Researchers from the University of Salerno in Italy have discovered that a simple blood test for tTG-IgA concentrations could serve as a diagnostic tool for predicting duodenal villous atrophy, a characteristic feature of celiac disease. The findings of their study, titled “Serum anti-tissue transglutaminase IgA and prediction of duodenal villous atrophy in adults with suspected celiac disease without IgA deficiency (Bi.A.CeD): a multicentre, prospective cohort study,” were published in The Lancet Gastroenterology & Hepatology.
The study involved a cohort of 436 participants suspected to have celiac disease and compared the diagnostic abilities of blood serum thresholds with endoscopy biopsies. The participants, recruited from various regions around the world, were divided into three groups based on their symptoms and clinical presentation.
Local pathologists at 14 different sites analyzed duodenal biopsy specimens from the participants and conducted histological assessments. Blood samples were collected to measure tTG-IgA concentrations in both local and central laboratories. A threshold of 1 times the upper limit of normal (ULN) was set for tTG-IgA, and concentrations greater than this threshold were considered positive.
The results showed that 363 participants (83%) had positive serum tTG-IgA, while 73 participants (17%) had negative serum tTG-IgA. Among those with positive serum tTG-IgA, 341 had positive histology (true positives), and 22 had negative histology (false positives) upon review. Seven of the 73 participants with negative serum tTG-IgA had positive histology (false negatives), and 66 had negative histology (true negatives) upon review.
Further analysis revealed that blood tTG-IgA concentrations greater than 5, 10, and 15 times the ULN had higher prediction power for diagnosing celiac disease. The researchers suggest that 10 times the ULN may be a useful threshold for clinical diagnosis.
This study supports the use of a simple blood test as a diagnostic tool for adults with suspected celiac disease. It aligns with the current diagnostic approach in children, which involves a “no-biopsy” strategy. With further research and implementation, this blood test could provide a quicker and less invasive method of diagnosing celiac disease in adults.
– Carolina Ciacci et al, Serum anti-tissue transglutaminase IgA and prediction of duodenal villous atrophy in adults with suspected coeliac disease without IgA deficiency (Bi.A.CeD): a multicentre, prospective cohort study, The Lancet Gastroenterology & Hepatology (2023). DOI: 10.1016/S2468-1253(23)00205-4