TableĀ 3

Features favouring IBD over acute infective colitis/acute self-limiting colitis

1. Highly reliableBasal plasmacytosis2GStrongest predictor of IBD
Highly consistent between studies
May be focal or diffuse
Basal plasma cells are normal in caecum/ascending colon
EL1a RGA4 18 32
Crypt distortion/crypt branching/abnormal crypt architecture2E,FHighly consistent between studies
Some interobserver variability
EL1a RGA1 4 18 25 26 32 33 58
Crypt atrophy2D<5 crypts per mm unique to IBD in one study
Some interobserver variability
EL1a RGA1 4 18 25 33 58
Irregular/villous mucosal surface2DSome interobserver variabilityEL1a RGA1 4 18 25 26 33
2. Fairly reliableGranulomas3AExclude cryptolytic granulomas; only valid for Crohn's disease; infective vs ulcerative colitis: not discriminantEL1a RGA4 18 25 26 33
Basal giant cellsNot assessed in some studiesEL1b RGB25 26 33
Basal lymphoid aggregates2HCan be difficult to distinguish from normal lymphoid aggregatesEL1b RGB18 25 26 33 58
3. Less reliableLamina proprial chronic inflammation/hypercellularityVariably defined; some overlap with the more precise terms above
Low reproducibility
EL1b RGD26 33 58
Paneth cell metaplasia (NOS/distal to the splenic flexure)3BWeak association in some studies
Utility may be restricted to longstanding disease
Some interobserver variability
EL1b RGD4 21 26 30
4. Limited dataDeep (rather than superficial) crypt abscessesEL2b RGC25
Variation in crypt diameterEL2b RGC4
High counts of crypt intraepithelial neutrophils/crypt lumenal neutrophils>10 per crypt or per crypt lumen, assessed in 10 cryptsEL2b RGC58
  • EL, evidence levels; IBD, inflammatory bowel disease; NOS, not otherwise specified.