Study: Non-White Patients Less Likely to Qualify for Alzheimer’s Drugs

New research shows that Asian, Black, and Hispanic patients are less likely to qualify for Alzheimer’s treatments like anti-amyloid monoclonal antibodies that may help change or slow down the progression of the disease.

According to the study’s findings, minority patients tend to have a lower incidence of amyloid plaques in the brain on PET scans—and having those plaques is often necessary to qualify for specific Alzheimer’s treatments.

The researchers also noted that the cognitive impairment of patients in these groups is more likely to be caused by other forms of dementia that may not be related to amyloid plaques. 

Marc Gordon, MD, the chief of neurology at Zucker Hillside Hospital and a professor of neurology and psychiatry at the Donald and Barbara Zucker School of Medicine, told Verywell that amyloid plaques are groupings of misfolded proteins (like beta-amyloid peptides) that form in the spaces between nerve cells in the brain. A buildup of amyloid plaques can damage the brain and may contribute to the development of Alzheimer’s disease.

“Amyloid PET scans have established value in detecting amyloid plaques and contributing to an accurate and earlier Alzheimer’s diagnosis as well as enrolling the right individuals in clinical trials,” Maria Carrillo, PhD, co-author of the study and the Alzheimer’s Association chief science officer, said in a statement.

However, Carrillo said that their study shows that some people from underrepresented populations “have been inaccurately diagnosed with Alzheimer’s and may have a different form of dementia, more likely vascular in origin.”

Asian Participants Were Least Likely to Have Amyloid Plaques

Researchers from the University of California San Fransisco looked at the amyloid deposition in the brains of 17,000 Asian, Black, Hispanic and White participants. The patients were all Medicare beneficiaries who are enrolled in the Imaging Dementia—Evidence for Amyloid Scanning (IDEAS) study. 

The participants either had dementia or mild cognitive impairment—an early stage of memory loss or decline in thinking abilities.

The authors found that about 61% of the participants had mild cognitive impairment, meaning they had symptoms of cognitive decline but were still able to live on their own. Thirty-nine percent had dementia, meaning they had cognitive symptoms that had progressed to the point where they needed help with their daily activities.

Matching Participants

The researchers matched 313 White participants with 313 Asian participants based on age, sex, education, level of cognitive impairment, living arrangements, history of diabetes, blood pressure levels, and family history of dementia.

They found that 45% of the Asian participants tested positive for amyloid plaques while 58% of the White participants did.

The researchers followed the same process for both Black and Hispanic participants. After matching 615 Black participants with 615 White participants, they found that 54% of Black participants had amyloid plaques compared to 58% of White participants.

After matching 780 Hispanic participants with the same number of White participants, researchers found that 55% of Hispanic participants had plaques compared to 62% of White participants.

However, when the researchers only looked at the participants with mild cognitive impairment within these matched groups and not participants with dementia, they found the percentage of positive amyloid plaques in the PET scans went down:

• 36% for Asian participants vs. 53% for White participants
• 42% for Black participants vs. 49% for White participants
• 46% for Hispanic participants vs. 53% for White participants

Limitation: Study Participants Skewed White

Gordon, who was not involved in the study, said that on the amyloid PET scans the incidence of amyloid plaques (what is called amyloid positivity) was statistically higher in White participants compared to Hispanic and Asian participants. It was also higher in number, but not significantly, for White participants compared to Black participants.

Gordon, who was not involved in the study, noted that there was an overall low number of Black, Hispanic, and Asian participants in the study, which he said highlights the need for future research that’s more representative of the ethnic diversity of the overall population.

“Asians, Hispanics, and African Americans were clearly underrepresented in this study,” said Gordon. “So it certainly raises a question as to why is that?”

According to Gordon, “there is certainly work that needs to be done to make studies more inclusive so that we actually can judge whether people will have in the real world the same results as seen in those highly selected populations that are enrolled in studies.”

What Exactly Are Anti-Amyloid Monoclonal Antibodies? 

Charles Duffy, MD, PhD, a professor of neurology at the Case Western Reserve University School of Medicine, told Verywell that anti-amyloid monoclonal antibodies like the controversial drug Aduhelm are new, first-class treatments that are designed to reduce amyloid accumulation in the brain. 

Duffy explained that the treatment is infused through an IV and delivers “a molecule that is designed to attack abnormal proteins that build up in your brain cells and help wash it away and prevent your neurons—your brain cells—from dying.”

However, Duffy added that there is currently no disease-modifying treatment available that would cure Alzheimer’s disease. The point of having treatments like anti-amyloid monoclonal antibodies is to help with the symptoms of the disease and possibly change or slow its progression. 

How Do You Get Diagnosed and Qualify for Treatment?

Patients need to show signs and symptoms of Alzheimer’s disease before medical providers can make a diagnosis and recommend the treatment.

Gordon said that having amyloid plaques is necessary, but it’s not clear if it’s sufficient to get an Alzheimer’s diagnosis and be eligible for anti-amyloid treatment.

“If we’re going to be giving somebody an anti-amyloid therapy—and recognizing that a substantial percentage of people that on a clinical basis might be considered for one of those therapies—it would behoove people to make sure that they’re amyloid positive,” Gordon said.

Why Getting the Right Diagnosis Matters

To verify that a patient is amyloid positive, Gordon said that a PET scan or a special kind of spinal tap (lumbar puncture) can be used.

Gordon said doing these tests to confirm the diagnosis is important because the treatment can have adverse effects and is very expensive. In short, providers want to make sure they have the right disease before they start a patient on it.

“The amazing diversity and power of the brain imaging systems that are evolving today are very exciting,” Duffy said. However, he does not think that amyloid scans should be the only thing that determines if a patient gets a diagnosis and can receive treatment.

“We have to be careful about making sure that we are not jumping to conclusions, based on what is likely not a full understanding of what these things mean,” Duffy said.

What Makes a ‘Proper’ Alzheimer’s Diagnosis?

Reza Ghomi, MD, a neuropsychiatrist, faculty member at the University of Washington Department of Neurology and Institute for Neuroengineering, and Chief Medical Officer of BrainCheck, told Verywell that having the right information is key for understanding the process of getting an Alzheimer’s diagnosis.

The first step is usually a clinical interview that where a patient is asked clear and specific questions about their memory and functioning. Basic lab work, cognitive testing, and possibly brain imaging may also be required to make a proper diagnosis.

According to Ghomi, the only real criteria for patients to meet are clinical.

“They have a history of a slow and steady decline consistent with dementia,” he said.

From there, patients may undergo cognitive testing, a brain MRI, or a head CT scan to show patterns of atrophy consistent with dementia.

Why More Research Is Needed

The number of people living with Alzheimer’s disease is expected to triple by 2050. The disease also affects Black and Hispanic people at higher rates than their White counterparts.

Amyloid PET scans are valuable for detecting brain changes that could be early signs of Alzheimer’s, but the authors of the latest study believe that underrepresented populations may not get properly diagnosed with the disease because of the different forms of dementia they may have.

The study authors acknowledged that more research is needed to identify and understand the other structural and systemic factors that may influence the development of non-amyloid pathologies in underrepresented groups.

In a statement, Charles Windon, MD, an assistant professor of clinical neurology at the University of California San Francisco Memory and Aging Center and one of the study authors, said that these factors could include “economic and social policies that affect neighborhood conditions, housing, education access, and health care access,” and that “exposure to these factors may have differed between racial and ethnic groups in the study.” 

As for the next steps, Carrillo said that the Alzheimer’s Association is leading a follow-up study—the New IDEAS study—to research the use of amyloid PET scans in the diagnosis of Alzheimer’s for racially and ethnically diverse patients with memory loss.