Childhood Section at the National Institute of Neurological Disorders and Stroke (NINDS), part of NIH. “I think it marks the first time it has been shown that a sensory nerve affected in a genetic degenerative disease can actually be rescued with a gene therapy such as this.”
Biopsy of a sensory nerve from a participant in the GAN gene therapy trial (arrows indicate giant axons; regenerating nerve cluster in upper left). Some patients regained sensory nerve response after treatment.
The drug minocycline, an antibiotic that also decreases inflammation, failed to slow vision loss or expansion of geographic atrophy in people with dry age-related macular degeneration (AMD), according to a phase II clinical study at the National Eye Institute (NEI), part of the National Institutes of Health.
Dry AMD affects the macula, the part of the eye’s retina that allows for clear central vision. In people with dry AMD, patches of light-sensing photoreceptors and their nearby support cells begin to die off, leaving regions known as geographic atrophy. Over time, these regions expand, causing people to lose more and more of their central vision. Microglia, immune cells that help maintain tissue and clear up debris, are present at higher levels around damaged retinal regions in people with dry AMD than in people without AMD. Scientists have suggested that inflammation — and particularly microglia — may be driving the expansion of geographic atrophy regions.
This study, led by Tiarnan Keenan, M.D., Ph.D., a Stadtman Tenure-Track Investigator at the NEI’s Division of Epidemiology and Clinical Applications, tested whether inhibiting microglia with minocycline might help slow geographic atrophy expansion and its corresponding vision loss. The trial enrolled 37 participants at the NIH Clinical Center in Bethesda, Maryland, and at the Bristol Eye Hospital, United Kingdom. After a nine-month period where the researchers tracked each participant’s rate of geographic atrophy expansion, the participants took twice-daily doses of minocycline for two years. The researchers compared each participant’s rate of geographic atrophy expansion while taking minocycline to their baseline rate, and found there was no difference in geographic atrophy expansion rate or vision loss with minocycline.
Retina, showing a large region of geographic atrophy.
Compared to healthy volunteers, affected U.S. government personnel did not exhibit differences that would explain symptoms
Using advanced imaging techniques and in-depth clinical assessments, a research team at the National Institutes of Health (NIH) found no significant evidence of MRI-detectable brain injury, nor differences in most clinical measures compared to controls, among a group of federal employees who experienced anomalous health incidents (AHIs). These incidents, including hearing noise and experiencing head pressure followed by headache, dizziness, cognitive dysfunction and other symptoms, have been described in the news media as 'Havana Syndrome' since U.S. government personnel stationed in Havana first reported the incidents. Scientists at the NIH Clinical Center conducted the research over the course of nearly five years and published their findings in two papers in JAMA today.
“Our goal was to conduct thorough, objective and reproducible evaluations to see if we could identify structural brain or biological differences in people who reported AHIs,” said Leighton Chan, M.D., chief, rehabilitation medicine and acting chief scientific officer, NIH Clinical Center, and lead author on one of the papers. “While we did not identify significant differences in participants with AHIs, it’s important to acknowledge that these symptoms are very real, cause significant disruption in the lives of those affected and can be quite prolonged, disabling and difficult to treat.”
Researchers designed multiple methods to evaluate more than 80 U.S. government employees and their adult family members, mostly stationed abroad, who had reported an AHI and compared them to matched healthy controls. The control groups included healthy volunteers who had similar work assignments but did not report AHIs. In this study, participants underwent a battery of clinical, auditory, balance, visual, neuropsychological and blood biomarkers testing. In addition, they received different types of MRI scans aimed at investigating volume, structure and function of the brain.
