Correlation of Tissue Transglutaminase Antibody with Duodenal Histologic Marsh Grading

BACKGROUND Recent guidelines have proposed that there is a correlation between tissue transglutaminase (tTG) antibody titers and degrees of duodenal biopsy, and that duodenal biopsy can be omitted in some patients with high levels of tTG antibody. Using data of registered patients in a gastrointestinal clinic we aimed to assess the correlation between tissue transglutaminase antibody with duodenal histologic Marsh grading in Iranian patients with celiac disease. METHODS We retrospectively reviewed hospital files of registered patients in the gastrointestinal clinic of Firoozgar Hospital, Tehran, Iran. Demographic, laboratory, and histology data of those who had tTG titer and pathology reports of duodenal biopsy based on the modified Marsh classification were extracted and used for the study. RESULTS 159 patients with available tTG titer and pathology reports were enrolled in our study. Mean ±SD of the patients was 35.6±15.2 and 100 (62.9%) of them were women. 133 out of 153 patients had villous atrophy (Marsh IIIa-IIIc). Anemia was the most common sign and bloating, abdominal pain, and diarrhea were the first three common symptoms in these patients. Mean tTG titers was significantly higher in patients graded as Marsh III (p for trend=0.003). Our results showed that tTG titer more than 9 folds higher than the kit’s cut-off value was about 97.2% sensitive for Marsh II and more duodenal damage. CONCLUSION There was a correlation between tTG titers and degrees of duodenal damage in patients with celiac disease. Duodenal biopsy is not always necessary for diagnosing celiac disease and when tTG level is more than 9 folds higher than the manufacture’s recommended cut-off value it can be avoided. Meanwhile in case of high clinical suspicion, low tTG levels do not exclude diagnosis of celiac disease and further investigations including small intestinal biopsy should be considered.