Figure 9: (a) Normal duodenal mucosa with a villous crypt ratio of 2 : 1 (Corazza Grade A, Marsh Type 0, Oberhuber Type 0) and negative serology. (b) Duodenal mucosa with partial villous atrophy, villous crypt ratio of 1 : 1, and an intraepithelial lymphocyte (IELs) count of 30 per 100 enterocytes (Corazza Grade B1). Brunner’s glands are present. Serological levels of tissue transglutaminase (tTg)>100 EliA U/ml and strongly positive for endomysial antibodies (EMA). (c) Duodenal mucosa with total villous atrophy with an IEL count of 60 per 100 enterocytes, crypt hyperplasia, eosinophil infiltrate, and numerous occurrences of mitoses in established celiac histopathological analysis (Corazza Grade B2, Marsh Type 3, Oberhuber Type 3c). Tissue transglutaminase (tTg) levels>100 EliA U/ml and strongly positive for endomysial antibodies (EMA) 3.