Celiac Disease Blood Test to Eliminate Painful Biopsies

There is still a controversy over whether it is possible to diagnose celiac disease in adults using only serology. Now, a study has found that a simple test for measuring the levels of anti-tissue transglutaminase IgA (tTG-IgA) in the blood could be used as a diagnostic threshold in predicting duodenal villous atrophy, a key feature of celiac disease.

Researchers from the University of Salerno (Fisciano SA, Italy) conducted a study on a cohort of individuals suspected to have celiac disease. After certain exclusions, the final cohort included 436 individuals, comprising 296 women and 140 men, with an average age of 40. These participants hailed from various global regions, mostly Europe, followed by Asia, Oceania, and South America.

Based on their symptoms, the participants were divided into three categories: those showing classical symptoms like anemia, weight loss, or diarrhea; those with atypical symptoms; and those who were suspected to have celiac disease based on family history or other associated autoimmune conditions. Duodenal tissue samples were collected from the participants via endoscopy and were assessed by local pathologists at 14 different sites. Additionally, tTG-IgA levels were measured in both local and central labs. A result was considered positive if tTG-IgA levels exceeded one time the upper limit of normal (ULN).

Out of the cohort, 363 participants (or 83%) had tTG-IgA levels above the threshold, while 73 (or 17%) had levels below it. Among those with elevated tTG-IgA, 341 were confirmed to have celiac disease through histological review, whereas 22 did not have the disease. Of the participants with low tTG-IgA, seven were false negatives with positive histology, and 66 were true negatives. Importantly, the study found that tTG-IgA concentrations that were 5, 10, or 15 times higher than the ULN offered the most reliable diagnostic accuracy, suggesting that 10 times the ULN could be a useful diagnostic threshold. This study validates the use of a blood test for diagnosing celiac disease in adults, similar to the "no-biopsy" approach currently used in children. The detailed findings of the study were published in The Lancet Gastroenterology & Hepatology.

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University of Salerno