Celiac disease (CD) is a chronic autoimmune disorder in which ingestion of gluten triggers an immune attack on the small intestine in genetically predisposed individuals. Affecting roughly one percent of the global population, its classic form is characterized by damage to the small bowel mucosa, leading to malabsorption and a range of gastrointestinal symptoms, including chronic diarrhea, abdominal pain and distension, weight loss, and, in children, poor growth.
However, recent screening studies in children and adolescents suggest that the prevalence of CD may be much higher, reaching approximately three percent in certain populations. This suggests the need for more systematic and accurate diagnostic approaches, as a large number of cases likely remain undetected.
For many patients, though, the journey to diagnosis is long, uncertain, and often invasive. A recent qualitative study in the British Journal of General Practice found that adults with CD frequently experience long delays before receiving a diagnosis, with another study estimating the average wait at 13 years. These delays can take a significant toll on quality of life and may carry long-term health consequences, including impaired bone health and increased risk of malignancy.
Traditionally, diagnosis relies on serological testing followed by intestinal biopsy, which remains the gold standard for confirming CD. However, this approach is invasive and requires patients to maintain a gluten-containing diet, a process that can be physically and emotionally burdensome. Now, a new study suggests that a simple blood test could soon provide much of the same information, and maybe more.
Researchers from Adaptive Biotechnologies, in collaboration with investigators from Mayo Clinic and other institutions, recently shared the discovery of shared T-cell receptor (TCR) signatures in the blood of people with CD that strongly distinguish them from healthy controls — and that are independent of gluten intake. The study, currently available as a preprint, uses high-throughput immune sequencing to reveal patterns in the adaptive immune system that may finally allow clinicians to monitor disease without invasive testing.
Why T cells matter
CD is fundamentally a T-cell-mediated autoimmune condition. In genetically susceptible people, exposure to gluten triggers CD4⁺ T cells in the intestine, activating a cascade of immune activity that mediates intestinal damage. This leads to villous atrophy, malabsorption, and a range of gastrointestinal and systemic symptoms. Traditionally, researchers and clinicians have focused on these gluten-reactive T cells in the gut to understand disease.
However, there’s other important information in the bloodstream too. “By sequencing an individual’s TCR repertoire, we get a full, accurate picture of that person’s T cell response to disease antigens,” Rebecca Elyanow, Associate Principal Computational Biologist at Adaptive, told DDN.
Where traditional tests capture only antibodies or tissue changes at a single point in time, deep TCR sequencing reveals the full landscape of adaptive immune responses in celiac disease, providing insights that could improve both diagnosis and patient care.
In the study, researchers performed high-throughput TCR-beta sequencing on peripheral blood from over 1,600 biopsy-confirmed celiac disease patients, including individuals on long-term gluten-free diets, and compared them with more than 1,100 healthy controls. They identified hundreds of shared, disease-associated TCRs that were enriched specifically in patients with CD. Importantly, these signatures were detectable regardless of gluten intake, reflecting persistent memory T-cell populations that remain in circulation even when intestinal inflammation is absent.
“By taking this population scale, unbiased approach, we capture a broader set of CD-specific T cells that are gluten-specific, including those that might not bind to the set of known gluten antigens,” said Elyanow.
Why TCR sequencing
The concept of shared or "public" TCRs might seem surprising given the enormous diversity of the adaptive immune system. Each T cell develops a unique TCR through random recombination, producing billions of possible receptors that vary widely between individuals. However, biases in receptor generation and selection mean that certain sequences recur across many people. These shared TCRs can reflect common antigen exposures or underlying disease processes, making them powerful biomarkers for conditions like CD.
What makes the Adaptive team’s findings compelling is that the celiac-associated TCRs they identified are enriched specifically in patients compared with controls and persist even when gluten has been removed from the diet. This persistence suggests that these T cells represent long-lived memory responses or ongoing disease-associated immune activity.
“Our data demonstrates that these T cells are memory cells because they remain clonally expanded even after individuals have been on gluten-free diets for several years,” Elyanow explained. “That is why the public CD T-cell signature that we identified could be used to diagnose early onset of celiac disease.”
Towards a non-invasive diagnostic
For clinicians and patients, one of the most exciting implications of this work is the potential for a blood-based test that could reduce or even replace the need for intestinal biopsies. The new TCR signatures identified by the researchers show a robust correlation with disease status and intestinal damage severity — raising the possibility that TCR sequencing could serve as a sensitive, non-invasive biomarker of disease activity.
“This is certainly our hope, particularly given that we only need a small amount of blood to detect these TCRs,” Elyanow said. “Our data indicate that TCR sequencing could potentially be used as a non-invasive option to quantify and longitudinally monitor the level of these disease-specific TCRs.” However, she noted that a definitive study linking TCR dynamics with biopsy results over time would be needed to fully validate this application.
Tracking disease progression and treatment response
Beyond its diagnostic utility, unbiased TCR profiling could be a powerful tool in clinical trials and disease monitoring. As new therapies for CD advance through development, being able to track changes in disease-associated T cell populations could provide insights into treatment efficacy long before clinical symptoms change.
“Many pharma and biotech companies are already using our TCR sequencing assay in clinical trials to understand patients’ T-cell responses before and after therapy,” Elyanow said. “As drugs currently under development for celiac disease become available, our CD T cell signature could be used to monitor treatment response by measuring the reduction or elimination of these pathogenic T cells.”
A better approach for autoimmune diseases
While this study focuses on CD, its implications extend beyond a single condition. Similar TCR-based approaches have shown promise in other disorders, and the concept of using immune repertoire signatures as diagnostic and prognostic biomarkers is gaining traction across fields. Techniques that integrate immune profiling with machine learning have already demonstrated high performance in classifying complex conditions like lupus and multiple sclerosis.
For patients, this could mean earlier diagnosis, fewer invasive procedures, and greater confidence in tracking disease without the uncertainty of gluten reintroduction. For clinicians and researchers, TCR sequencing provides a window into the underlying biology of disease, enabling more precise, personalized approaches to care. As the field continues to expand, this technology may transform how autoimmune diseases are diagnosed, monitored, and ultimately treated — moving medicine toward solutions that are both less invasive and more tailored to each patient’s immune profile.
