TRACK DCAA

TRACK D-CAA

We know that Dutchtype CAA is caused by a protein (amyloid beta) that causes (mini)strokes by sticking to the walls of the brain's blood vessels. We would like to know exactly how this develops in the brain of gene carriers. In recent years, we have learned more through research at the Leiden University Medical Centre (LUMC) in the Netherlands, through so-called 'natural history studies' like EDAN and AURORA and in Australia through DIAN. Since 2021 Leiden and Perth have been working together towards a drug trial with the natural history study TRACK DCAA. Family members from the Netherlands and Australia in the TRACK DCAA study are working together to help us understand disease progression and with that, get us closer to a trial.

We hope to answer these questions: How does the disease develop? At what age does protein deposition begin in the brain? How can we best measure disease progression? This is important to know because, during the several phases of drug development, you want to find out when it is the best time to start treatment (what age do we first see symptoms?) and how to measure its effect (how do we measure effect on amyloid beta levels in the brain?). To do this properly, we must be able to measure how the toxic amyloid develops in the brain and from what age.

The DCAA patient association has been in a partnership, a consortium, together with the DUTCH CAA Foundation, the LUMC, researchers in America and Australia who are involved in (D)CAA and with a pharmaceutical company since 2021. As a result of that consortium and the new investments in research, we designed TRACK DCAA, which follows a select group of DCAA family members extensively. We hope to obtain a lot of information about the course of the disease in a short period of time. Because we want to look for signals early on, people from 25 years of age can participate. A genetic test will be done, but you will not be informed of the result and it will not appear in your health record. You can therefore in no way find out whether you are a gene carrier through participation. Anyone between the age of 25 and 60 years, who is a gene carrier or has a 50% chance (because one of the parents carries the gene) or 25% chance (because one of their grandparents carries the gene) of being a gene carrier is welcome to participate. There is a limit to the number of strokes you may have had to be part of the study. The team can tell you more about this.

The main goal of TRACK DCAA is finding out more about how the “toxic” protein behaves in the brain and what is the best way to measure this. Because it is impossible to look for it directly in the brains of living subjects, TRACK DCAA consist of several different indirect measures. One of those is a MRI scan, which shows any damage, such as microbleeds or larger bleedings. Another part of TRACK DCAA is a lumbar puncture, a spinal tap. Cerebrospinal fluid is taken from the lower back, between 2 vertebrae. This fluid is in a kind of balloon around your brain and spinal cord and serves as protection, but also as a 'waste system’ of the brain. Researchers look for the amount of toxic protein in your spinal fluid. The lumbar puncture will be the most important way in a drug trial to measure whether a drug does what you hope it does: ensure that less protein sticks to the brain and slows down the disease. We understand that undergoing a lumbar puncture is nobody's hobby and we would never ask you to undergo one if it was not very important (and safe!).

Another way to visualize the protein is through a PET-CT scan. During the scan a ‘compound’ that sticks to the protein is injected through an IV, which then goes through to the brain, where it lights up on a scan. The PET-CT scan has been part of Alzheimer’s research for a long time. By making it part of TRACK DCAA, researchers check whether PET-CT scans also help us visualise DCAA in the brain. In addition to the lumbar puncture, this is an important way of imaging the protein.

In addition to the methods aimed at imaging the brain and the protein, neuropsychological research is being carried out. These tests are used to look at how, for example, attention and memory function, things that are controlled by your brain and can be affected in people with DCAA. We ask you to bring someone close to you, who can report on your skills from an outside (but close) perspective.

We ask participants to visit Perth to take part in the MRI, PET, LP and cognitive tests each year for about two weeks. Travel and accommodation costs are covered by the research team to a reasonable limit. Accommodation can be booked for you by the team if you prefer. There will be three visits over the course of two years.

TRACK DCAA is ongoing in both Leiden and in Perth. Our aim is to find 50 people to participate on both sites. Leiden welcomed their 50th participant on June 24th 2023. From the Australian families with DCAA 24 people already participate in TRACK DCAA (as of July 2023). We are not sure if 50 participants is a realistic outcome, but we are hoping to get the number up. This will make it more likely that Australia will be part of a drug trial with ALN-APP. For more information you can reach out to our patient advocate Sanne van Rijn (svanrijn@hchwa-d.nl) or the research team through Samantha Gardener (s.gardener@ecu.edu.au). Also, make sure to check our FAQs, that might help you answer some of your questions.

We realise that participation is not something to be taken lightly and understand that you might have many questions before actually saying yes or no. We are very open to all your questions and you are allowed to say no during any phase of the process.