Second patient with ‘natural immunity’ against Alzheimer’s warded off disease for 20 years

A man managed to ward off Alzheimer’s disease thanks to his natural immunity, despite having a gene that made him more susceptible – making him the second known case.

A team of international scientists found the Colombian man, who was predicted to have dementia in his 40s, also carried a separate genetic variation that helped protect him from the debilitating memory condition.

The man died at the age of 74 with only moderate dementia.  

Researchers hope their findings could lead them to specific areas in the brain where the disease can be stopped or delayed from progression – bringing hope to 6.7 million Americans who have Alzheimer’s.

It comes as scientists at the Massachusetts Institute of Technology (MIT) discovered a new way to reverse Alzheimer’s, using a string of amino acids to interfere with an enzyme in mice that is typically overactive in the brains of people with the disease.

The man, a former mechanic from Colombia, inherited the Paia gene mutation when he was born, which predicts the disease would have killed him in his 60s.

This mutation is the most common cause of the early onset of Alzheimer’s and is commonly found among those living in Colombia.

Mild cognitive impairment sets in around age 45 and dementia by age 50. 

Instead, the man studied by the scientists sustained resilience and retired in his early 60s.

Scientists report the man later developed moderate dementia before dying in 2019 at 74.

The man was first examined by neurologists at aged 67, who found he was cognitively normal, and he nor his family were worried about his memory. 

He is only the second patient ever to resist the powers of the Alzheimer’s gene, a team of scientists in the journal Nature Medicine said.

Researchers looked through his genome to find a different mutation that might have helped protect him from the disease.

They also went through brain scans from when the man was 73 to examine an important area that looked to be quite protected against the tau protein tangles that can happen in those with Alzheimer’s.

The Colombian man was found to have a mutation in a gene named reelin. 

He had the hallmark signs of Alzheimer’s, including amyloid plaques and tau tangles in his brain, but he had a limited number of tau tangles in his entorhinal cortex, which is vital for memory.

Joseph Arboleda-Velasquez, an associate scientist at Mass Eye and Ear, a Harvard teaching hospital, and one of the leaders of the study, told the Washington Post: ‘I think it’s important that we listen to the patients. And I think what the patients are telling us is… there is a pathway for protection.’

He said: ‘The genetic variant we have identified points to a pathway that can produce extreme resilience and protection against Alzheimer’s disease symptoms. 

‘These are the kinds of insights we cannot gain without patients. They are showing us what’s important when it comes to protection and challenging many of the field’s assumptions about Alzheimer’s disease and its progression.’

He added: ‘The possibility that just by protecting the entorhinal cortex, even if you have a lot of Alzheimer’s pathology elsewhere, you can have that protection? Wouldn’t that be amazing? That’s what’s very tantalizing.’ 

In 2019, researchers discovered a woman, Aliria Rosa Piedrahita de Villegas, who avoided dementia until her 70s.

She was found to have a different genetic mutation which kept Alzheimer’s at bay, known as Christchurch.

While her brain did exhibit lots of amyloid plaques typically found in Alzheimer’s patients, it did not have the tau tangles also linked to the condition.

Physicians hope the cases will allow for the creation of new treatments for the disease but recognize that there could be multiple contributing factors to extending the lifespan of one’s memory rather than a single explanation.