The Atlanta Journal-Constitution
Race in Alzheimer’s trials does matter
Black people are twice as likely as whites to be diagnosed with Alzheimer’s disease, and Latinos are 1.5 times as likely, according to the Alzheimer’s Association.
People still get their feathers ruffled when such differences are pointed out, but here’s why race is crucial when it comes to not just diagnosing Alzheimer’s but treating it — beta-amyloid and tau protein levels. Studies show when it comes to these proteins, race really does matter.
According to Dr. Monica Parker, a family physician and Emory University researcher, concentrations of tau protein and its phosphorylated isoform in cerebrospinal fluid differed significantly between African American and white individuals diagnosed with Alzheimer’s disease.
For instance, Parker said that while Black patients and white patients with Alzheimer’s had similar findings on the MRI or PET scans, the cerebrospinal fluid biomarkers were different. Low tau proteins were associated with a lesser degree of brain damage or memory loss. But in Black patients, that wasn’t the case.
Despite this, it’s safe to say that almost everything we’ve learned about Alzheimer’s disease in the past 35 years has come from research studies in which participants were almost totally white.
So, here’s a bit of good news. The Global Alzheimer’s Platform Foundation expects a minimum of 20% of the estimated 1,000 recruits will be Black and Latino in an Alzheimer’s biomarker clinical trial it is developing and plans to launch later this year.
“The study will remain open until at least 200 Black and Latinx people have enrolled,” John Dwyer told me recently. “That’s
a promise. If a qualifying person of color wants in this study, we want them in.”
Dwyer is president of GAP, a national nonprofit working to improve the quality and reduce the time and cost of clinical trials like the Bio-Hermes, scheduled to get underway at sites later this year.
Because it will examine the efficacy of digital and blood biomarkers in detecting Alzheimer's, having high levels of diversity is critical, Dwyer said. He hopes to involve Emory University and the Morehouse School of Medicine. Both have years of experience recruiting Black clinical trial volunteers in metro Atlanta.
“We're trying to do a study that will look at blood and digital markers that will allow us to make judgments about people's cognitive ability and decide if they are showing early signs of Alzheimer's disease,” Dwyer said. “Historically, this is hard because unlike cancer, we do not have a tumor. In Alzheimer's, people may be losing their memory, but they look normal.”
That's one hurdle that must be overcome. The other is recruiting people of color for clinical trials in general.
“The disease is devastating minority populations at a much faster rate than whites, but they don't enroll in trials at the same levels whites do for two reasons,” Dwyer said. “Studies frequently aren't done in their neighborhoods or may not be convenient for them to enroll. The second problem is the Black and Latino community generally speaking aren't aware of studies and that they are vitally important to their health, their family and community. They have to be aware and motivated to come to them, but we need to make location and transportation easier to get to studies.”
Dwyer said he's working on that. GAP has already entered into a deal that will allow study recruits to take a Lyft car to a study site at GAP's expense.
According to the Alzheimer's Association, some 5.8 million Americans age 65 and older are living with Alzheimer's dementia in 2020. Eighty percent are age 75 or older. As the number of older Americans grows rapidly, so too will the number of new and existing cases of Alzheimer's. Barring the development of medical breakthroughs to prevent, slow or cure the disease, the number of people age 65 and older with Alzheimer's dementia may grow to a projected 13.8 million by 2050.
Parker said, however, Black people are more likely to be diagnosed with vascular dementia than Alzheimer's dementia. Alzheimer's disease is characterized by an accumulation of ABeta and tau proteins in the brain. These proteins are necessary for the diagnosis of Alzheimer's but not with other types of dementia.
“If we can take blood biomarkers that are easier and cheaper to use, we may be able to get more people in studies,” she said. “It looks promising.”
In addition to the barriers Dwyer cited, research procedures, such as lumbar punctures (spinal taps) or PET scans, are deterrents for many people participating in Alzheimer's trials.
“Research is optional, not something you must do but choose to do,” Parker said. “We want to make it easier for you to opt in.”
Finding blood biomarkers that are as specific and sensitive for Black patients as they are for white patients will expedite the process and ensure efficacy of treatment trials. Parker said the goal is to identify people with risk factors for Alzheimer's early, before they have symptoms, to enroll in an interventional therapeutic drug trial.
For instance, Parker said, “we all prescribe the same medications for hypertension, but medications prescribed may not be as effective for Blacks. We don't know why because a sufficient number of Blacks weren't included in the research development of the medication.”
That's what makes GAP's efforts so important.
“Research isn't like something you sell in stores,” Parker said. “You have to carefully cultivate an audience. If you live in a place like Atlanta, you want the study participants to be reflective of the general population.”
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