Does Serum Anti-tissue Transglutaminase Level Predict Duodenal Histopathology and Clinical Manifestations of Celiac Disease in Adults?

Background: Celiac disease (CD) is an autoimmune disorder triggered by gluten ingestion. This study aimed to evaluate the correlation between anti-tTG antibodies and histopathology, as classified by the Marsh system, and clinical manifestations. Methods: This retrospective cross-sectional study analyzed the records of 346 patients with confirmed CD from 2010 to 2021. Anti-tTG levels, clinical manifestations, body mass index (BMI), and pathological results were reviewed. Results: This study included 346 patients (mean age 26.5±16.6 years; 56.4% female). Most patients (53.2%) had atypical CD, and normal BMI was prevalent (57.1%). Common symptoms included anxiety (70.2%), fatigue/weakness (64.2%), borborygmi (53.2%), abdominal pain (51.2%), and bloating (46.8%). Disease severity analysis revealed 75.1% had Marsh III, while 15.9% had normal/Marsh I and 9.0% had Marsh II. Anti-tTG levels were significantly higher in advanced Marsh classes (Marsh III: 169.27±180.17 vs. normal/Marsh I: 70.94±116.45, P<0.001) and in typical CD (180.44±216.22) compared to atypical CD (126.20±121.72, P=0.005). Diarrhea, arthralgia, and osteoporosis/osteomalacia showed significant correlations with anti-tTG levels (P<0.05). ROC analysis for anti-tTG in diagnosing Marsh II or higher yielded an AUC of 0.733. Conclusion: Anti-tTG demonstrated moderate diagnostic accuracy for advanced duodenal damage, highlighting its utility as a biomarker in CD. Larger studies are needed to validate these findings further.