What is this study about?
The aim of this study is to learn more about the role of oxygen in people with mitochondrial disease, and in other conditions where the mitochondria do not function properly.
Mitochondria are important parts of the cell that are responsible for producing energy. The amount of energy they produce depends on how much energy your body needs to function and this energy production can be severely impaired in people with mitochondrial disease. Mitochondrial disorders affect 1/5000 of the UK population and there is currently no cure. Oxygen is essential for production of the body’s main source of energy (adenosine triphosphate or ATP) through a process called oxidative phosphorylation (OXPHOS). When people with mitochondrial disease develop acute illnesses, or have routine surgical operations, they are routinely given very high oxygen levels to breathe. Doctors do this because they think it will be helpful. However, recent studies in animals with faulty mitochondria suggest that this might make mitochondrial function worse in some situations. We want to know whether this happens in humans, so that we only use high oxygen treatments when it is safe and helpful to do so.
We will study the effects of inhaling high oxygen levels in patients with mitochondrial disease, and compare them to people who do not have mitochondrial disease. We will compare the effects of regular room air (roughly 20% oxygen) and high level oxygen (60%) inhaled for up to 4 hours. This is the level of oxygen routinely used in hospital, which does not cause any side effects in most people.
Who can take part?
Patients with a confirmed diagnosis of mitochondrial disease caused by the m.3243A>G mutation in mitochondrial DNA (MELAS) who are aged between 16 and 70 years and based in the UK. There are some ‘exclusion criteria’ which might mean that you cannot take part – the study team will go through these with you in full detail before signing up.
What's involved in taking part?
As a participant in this study, you would be asked to come in for two study visits, one of which would involve tests on two consecutive days (with an overnight stay if required). As part of the tests, we would ask you to have 2 MRI scans, donate samples of blood and undergo non-invasive blood oxygen measurement and cognitive assessment. All tests will be performed under the careful supervision of a team of doctors and scientists.
Are there any risks?
The study involves some standard clinical tests that are routinely carried out in clinical practice. This includes blood samples, and two MRI scans. Taking blood samples may cause some discomfort or bruising and can cause some people to faint. Some people may find having the MRI scan claustrophobic and they can be noisy, but you will be in voice contact with the team at all times in case you feel uncomfortable.
The study also involves breathing 60% oxygen – a level that is used routinely in hospitals. Although we think it is unlikely, it is possible that the high oxygen level will cause side effects. However, you will be carefully supervised during this study. We will also ask you to inhale 60% oxygen for one hour during your screening visit to make sure that there are no significant side effects.
As part of the screening visit, we may also measure your blood oxygen levels using the MSOT Acuity device. There are very few risks attached to having this examination, which is considered a safe imaging technique. However, the laser light can damage the eye if it is shone directly into the eye. Hence you will be required to wear safety eye wear. There is no risk of skin damage or burning with this machine. If you have very sensitive skin there is a small chance that you will feel warmth and slight redness of the skin, which will resolve on its own.
Who will benefit?
There is no direct benefit to you from taking part in this research. However, knowledge gained from the study may ultimately improve the treatment of patients with mitochondrial disease
Who is running the study?
The Chief Investigator is a doctor called Professor Patrick Chinnery, who carries out specialist research into mitochondrial disease at the University of Cambridge and Addenbrooke’s Hospital.
How do I find out more?
If you think you might be eligible and are interested in taking part in this research, or would like any further information, please contact the study team directly.
Email: [email protected]
Tel: 01223 331506