Comparison and importance of bulb and distal duedonum biopsies in diagnosis of celiac disease

Aim: Duedonal bulb is accepted as the first region of duedonum that interaction with gluten occurs in. That's why, we have aimed evaluating the importance of bulbus biopsy in patients with suspected Celiac disease and comparised the biopsies of bulbus and distal duedonum according to Modified Marsh-Oberhuber scoring, intraepithelial lymphocyte count, villus atrophy and crypt hyperplasia. Materials and Methods: The study was performed with biopsies taken by Zonguldak Bulent Ecevit University Department of Pediatric Gastroenterology. Biopsies were evaluated by Zonguldak Bulent Ecevit University Medical Pathology Laboratory. Results: In total, 35 Celiac disease patients were included in the study. We detected bulb involvement in all Celiac patients. When bulbus (D1) and distal duedonum (D2) samples were comparised according to Modified Marsh-Oberhuber scoring, we detected 17 patients with different D1 and D2 biopsies. Bulb involvement was more severe 6 of them, whereas D2 involvement was more severe 10 of them. We haven't detected any patient with only D1 or D2 involvement. Intraepithelial lymphocyte (IEL) count was different in 7 patients, whereas D1 and D2 were more severe in 1 and 6 patients, respectively. When IEL distribution was evaluated, difference was observed in 12 patients. D1 involvement was more severe in 3 patients, whereas distal involvement was more severe in 9 patients. Villus crypt (V/C) ratio was found different in 15 patients. Atrophy was more severe in D1 for 6 patients and in D2 for 9 patients. Discussion-Conclusion: Although the severity of involvement in D1 and D2 varies from patient to patient, pathological clasification of all Celiac disease findings, such as Marsh classification, is created considering the distal duedonum and the evaluation of these findings in the bulbus according to these scores may be misleading. Therefore, it may be possible to make different interpretations, after development of bulb-specific staging. Although it was not observed in our study, it should be kept in mind that Ultra-Short Celiac disease (USCD) can be observed in patients evaluated due to serological positivity but who have been detected with normal distal duedonal biopsies. Therefore, biopsy from the bulb should not be omitted, even if the appearance is completely normal on endoscopic evaluation. In contrast to USCD, some patients have distal duodenal involvement without bulbus involvement. That's why, bulb and distal duodenal biopsies should be perfomed together in the diagnosis of CD.