Disposable device for coeliacs

Earlier diagnosis of coeliac disease could soon be possible with a £10m (€13m) project aimed at creating a portable screening device.

Earlier diagnosis of coeliac disease, a potentially life-threatening autoimmune condition caused by gluten intolerance, could soon be possible with a £10m (€13m) project aimed at creating a portable screening device.

The EC has partly funded a partnership of 20 organisations across Europe to work on the CD-MEDICS (coeliac disease management monitoring diagnosis using biosensors and integrated chip systems) project. The aim is to develop a testing device that can be used in a GP’s surgery to diagnose and monitor people with the disease.

‘We will have a disposable, completely integrated polymer chip which is put into an instrument, such as a small laptop, which will have embedded communication abilities so that the results of the test are automatically sent to the patient’s electronic medical records,’ claimed project co-ordinator Dr Ciara O’Sullivan.

‘You apply a finger prick of blood on to the chip, press a button and, in 10 to 15 minutes you will have the results,’ she added.

The researchers aim to produce three different chips — one for primary diagnosis, one for regular monitoring of a person diagnosed with coeliac disease and one to test new-born babies so their diet can be carefully controlled.

For people with the disease, eating gluten damages the lining of the gut, which prevents normal digestion and the absorption of food and nutrients. The only way to treat the condition is to maintain a strict gluten-free diet.

At present, the primary diagnosis of the condition involves a blood test that is sent to a pathology lab, and if the results come back positive, an individual would then need to have a minor bowel biopsy to discover what is happening to the gut.

The researchers hope to eventually eliminate the need for a biopsy by using the device to look for genetic markers and certain autoantibodies associated with the disease. The presence of HLA-DQ2 and DQ8 genes indicate a person’s genetic predisposition to the condition. the scientists aim to sense autoantibodies such as gliadins.

‘In a primary diagnosis, when we introduce a drop of blood on to a chip, it gets divided into two streams — one to the genetic analysis and one for the antibody analysis.

‘For the genetic analysis, we have a PCR [polymerase chain reaction — a process for amplifying DNA] inbuilt into the chip and then this goes on to be detected by biosensor arrays. We have specific probes immobilised on an electrode surface that detects different HLA-associated amplicons — the products of PCR.

‘On the other side, we look at different antibody levels, transglutaminase, gliadins and glutens. We need the two things to be combined for the primary diagnosis because very often people have very low antibody levels. but if you see there is a predisposition and they have the symptoms, then you follow the antibody levels more closely,’ said O’Sullivan.

The second chip the researchers plan to develop will look just at the levels of antibodies, which will benefit people who require regular monitoring after being diagnosed with the condition.

‘Gluten is often hidden in products, particularly processed foods. Some people find it very difficult to maintain the diet, so this particular test will be potentially very useful for people who are newly diagnosed and trying to get used to the diet in the first year or two.

It will also allow the doctor to see pretty quickly whether they are still ingesting gluten or not. That will be an improvement because they do not often use blood testing to look for that because it means sending it off to the pathology lab and so on,’ said Sarah Sleet, chief executive of Coeliac UK, one of the consortium members.

Finally, the third chip will have just the biosensing platform for HLA genes, which would be useful for new-born babies who do not have antibodies and will not have yet eaten gluten.

While the technology will have obvious benefits to those with coeliac disease, O’Sullivan also highlighted its cost advantages.

‘Predisposition tests are generally just done for families, so if one person is diagnosed, the other members of the family are checked. It is expensive to do so because it has to be sent to a lab.

‘The new method is cheap because the test is all done in situ, there is no need for sending away, no specialist personnel and there are no sterilisation issues,’ she said.

The researchers are aiming to develop an antibody chip that will cost €15, a combined chip for €30 and a HLA gene chip for €20.