In type 1 diabetes, the body’s immune system mistakenly identifies insulin-making cells as a threat and sets about destroying them.
Thanks to decades of research, scientists have been able to home in on what happens in the immune system in the months and years before someone is diagnosed with type 1.
They’ve discovered signs that tell us the immune attack that causes the condition has begun. We can spot these signs, called autoantibodies, with a simple blood test and find people will almost certainly develop type 1 diabetes in the future. This opens a window to use new treatments, called immunotherapies, to delay or prevent type 1 diabetes from developing.
What are autoantibodies?
Our immune system normally makes antibodies to help us fight illnesses and infections. Antibodies stick to the surface of harmful bacteria or virus and alert the immune system that they need to be destroyed.
But when the immune system starts attacking your own body, like it does in people with type 1 diabetes, it makes autoantibodies instead. In type 1 diabetes, the autoantibodies are designed to attach to insulin-making beta cells and earmark them for destruction. They can appear in the blood years, or sometimes decades, before you get any symptoms of type 1 diabetes.
Because of this, we can test for autoantibodies to predict if someone is likely to develop type 1 diabetes in their lifetime. This is known as type 1 diabetes screening.
How can I get tested?
Type 1 diabetes screening is only available as part of research studies at the moment. In the UK, the ELSA study is screening 20,000 children aged 3-13 to test them for autoantibodies with a quick finger prick blood test. ELSA is funded by Diabetes UK and JDRF and will answer important questions that could help to make type 1 diabetes screening in children a reality in the UK.
Any child aged 3-13 years can take part in ELSA and find out their risk of developing type 1 diabetes in the future. ELSA is currently recruiting nationwide.
Adults aged between 18 and 70 years can sign up for a similar study, called the T1DRA study. It's recruiting 20,000 adults to identify those at high risk and understand more about how type 1 diabetes develops in adults.
People aged 45 years or younger who have a close family members living with type 1 diabetes can also sign up to a research project, called INNODIA. If you’re eligible to take part, you could be tested for autoantibodies.
What does it mean if I have autoantibodies?
There are different parts of beta cells that the immune system homes in on and produces autoantibodies against. Type 1 diabetes screening tells if you have autoantibodies and how many you have. Your risk of developing type 1 diabetes increases with the number of autoantibodies found. Here's what your results could mean:
- You have no autoantibodies. This means you're at low risk of developing type 1 diabetes. It's not a guarantee that you'll never get the condition, but we know your immune system isn't planning an attack at the moment.
- You have one autoantibody. You have a higher risk of developing type 1 in the future than someone who has no autoantibodies. Autoantibodies can increase, stay the same or decrease over time. It might be helpful to get retested later on to keep an eye on this.
- You have two or more autoantibodies. At this point, type 1 diabetes has started to develop. We know that for children, your likelihood of being diagnosed with the condition within the next 15 years is around 85%. And you have almost a 100% chance of getting a diagnosis in your lifetime. At this stage, you can still have normal blood sugar levels and not need any treatment. Over the following months or years, your immune system will start to kill off more and more beta cells. Once so many have been destroyed that you’re no longer able to make enough of your own insulin, blood sugar levels become high and the symptoms of type 1 diabetes appear. This is usually the point you’d get diagnosed.
How screening could help
Screening for type 1 diabetes could give a window of opportunity to make sure people have the best possible start to life with type 1 diabetes. The benefits could include:
Early diagnosis and treatment
Around 25% of children don’t get diagnosed with type 1 diabetes until they are in potentially life-threatening diabetic ketoacidosis (DKA). Finding out early who is at high risk gives healthcare professionals the chance to follow them up closely and start treatment sooner, before blood sugar levels become dangerously high.
Researchers have shown that screening children for type 1 diabetes can dramatically reduce the risk of DKA at diagnosis by around five times.
There’s also evidence that starting insulin sooner and avoiding DKA at diagnosis can have benefits years down the line. It has been linked with closer-to-target blood sugar levels over 15 years later, which we know can help to protect against diabetes complications.
Time to prepare
Knowing who is at high risk could also give people the support and education they need to prepare for living with type 1 diabetes, including learning about insulin injections, carb counting and hypos. This could give a ‘soft landing’ into life with type 1 diabetes.
Access to new treatments
People at high risk could be eligible to take part in research studies testing promising treatments that tackle the root cause of type 1 diabetes and aim to hold off it development or even prevent it entirely.
But finding out your or your child’s risk is a very personal decision. For some people, knowing you’re very likely to one day develop type 1 diabetes can cause real anxiety. And because screening is only available within research studies, healthcare services aren’t fully equipped yet to make sure people at risk get the right support and follow up care they need.
We also know that autoantibody testing isn’t failproof. Not everyone with type 1 diabetes has autoantibodies and autoantibodies can disappear. This means some people at risk could test negative and fall through the cracks.
Can type 1 diabetes be prevented or delayed?
Our scientists are busy testing new treatments for type 1 diabetes, called immunotherapies. They are designed to reprogramme the immune system to halt its attack, and delay or prevent a type 1 diagnosis.
In November 2022, the first ever immunotherapy to delay type 1 diabetes was approved for use in the United States. The drug, called teplizumab, can delay a diagnosis of type 1 by up to three years in people at high risk (those who had at least two autoantibodies). That’s three years without insulin injections, testing your blood sugars, carb counting, or worrying about complications.
Teplizumab isn't available in the UK yet, but it's under review right now with the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) who make decisions on whether breakthrough treatments are safe and effective and should be made available for use here in the UK.
These game-changing developments provide real hope that with more research, immunotherapies could extend the delay and move us closer to preventing the condition altogether.
If teplizumab does get the green light for use in the UK, we would need to know who to give it to. This is when screening for type 1 diabetes could become invaluable – helping to find people at risk who could benefit from the immunotherapy.
The future of screening
The ELSA study and further research will be vital to lay the groundwork for widespread routine type 1 diabetes screening in the UK. Important questions we need to answer include:
- What’s the best way to screen for type 1 diabetes risk?
- When’s the best age to screen people?
- How is it best to care for people who are at risk, including looking after their physical and emotional health?
- How can we improve knowledge about type 1 diabetes among the general public so more people see the value of screening and are willing to take part?
- Do the potential benefits of screening outweigh any negatives?
- Is screening cost-effective for the NHS?
We’ll continue funding research and working with key players in the NHS to pave the way for a future where we no longer wait until type 1 diabetes develops to treat it. Screening could make sure everyone has the earliest, safest diagnosis possible, and access to transformative new treatments.
If you’re worried about your or your child’s risk of type 1 diabetes, the most important thing you can do is be aware the signs and symptoms of the condition and to see a healthcare professional if you notice any of them.
