Table 2.
Modern MARSH classification system.
| MARSH grade | Significance | IEL count/100 enterocytes (duodenum) | IEL count/100 enterocytes (jejunum) |
|---|---|---|---|
| MARSH type 0 | Normal villi, Normal crypt hyperplasia | <30 | <40 |
| MARSH type I | Lymphocytic infiltration of villous epithelial layer | >30 | >40 |
| MARSH type II | Lymphocytosis along with crypt hyperplasia and high mitotic activity. Villous height/ crypt ratio decreases below normal value of 3–5 | >30 | >40 |
| MARSH type IIIa | Partial villous atrophy with villi height/crypt ratio <1 | >30 | >40 |
| MARSH type IIIb | Subtotal villous atrophy | >30 | >40 |
| MARSH type IIIc | Total villous atrophy with no distinguishable digitations | >30 | >40 |
| MARSH type IV | Describes a rare histologic finding of a flat atrophic mucosa which signifies irreversible injury caused by chronic inflammation | >30 | >40 |
Table adapted from Siriweera et al. (134) and Pena (135). Table shows the MARSH classification system for the detection of CD in patients on the basis of duodenal biopsy. MARSH type 0 represents villi of the normal healthy individual with IEL count of <30 per 100 enterocytes in duodenum as well as jejunum; whereas, increased MARSH type represents increased intestinal and villi damage. MARSH type IV represents completely damaged and eroded flat villi in patients. CD patients have MARSH type III or IV. IEL, intra epithelial lymphocytes; MARSH; Mucosal Algorithmic Rules for Scoring Histology.