Coeliac disease is an autoimmune condition in which the body’s immune system reacts adversely to gluten. When a person with coeliac disease eats food containing gluten, inflammation develops in the gut. This damages the intestine and impairs its ability to absorb nutrients from food.
In Norway, around one to two in every 100 people have coeliac disease, according to Helsenorge, Norway’s official public health portal. The treatment is to avoid gluten entirely.
“Many people with coeliac disease are very diligent in following the diet, but they still live with uncertainty because the blood tests do not always give clear answers about how the disease is progressing,” says Jostein Holen Ibsen, a PhD fellow and physician.
Could new biomarkers provide better answers?
Biomarkers are measurable substances in the body that may indicate disease activity. In a new study, Ibsen and his colleagues explored one possible approach. They measured proteins in the blood of people with coeliac disease, both before and after they began treatment.
“The findings show that some of these proteins may provide information that can be used to monitor patients,” says Ibsen, who works at the Norwegian Coeliac Disease Research Centre at the University of Oslo and the Clinical and Translational Coeliac Disease Centre at Oslo University Hospital.
The study is published in Gastroenterology.
The researchers identified several proteins linked to intestinal damage
Proteins help to build and drive almost every process in the body. Levels of different proteins in the blood can therefore provide insights into what is happening inside it.
In the study, the researchers examined proteins produced during inflammation, one of the hallmarks of coeliac disease. They wanted to find out whether the levels of these biomarkers in the blood reflect inflammation in the gut.
“In the study, we identified 24 proteins associated with coeliac disease that tell us something about disease activity,” Ibsen explains.
“Nine of these, in particular, can tell us about the extent of damage in the gut and may therefore indicate how far the disease has progressed,” he continues.
Several of the proteins identified by the researchers had not been detected in previous studies.
“I am surprised that we found so many. It is incredibly exciting when research produces such clear answers,” Ibsen says.
Current blood tests can be somewhat misleading
Today, coeliac disease is usually diagnosed using a blood test and an examination known as a gastroscopy, during which doctors take tissue samples from the small intestine. The blood test currently used measures levels of the transglutaminase antibody, known as anti-tTG IgA, as well as total IgA levels.
Patients diagnosed with coeliac disease are followed up by their GP. Most improve considerably, and the gut may gradually heal. To monitor how patients are doing over time, doctors repeat the same blood test.
“The problem with this blood test is that it simply does not work as well once patients have started treatment with a gluten-free diet,” Ibsen says.
“We have research showing that it can be somewhat misleading about what is actually happening in the gut,” he adds.
Patients on a gluten-free diet still had some inflammation in the gut
The researchers examined blood and tissue samples from patients with coeliac disease at Oslo University Hospital. The samples had been collected at two points in time: before treatment began and after one year on a gluten-free diet. They also studied samples from people without coeliac disease. All participants had consented to their samples being used for research.
In total, they analysed 264 samples. The researchers used a method known as proteomics, which enables large numbers of proteins to be analysed simultaneously.
“For many of the proteins, we found a clear difference between people with untreated coeliac disease and healthy individuals,” Ibsen says.
People with coeliac disease who had not yet started treatment had the highest levels of inflammatory proteins, while healthy individuals had the lowest.
“However, we also found a clear difference in the proteins measured in patients before and after treatment. This shows that proteins in the blood can provide detailed information about the degree of inflammation and healing in the gut,” he says.
In addition, people with coeliac disease who followed a gluten-free diet had slightly higher levels than healthy individuals.
“The findings therefore suggest that patients have some inflammation in the gut even when they follow the diet,” he says.
Better tests could provide more reassuring follow-up for people with coeliac disease
The researchers hope that the study’s findings may pave the way for better methods of monitoring patients with coeliac disease. According to Ibsen, there is a great need for this.
“Tests based on new biomarkers should not replace the biomarkers we use today. However, they could help to provide a more accurate picture of how the disease is developing and offer more reassuring follow-up.”
Professor Knut E. A. Lundin is also highly positive about the study’s findings.
“There is potential for tests based on these new biomarkers to be used alongside serology, which is the test used today and which does not distinguish clearly enough between ongoing intestinal damage and healing,” Professor Lundin says.
Ibsen believes that new biomarkers could also potentially be used to detect the disease earlier than is currently possible.
“However, we are still some distance away from being able to put this method into practice. We first need to carry out more studies involving more patients. We also need to select a number of proteins that we believe hold the greatest promise and investigate them further,” he stresses.
Patient contributions are vital to the research
The samples used in the study were collected from patients with coeliac disease at Rikshospitalet between 2018 and 2024.
“It is so valuable and important that patients donate samples to us. Patient contributions to research are crucial. Without them, we would not have been able to conduct this research,” Ibsen says.
“I would therefore like to thank the patients and healthy control participants who consented to take part,” he adds.
The study was conducted at the Norwegian Coeliac Disease Research Centre at the University of Oslo and the Clinical and Translational Coeliac Disease Centre at Oslo University Hospital.
Jostein Holen Ibsen’s supervisors are Professor Knut E. A. Lundin and researcher Louise Fremgaard Risnes.
Reference
Ibsen, J. H., Stamnæs, J., Lund, S. R., Sollid, L. M., Risnes, L. F., & Lundin, K. E. (2026). Targeted Serum Proteomics Reveals Profiles Associated With Gut Pathology in Celiac Disease. Gastroenterology. doi: https://doi.org/10.1053/j.gastro.2026.07.033
