Table 3.
Most common duodenal infections potentially mimicking gluten-sensitive enteropathy
| Agent | Villi | CH | LPI | IELs | PMNs | Sup.-D. | Target | Site | Stain | |
| Giardiasis | G. lamblia | 0-3A | Nil | 0/+/++ | < 20/↑ | Rarely | Nil | None | IL | GS |
| Cryptosporidia | C. parvum | 1-3A | + | +/++ | < 20 | Focal | Focally | Enterocytes | IE | WS |
| Microsporidia | E. bieneusi | 1-3A | + | +/++ | < 20 | Nil | Focally | Enterocytes/macrophages | IEv/ IEc | WS |
| E. intestinalis | ||||||||||
| Cyclospora | C. coyetanensis | 1-3A | + | +/++ | < 20/↑ | Nil | Focally | Enterocytes | IEv | NA |
| Isospora | I. belli | 1-3A | + | +/++ | < 20 | Nil | Focally | Enterocytes | IEv | NA |
| Whipple D | T. whipplei | 1-3A | Nil | ++1 | ↑ | Nil | Nil | Macrophages | LP | PAS |
| ZN | ||||||||||
| MAI | M. avium intracellulare | 1-3A | Nil | ++1 | < 20 | Nil | Nil | Macrophages | LP | PAS |
| ZN | ||||||||||
| AR | ||||||||||
| Leishmaniasis | L. donovani | 1-3A | Nil | +/++ | < 20 | Nil | Nil | Macrophages | LP | NA |
| Cryptococcosis | C. neoformans | 1-3A | Nil | 0/+ | < 20 | Nil | Nil | None | LP | DPAS |
| MS | ||||||||||
| CMV | Cytomegalovirus | Ulcers | 2 | +/++ | < 20/↑ | +/- | Focally | Epithelium/endothelium | LP | IHC |
1
Pale macrophages;
2
Crypt damage; IIIA partial atrophy, IIIB subtotal atrophy, IIIC total atrophy. 0-3A: 0, no inflammation, 1, IELs, 2 mild hyperplasia/mild inflammation. IL: Intraluminal; IE: Intraepithelial (surface and crypt epithelium); IEv: Intraepithelial at the villous tips; IEc: Intraepithelial at the crypts; LP: Lamina propria; CH: Crypt hyperplasia; AR: Auramine-rhodamine stain; DPAS: Diastase-periodic acid Schiff stain; GS: Giemsa stain; IHC: Immunohistochemistry with antibodies against the cytomegalovirus antigens; MS: Methenamine-silver stain; WS: Warthin-Starry stain; ZN: Ziehl-Nielsen stain.