Understand the challenges of celiac disease diagnosis
Only 15% of people with the disease are diagnosed
Traditionally, celiac disease was considered to occur primarily in children. However, recent research shows that the disease presents in adults even more commonly than in children. This is primarily because celiac disease can first appear and be diagnosed at any adult age. Approximately 20% of patients are older than 55 years at the time of diagnosis.
Children often present with gastrointestinal symptoms. In contrast, adults usually present with fewer digestive manifestations, the absence of malabsorption, and extra-digestive complaints with various accompanying conditions, thereby rendering diagnosis more challenging.
Because of these diagnostic challenges, an estimated 90% of people with celiac disease remain undiagnosed.
Antibody and genetic tests aid diagnosis
In a person suspected of having celiac disease, antibody blood testing is the first step in diagnosis. Levels of the following antibodies are measured:
- Anti-tissue transglutaminase (tTG)
- Anti-endomysium (EMA)
- Anti-deamidated gliadin peptides (DGP)
Genetic testing is also useful to confirm that genes necessary to develop the disease are present. These genes include:
For more information, see Screening.
Endoscopic biopsy is required
Definitive diagnosis depends on a positive small bowel biopsy and a demonstrated response to a gluten-free diet. Diagnostic criteria include architectural changes in the small intestine, including mucosal villous atrophy with crypt hyperplasia and increased intraepithelial lymphocytosis. The rate of change may be slow and the changes nonspecific.
Multiple tissue samples are vital to an accurate diagnosis. Celiac disease can cause patchy lesions in the duodenum, which can be missed if only 1 or 2 samples are taken. Research shows that when only 2 duodenal biopsies are obtained, diagnosis is confirmed in 90% of cases. However, 3 and 4 biopsies increased detection to 95% and 100%, respectively.
Marsh Scores rate intestinal damage
Biopsies are given a celiac disease Marsh Score. Scores range from stage 0 (normal intestinal mucosa, celiac disease unlikely) to stage 3 (villi are totally atrophied and crypts are elongated and increased in number). Unfortunately, celiac disease is not the only disorder that can cause these changes. A celiac disease diagnosis, therefore, must be confirmed through other blood tests and the patient’s response to a gluten-free diet.
Early diagnosis is beneficial
Early diagnosis and treatment are important in celiac disease because associated complications may be irreversible unless the disease is treated. Celiac disease−related tooth discoloration, enamel loss, and growth failure may remain permanent if not treated early. Delayed diagnosis is also associated with increased risk of developing other autoimmune disorders, osteoporosis, or malignancy, and even causing death.
For more information
Learn more about the challenges of diagnosis in the Diagnosis of Celiac Disease Factsheet.