An extended family in Colombia is providing the research world a one-of-a-kind opportunity to observe whether preventing Alzheimer's disease is possible.
Francisco Lopera, a clinical and behavioral neurologist at the University of Antioquia, had observed a rash of early-onset Alzheimer's cases in and around Medellin, the capital of Colombia’s Antioquia province. He and his nurse Lucia Madrigal, who had relatives suffering from the disease, began researching and traced the symptoms back hundreds of years in the community. They found that all of the different local families were actually one large extended family with common ancestors who had died young of "softening of the brain." What they had discovered was the largest concentration of people worldwide to carry a rare genetic defect that makes them 100 percent certain to develop Alzheimer's disease, reports CBS' 60 Minutes. In particular, the mutation causes early-onset dementia, which strikes people in their mid-40s and leads to early death.
Lopera eventually teamed up with an American professor, Kenneth S. Kosik, M.D., who helped to identify the responsible gene, E280A, that was causing the disease to run rampant in this family, and helped obtain grant funding for an important trial research project, including $15 million from the National Institutes of Health. The project will enroll 300 members of the extended family, which suffers from a specific mutation in the gene. Their unique situation offers many opportunities for researchers, Kosik, a neurologist and professor at the University of California, Santa Barbara, tells AARP.
Getting ahead of the symptoms
"People in the Alzheimer's field have been searching for a drug [to treat the disease] with quite a few failures in the last few years," Kosik says. "The idea surfaced a number of years ago that we could make an inroad if we catch the disease before symptoms strike."
In this Colombian population, researchers know who will get the disease and that their cognitive impairment will begin at age 45. "They are getting it like clockwork. So we can follow this effect on their trajectory quite well," Kosik says.
Researchers will be able to track whether the introduction of medicine to address the brain plaques and tangles associated with Alzheimer's, before people start having symptoms, is able to effectively stop the disease before it starts. Although this group has the early-onset type of dementia, the trial offers hope for later-onset Alzheimer's patients as well, researchers say.
"In this trial, not only is the preventive efficacy of a drug being tested, but many biomarkers of disease initiation and evolution that might be applicable in the future are also being evaluated to identify people at risk of developing sporadic Alzheimer late onset, and could eventually use preventive treatments in this type of population as well," Lopera tells AARP.
With Alzheimer's disease, Lopera says, two protein wastes, amyloid and tau, are deposited in the brain, causing the death of neurons and loss of connections. For this trial, researchers are testing an antibody that cleans the amyloid, which they believe is deposited first. "We hope that by cleansing the amyloid we can prevent the tau and the onset of the symptoms of Alzheimer's disease," Lopera says.
Family offers ideal testing ground
The family has additional factors that provide a fertile ground for researchers, including the fact that they are a very homogenous group, Kosik says. They have the same gene mutation, lifestyles, diet and education levels. "They are also a large number of people, so they are the perfect population for a drug trial," Kosik says.
All of the participants are healthy and have no memory loss currently. Two hundred of the participants have the gene mutation and the other 100 do not. Of the 200 with the mutation, half of the participants get injections of the drug and the rest receive a placebo. Participants will come in every two weeks for at least five years to see if those taking the drug remain healthier than the group taking the placebo. The final results are expected in 2022.
"I like to think the family will be the first beneficiary of the trial. Having this gene in your family, it must be so scary, but now to have the attention to the world and a drug trial that we know is safe, they are extremely welcoming" of the research, Kosik says.
Researchers believe that a Spanish conquistador carried the mutation to the New World and that his offspring are the ones now dealing with the disease, Kosik says. "If the mutation is dominant, they will get the disease, and their children have a 50 percent chance of inheriting it."
If the study ends up preventing the disease in the participants, it could lead to trials of the medication on older people at risk for Alzheimer's around the world, Kosik says. "If this is successful ... it could change the downhill course that this disease always causes ... it will be the first time we have been able to slow or halt the progress of Alzheimer's."
"Right now the drugs we have are just little more than Band-Aids — they may give a little bump in the symptoms, but don't affect the downward trajectory of the disease," he adds. The drug trial in Colombia offers "a very different approach that could change the course of the disease. This is the first time we've ever seen that in the Alzheimer's world."