Histological healing in inflammatory bowel disease: A still unfulfilled promise

Table 1 Score for histological assessment of ulcerative colitis

No significant inflammation	Mucosa free from active inflammation; no erosions or crypt abscesses; surface and glandular epithelial cells intact; general architecture of the mucosa often disturbed; edema and fibrosis of the lamina propria with occasional foci of lymphocytes
Mild to moderate inflammation	Epithelium usually intact; Glandular tubules irregularly arranged and often showing increased proliferative activity; Edema, vascular congestion, and interstitial hemorrhage presented in the lamina propria; Lymphocytes, plasma cells, and eosinophils increased in number, neutrophils often present, but less numerous than in the more severely affected specimens; Variation in intensity of inflammatory change in individual specimens giving a range of appearances from relatively quiescent to active inflammation
Severe inflammation	Mucosal surface often irregular due to edema, interstitial, hemorrhage, or inflammatory exudate in the lamina, propria; Small epithelial breaches common, sometimes with frank erosions and purulent exudate; Neutrophils and eosinophils passing through the damaged epithelium; Areas of flattened and cuboidal cells especially found near erosions; Mucosa showing heavy interstitial infiltration by lymphocytes, plasma cells, eosinophils and neutrophils; Glandular abnormalities (neutrophilic invasion of the tubules, epithelial focal degeneration and shedding of necrotic/viable cells into the glandular lumina; crypt abscesses (neutrophils, eosinophils, and epithelial debris); Sometimes, breaking down of the wall of the tubule with inflammatory exudate passing from the tubule into the lamina propria

Adapted from Truelove et al[23], 1956.

Table 2 Modified scoring system for histological assessment of ulcerative colitis

Inflammation grade	Score	Intensity	Histological criteria
Active inflammation	0	Normal	Neutrophils not present in crypt or surface epithelium and no exudate, erosion or ulceration
	1	Low grade	Neutrophils present transmigrating through the crypt epithelium or within crypt lumina in < 20% of crypts; no erosions or ulcers
	2	Moderate	Neutrophilic infiltration in > 20% of crypts or presence of erosions
	3	High grade	Presence of ulcers
Chronic inflammation	0	No increase	Normal number of chronic inflammatory cells present primarily in the superficial lamina propria
	1	Moderate	Moderate number of mononuclear cells
			Aggregated between crypts at the base of the lamina propria
	2	Severe	Marked increase in chronic inflammation shown by sheets of chronic cells
Crypt distortion	0	None	Crypts had normal outlines with only artifactual irregularities
	1	Mild	Scattered or rare crypts showing irregular (bent, forked) outline
	2	Moderate	Approximately 25%-50% of crypts with an irregular outline
	3	Severe	> 50% of crypts with an irregular outline

Adapted from Hanauer et al[50], 1998.

Table 3 Histological scoring system for ulcerative colitis and Crohn’s disease

Ulcerative colitis
Grade 0	Structural (architectural change)
0	No abnormality
0.1	Mild abnormality
0.2	Mild or moderate diffuse or multifocal abnormalities
0.3	Severe diffuse or multifocal abnormalities
Grade 1	Chronic inflammatory infiltrate
1	No increase
1.1	Mild but unequivocal increase
1.2	Moderate increase
1.3	Marked increase
Grade 2	Lamina propria neutrophils and eosinophils
2A. Eosinophils
2A.0	No increase
2A.1	Mild but unequivocal increase
2A.2	Moderate increase
2A.3	Marked increase
2B. Neutrophils
2B.0	None
2B.1	Mild but unequivocal increase
2B.2	Moderate increase
2B.3	Marked increase
Grade 3	Neutrophils in epithelium
3	None
3.1	< 5% crypt involved
3.2	< 50% crypt involved
3.3	> 50% crypt involved
Grade 4	Crypt destruction
4	None
4.1	Probable-local excess of neutrophils in part of crypt
4.2	Probable-marked attenuation
4.3	Unequivocal crypt destruction
Grade 5	Erosion or ulceration
5	No erosion, ulceration, or granulation tissue
5.1	Recovering epithelium plus adjacent inflammation
5.2	Probable erosion-focally stripped
5.3	Unequivocal erosion
5.4	Ulcer or granulation tissue
Crohn’s disease
Epithelial damage
0	Normal
1	Focal pathology
2	Extensive pathology
Architectural changes
0	Normal
1	Moderately disturbed (< 50%)
2	Severely disturbed (> 50%)
Infiltration of mononuclear cells in the lamina propria
0	Normal
1	Moderate increase
2	Severe increase
Infiltration of polymorphonuclear cells in the lamina propria
0	Normal
1	Moderate increase
2	Severe increase
Polymorphonuclear cells in the epithelium
1	In surface epithelium
2	Cryptitis
3	Crypt abscess
Presence of erosions and/or ulcers
0	No
1	Yes
Presence of granuloma
0	No
1	Yes
No. of biopsy specimens affected
0	None (0 of 6)
1	< 33% (1 or 2 of 6)
2	33%-66% (3 or 4 of 6)
3	> 66% (5 or 6 of 6)

Each topic scored independently. Moderate increase, up to twice the number of cells that can normally be expected; severe increase, more than twice the normal number of cells.