What is Type 1 Diabetes?
Our immune system protects us against foreign pathogens (e.g. viruses, bacteria and cancerous cells). It is regulated to ignore our own healthy cells and to tolerate unharmful external particles (e.g. food and pollen). Occasionally this regulation goes wrong leading to autoimmune conditions and allergies.
Type 1 diabetes is an autoimmune condition. In this case the immune system mistakenly attacks and destroys the beta cells in the pancreas that produce insulin. Insulin does an essential job in our body, it allows the glucose in our blood to enter our cells and fuel all of our bodies functions.
Just before diagnosis people may experience the following symptoms (these symptoms and more are explained here: Type 1 diabetes symptoms | Diabetes UK):
- Toilet – going for a wee more often, especially at night.
- Thirsty – being constantly thirsty and not being able to quench it.
- Tired – being incredibly tired and having no energy.
- Thinner – losing weight without trying to, or looking thinner than usual.
If type 1 diabetes is left undiagnosed, it can make someone seriously ill, leading to a condition called diabetic ketoacidosis (DKA) which can be fatal.
The Pancreas
The human pancreas is part of the digestive system, it produces several important hormones including insulin.
The pancreas contains groups of cells called Islets of Langerhans. These Islets contain beta cells that produce insulin, it is these beta cells that are attacked and destroyed by the immune system, causing type 1 diabetes.
Islet Autoantibodies
We test your blood for the presence of four islet autoantibodies that indicate an autoimmune attack is happening in the body. Each of these autoantibodies target a different protein found in beta cells.
We can detect autoantibodies years before type 1 diabetes is clinically diagnosed. Therefore they are excellent marker of disease risk.
Studies, largely carried out in children, have shown that the more autoantibodies an individual has, the higher their risk of developing type 1 diabetes.
Research has shown that children with a single autoantibody have a 15% chance of developing type 1 diabetes within 10 years. Children with two or more autoantibodies have a 70% chance of developing type 1 diabetes within 10 years.
Studies in children have shown that different autoantibodies often appear or develop in a particular sequence, progressively increasing in number. This can help to us to determine the progression stage of autoimmunity in an individual.
We hope that as a result of samples collected in T1DRA and ARAD we will be able to show if/how the autoimmune process is different in adults.
Why does our immune system start to target our own cells?
We know that certain combinations of genes increase the risk of developing type 1 diabetes. However, these genes alone are not sufficient to cause the condition, many people with the high risk genes do not go on to develop the disease.
Scientists don’t yet fully understand what triggers the autoimmune process but it’s likely to be a complex combination of different genetic, environmental and biological factors.
Once an autoimmune response has been triggered it can be many months or even years before enough beta cells have been destroyed to cause an individual to experiencing symptoms due to the lack of insulin in their body.
Does everyone with two or more autoantibodies develop diabetes?
The time taken to progress to clinically diagnosed type 1 diabetes varies between individuals. Most young children with multiple autoantibodies do progress to diabetes by 20 years old, but until now, very few research studies have focused on adulthood type 1 diabetes.
We worked with other scientists around the world to study a rare group of people who take a long time to develop diabetes/have not progressed to diabetes despite having two or more autoantibodies. These studies found that these people had overall similar genetic and autoantibody markers to people who progressed more quickly. However, for some of them the autoantibodies faded/reduced over time and there were some differences in the immune cells which might help explain why the damage to their beta cells is relatively slow.
Type 1 Diabetes in Adults
Type 1 diabetes is often diagnosed in childhood, however more than half of all cases are diagnosed in adults. Scientists have found definite genetic and immune differences between adult and childhood-onset type 1 diabetes but these are not well understood. Adult type 1 diabetes is often less aggressive or progresses slowly and may not immediately require insulin at diagnosis, this can lead to cases being misdiagnosed as type 2 diabetes with incorrect treatment.
T1DRA aims to increase our understanding of adult type 1 diabetes by identifying the level of risk in the general population and by follow up those found to be at risk.
What are the benefits of research?
Participating in research helps scientist expand their knowledge of conditions which hopefully leads to better diagnosis, treatment and ultimately the prevention of diseases. Currently most type 1 diabetes research has focused on children. We would like to find out more about the disease in adults and determine the amount of autoimmune risk in our population. We cannot do this without participants who are willing to help.
In order to accurately represent the UK adult population, we want to encourage participation from all ethnic backgrounds.
Will participating benefit you?
Participation may not directly benefit you in any way. However, if you find out you are at increased risk of developing type 1 diabetes, that information can help prevent you from becoming seriously unwell by getting an early diagnosis. People with at risk markers may also be eligible to join clinical trials which could delay or prevent disease.
What are the follow up samples used for?
If you are identified as someone who has risk markers in their blood we will request further samples from you to monitor your markers and help with our research.
Mouth swab sample: We use the mouth swab sample to extract DNA for genetic testing. We do not report this back to you as it is used for population trends and isn’t diagnostically relevant to an individual.
Urine sample: We use urine to test for C-peptide. C-peptide a protein that is produced and released by the pancreas as a result of natural insulin production. Measuring the levels of C-peptide in urine collected 2 hours after a big meal gives us a good indication of how much insulin the pancreas is producing. People who have had type 1 diabetes for a while often have no detectable C-peptide in their urine, showing their pancreas is no longer producing insulin.
Finger prick blood sample into a purple top tube (EDTA): This sample is used to measure glycated haemoglobin (HbA1c) which shows your average blood glucose levels over the last two to three months. Higher than normal levels can be the first indication that your pancreas is struggling to produce enough insulin to turn your blood glucose into energy. We will inform you if your HbA1c result is above the normal range so that you can inform your GP.
Finger prick blood sample into a brown top tube – yearly repeat for autoantibody tests: We will send repeat of the original finger prick kit once a year to monitor the autoantibodies in your blood. We will inform you of the result and give you more information if the number of antibodies has changed.
Stool sample: We test stool samples for markers of pancreatic function. These markers can help us study what is happening in the pancreas of people that have tested positive for islet autoimmunity. These results are not reported to participants, the data is used to increase our understanding of the disease and it’s progression.