, Nonthalee Pausawasdi
Division of Gastroenterology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
© Copyright 2021. Korean Association for the Study of Intestinal Diseases. All rights reserved.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Funding Source
The authors received no financial support for the research, authorship, and/or publication of this article.
Conflict of Interest
No potential conflict of interest relevant to this article was reported.
Author Contribution
Conceptualization: Limsrivilai J. Methodology: Limsrivilai J. Writing - original draft: Limsrivilai J. Writing - review and editing: Limsrivilai J, Pausawasdi N. Approval of final manuscript: all authors.
Non-Author Contribution
The authors gratefully acknowledge Kevin P. Jones (Siriraj Medical Research Center, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand) for language editing.
| Author (year) | Country | Study design | Model type | Parameters | Model detail | Performance |
|---|---|---|---|---|---|---|
| Lee et al. (2006) [14] | Korea | Prospective, CD 44, ITB 44 | Scoring system | 8 Endoscopic findings | Favor CD (+1/each): longitudinal ulcer, aphthous ulcer, cobblestone appearance, anorectal involvement | Correct diagnosis: 87.5% |
| Favor ITB (-1/each): transverse ulcer, scars or pseudopolyps, patulous ileocecal valve, involvement <4 segments | Incorrect diagnosis: 8% | |||||
| Final score: | Indeterminate: 4.5% | |||||
| 1–4: CD | ||||||
| 0: indeterminate | ||||||
| –1 to -4: ITB | ||||||
| Makharia et al. (2010) [6] | India | Prospective, CD 53, ITB 53 for training; CD 20, ITB 20 for validation | LR model | 4 Findings (2 clinical, 1 endoscopic, and 1 pathologic) | +2.3 × weight loss | AUROC |
| –2.1 × blood in stool | Training: 0.906 | |||||
| –2.5 × sigmoid colon involvement | Validation: 0.893 | |||||
| –2.1 × focally-enhanced colitis | ||||||
| +7 | ||||||
| Li et al. (2011) [15] | China | Retrospective, CD 130, ITB 122 | LR model | 6 Clinical and 6 endoscopic findings | Clinical score: | Clinical: |
| Hematochezia | Sen. 90% | |||||
| History of surgery | Spec. 77% | |||||
| Perianal disease | Acc. 84% | |||||
| Pulmonary TB | Endoscopy: | |||||
| Ascites | Sen. 83% | |||||
| PPD skin test | Spec. 82% | |||||
| Endoscopy score: | Acc. 83% | |||||
| Rectum | ||||||
| Longitudinal ulcer | ||||||
| Cobblestone appearance | ||||||
| IC valve involve | ||||||
| Transverse ulcer | ||||||
| Rodent-like ulcer | ||||||
| Yu et al. (2012) [16] | China | Retrospective, CD 53, ITB 43 | LR model | 3 Findings (1 clinical, 1 endoscopic, and 1 pathologic) | – 2.0 × night sweat | AUROC: 0.864 |
| + 3.6 × longitudinal ulcer | ||||||
| – 3.8 × granuloma | ||||||
| Jung et al. (2016) [17] | Korea | Retrospective, CD 79, ITB 49 for training; CD 79, ITB 49 for validation | LR model | 7 Findings (4 clinical and 3 endoscopic) | Age | AUROC |
| Female sex | Training: 0.979 | |||||
| Diarrhea | Validation: 0.978 | |||||
| Ring-shaped ulcer | ||||||
| Longitudinal ulcer | ||||||
| Sigmoid colon involvement | ||||||
| Suspected pulmonary TB |
| Author (year) | Country | Study design | Model type | Parameters | Model detail | Performance |
|---|---|---|---|---|---|---|
| Zhao et al. (2014) [24] | China | Retrospective, CD 141, ITB 47 | LR model | 6 Clinical and 8 CTE findings | Clinical model: | AUROC |
| Hematochezia | Clinical model: 0.916 | |||||
| Perianal disease | CTE model: 0.986 | |||||
| PPD test | ||||||
| Ascites | ||||||
| Pulmonary TB | ||||||
| Night sweats | ||||||
| CTE model: | ||||||
| Left colon | ||||||
| Asymmetrical wall | ||||||
| Abscess | ||||||
| Comb sign | ||||||
| LN along right colic artery | ||||||
| Contracted IC | ||||||
| Fixed patulous IC | ||||||
| LN with necrosis | ||||||
| Mao et al. (2015) [18] | China | Prospective, consecutive 67 CD, 38 ITB for training; 40 CD, 20 ITB for validation | Algorithm (combined with Lee’s endoscopic score) | 2 CTE findings and 8 endoscopic findings | Presence of comb sign and/or segmental small bowel lesion | Increased accuracy of endoscopic score alone 71.6% to 88.3% |
| Zhang et al. (2015) [25] | China | Prospective, CD 92, ITB 31 | LR model | 1 Clinical, 2 endoscopic, and 3 CTE findings | Perianal disease | AUROC 0.994 |
| Transverse ulcer | ||||||
| Rodent-like ulcer | ||||||
| Skip lesion (CTE) | ||||||
| Fixed patulous IC (CTE) | ||||||
| Comb sign (CTE) | ||||||
| Kedia et al. (2015) [26] | India | Retrospective, CD 54, ITB 50 | Scoring system | 3 CT/CTE findings | Long segment involvement + (1–ileocecal region involvement) + (1–LN ≥ 1 cm) | Risk score for CD 3: Sen. 37%, Spec. 90% |
| Risk score for ITB 0: Sen. 14%, Spec. 100% | ||||||
| Kedia et al. (2018) [28] | India | Retrospective, 32 CD, 27 ITB for training; 38 CD, 31 ITB for validation | Scoring system | 2 CT/CTE findings | VF/SC ratio >0.63 + long segment involvement | Validation set: Risk score for CD 2: Sen. 50%, Spec. 97% |
| Risk score for ITB 0: Sen. 61%, Spec. 84% |
CTE, computed tomography enterography; CD, Crohn’s disease; ITB, intestinal tuberculosis; LR, logistic regression; PPD, purified protein derivative; TB, tuberculosis; LN, lymph node; IC, ileocecal valve; AUROC, area under receiver operating characteristic curve; Sen., sensitivity; Spec., specificity; VF/SC ratio, visceral fat to subcutaneous fat ratio.
| Author (year) | Country | Study design | Model type | Parameters | Model detail | Performance | |
|---|---|---|---|---|---|---|---|
| Huang et al. (2015) [34] | China | Prospective, CD 25, ITB 40 | Scoring system | 12 Findings (2 clinical, 5 endoscopic, 4 CTE, and 1 IGRA) | Favor CD (+1) | Favor ITB (–1) | AUROC: 0.997 |
| Longitudinal ulcer | Night sweats | ||||||
| Nodular hyperplasia | Positive PPD test | ||||||
| Cobblestone appearance | Positive T-SPOT.TB | ||||||
| Intestinal diseases | Ring-shaped ulcer | ||||||
| Intestinal fistulas | Ulcer scars | ||||||
| Target sign | |||||||
| Comb sign | |||||||
| Bae et al. (2017) [35] | Korea | Prospective, CD 40, ITB 40 for training; CD 14, ITB 23 for validation | Scoring system | 8 Endoscopic findings, 2 Images (CXR, SBFT), and 2 laboratory tests (ASCA, IGRA) | Endoscopic score (8 findings) | Lab-Radio score | AUROC |
| (+)→1, 0→0, (–)→(–1) | Favor CD (+1) | Training: 0.990 | |||||
| Proximal SB (SBFT) ASCA | Validation: 0.981 | ||||||
| Favor ITB (–1) | |||||||
| Pulmonary TB (CXR) IGRA | |||||||
| (+)→1, 0→0, (–)→(–1) | |||||||
| Summation: (–2, –1)→ITB, (0, 1, 2)→CD | |||||||
| Wu et al. (2018) [36] | China | Prospective, CD 107, ITB 60 for training; CD 46, ITB 26 for validation | LR model | 5 Findings (2 clinical, 2 endoscopic, and 1 IGRA) | Perianal disease | AUROC | |
| Longitudinal ulcer | Training: 0.975 | ||||||
| Left colon | Validation: 0.950 | ||||||
| Pulmonary TB | |||||||
| TB-specific Ag to phytohaemagglutinin | |||||||
| He et al. (2019) [37] | China | Prospective, CD 143, ITB 69 for training; CD 76, ITB 22 for validation | Step1: select variable from a random forest regression model | 2 Models | Model 1 | AUROC | |
| 8 Findings (1 clinical, 2 endoscopic, 3 CTE, and 2 IGRA/PPD) | Age | Training: 0.977 | |||||
| Step 2: LR model | Rectal involvement | Validation (cutoff P=0.5) | |||||
| Transverse ulcer | Sen. 86.8% | ||||||
| Skip involvement of small bowel | Spec. 90.9% | ||||||
| Comb sign | Acc. 87.8% | ||||||
| IGRA | AUROC | ||||||
| Model 2 | Training: 0.930 | ||||||
| Age | Validation (cutoff P=0.5) | ||||||
| Rectal involvement | Sen. 84.2% | ||||||
| Transverse ulcer | Spec. 100% | ||||||
| Skip involvement of small bowel | Acc. 87.8% | ||||||
| Target sign | |||||||
| PPD | |||||||
| Limsrivilai et al. (2017) [38] | Meta-analysis | Step 1: select significant variables with low heterogeneity based on meta-analytic results | 9 Clinical, 8 endoscopic, 5 pathologic, 5 CTE, and 1 IGRA (can select only available parameters) | bit.ly/ITBvsCD | AUROC | ||
| Validation cohort 29 CD, 22 ITB | Step 2: integrate the variables into Bayesian model | Clinical+endoscopy: 0.920 | |||||
| Clinical+endoscopy+pathological findings: 0.943 | |||||||
CD, Crohn’s disease; ITB, intestinal tuberculosis; CTE, computed tomography enterography; IGRA, interferon-gamma release assay; PPD, purified protein derivative; T-SPOT.TB, a type of ELISpot assay that is used for tuberculosis diagnosis that belongs to the group of IGRAs; AUROC, area under receiver operating characteristic curve; CXR, chest X-ray; SB, small bowel; SBFT, small bowel follow through; ASCA, anti-Saccharomyces cerevisiae antibody; LR, logistic regression; TB, tuberculosis; Sen., sensitivity; Spec., specificity; Acc., accuracy.
| Author (year) | Country | Study design | Model type | Parameters | Model detail | Performance |
|---|---|---|---|---|---|---|
| Lee et al. (2006) [14] | Korea | Prospective, CD 44, ITB 44 | Scoring system | 8 Endoscopic findings | Favor CD (+1/each): longitudinal ulcer, aphthous ulcer, cobblestone appearance, anorectal involvement | Correct diagnosis: 87.5% |
| Favor ITB (-1/each): transverse ulcer, scars or pseudopolyps, patulous ileocecal valve, involvement <4 segments | Incorrect diagnosis: 8% | |||||
| Final score: | Indeterminate: 4.5% | |||||
| 1–4: CD | ||||||
| 0: indeterminate | ||||||
| –1 to -4: ITB | ||||||
| Makharia et al. (2010) [6] | India | Prospective, CD 53, ITB 53 for training; CD 20, ITB 20 for validation | LR model | 4 Findings (2 clinical, 1 endoscopic, and 1 pathologic) | +2.3 × weight loss | AUROC |
| –2.1 × blood in stool | Training: 0.906 | |||||
| –2.5 × sigmoid colon involvement | Validation: 0.893 | |||||
| –2.1 × focally-enhanced colitis | ||||||
| +7 | ||||||
| Li et al. (2011) [15] | China | Retrospective, CD 130, ITB 122 | LR model | 6 Clinical and 6 endoscopic findings | Clinical score: | Clinical: |
| Hematochezia | Sen. 90% | |||||
| History of surgery | Spec. 77% | |||||
| Perianal disease | Acc. 84% | |||||
| Pulmonary TB | Endoscopy: | |||||
| Ascites | Sen. 83% | |||||
| PPD skin test | Spec. 82% | |||||
| Endoscopy score: | Acc. 83% | |||||
| Rectum | ||||||
| Longitudinal ulcer | ||||||
| Cobblestone appearance | ||||||
| IC valve involve | ||||||
| Transverse ulcer | ||||||
| Rodent-like ulcer | ||||||
| Yu et al. (2012) [16] | China | Retrospective, CD 53, ITB 43 | LR model | 3 Findings (1 clinical, 1 endoscopic, and 1 pathologic) | – 2.0 × night sweat | AUROC: 0.864 |
| + 3.6 × longitudinal ulcer | ||||||
| – 3.8 × granuloma | ||||||
| Jung et al. (2016) [17] | Korea | Retrospective, CD 79, ITB 49 for training; CD 79, ITB 49 for validation | LR model | 7 Findings (4 clinical and 3 endoscopic) | Age | AUROC |
| Female sex | Training: 0.979 | |||||
| Diarrhea | Validation: 0.978 | |||||
| Ring-shaped ulcer | ||||||
| Longitudinal ulcer | ||||||
| Sigmoid colon involvement | ||||||
| Suspected pulmonary TB |
| Author (year) | Country | Study design | Model type | Parameters | Model detail | Performance |
|---|---|---|---|---|---|---|
| Zhao et al. (2014) [24] | China | Retrospective, CD 141, ITB 47 | LR model | 6 Clinical and 8 CTE findings | Clinical model: | AUROC |
| Hematochezia | Clinical model: 0.916 | |||||
| Perianal disease | CTE model: 0.986 | |||||
| PPD test | ||||||
| Ascites | ||||||
| Pulmonary TB | ||||||
| Night sweats | ||||||
| CTE model: | ||||||
| Left colon | ||||||
| Asymmetrical wall | ||||||
| Abscess | ||||||
| Comb sign | ||||||
| LN along right colic artery | ||||||
| Contracted IC | ||||||
| Fixed patulous IC | ||||||
| LN with necrosis | ||||||
| Mao et al. (2015) [18] | China | Prospective, consecutive 67 CD, 38 ITB for training; 40 CD, 20 ITB for validation | Algorithm (combined with Lee’s endoscopic score) | 2 CTE findings and 8 endoscopic findings | Presence of comb sign and/or segmental small bowel lesion | Increased accuracy of endoscopic score alone 71.6% to 88.3% |
| Zhang et al. (2015) [25] | China | Prospective, CD 92, ITB 31 | LR model | 1 Clinical, 2 endoscopic, and 3 CTE findings | Perianal disease | AUROC 0.994 |
| Transverse ulcer | ||||||
| Rodent-like ulcer | ||||||
| Skip lesion (CTE) | ||||||
| Fixed patulous IC (CTE) | ||||||
| Comb sign (CTE) | ||||||
| Kedia et al. (2015) [26] | India | Retrospective, CD 54, ITB 50 | Scoring system | 3 CT/CTE findings | Long segment involvement + (1–ileocecal region involvement) + (1–LN ≥ 1 cm) | Risk score for CD 3: Sen. 37%, Spec. 90% |
| Risk score for ITB 0: Sen. 14%, Spec. 100% | ||||||
| Kedia et al. (2018) [28] | India | Retrospective, 32 CD, 27 ITB for training; 38 CD, 31 ITB for validation | Scoring system | 2 CT/CTE findings | VF/SC ratio >0.63 + long segment involvement | Validation set: Risk score for CD 2: Sen. 50%, Spec. 97% |
| Risk score for ITB 0: Sen. 61%, Spec. 84% |
| Author (year) | Country | Study design | Model type | Parameters | Model detail | Performance | |
|---|---|---|---|---|---|---|---|
| Huang et al. (2015) [34] | China | Prospective, CD 25, ITB 40 | Scoring system | 12 Findings (2 clinical, 5 endoscopic, 4 CTE, and 1 IGRA) | Favor CD (+1) | Favor ITB (–1) | AUROC: 0.997 |
| Longitudinal ulcer | Night sweats | ||||||
| Nodular hyperplasia | Positive PPD test | ||||||
| Cobblestone appearance | Positive T-SPOT.TB | ||||||
| Intestinal diseases | Ring-shaped ulcer | ||||||
| Intestinal fistulas | Ulcer scars | ||||||
| Target sign | |||||||
| Comb sign | |||||||
| Bae et al. (2017) [35] | Korea | Prospective, CD 40, ITB 40 for training; CD 14, ITB 23 for validation | Scoring system | 8 Endoscopic findings, 2 Images (CXR, SBFT), and 2 laboratory tests (ASCA, IGRA) | Endoscopic score (8 findings) | Lab-Radio score | AUROC |
| (+)→1, 0→0, (–)→(–1) | Favor CD (+1) | Training: 0.990 | |||||
| Proximal SB (SBFT) ASCA | Validation: 0.981 | ||||||
| Favor ITB (–1) | |||||||
| Pulmonary TB (CXR) IGRA | |||||||
| (+)→1, 0→0, (–)→(–1) | |||||||
| Summation: (–2, –1)→ITB, (0, 1, 2)→CD | |||||||
| Wu et al. (2018) [36] | China | Prospective, CD 107, ITB 60 for training; CD 46, ITB 26 for validation | LR model | 5 Findings (2 clinical, 2 endoscopic, and 1 IGRA) | Perianal disease | AUROC | |
| Longitudinal ulcer | Training: 0.975 | ||||||
| Left colon | Validation: 0.950 | ||||||
| Pulmonary TB | |||||||
| TB-specific Ag to phytohaemagglutinin | |||||||
| He et al. (2019) [37] | China | Prospective, CD 143, ITB 69 for training; CD 76, ITB 22 for validation | Step1: select variable from a random forest regression model | 2 Models | Model 1 | AUROC | |
| 8 Findings (1 clinical, 2 endoscopic, 3 CTE, and 2 IGRA/PPD) | Age | Training: 0.977 | |||||
| Step 2: LR model | Rectal involvement | Validation (cutoff P=0.5) | |||||
| Transverse ulcer | Sen. 86.8% | ||||||
| Skip involvement of small bowel | Spec. 90.9% | ||||||
| Comb sign | Acc. 87.8% | ||||||
| IGRA | AUROC | ||||||
| Model 2 | Training: 0.930 | ||||||
| Age | Validation (cutoff P=0.5) | ||||||
| Rectal involvement | Sen. 84.2% | ||||||
| Transverse ulcer | Spec. 100% | ||||||
| Skip involvement of small bowel | Acc. 87.8% | ||||||
| Target sign | |||||||
| PPD | |||||||
| Limsrivilai et al. (2017) [38] | Meta-analysis | Step 1: select significant variables with low heterogeneity based on meta-analytic results | 9 Clinical, 8 endoscopic, 5 pathologic, 5 CTE, and 1 IGRA (can select only available parameters) | bit.ly/ITBvsCD | AUROC | ||
| Validation cohort 29 CD, 22 ITB | Step 2: integrate the variables into Bayesian model | Clinical+endoscopy: 0.920 | |||||
| Clinical+endoscopy+pathological findings: 0.943 | |||||||
CD, Crohn’s disease; ITB, intestinal tuberculosis; LR, logistic regression; AUROC, area under receiver operating characteristic curve; TB, tuberculosis; PPD, purified protein derivative; IC, ileocecal; Sen., sensitivity; Spec., specificity; Acc., accuracy.
CTE, computed tomography enterography; CD, Crohn’s disease; ITB, intestinal tuberculosis; LR, logistic regression; PPD, purified protein derivative; TB, tuberculosis; LN, lymph node; IC, ileocecal valve; AUROC, area under receiver operating characteristic curve; Sen., sensitivity; Spec., specificity; VF/SC ratio, visceral fat to subcutaneous fat ratio.
CD, Crohn’s disease; ITB, intestinal tuberculosis; CTE, computed tomography enterography; IGRA, interferon-gamma release assay; PPD, purified protein derivative; T-SPOT.TB, a type of ELISpot assay that is used for tuberculosis diagnosis that belongs to the group of IGRAs; AUROC, area under receiver operating characteristic curve; CXR, chest X-ray; SB, small bowel; SBFT, small bowel follow through; ASCA, anti-
