Intestinal epithelium, intraepithelial lymphocytes and the gut microbiota - Key players in the pathogenesis of celiac disease

Figure 4 A schematic illustration of progressive histopathological changes in the small intestine according to the modified Marsh-Oberhuber grading scale. Type 0: Normal mucosa with IEL count < 25 per 100 enterocytes; Type 1: Normal mucosa with an increased IEL count; Types 2 and 3 show increased IEL counts and lymphocytes in the lamina propria. IELs are presented as black dots. IEL: Intraepithelial lymphocyte.