Lack of diversity impacts research into Alzheimer’s and dementia

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A National Institutes of Allergy and Infectious Diseases clinical trial admissions coordinator collects information from a volunteer to create a medical record. Credit: NIAID

Alzheimer’s research has been in the news a lot lately, and not for the right reasons. The controversial decision by the Food and Drug Administration (FDA) to approve the drug Aduhelm left many people wondering how, when, or even if it should be used on people battling Alzheimer’s disease. Now a new study is raising questions about many of the clinical trials used to test medications like Aduhelm.

The research, published in the journal Jama Neurology, looked at 302 studies on dementia published in 2018 and 2019. Most of these studies were carried out in North America or Europe, and almost 90 percent of those studied were white.

In an accompanying editorial in the journal, Dr. Cerise Elliott, PhD, of the National Institute on Aging (NIA) in Bethesda, Maryland, and co-authors wrote that this limited the value of the studies: “This, combined with the fact that only 22% of the studies they analyzed even reported on race and ethnicity, and of those, a median 89% of participants were white, reflects the fact that recruitment for research participation is challenging; however, it is unacceptable that studies continue to fail to report participant demographics and that publishers allow such omissions.”

That bias is made all the more glaring by the fact that recent data from the Centers for Disease Control and Prevention shows that among people 65 and older, the Black community has the highest prevalence of Alzheimer’s disease and related dementias (13.8%), followed by Latinx (12.2%), non-Hispanic white (10.3%), American Indian and Alaskan Native (9.1%), and Asian and Pacific Islander (8.4%) populations.

The researchers admitted that the limited sample size – more than 40 percent of the studies they looked at included fewer than 50 patients – could have impacted their findings. Even so this clearly suggests there is a huge divide between the people at greatest risk of developing Alzheimer’s, or some other form of dementia, and the people being studied.

In the editorial, Elliott and his colleagues wrote that without a more diverse and balanced patient population this kind of research: “will continue to underrepresent people most affected by the disease and perpetuate systems that exclude important valuable knowledge about the disease.”


There are more details on this in Medpage Today.

An editorial in the New England Journal of Medicine highlights how this kind of bias is all too common in medical research.

“For years, the Journal has published studies that simply do not include enough participants from the racial and ethnic groups that are disproportionately affected by the illnesses being studied to support any conclusions about their treatment. In the United States, for example, Black Americans have high rates of hypertension and chronic kidney disease, Hispanic Americans have the highest prevalence of nonalcoholic fatty liver disease, Native Americans are disproportionately likely to have metabolic syndrome, and Asian Americans are at particular risk for hepatitis B infection and subsequent cirrhosis, but these groups are frequently underrepresented in clinical trials and cohort studies.”

“For too long, we have tolerated conditions that actively exclude groups from critical resources in health care delivery, research, and education. This exclusion has tragic consequences and undermines confidence in the institutions and the people who are conducting biomedical research. And clinicians cannot know how to optimally prevent and treat disease in members of communities that have not been studied.”

The encouraging news is that, finally, people are recognizing the problem and trying to come up with ways to correct it. The not so encouraging is that it took a pandemic to get us to pay attention.

At CIRM we are committed to being part of the solution. We are now requiring everyone who applies to us for funding to have a written plan on Diversity, Equity and Inclusion, laying out how their work will reflect the diversity of California. We know this will be challenging for all of us. But the alternative, doing nothing, is no longer acceptable.

Study shows connection between bipolar disorder and neuroinflammation

Astrocytes, which provide structural support and protection for neurons and also supply them with nutrients and oxygen.

Bipolar disorder (BPD) is a mental disorder that causes unusual shifts in mood, energy, activity levels, concentration, and the ability to carry out day-to-day tasks. In the United States, recent research has shown that 1.6% of the population has BPD, which is roughly over 4 million people. Those with BPD are more likely to have conditions associated with chronic inflammation such as hypertension and diabetes. It is because of this that scientists have been studying the connection between inflammation and BPD for quite some time.

In a new study, researchers at the Salk Institute for Biological Studies, UC San Diego, and the Institute of Psychiatry and Neuroscience of Paris have found evidence that astrocytes, a certain type of brain cell, can trigger inflammation more easily in those that have BPD. What’s more, these astrocytes can be linked to decreased brain activity that could be harmful to mental health.

Astrocytes are star shaped (as the word “astro” might suggest) and help support neurons, the cells that relay information around the brain. One of these supporting roles includes helping trigger inflammation in the brain and the surrounding nervous system to help with injury or infection. The researchers believe that this process can go wrong in people with BPD and that astrocytes can play a role in this dysfunctional inflammation.

For this study, the team used induced pluripotent stem cells (iPSCs), a kind of stem cell that can turn into virtually any type of cell, that they created from patients with BPD and patients without BPD. They converted these iPSCs into astrocytes and compared those that came from BPD patients to those that did not. What they found is that the astrocytes from patients with BPD were noticeably different. The BPD astrocytes had a higher expression of a protein that triggers an inflammatory response when compared to the non-BPD astrocytes. When they exposed neurons to the BPD astrocytes, the team saw decreased levels of neural activity compared to the non-BPD astrocytes. Lastly, when the researchers blocked the inflammatory protein, the neurons were less affected by the BPD astrocytes.

“Our study suggests that normal function of astrocytes is affected in bipolar disorder patients’ brains, contributing to neuroinflammation,” said Dr. Renata Santos, a researcher at the Salk Institute as well as the Institute of Psychiatry and Neuroscience of Paris, in a news release.

The team hopes that their findings can not only provide insight into BPD, but to other mental illnesses linked to inflammation such as schizophrenia. The ultimate goal is to help advance research into astrocytes and inflammation in order to develop treatments that might reverse the harmful bodily changes seen in those with BPD and other mental disorders.

The full study was published in Stem Cell Reports.

Charting a course for the future

A new home for stem cell research?

Have you ever been at a party where someone says “hey, I’ve got a good idea” and then before you know it everyone in the room is adding to it with ideas and suggestions of their own and suddenly you find yourself with 27 pages of notes, all of them really great ideas. No, me neither. At least, not until yesterday when we held the first meeting of our Scientific Strategy Advisory Panel.

This is a group that was set up as part of Proposition 14, the ballot initiative that refunded CIRM last November (thanks again everyone who voted for that). The idea was to create a panel of world class scientists and regulatory experts to help guide and advise our Board on how to advance our mission. It’s a pretty impressive group too. You can see who is on the SSAP here.  

The meeting involved some CIRM grantees talking a little about their work but mostly highlighting problems or obstacles they considered key issues for the future of the field as a whole. And that’s where the ideas and suggestions really started flowing hard and fast.

It started out innocently enough with Dr. Amander Clark of UCLA talking about some of the needs for Discovery or basic research. She advocated for a consortium approach (this quickly became a theme for many other experts) with researchers collaborating and sharing data and findings to help move the field along.

She also called for greater diversity in research, including collecting diverse cell samples at the basic research level, so that if a program advanced to later stages the findings would be relevant to a wide cross section of society rather than just a narrow group.

Dr. Clark also said that as well as supporting research into neurodegenerative diseases, such as Alzheimer’s and Parkinson’s, there needed to be a greater emphasis on neurological conditions such as autism, bipolar disorder and other mental health problems.

(CIRM is already committed to both increasing diversity at all levels of research and expanding mental health research so this was welcome confirmation we are on the right track).

Dr. Mike McCun called for CIRM to take a leadership role in funding fetal tissue research, things the federal government can’t or won’t support, saying this could really help in developing an understanding of prenatal diseases.

Dr. Christine Mummery, President of ISSCR, advocated for support for early embryo research to deepen our understanding of early human development and also help with issues of infertility.

Then the ideas started coming really fast:

  • There’s a need for knowledge networks to share information in real-time not months later after results are published.
  • We need standardization across the field to make it easier to compare study results.
  • We need automation to reduce inconsistency in things like feeding and growing cells, manufacturing cells etc.
  • Equitable access to CRISPR gene-editing treatments, particularly for underserved communities and for rare diseases where big pharmaceutical companies are less likely to invest the money needed to develop a treatment.
  • Do a better job of developing combination therapies – involving stem cells and more traditional medications.

One idea that seemed to generate a lot of enthusiasm – perhaps as much due to the name that Patrik Brundin of the Van Andel Institute gave it – was the creation of a CIRM Hotel California, a place where researchers could go to learn new techniques, to share ideas, to collaborate and maybe take a nice cold drink by the pool (OK, I just made that last bit up to see if you were paying attention).

The meeting was remarkable not just for the flood of ideas, but also for its sense of collegiality.  Peter Marks, the director of the Food and Drug Administration’s Center for Biologics Evaluation and Research (FDA-CBER) captured that sense perfectly when he said the point of everyone working together, collaborating, sharing information and data, is to get these projects over the finish line. The more we work together, the more we will succeed.