Dirty Air Might Raise Your Odds for Dementia

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News Picture: Dirty Air Might Raise Your Odds for DementiaBy Alan Mozes
HealthDay Reporter

TUESDAY, March 31, 2020 (HealthDay News) — Smog drives up dementia risk, particularly for older men and women with heart disease, according to a new Swedish study.

For more than a decade, researchers tracked exposure to air pollution and dementia cases among nearly 3,000 Stockholm residents aged 60 and up.

Lead author Dr. Giulia Grande noted that exposure to dirty air has long been linked to an increased risk for lung and heart disease.

“More recently, several research groups have started to focus on the damages of air pollution on the brain — for example, its impact on cognitive functions in older adults,” she said.

The current research builds on that work. Participants were 74 years old on average and nearly two-thirds were women. All were free of dementia when the study began in 2001; they were tracked until 2013.

With strict air pollution rules in place, Stockholm has relatively good ambient air quality, said Grande, of the Aging Research Center at the Karolinska Institute and Stockholm University.

Her team pegged the city’s average annual pollution levels at about 2.5 microns of particulate matter or less — a level considered “low” by international standards.

Still, more than 12% of participants (364) developed dementia over the study period, the findings showed.

“And we found that people continuously exposed to higher levels of air pollution were at increased risk of dementia, as compared with those exposed to lower levels,” Grande said. That link was especially strong among participants who had a history of heart failure, ischemic heart disease or stroke.

Almost half of the pollution-related cases of dementia were connected to stroke, Grande said.

The findings dovetail with other research that has linked cardiovascular disease to a more rapid rate of cognitive (“thinking”) decline.

But why would air pollution increase dementia risk in the first place?

“Unfortunately, the biological mechanisms through which air pollution affects the brain are not completely understood,” Grande said. “But several pathways are possible.”

One possibility is that after inhaled pollutants penetrate the brain, they speed up accumulation of plaques that increase dementia risk, she said.

Poor air quality could also have an indirect effect, Grande added. Air pollution is an established risk to heart health and an “important trigger” for heart attacks and stroke. So, it could be the onset of heart disease that paves the way for development of dementia, she said.

That line of thinking made sense to Dr. Jesus Araujo, director of environmental cardiology at the David Geffen School of Medicine at UCLA. He said the kind of vascular damage brought on by heart disease may be an essential pre-requisite for dementia.

Araujo added that extensive evidence indicates that air pollution can trigger inflammation and hardening of the arteries (atherosclerosis), while also throwing the immune system out of whack (oxidative stress).

All of these factors “are important in the development of both cardiovascular disease and dementia,” according to Araujo, who was not involved with the new study.

Grande said the findings are one more reason to strengthen existing air-quality laws.

“By 2050, 68% of the world population is expected to live in urban areas, being continuously exposed to air pollution,” she pointed out. Her team projects that global dementia numbers will triple by 2050.

“Together with the worldwide aging of the population, this poses global challenges when it comes to preventive strategies for dementia,” Grande said. “So establishing and characterizing the relationship between air pollution and dementia has enormous impact.”

The report was published online March 30 in JAMA Neurology.

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References

SOURCES: Giulia Grande, M.D., Ph.D. candidate in geriatric epidemiology, Aging Research Center, Karolinska Institute and Stockholm University, Stockholm, Sweden; Jesus Araujo, Ph.D., M.D., assistant professor of medicine, director of environmental cardiology, David Geffen School of Medicine, and associate professor of environmental health sciences, Fielding School of Public Health, University of California, Los Angeles (UCLA); March 30, 2020, JAMA Neurology, online

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Temperature Check: Tips For Tracking A Key Symptom Of Coronavirus Contagion

After I was told I’d been exposed to the novel coronavirus, I tried to follow the best medical advice. I started working from home. I socially isolated. And I “self-monitored” for signs I’d been infected.

Or, at least, I tried to.

COVID-19 symptoms seem pretty clear. The dry cough and difficulty breathing. Fatigue. And the fever.

To track all that, the federal Centers for Disease Control and Prevention recommends that people who may have been exposed take their temperature twice daily. As someone who covers the outbreak, I understand the soundness of this advice. There’s a nationwide shortage of coronavirus diagnostics, so health care providers are trying to reserve tests for people who have been exposed, are symptomatic or are at clear risk of dangerous complications.

What the CDC’s guidelines don’t note: Taking your temperature is surprisingly difficult.

Especially when, like most of my 20-something friends, you don’t own a thermometer. (I do have a candy thermometer, but those aren’t useful here. A meat thermometer wouldn’t be, either.) I called my local CVS. They were sold out. Another friend told me he had checked four stores in our neighborhood and come up empty-handed. My twin brother was able to find one — but he lives in Connecticut, almost 400 miles from me.

When I checked online, I discovered I’d have to wait weeks to months for a thermometer, unless I was willing to shell out at least $50. I was not.

Since I had no symptoms ― I still felt comfortable going out for a run or doing yoga in my kitchen — I decided to wait and watch. It’s been two weeks, officially, and my only symptoms are cabin fever and existential anxiety. The coronavirus seemed a no-show.

But was that the best course of action? And what should people in my situation do?

I did what any health journalist would do. I researched and called the experts.

Their advice was comforting. Splurging on a pricey thermometer isn’t the right move, especially if you aren’t showing symptoms. There are other ways to figure out if you have a fever, or are at risk of COVID-19 complications. And a few principles are worth considering.

The Number Varies

First of all, for people like my brother, who was able to find a thermometer in stock and buy it, or those who actually owned one long before this need arose, the number you’re looking for varies.

We’re taught the average human temperature is 98.6 degrees Fahrenheit. But that isn’t necessarily correct. Research published this year suggests the average human body temperature is a bit lower ― maybe 97.9. It differs from person to person, based on factors like body weight, height, the weather, age or gender.

“Some people are like, ‘Oh, I run a low temperature.’ ‘Oh, I run high.’ That’s right! There is variation,” said Dr. William Schaffner, a professor of preventive medicine and infectious diseases at Vanderbilt University.

Generally, keep an eye out for a temperature of 100.5 F or higher. But the timing matters, too. Some people running a fever might not register a high number in the morning but will by afternoon. That’s because people run cooler in the morning, and their temperature peaks in the evening, usually from 4 to 9 p.m., he told me.

If you are taking your temperature twice a day, at least one of those should be done during that evening window — and ideally around the same time every day, to account for daily fluctuation.

Another factor to consider when using oral thermometers, advised Dr. Leigh Vinocur, a Maryland-based physician and spokesperson for the American College of Emergency Physicians: If you’ve just had hot coffee, or water or ice cream, wait a little bit before checking for fever.

The Equipment?

That gets at another question. Are specific kinds of thermometers better than others?

If you can’t find a thermometer, everyone told me ― again, don’t worry. (There are lots of other things to worry about!) But if you have options, you don’t need anything fancy.

High-tech models, like the smart thermometer Kinsa, track and map where people register fevers. This has been touted as a way to help predict the spread of disease. But they’re expensive. When in stock, they retail for between $35 and $69, per the manufacturer’s website.

There are other digital scanning thermometers that use infrared technology to scan someone’s forehead — from a distance! ― and deliver an accurate temperature reading.

These are the kinds used in high-traffic settings like the airport, or before journalists can enter White House press briefings — scenarios in which you don’t want to stick the same thermometer in multiple people’s mouths, spreading germs. When in stock (and again, many are not), those can cost $60-$80. That doesn’t include shipping, if you’re ordering online.

But those high-end devices aren’t necessary, especially at home.

“You don’t have to have the most expensive one. You can get a cheap one,” urged Dr. Brad Uren, an assistant professor and emergency doctor at the University of Michigan. Simple, under-the-tongue thermometers that (normally) retail for less than $10 are more than sufficient.

Actually, scanning devices can be more vulnerable to user error, said Dr. Rob Davidson, an emergency physician in western Michigan. He has seen them misread temperatures as lower than what’s accurate.

In fact, when I was still trying to buy a thermometer, one friend warned me she has seen those lower readings occur at home — a reason she refuses to buy scanning devices now. (She also doesn’t currently have a thermometer.)

Products marketed for children are fine for adults. The only real precaution, doctors told me, is to make sure you properly clean it between uses and among people ― soapy water or sterilizing alcohol will usually do the trick.

Mom Had The Right Idea

But for people like my friends, these are moot points. If we don’t have thermometers and aren’t ready to drop $50 on one, what else can we do?

Don’t sweat the number. A specific temperature is only one of many indications of a fever. People will also have alternating chills and sweats, and body aches. And doctors don’t consider the precise number when deciding whether someone is ill.

“Fever is a yes-no thing, and chills are a big thing,” Davidson told me.

The childhood forehead test may be less precise than a digital reading, but it’s generally accurate in gauging sickness, he added. No wonder my mom relied on it to determine if her kids were well enough to go to school.

Since talking to Davidson, my social isolation partner and I have designated each other as sole “forehead testers” for the duration of this period: an effective way to self-monitor and mitigate germ-spreading from either of us to the rest of the world.

And if you are sick and seem to be registering a high body temperature? Call the doctor. If you’re really worried (or if, like me, you don’t have a primary care doctor), you may have to call the ER instead.

That said, the severe shortage of coronavirus tests and medical supplies — a shortage many worry will soon include hospital beds themselves ― means running a temperature or having a fever won’t get you into the hospital, even if you might have the coronavirus. It probably won’t even qualify you for diagnostic testing.

To register that level of concern, doctors said, you need to experience trouble breathing so bad that you feel winded walking to the mailbox or even to the refrigerator.

If that doesn’t happen, care for yourself at home. Self-isolate. Rest. Drink plenty of fluids, and take acetaminophen. (And my grain-of-salt advice: I swear by the healing powers — or at least comfort capacity ― of Cocoa Puffs and Ritz crackers.)

Otherwise, follow basic infection-control guidelines (which don’t necessarily involve rushing out to the drugstore as soon as a new stock of thermometers is delivered): Wash your hands frequently with soap. Avoid touching your face. Put on your favorite isolation playlist, or some early-season “Gilmore Girls,” and practice your social distancing.

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Cost and Quality Public Health

CDC COVID-19

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Israelis told to wear face masks in public, mark religious holidays with close family only

JERUSALEM (Reuters) – All Israelis should wear face masks while in public as a precaution against the coronavirus, and upcoming Jewish, Muslim and Christian holidays should be marked only with immediate family, Prime Minister Benjamin Netanyahu said on Wednesday.

FILE PHOTO: Israeli Prime Minister Benjamin Netanyahu gestures as he delivers a statement during his visit at the Health Ministry national hotline, in Kiryat Malachi, Israel March 1, 2020. REUTERS/Amir Cohen

In televised remarks, Netanyahu also announced curbs on movement around an ultra-Orthodox Jewish town that has experienced a disproportionately large outbreak.

Israel has taken stringent measures to try to halt the spread of the virus, after recording more than 6,000 cases. At least 25 Israelis have died of COVID-19, according to Health Ministry data.

“We ask you, citizens of Israel, all of you, to wear masks in the public sphere,” Netanyahu said in televised remarks, adding that people could improvise “with a scarf or any other facial covering” in the absence of factory-produced masks.

Increasingly tight restrictions have largely confined Israelis to their homes, forcing businesses to close and causing unemployment to skyrocket to 24.4%.

On Monday, Netanyahu and Finance Minister Moshe Kahlon said Israel would spend 80 billion shekels ($22 billion) to help the economy weather the crisis and predicted a gradual return of business activity after the Passover holiday from April 8-15.

Netanyahu on Wednesday said the government would give Israeli families 500 shekels per child, up to a maximum of four children. The elderly would also receive 500 shekels, Netanyahu said, terming all the payments a “Passover gift”.

Those stipends would cost the state a total of 1.5 billion shekels, public broadcaster Kan estimated.

Netanyahu also said Israel’s majority Jews must mark Passover “with the nuclear family only,” adding that including elderly relatives in celebrations “would be to endanger them”.

Those same restrictions apply to Muslims and Christians, Netanyahu said, who make up most of Israel’s 21% Arab minority and will mark Easter and the beginning of Ramadan, respectively, later this month.

Israeli authorities will also tighten curbs on movement around Bnai Brak, an ultra-Orthodox Jewish town near Tel Aviv, which the Channel 12 TV news on Wednesday projected may account for as many as 30% of the coronavirus cases nationwide.

“We have decided to reduce to the minimum necessary the access and egress from the city,” Netanyahu said, while adding that residents would still be allowed to move around within the city if required.

Israeli officials describe the ultra-Orthodox as especially prone to contagion because their districts tend to be poor and congested, and in normal times they are accustomed to holding thrice-daily prayers with often large congregations. Some ultra-Orthodox rabbis have also cast doubt on the coronavirus risk.

Reporting by Rami Ayyub; Additional reporting by Dan Williams, Steve Scheer and Tova Cohen; Editing by Chizu Nomiyama and Hugh Lawson

Our Standards:The Thomson Reuters Trust Principles.

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COVID-19 infections growing exponentially, deaths nearing 50,000: WHO

GENEVA (Reuters) – The head of the World Health Organization (WHO) voiced deep concern on Wednesday about “the rapid escalation and global spread” of COVID-19 cases from the new coronavirus, which has now reached 205 countries and territories.

FILE PHOTO: Director General of the World Health Organization (WHO) Tedros Adhanom Ghebreyesus attends a news conference on the situation of the coronavirus (COVID-2019), in Geneva, Switzerland, February 28, 2020. REUTERS/Denis Balibouse

WHO Director-General Tedros Adhanom Ghebreyesus said that his agency, the World Bank and the International Monetary Fund (IMF) backed debt relief to help developing countries cope with the pandemic’s social and economic consequences.

“In the past five weeks there has been a near-exponential growth in the number of new cases and the number of deaths has more than doubled in the past week,” Tedros told a virtual news conference in Geneva where the U.N. health organization is based.

“In the next few days we will reach 1 million confirmed cases and 50,000 deaths worldwide,” he said.

China, where the coronavirus outbreak first emerged in December, reported dwindling new infections on Wednesday and for the first time disclosed the number of asymptomatic cases, which could complicate how trends in the outbreak are read. Its latest figures excluded 130 new sufferers of the highly contagious disease who do not show symptoms, its statistics showed.

Asked about the distinction, Dr. Maria ver Kerkhove, a WHO epidemiologist who was part of an international team who went to China in February, said WHO’s definition included laboratory-confirmed cases “regardless of the development of symptoms”.

“From data that we have seen from China in particular, we know that individuals who are identified, who are listed as asymptomatic, about 75 percent of those actually go on to develop symptoms,” she said, describing them as having been in a “pre-symptomatic phase”. The new coronavirus causes the respiratory disease COVID-19.

The outbreak continues to be driven by people who show signs of disease including fever and cough, but it is important for the WHO to capture that “full spectrum of illness”, she added.

Tedros, referring to proposed debt relief, said: “Many countries, developing countries cannot really support their societies especially during lockdowns, especially those community members who work for their daily bread. That is why we call on the international community to have debt relief to support those countries.

“We are proposing an expedited process to support countries so their economies are not getting into crisis, (and) their communities are not getting into crisis,” he said.

Reporting by Stephanie Nebehay and Kate Kelland; Editing by Franklin Paul and Jonathan Oatis

Our Standards:The Thomson Reuters Trust Principles.

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Medicare covers alcohol misuse screening

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It’s important to remember that as you get older you have an increased sensitivity to alcohol. This means that you experience the symptoms from drinking more quickly than you may have when you were younger. And, alcohol misuse can have a serious impact on your medications and current health problems.

Medicare covers an alcohol misuse screening once per year if you’re an adult who uses alcohol but doesn’t meet the medical criteria for alcohol dependency. You can also get 4 brief face-to-face counseling sessions each year if you’re competent and alert during counseling. Medicare covers these substance misuse counseling services if they’re provided in a primary care setting, like a doctor’s office, and if your qualified primary care doctor or practitioner accepts assignment.

If you’re concerned you may be misusing alcohol, call your doctor today. April is Alcohol Awareness Month, and we want to help you stay healthy and safe.

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Men with erectile dysfunction have higher risk of death, study suggests

Reviewed by Emily Henderson, B.Sc.Mar 31 2020

Men with erectile dysfunction have a higher risk of death, regardless of their testosterone levels, suggests a study accepted for presentation at ENDO 2020, the Endocrine Society’s annual meeting, and publication in a special supplemental section of the Journal of the Endocrine Society.

As both vascular disease and low testosterone levels can influence erectile function, sexual symptoms can be an early sign for increased cardiovascular risk and mortality.”

Leen Antonio, M.D., Ph.D., lead researcher, KU Leuven-University Hospitals in Belgium

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Low testosterone levels have been linked to a higher risk of death in middle-aged and older men, but results from large studies are inconsistent, Antonio said. Studies have also linked sexual dysfunction with mortality in older men.

The new study used data from the European Male Ageing Study (EMAS), a large observational study that was designed to investigate age-related hormonal changes and a broad range of health outcomes in elderly men. The researchers analyzed data from 1,913 participants in five medical centers. They analyzed the relationship between their hormone measurements and sexual function at the beginning of the study, and whether they were still alive more than 12 years later.

During the average follow-up period of 12.4 years, 483 men–25 percent–died. In men with normal total testosterone levels, the presence of sexual symptoms, particularly erectile dysfunction, increased the risk of death by 51 percent compared with men without these symptoms.

Men with low total testosterone levels and sexual symptoms had a higher risk of death compared with men with normal testosterone levels and no sexual symptoms.

Men with erectile dysfunction, poor morning erections and low libido had a higher mortality risk compared to men with no sexual symptoms. In men with these three sexual symptoms, the risk of dying was almost 1.8 times higher compared to men without symptoms. In men with just erectile dysfunction, the risk of dying was 1.4 times higher compared to men without erectile dysfunction.

Levels of free testosterone (the testosterone that is easily used by the body) were lower in those who died. Men who had the lowest levels of free testosterone had a higher risk of death compared to men who had the highest levels.

Source:

The Endocrine Society

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FDA to trial malaria drugs Chloroquine and Hydroxychloroquine for COVID-19

The U.S. Food and Drug Administration (FDA) this week provided the necessary authorization for clinical trials of chloroquine and hydroxychloroquine for the treatment of the novel coronavirus. These two drugs have been claimed by President Donald Trump to be a potential treatment for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which causes COVID-19 disease. To date, there has been no conclusive proof regarding the safety and efficacy of these drugs in COVID-19 cases, say officials.

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What is the risk?

President Donald Trump, a few days back, had claimed to the media that the FDA had approved the drug for coronavirus treatment. The FDA has since then negated this claim. After Trump’s announcement, there was a rush for over the counter chloroquine, and this ended tragically for one Arizona man who consumed not-for-human-use chloroquine used to clean fish tanks. He sadly died due to the toxicity.

The Centre for Disease Control and Prevention (CDC), has warned the general public against taking non-pharmaceutical chloroquine phosphate and even medicinal chloroquine or hydroxychloroquine without prescription of a healthcare provider and always under the supervision of a healthcare provider because it can lead to “serious health consequences, including death.”

The media attention on this drug has led to many doctors stockpiling hydroxychloroquine sold as Plaquenil and prescribing it for themselves and their family members. State pharmacy boards of Texas, Louisiana, North Carolina, and Ohio have thus limited the prescriptions the healthcare providers can write for the drugs.

However, there is no sound evidence in the form of clinical trials showing the efficacy of these agents in the treatment and prevention of COVID-19, say the officials.

Announcement from the Department of Health and Human Services

The Department of Health and Human Services this Sunday (29th of March 2020) issued a statement saying that both hydroxychloroquine and chloroquine products can “be distributed and prescribed by doctors to hospitalized teen and adult patients with COVID-19, as appropriate, when a clinical trial is not available or feasible.”

Germany’s Sandoz, said the officials had given 30 million doses of hydroxychloroquine to the Strategic National Stockpile. This stockpile is the government supply of essential medicines during public health emergencies. Bayer, too has donated one million doses of chloroquine to the government stockpile.

FDA and clinical trials

Approvals for clinical trials usually take time, say FDA officials. The clinical trials may take years. But with the current emergency and rising number of COVID-19 cases across the nation, the whole process is being fast-tracked, says the FDA. The USA, as of today, has recorded 188,547 cases and 3,899 deaths.

The clinical trials are planned for New York, the worst affected region, say officials. This emergency authorization was issued to measure the potential benefits against the harm caused by the treatment.

The Department of Health and Human Services said that there are “anecdotal reports suggest that these drugs may offer some benefit in the treatment of hospitalized COVID-19 patients, but clinical trials are needed to provide scientific evidence that these treatments are effective.”

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FDA’s chief scientist, Denise Hinton, wrote in a letter of fast-tracked approval, saying, “It is reasonable to believe that chloroquine phosphate and hydroxychloroquine sulfate may be effective in treating COVID-19.”

The rationale behind chloroquine and hydroxychloroquine in COVID-19 prevention and treatment

Chloroquine and hydroxychloroquine have been prescribed for the last several decades as a standard drug for the treatment of malaria and several autoimmune conditions such as systemic lupus erythematosus (SLE) and rheumatoid arthritis. These drugs are not free of adverse effects and have proved to be toxic to the eyes and the heart. Many users complain of irregular heartbeat and may develop arrhythmias, and cardiac arrest, say experts.

Clinical trial enrolment

Infectious disease specialist, Dr. David Boulware from the University of Minnesota at present is running two experimental trials to look at the efficacy of hydroxychloroquine in a large population. Enrolment for the studies are on at present and began around a couple of weeks ago. Persons interested can enroll in the study at trialcovid.com.

While one of his trials is looking at the preventive capacity of hydroxychloroquine to protect a healthy person from getting COVID-19 after being exposed to it, the other trial is to check if hydroxychloroquine can be used to reduce the rate of the severity of symptoms in COVID-19 positive patients and reduce their risk of getting hospitalized. This trial is including those patients who have begun to show symptoms. The cut off for their eligibility to enroll in the trial is four days after they become symptomatic. Those who enroll in the study will receive a package by post containing either active drug pills or placebo (inert pills) to be taken.

By the 30th of March, a total of 537 individuals have enrolled in the first prevention study, and 74 people with the early appearance of symptoms of COVID-19 have enrolled in the second trial. The final target is to enroll 1,500 participants in both trials. The dose of hydroxychloroquine given to participants is 800 milligrams at the start, along with 500 milligrams per day for the next five days.

At the end of two weeks after taking the drugs, the participants would have to fill at least four out of five questionnaires that ask them about the side effects, symptoms of COVID-19, and if they needed to be hospitalized. Recruitment would be completed within two weeks, and results from both trials are expected by the end of one month, say the researchers.

Dr. David Boulware said in his statement, “There’s some suggestion that maybe it works, but there isn’t any good data.” He added, “If we’re going to give this medicine to tens of thousands, or hundreds of thousands, or millions of people, we should know if it works.” He said, “My goal is to figure out does it work. I don’t know the answer, but we’ll know soon.”

Dr. Boulware explained, “The vast majority of people are not hospitalized. Besides social distancing and quarantine, if we can break that chain of infection by identifying somebody and then prophylaxis everyone around them that’s been in contact with them to prevent infection, you can stamp out stuff much quicker.”

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Total-body PET provides suitable images of antibodies up to 30 days after injection

Reviewed by Emily Henderson, B.Sc.Mar 31 2020

Combining 89Zr-labeled antibodies with total-body positron emission tomography (PET) has extended the utility of novel total-body PET scanners, providing suitable images up to 30 days after the initial injection. A new study, published in the March issue of the Journal of Nuclear Medicine, compared four different types of 89Zr-labeled antibodies in preclinical trials, noting excellent consistency for each radiotracer even at very late time points, as well as differences in antibody behavior that are critical to understanding future outcomes of total-body PET in humans.

Monoclonal antibodies–laboratory-developed proteins designed to recognize specific targets–have been used in medicine for decades to treat various diseases, such as cancer, rheumatoid arthritis, multiple sclerosis and cardiovascular disease. Many new engineered monoclonal antibodies have been developed with specific molecular functions in order to achieve a balance between potency and safety in patient treatment.

“The tissue biodistribution of these newly engineered antibodies must be measured in vivo over the course of weeks to select the most appropriate candidates for novel therapeutics and understand how to use them in humans to best effect,” said Simon Williams, Ph.D., principal scientist, molecular imaging at Genentech, Inc. “In our study, we assessed the feasibility of using a novel total-body PET scanner to image 89Zr-labeled antibodies up to 30 days after injection, allowing for the measurement of tissue biodistribution over a long period of time.”

Researchers prepared four types of 89Zr-labeled antibodies, each with a different chelator-linker, to be compared across 12 young rhesus monkeys (three animals for each chelator-linker combination). Each group of animals received an intravenous injection of one of the four 89Zr-labeled antibodies in the left arm, along with an additional mass dose of unlabeled antibodies in the right arm. The animals were imaged on the day of injection, as well as three, seven, 14, 21 and 30 days after the injection.

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Excellent image quality was obtained on the initial total-body PET scans for all four types of 89Zr-labeled antibodies. Results from the 30-day scans showed image quality across the four antibody types sufficient to readily identify activity in the liver, kidneys and upper and lower limb joints. However, significant differences in uptake between the various chelator-linker combinations were noted in the late time point liver, bone, and in whole-body clearance. These differences were determined to be partly related to the stability of the radiolabeled compounds prior to injection.

The results of this study have two key implications for the field of molecular imaging. First, and most obvious, is that the increase in sensitivity of total-body PET, when compared to conventional PET, enables radiotracers to be followed for a longer period of time thus extending the imaging window. Using 89Zr as the radiolabel, this allows the assessment of slow biological processes and the ability to determine the ultimate fate of agents introduced into the body over a one-month timeframe.”

Second, studies with 89Zr can be conducted with much lower injected doses of radioactivity. The late time point total-body imaging conducted in this study clearly demonstrates that acceptable quality imaging with 89Zr can be accomplished when there is as little as 1/100th of the activity remaining in the subject. This paves the way for broad and repeat use of 89Zr-radiolabeled tracers in patients with extremely low effective doses.”

Simon R. Cherry, PhD, distinguished professor at the University of California, Davis

Source:

Society of Nuclear Medicine and Molecular Imaging

Journal reference:

Berg, E., et al. (2020) Total-Body PET and Highly Stable Chelators Together Enable Meaningful 89Zr-Antibody PET Studies up to 30 Days After Injection. Journal of Nuclear Medicine. doi.org/10.2967/jnumed.119.230961.

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