16 Jan 2012

Colombian Alzheimer’s families travel to US

Channel 4 News Science Editor Tom Clarke follows a group of Colombian families blighted by Alzheimer’s to the US, where the hope is that a new study could help those suffering from the condition.

Amid the cattle ranches and coffee plantations of mountainous northern Colombia, are entire towns cursed by Alzheimer’s disease.

It does not just strike here often, it strikes early – the average age of its victims is just 45.

Thousands of people here carry a rare genetic mutation that causes this early-onset form of Alzheimer’s. Last year Channel 4 News visited these previously isolated families as they volunteered in global scientific campaign to prevent Alzheimer’s.

Now we have followed them to the United States, where they are about to embark on the first step of that study. It has the potential to help not just the Colombian families, but 35 million ordinary Alzheimer’s patients around the world.

In recent years drug companies have developed a number of promising treatments for Alzheimer’s, but none have proved effective at treating the disease once the worst symptoms are apparent. This latest approach wants to try those drugs in patients, like the Colombian families, who it is known will go on to develop the disease.

“This is the first time in history that we have treatments that might strike Alzheimer’s hard,” says Eric Reiman, executive director of the Banner Alzheimer’s Institute in Phoenix, Arizona, the US partner in the Colombia-based trial.

“We are either going to find treatments that could help, or we’re going to provide the most definitive information yet that the field should use to redirect their drug discovery effort,” he said.

‘I have resigned myself’

One volunteer in the trial is 21-year-old Alejandra Sepulveda. She lives on the outskirts of northern Colombia’s regional capital, Medellin, with her mother Yolanda, who has Alzheimer’s.

Yolanda’s memory started to go when she was just 45. Now, six years on, she requires full-time care. Alejandra looks after her own six-year-old daughter and a younger sister as well. And now her uncle has been diagnosed with Alzheimer’s. He’s still in the early stages but soon she’ll be looking after him, too.

“Effectively I have three daughters and soon I will have four children, counting my uncle as well,” said Alejandra.

She’s watched her grandmother, great uncle and several distant cousins die of Alzheimer’s. Because her mother carries the mutation, there’s a 50:50 chance Alejandra will have it too.

“I have resigned myself. It’s very sad, it’s a huge responsibility, but it is what it is. Now we have the hope that they might find a cure,”

Anonymised test results

And heading off to America, Alejandra might help find one. It is a trip most ordinary Colombians could never hope to make – but to scientists Alejandra is far from ordinary. Along with 14 other young Colombians, all from families with the mutation, she is being escorted to Phoenix by Colombian scientists collaborating in the trial.

Researchers at the University of Antioquia in Colombia have been planning a trial like this for years. By now many of the volunteers are friends. But one thing they do not know about each other – or even themselves – is who has the mutation. They have agreed their test results should be anonymised – even the researchers studying don’t know their status.

The reason they are going to America is because researchers there can look inside the living brain for signs of Alzheimer’s.

The Banner Institute helped to develop an experimental scanning technique to identify Alzheimer’s in the living brain – before the technique, the only way to see Alzheimer’s pathology was in an autopsy.

The basis for the technique is a radioactive tracer which sticks to a protein called amyloid beta, which builds up in the brains of Alzheimer’s sufferers. That tracer then shows up in a conventional brain scanner.

“What this amyloid imaging represents is an opportunity to identify the disease before you have symptoms,” says Dr Adam Fleisher, a neurologist at the Banner Institute. “That gives us the ability to potentially stop the disease before it causes irreversible damage to the brain.”

‘Important for next generations’

The scans of 50 volunteers in their 20s and 30s will be used to establish any evidence of Alzheimer’s. Later this year, once Alzheimer’s drugs have been approved for use in the trial by US and Colombian regulators, they plan to give them to select groups of volunteers.

They will then be scanned again after two years to see if the drugs have had any affect on the progression of Alzheimer’s. If the volunteer doesn’t have the mutation – and therefore no disease – their scans are still essential to compare with those who whose disease is progressing.

Even though Alejandra has chosen not to know whether or not she has the mutation, it does not make being an experimental subject any easier. The procedure involves a slow injection of radioactive tracer, and then several hours waiting around for the brain scan.

But she gladly volunteered. ” It’s important for my family and all the families that go through this disease, for the next generations – even if we don’t get to see the benefits.”