Differentiation of Crohn's disease from intestinal tuberculosis by clinical and CT enterographic models

Crohn's Disease With Latent Tuberculosis Infection or Intestinal Tuberculosis: Rapid Discrimination by Targeted Next-Generation Sequencing

BACKGROUND

Discriminating Crohn's disease (CD) with latent tuberculosis infection (LTBI) from intestinal tuberculosis (ITB) in tuberculosis-endemic regions remains challenging.

AIM

To assess whether targeted next-generation sequencing (tNGS) could be an efficient method for ITB diagnosis and discrimination from CD with LTBI.

METHODS

The study was conducted prospectively from September 2020 until December 2023. We recruited patients with undetermined intestinal ulcers and positive interferon-gamma release assay. We compared tNGS (using fresh biopsy tissue samples from ulcer bases) to pathological detection of caseous necrotising granuloma, acid-fast bacillus (AFB) staining, tuberculosis polymerase chain reaction (TB-PCR) for diagnostic efficiency. ITB was diagnosed based on cure by anti-tuberculosis therapy and comprehensive clinical evaluation.

RESULTS

Of the 100 patients included, 66 had ITB and 34 had CD with LTBI. The sensitivity, specificity, positive predictive value and negative predictive value of tNGS for ITB were 83% (72%-91%), 100% (87%-100%), 100% (92%-100%) and 76% (60%-87%), respectively. TNGS had significantly higher diagnostic sensitivity than AFB staining [15% (4%-39%), p < 0.05], TB-PCR [22% (12%-36%), p < 0.05] and detection of caseous necrotising granulomas [17% (9%-28%), p < 0.05]. The models combining multiclinical factors increased sensitivity (97% vs. 83%) than tNGS alone. No patients with CD and LTBI had positive tNGS.

CONCLUSIONS

TNGS using fresh biopsy tissue from ulcer bases is highly sensitive and specific, with superiority over other traditional diagnostic methods for ITB detection. TNGS could facilitate rapid diagnosis of ITB and discrimination from CD with LTBI, particularly in high TB-endemic countries.

Quantitative assessment of transmural remission in Crohn's disease using low dose computed tomography (CT) enterography perfusion imaging: a single-centre study based on intestinal microcirculation

AIM

To assess transmural remission in patients with Crohn's disease using low-dose small bowel computed tomography (CT) perfusion scans.

MATERIALS AND METHODS

Forty six patients were divided into active and remission phases based on Crohn's Disease Activity Index (CDAI) and C-reactive protein (CRP). Dual-source CT enterography with low-dose perfusion scans was conducted to generate perfusion parameter maps, including blood flow (BF), blood volume (BV), time to peak (TTP), mean transit time (MTT), and permeability of surface (PS). We compared differences in perfusion parameter values of intestinal walls, mesenteric fat, and lymph nodes between two groups. Receiver operating characteristic (ROC) curves were plotted, and area under the curve (AUC), sensitivity, specificity, and cutoff values were calculated.

RESULTS

The BF, BV, TTP, MTT, and PS values of the intestinal wall were significantly higher in the active phase (P0.05). Additionally, lymph node BF and TTP displayed significant differences (P<0.01).

CONCLUSION

Dual-source CT enterography with low-dose perfusion scans enables quantitative assessment of Crohn's disease microcirculation in intestinal walls, mesenteric fat, and lymph nodes. These quantitative indicators provide strong diagnostic efficacy and offer insights into whether the disease is in transmural remission.

Is the identification of caseating granuloma in the intestine indicative of tuberculosis? a rare case of Crohn's disease

BACKGROUND

Crohn's disease (CD) is a chronic intestinal inflammatory disorder, the etiology of which remains unknown, and is characterized by symptoms such as chronic abdominal pain, diarrhea, obstruction, and perianal lesions. Histopathology is widely regarded as the preferred method for diagnosing CD, although the histological diagnosis may lack specificity. The identification of granulomas is commonly believed to be the most reliable diagnostic indicator for CD, surpassing all other clinical features in significance. Nevertheless, research indicates that the detection rate of granulomas in CD exhibits considerable variability. Furthermore, granulomas can manifest in various specific infections including tuberculosis and Yersinia, as well as in a range of diseases characterized by macrophage reactions such as sarcoidosis and drug-induced enteritis. Granulomas associated with CD typically do not exhibit necrosis. However, the formation of caseous granulomas may occur as a result of secondary infections related to anti-CD drug treatment or perforation of the intestinal wall.

CASE PRESENTATION

In this study, we present a case of a 28-year-old female patient diagnosed with CD exhibiting histologic granulomas, including both caseating and non-caseating forms, which demonstrated a positive response to medical treatment.

CONCLUSION

In clinical practice, various forms of granulomas may indicate diverse underlying diseases, yet lack specificity. It is suggested that the presence of caseous granulomas should not be considered as a definitive exclusion criterion for the diagnosis when clinical, endoscopic, imaging and other histopathological features are consistent with CD. This study is the first report of caseous granulomas in CD without concomitant tuberculosis infection.

New diagnostic strategies to distinguish Crohn's disease and gastrointestinal tuberculosis

PURPOSE OF REVIEW

Despite advances in our radiological, histological and microbiological armamentarium, distinguishing between Crohn's disease (CD) and intestinal tuberculosis (ITB), especially in a TB endemic country, continues to be a challenging exercise in a significant number of patients. This review aims to summarize current available evidence on novel diagnostic techniques which have a potential to fill the gap in our knowledge of differentiating between ITB and CD.

RECENT FINDINGS

Both ITB and CD are associated with altered host immune responses, and detection of these altered innate and adaptive immune cells has potential to distinguish ITB from CD. ITB and CD have different epigenetic, proteomic and metabolomic signatures, and recent research has focused on detecting these differences. In addition, the gut microbiome, which is involved in mucosal immunity and inflammatory responses, is considerably altered in both ITB and CD, and is another potential frontier, which can be tapped to discriminate between the two diseases. With technological advancements, we have newer radiological modalities including perfusion CT and dual-layer spectral detector CT enterography and evidence is emerging of their role in differentiating ITB from CD. Finally, time will tell whether the advent of artificial intelligence, with rapidly accumulating data in this field, will be the gamechanger in solving this puzzle of diagnostic dilemma between ITB and Crohn's disease.

SUMMARY

Recent advances need to be clinically validated before they can be used as novel diagnostic measures to differentiate Intestinal TB from CD.

Deep Learning Radiomics Analysis of CT Imaging for Differentiating Between Crohn's Disease and Intestinal Tuberculosis

This study aimed to develop and evaluate a CT-based deep learning radiomics model for differentiating between Crohn's disease (CD) and intestinal tuberculosis (ITB). A total of 330 patients with pathologically confirmed as CD or ITB from the First Affiliated Hospital of Zhengzhou University were divided into the validation dataset one (CD: 167; ITB: 57) and validation dataset two (CD: 78; ITB: 28). Based on the validation dataset one, the synthetic minority oversampling technique (SMOTE) was adopted to create balanced dataset as training data for feature selection and model construction. The handcrafted and deep learning (DL) radiomics features were extracted from the arterial and venous phases images, respectively. The interobserver consistency analysis, Spearman's correlation, univariate analysis, and the least absolute shrinkage and selection operator (LASSO) regression were used to select features. Based on extracted multi-phase radiomics features, six logistic regression models were finally constructed. The diagnostic performances of different models were compared using ROC analysis and Delong test. The arterial-venous combined deep learning radiomics model for differentiating between CD and ITB showed a high prediction quality with AUCs of 0.885, 0.877, and 0.800 in SMOTE dataset, validation dataset one, and validation dataset two, respectively. Moreover, the deep learning radiomics model outperformed the handcrafted radiomics model in same phase images. In validation dataset one, the Delong test results indicated that there was a significant difference in the AUC of the arterial models (p = 0.037), while not in venous and arterial-venous combined models (p = 0.398 and p = 0.265) as comparing deep learning radiomics models and handcrafted radiomics models. In our study, the arterial-venous combined model based on deep learning radiomics analysis exhibited good performance in differentiating between CD and ITB.

A novel multidisciplinary machine learning approach based on clinical, imaging, colonoscopy, and pathology features for distinguishing intestinal tuberculosis from Crohn's disease

OBJECTIVES

Differentiating intestinal tuberculosis (ITB) from Crohn's disease (CD) remains a diagnostic dilemma. Misdiagnosis carries potential grave implications. We aim to establish a multidisciplinary-based model using machine learning approach for distinguishing ITB from CD.

METHODS

Eighty-two patients including 25 patients with ITB and 57 patients with CD were retrospectively recruited (54 in training cohort and 28 in testing cohort). The region of interest (ROI) for the lesion was delineated on magnetic resonance enterography (MRE) and colonoscopy images. Radiomic features were extracted by least absolute shrinkage and selection operator regression. Pathological feature was extracted automatically by deep-learning method. Clinical features were filtered by logistic regression analysis. Diagnostic performance was evaluated by receiver operating characteristic (ROC) curve and decision curve analysis (DCA). Delong's test was applied to compare the efficiency between the multidisciplinary-based model and the other four single-disciplinary-based models.

RESULTS

The radiomics model based on MRE features yielded an AUC of 0.87 (95% confidence interval [CI] 0.68-0.96) on the test data set, which was similar to the clinical model (AUC, 0.90 [95% CI 0.71-0.98]) and higher than the colonoscopy radiomics model (AUC, 0.68 [95% CI 0.48-0.84]) and pathology deep-learning model (AUC, 0.70 [95% CI 0.49-0.85]). Multidisciplinary model, integrating 3 clinical, 21 MRE radiomic, 5 colonoscopy radiomic, and 4 pathology deep-learning features, could significantly improve the diagnostic performance (AUC of 0.94, 95% CI 0.78-1.00) on the bases of single-disciplinary-based models. DCA confirmed the clinical utility.

CONCLUSIONS

Multidisciplinary-based model integrating clinical, MRE, colonoscopy, and pathology features was useful in distinguishing ITB from CD.

Differential diagnosis of Crohn's disease and intestinal tuberculosis based on ATR-FTIR spectroscopy combined with machine learning

BACKGROUND

Crohn's disease (CD) is often misdiagnosed as intestinal tuberculosis (ITB). However, the treatment and prognosis of these two diseases are dramatically different. Therefore, it is important to develop a method to identify CD and ITB with high accuracy, specificity, and speed.

AIM

To develop a method to identify CD and ITB with high accuracy, specificity, and speed.

METHODS

A total of 72 paraffin wax-embedded tissue sections were pathologically and clinically diagnosed as CD or ITB. Paraffin wax-embedded tissue sections were attached to a metal coating and measured using attenuated total reflectance fourier transform infrared spectroscopy at mid-infrared wavelengths combined with XGBoost for differential diagnosis.

RESULTS

The results showed that the paraffin wax-embedded specimens of CD and ITB were significantly different in their spectral signals at 1074 cm-1 and 1234 cm-1 bands, and the differential diagnosis model based on spectral characteristics combined with machine learning showed accuracy, specificity, and sensitivity of 91.84%, 92.59%, and 90.90%, respectively, for the differential diagnosis of CD and ITB.

CONCLUSION

Information on the mid-infrared region can reveal the different histological components of CD and ITB at the molecular level, and spectral analysis combined with machine learning to establish a diagnostic model is expected to become a new method for the differential diagnosis of CD and ITB.

Visceral Fat Indices: Do They Help Differentiate Crohn's Disease and Intestinal Tuberculosis in Children?

BACKGROUND AND AIMS

Crohn's disease [CD] and intestinal tuberculosis [ITB] are often difficult to differentiate. Mesenteric fat hypertrophy is a feature of CD. We evaluated the utility of fat indices (visceral fat [VF] and subcutaneous fat [SF]) in differentiating CD and ITB in children.

METHODS

Symptomatic children diagnosed to have CD or ITB based on recommended criteria were enrolled. Clinical, anthropometric, and laboratory details were noted. Abdominal fat was measured on computed tomography in supine position at the level of L4 vertebrae. VF and SF area was measured separately by a radiologist, blinded to the diagnosis. The sum of VF and SF was taken as total fat [TF]. VF/SF and VF/TF ratios were calculated.

RESULTS

Thirty-four (age 14 years [10.8-17.0], 14 boys) children were recruited: 12 had CD [seven boys, age 13.0 years] and 22 had ITB [seven boys, age 14.5 years]. VF area was higher in CD compared to ITB (18.34 cm2 [15.62-40.01] vs 6.48 cm2 [2.65-21.96]; p = 0.012). The SF and TF area was similar in ITB and CD. The ratios of VF/SF (0.82 [0.57-1.5] vs 0.33 [0.16-0.48]; p = 0.004) and VF/TF (0.45 [0.36-0.60] vs 0.25 [0.13-0.32]; p = 0.004) were significantly higher in CD. On comparing CD and ITB in boys and girls separately, the difference was significant for boys but not for girls. A VF/SF ratio of 0.609 predicted CD with a good sensitivity [75%] and specificity [86.4%] [area under the curve 0.795, 95% confidence interval 0.636-0.955; p = 0.005].

CONCLUSION

The VF/SF ratio is a simple, non-invasive, objective parameter to differentiate CD and ITB in children, particularly boys. Larger studies are needed to validate this in girls.

Crohn's Disease: Basic Characteristics of the Disease, Diagnostic Methods, the Role of Biomarkers, and Analysis of Metalloproteinases: A Review

Crohn's disease is a chronic inflammatory bowel disease that affects the ileum and/or large intestine. At the same time, it can also affect any other part of the human body, i.e., from the mouth to the anus. In Crohn's disease, the physiology and functioning of the epithelial barrier are inhibited due to the correlation of various factors, such as the environment, genetic susceptibility or intestinal microbiota. The symptoms are very troublesome and cause a significant reduction in quality of life, sometimes occurring with paralyzing permanent damage to the digestive tract, requiring enteral or parenteral nutrition throughout life. In order to make a proper and accurate diagnosis, an appropriately selected diagnostic path in a given clinical entity is necessary. Standard diagnostic methods are: laboratory examination, histopathological examination, endoscopic examination, X-ray, computed tomography, ultrasound examination and magnetic resonance imaging. Medical biology and the analysis of metalloproteinases have also proved helpful in diagnosing changes occurring as a result of Crohn's disease. Here we provide a thorough review of the latest reports on Crohn's disease and its genetic conditions, symptoms, morphology, diagnosis (including the analysis of Crohn's disease biomarkers, i.e., metalloproteinases) and treatment.

Differentiating gastrointestinal tuberculosis and Crohn's disease- a comprehensive review

Gastrointestinal Tuberculosis (GITB) and Crohn's disease (CD) are both chronic granulomatous diseases with a predilection to involve primarily the terminal ileum. GITB is often considered a disease of the developing world, while CD and inflammatory bowel disease are considered a disease of the developed world. But in recent times, the epidemiology of both diseases has changed. Differentiating GITB from CD is of immense clinical importance as the management of both diseases differs. While GITB needs anti-tubercular therapy (ATT), CD needs immunosuppressive therapy. Misdiagnosis or a delay in diagnosis can lead to catastrophic consequences. Most of the clinical features, endoscopic findings, and imaging features are not pathognomonic for either of these two conditions. The definitive diagnosis of GITB can be clinched only in a fraction of cases with microbiological positivity (acid-fast bacilli, mycobacterial culture, or PCR-based tests). In most cases, the diagnosis is often based on consistent clinical, endoscopic, imaging, and histological findings. Similarly, no single finding can conclusively diagnose CD. Multiparametric-based predictive models incorporating clinical, endoscopy findings, histology, radiology, and serology have been used to differentiate GITB from CD with varied results. However, it is limited by the lack of validation studies for most such models. Many patients, especially in TB endemic regions, are initiated on a trial of ATT to see for an objective response to therapy. Early mucosal response assessed at two months is an objective marker of response to ATT. Prolonged ATT in CD is recognized to have a fibrotic effect. Therefore, early discrimination may be vital in preventing the delay in the diagnosis of CD and avoiding a complicated course.

Computed tomography enterography-based multiregional radiomics model for differential diagnosis of Crohn's disease from intestinal tuberculosis

PURPOSE

To build computed tomography enterography (CTE)-based multiregional radiomics model for distinguishing Crohn's disease (CD) from intestinal tuberculosis (ITB).

MATERIALS AND METHODS

A total of 105 patients with CD and ITB who underwent CTE were retrospectively enrolled. Volume of interest segmentation were performed on CTE and radiomic features were obtained separately from the intestinal wall of lesion, the largest lymph node (LN), and region surrounding the lesion in the ileocecal region. The most valuable radiomic features was selected by the selection operator and least absolute shrinkage. We established nomogram combining clinical factors, endoscopy results, CTE features, and radiomic score through multivariate logistic regression analysis. Receiver operating characteristic (ROC) curves and decision curve analysis (DCA) were used to evaluate the prediction performance. DeLong test was applied to compare the performance of the models.

RESULTS

The clinical-radiomic combined model comprised of four variables including one radiomic signature from intestinal wall, one radiomic signature from LN, involved bowel segments on CTE, and longitudinal ulcer on endoscopy. The combined model showed good diagnostic performance with an area under the ROC curve (AUC) of 0.975 (95% CI 0.953-0.998) in the training cohort and 0.958 (95% CI 0.925-0.991) in the validation cohort. The combined model showed higher AUC than that of the clinical model in cross-validation set (0.958 vs. 0.878, P = 0.004). The DCA showed the highest benefit for the combined model.

CONCLUSION

Clinical-radiomic combined model constructed by combining CTE-based radiomics from the intestinal wall of lesion and LN, endoscopy results, and CTE features can accurately distinguish CD from ITB.

Clinical Analysis of Intestinal Tuberculosis: A Retrospective Study

PURPOSE

This study aimed to summarize and analyze the clinical data of intestinal tuberculosis (ITB) in order to provide guidance for accurate diagnosis and treatment of ITB.

METHODS

This study consecutively included patients with ITB who were admitted to our hospital from 2008 to 2021 and retrospectively analyzed their clinical features.

RESULTS

Forty-six patients were included. The most common clinical symptom was weight loss (67.4%). Seventy percent of 20 patients were positive for tuberculin skin test; 57.1% of 14 patients were positive for mycobacterium tuberculosis specific cellular immune response test, while 84.6% of 26 patients were positive for tuberculosis infection T cell spot test. By chest computed tomography (CT) examination, 25% and 5.6% of 36 patients were diagnosed with active pulmonary tuberculosis and with inactive pulmonary tuberculosis, respectively. By abdominal CT examination, the most common sign was abdominal lymph node enlargement (43.2%). Forty-two patients underwent colonoscopy, and the most common endoscopic manifestation was ileocecal ulcer (59.5%), followed by colonic ulcer (35.7%) and ileocecal valve deformity (26.2%). ITB most frequently involved the terminal ileum/ileocecal region (76.1%). Granulomatous inflammation with multinucleated giant cells and caseous necrosis was found via endoscopic biopsies, the ultrasound-guided percutaneous biopsy of enlarged mesentery lymph nodes, and surgical interventions. The acid-fast bacilli were discovered in 53.1% of 32 samples. Twenty-one cases highly suspected of ITB were confirmed after responding to empiric anti-tuberculosis therapy.

CONCLUSIONS

It was necessary to comprehensively analyze clinical features to make an accurate diagnosis of ITB and aid in distinguishing ITB from diseases such as Crohn's disease and malignant tumors.

Differential diagnosis of Crohn’s disease and intestinal tuberculosis: development and assessment of a nomogram prediction model

Background

China is a region with a high incidence of tuberculosis, and the incidence of IBD has also been rising rapidly in recent years. Differentiating Crohn’s disease(CD) from intestinal tuberculosis (ITB) has become a very challenging issue. We aimed to develop and assess a diagnostic nomogram to differentiate between CD and ITB to improve the accuracy and practicability of the model.

Methods

A total of 133 patients (CD 90 and ITB 43) were analyzed retrospectively. Univariate and multivariate logistic regression analysis was included to determine the independent predictive factors and establish the regression equation. On this basis, the nomogram prediction model was constructed. The discrimination, calibration and clinical efficiency of the nomogram were assessed using area under the curve(AUC), C-index, calibration curve, decision curve analysis (DCA) and clinical impact curve.

Results

T-SPOT positive, cobblestone appearance, comb sign and granuloma were significant predictors in differentiating CD from ITB. Base on the above independent predictors, a diagnostic nomogram was successfully established. The sensitivity, specificity, accuracy of the prediction model are 94.4%, 93.0%, 94.0% respectively. The AUC and the C-index of the prediction model are both 0.988, which suggest that the model had a good discrimination power. The calibration curve indicated a high calibration degree of the prediction model. The DCA and clinical impact curve indicated a good clinical efficiency of the prediction model which could bring clinical benefits.

Conclusion

A nomogram prediction model for distinguishing CD from ITB was developed and assessed, with high discrimination, calibration and clinical efficiency. It can be used as an accurate and convenient diagnostic tool to distinguish CD from ITB, facilitating clinical decision-making.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02519-z.

Enterogenous Microbiotic Markers in the Differential Diagnosis of Crohn's Disease and Intestinal Tuberculosis

Crohn’s disease (CD) is a chronic intestinal disorder characterized by refractory gastrointestinal ulcerations. Intestinal tuberculosis (ITB) is one common intestinal disease in east Asia. The two diseases share similar clinical manifestations and endoscopic characteristics. Thus, it is difficult to establish a definite diagnosis of CD, CD concomitant with ITB (CD-ITB), and ITB in practice. Some enterogeneous microbiotic markers have been applied to differentiate CD and ITB, but it remains unknown how they work for the three groups of patients. The aim of our study was to explore the diagnostic values of these enterogeneous microbiotic markers (ASCA IgG, ASCA IgA, ACCA, Anti-I2 and AMCA) among CD, CD-ITB, and ITB patients. A total of 124 individuals were retrospectively enrolled in this study, namely, 103 CD patients, 10 CD-ITB patients, 9 ITB patients, and 68 healthy controls. The demographic and clinical characteristics of these patients were collected and analyzed. The values of these individual or combined enterogeneous microbiotic markers in diagnosis and classification were assessed in CD, CD-ITB, and ITB patients. ASCA IgG, ASCA IgA, and AMCA could accurately differentiate CD patients from healthy controls with an area under curve (AUC) of 0.688, 0.601, and 0.638, respectively. ASCA IgG was significantly higher in CD patients than in CD-ITB patients (P = 0.0003). The Anti-I2 antibody was appropriate for distinguishing CD-ITB from ITB patients (P = 0.039). In CD patients, ASCA IgG was higher in severe patients than in mild (P <0.0001) and inactive patients (P <0.0001), respectively. AMCA was significantly elevated in severe and moderate patients compared to inactive patients (P = 0.001, P = 0.003, respectively). AMCA was associated with a higher risk of CD-related surgery with a significant P-value of 0.0038. In our cohort, ASCAs and AMCA could accurately distinguish CD from healthy controls with an acceptable AUC. A combination of elevated ASCA IgG and AMCA antibodies established a higher sensitivity in differentiating CD from healthy controls. Elevated ASCA IgG demonstrated a differential diagnostic value between CD and CD-ITB. Anti-I2 could also distinguish CD-ITB from ITB. The level of AMCA was associated with both disease severity and CD-related surgery. Likewise, the level of ASCA IgG was also related to disease severity.

Differentiation of intestinal tuberculosis and Crohn's disease through an explainable machine learning method

Differentiation between Crohn’s disease and intestinal tuberculosis is difficult but crucial for medical decisions. This study aims to develop an effective framework to distinguish these two diseases through an explainable machine learning (ML) model. After feature selection, a total of nine variables are extracted, including intestinal surgery, abdominal, bloody stool, PPD, knot, ESAT-6, CFP-10, intestinal dilatation and comb sign. Besides, we compared the predictive performance of the ML methods with traditional statistical methods. This work also provides insights into the ML model’s outcome through the SHAP method for the first time. A cohort consisting of 200 patients’ data (CD = 160, ITB = 40) is used in training and validating models. Results illustrate that the XGBoost algorithm outperforms other classifiers in terms of area under the receiver operating characteristic curve (AUC), sensitivity, specificity, precision and Matthews correlation coefficient (MCC), yielding values of 0.891, 0.813, 0.969, 0.867 and 0.801 respectively. More importantly, the prediction outcomes of XGBoost can be effectively explained through the SHAP method. The proposed framework proves that the effectiveness of distinguishing CD from ITB through interpretable machine learning, which can obtain a global explanation but also an explanation for individual patients.

A Case of Intestinal Tuberculosis Mimicking Crohn's Disease: A Clinical and Diagnostic Dilemma

This case highlights the importance of differentiating between Crohn's disease and intestinal tuberculosis. The rates of misdiagnosis of Crohn's disease and intestinal tuberculosis range from 50% to 70% because of their non-specific and clinically similar manifestations.If intestinal tuberculosis is misdiagnosed as Crohn's disease, use of immunomodulatory drugs commonly used for Crohn's disease can increase the risk of disseminated tuberculosis. Here we present a case highlighting the clinical similarity between these two distinct medical conditions and suggest how a similar scenario can be approached, which can help to differentiate between the two otherwise very similar conditions.

LEARNING POINTS

Given the similarities, it is key to differentiate Crohn's disease from intestinal tuberculosis as early as possible.Patients undergoing colonoscopy for possible Crohn's disease should have colonic biopsy samples sent for AFB culture.Consider investigations for intestinal tuberculosis in uncontrolled Crohn's disease where intestinal tuberculosis has not been worked up previously.

A Novel Clinical Radiomics Nomogram to Identify Crohn's Disease from Intestinal Tuberculosis

Purpose

To establish a clinical radiomics nomogram to differentiate Crohn’s disease (CD) from intestinal tuberculosis (ITB).

Patients and Methods

Ninety-three patients with CD and 67 patients with ITB were recruited (111 in training cohort and 49 in test cohort). The region of interest (ROI) for the lesions in the ileocecal region was delineated on computed tomography enterography and radiomics features extracted. Radiomics features were filtered by the gradient boosting decision tree (GBDT), and a radiomics score was calculated by using the radiomics signature-based formula. We constructed a clinical radiomics model and nomogram combining clinical factors and radiomics score through multivariate logistic regression analysis, and the internal validation was undertaken by ten-fold cross validation. Analyses of receiver operating characteristic (ROC) curves and decision curve analysis (DCA) were used to evaluate the prediction performance. DeLong test was applied to evaluate the performance of the clinical, radiomics and combined model.

Results

The clinical radiomics nomogram, which was based on the 9 radiomics signature and two clinical factors, indicated that the clinical radiomics model had an area under the ROC curve (AUC) value of 0.96 (95% confidence interval [CI]: 0.93–0.99) in the training cohort and 0.93 (95% CI: 0.86–1.00) in validation cohort. The clinical radiomics model was superior to the clinical model and radiomics model, and the difference was significant (P = 0.006, 0.004) in the training cohort. DCA confirmed the clinical utility of clinical radiomics nomogram.

Conclusion

CTE-based radiomics model has a good performance in distinguishing CD from ITB. A nomogram constructed by combining radiomics and clinical factors can help clinicians accurately diagnose and select appropriate treatment strategies between CD and ITB.

Development and validation of a new algorithm model for differential diagnosis between Crohn's disease and intestinal tuberculosis: a combination of laboratory, imaging and endoscopic characteristics

Background

Sometimes in clinical practice, it is a great challenge to distinguish Crohn's disease (CD) and intestinal tuberculosis (ITB), we conducted this study to identify simple and useful algorithm for distinguishing them.

Methods

We retrospectively reviewed the medical history of the patients who were diagnosed as ITB or CD. We firstly identified ITB patients, and then the patients diagnosed with CD were matched by age, sex, and admission time in a 1:1 ratio. Patients who admitted between May 1, 2013 and April 30, 2019 were regarded as training cohort, and patients admitted between May 1, 2019 and May 1, 2020 were regarded as validation cohort. We used multivariate analysis to identify the potential variables, and then we used R package rpart to build the classification and regression tree (CART), and validated the newly developed model.

Results

In total, the training cohort included 84 ITB and 84 CD patients, the validation cohort included 22 ITB and 22 CD patients. Multivariate analysis showed that, positive interferon-gamma release assays (IGRAs), ≥ 4 segments involved, longitudinal ulcer, circular ulcer, and aphthous ulcer were confirmed as independent discriminating factors. Using these parameters to build the CART model made an overall accuracy rate was 88.64%, with sensitivity, specificity, NPV, and PPV being 90.91%, 86.36%, 90.48% and 86.96%, respectively.

Conclusion

We developed a simple and novel algorithm model covering laboratory, imaging, and endoscopy parameters with CART to differentiate ITB and CD with good accuracy. Positive IGRAs and circular ulcer were suggestive of ITB, while ≥ 4 segments involved, longitudinal ulcer, and aphthous ulcer were suggestive of CD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01838-x.

Case of Crohn's Disease Initially Misdiagnosed as Intestinal Tuberculosis Due to Active Pulmonary Tuberculosis

Differentiating Crohn's disease (CD) from intestinal tuberculosis (TB) is a challenge. In patients suspected of having CD or intestinal TB compounded with active pulmonary TB in its early stages, clinicians often lean towards a diagnosis of intestinal TB. A 14-year-old female patient was admitted with symptoms of abdominal pain and diarrhea with hematochezia. Colonoscopy revealed a stricture of the ileocecal valve and scattered longitudinal ulcers. Initial chest radiography showed consolidation in the left lower lobe of the lung. Chest CT revealed branching nodular opacities and consolidation. The TB PCR of the bronchial washing fluid was positive. The patient was diagnosed with pulmonary and intestinal TB. The colonoscopy findings favored CD. Despite this, anti-tubercular therapy was initiated based on the radiology findings and PCR test. After treatment with anti-tubercular therapy, the patient's diarrhea and abdominal pain worsened despite the improvement observed on her chest radiography. Follow-up colonoscopy revealed aggravation of her ulcers. The patient was diagnosed with CD and treated with prednisolone and mesalazine. Her clinical condition improved, and follow-up colonoscopy showed significant improvement of the ulcers. This case highlights the need for caution in diagnosis and suggests that clinicians consider reevaluation in similar cases.

Systematic reporting of computed tomography enterography/enteroclysis as an aid to reduce diagnostic dilemma when differentiating between intestinal tuberculosis and Crohn's disease: A prospective study at a tertiary care hospital

Background and Aim

Crohn's disease (CD) and intestinal tuberculosis (ITB) have similar symptomatology and overlapping features on imaging, endoscopy, and histopathology. It is important to differentiate ITB from CD to initiate correct medical management. This prospective study aimed to characterize imaging features on computed tomography enteroclysis/enterography (CTE) that help in differentiating ITB from CD.

Methods

A total of 300 consecutive patients who underwent CTE with the suspicion of small bowel diseases were evaluated. CTE findings were documented on a detailed "CTE case record form" and were correlated with other investigations like endoscopy, histopathological and microbiological examination, and improvement on empirical therapy to arrive at a final diagnosis. Only confirmed cases of ITB/CD were included for further analysis.

Results

Final diagnoses revealed that 61 patients had ITB, 24 had CD, 90 patients had a final diagnosis not related to ITB/CD, and 125 had no bowel-related diseases. The sensitivity of CTE (ITB vs CD, 90.2 vs 91.6%) was higher than the sensitivity of ileocolonoscopy (ITB vs CD, 87 vs 83.3%). A homogenous pattern of bowel wall thickening and confluent bowel involvement were significantly more common in ITB. Stratified bowel wall thickening with mucosal hyperenhancement, skip lesions in the bowel, and a comb sign were significantly more common in CD. Stratified bowel wall enhancement with an intervening layer of fat was specifically (P < 0.001) seen in patients with CD, and necrotic (P = 0.002) and calcified (P = 0.055) lymph nodes were specifically seen in patients with ITB.

Conclusion

We propose a systematic approach to the radiological differentiation of ITB from CD.

Validation of models using basic parameters to differentiate intestinal tuberculosis from Crohn's disease: A multicenter study from Asia

BACKGROUND

Data on external validation of models developed to distinguish Crohn's disease (CD) from intestinal tuberculosis (ITB) are limited. This study aimed to validate and compare models using clinical, endoscopic, and/or pathology findings to differentiate CD from ITB.

METHODS

Data from newly diagnosed ITB and CD patients were retrospectively collected from 5 centers located in Thailand or Hong Kong. The data was applied to Lee, et al., Makharia, et al., Jung, et al., and Limsrivilai, et al. model.

RESULTS

Five hundred and thirty patients (383 CD, 147 ITB) with clinical and endoscopic data were included. The area under the receiver operating characteristic curve (AUROC) of Limsrivilai's clinical-endoscopy (CE) model was 0.853, which was comparable to the value of 0.862 in Jung's model (p = 0.52). Both models performed significantly better than Lee's endoscopy model (AUROC: 0.713, p<0.01). Pathology was available for review in 199 patients (116 CD, 83 ITB). When 3 modalities were combined, Limsrivilai's clinical-endoscopy-pathology (CEP) model performed significantly better (AUROC: 0.887) than Limsrivilai's CE model (AUROC: 0.824, p = 0.01), Jung's model (AUROC: 0.798, p = 0.005) and Makharia's model (AUROC: 0.637, p<0.01). In 83 ITB patients, the rate of misdiagnosis with CD when used the proposed cutoff values in each original study was 9.6% for Limsrivilai's CEP, 15.7% for Jung's, and 66.3% for Makharia's model.

CONCLUSIONS

Scoring systems with more parameters and diagnostic modalities performed better; however, application to clinical practice is still limited owing to high rate of misdiagnosis of ITB as CD. Models integrating more modalities such as imaging and serological tests are needed.

Intestinal tuberculosis or Crohn's disease: a review of the diagnostic models designed to differentiate between these two gastrointestinal diseases

Differentiating Crohn’s disease (CD) from intestinal tuberculosis (ITB) is a diagnostic dilemma, particularly in regions where ITB is prevalent and CD incidence is increasing, because both diseases can present quite similarly, and diagnostic tests to identify Mycobacterium tuberculosis in tissue samples have rather poor sensitivity. Studies that were conducted to determine the factors that differentiate CD from ITB identified some significant characteristics, but none of those characteristics are exclusive to either ITB or CD. Many diagnostic models or scoring systems that use one to several diagnostic parameters have been proposed to help distinguish these two intestinal diseases. Early models consisted of parameters common to routine clinical practice, such as clinical features, and endoscopic and pathologic findings. The later models also include more advanced diagnostic parameters like high-resolution imaging and serological testing. However, the number and types of parameters differ among diagnostic models, and the systems used to calculate scoring also vary from model to model. Enhanced awareness and understanding of the currently available diagnostic models will help physicians determine which model(s) is/are most suitable for differentiating CD from ITB in their clinical practice.

Gastrointestinal Tuberculosis Mimicking Crohn's Disease

We present the case of a 24-year-old woman with complaints of abdominal pain, bloody diarrhea, and weight loss for 3 months. An outpatient colonoscopy revealed scattered ulcers, suggestive of Crohn's disease (CD). Histopathology also favored the diagnosis of CD. However, after admission to our hospital for further investigation, a chest radiograph revealed pulmonary cavitations. A computed tomography scan suggested the diagnosis of active pulmonary tuberculosis (TB). Therefore, a bronchofibroscopy, a total colonoscopy with ileoscopy, and an upper endoscopy were performed. Not only were acid-fast bacilli present in both bronchoalveolar lavage fluid and gastric juice, but also in colonic biopsies. A complete resolution of gastrointestinal symptoms was achieved 2 weeks after starting anti-TB drugs.

Serum proteome profiles to differentiate Crohn disease from intestinal tuberculosis and primary intestinal lymphoma: A pilot study

The differential diagnosis of Crohn disease (CD) from intestinal tuberculosis (ITB) and primary intestinal lymphoma (PIL) is challenging in patients who exhibit atypical clinical characteristics. The aim of the present study was to explore the serum proteome profiles of CD, PIL and ITB and to identify their differentiations.Treatment-naïve patients with CD (n = 10), PIL (n = 10) and ITB (n = 10) were enrolled in the present study. Differentially expressed proteins (DEPs) in patient serum samples were compared between groups using tandem mass tag labeled proteomic technology. A principal component analysis (PCA) plot and volcano maps were also visualized. Functional pathway analysis was performed using Reactome. The Area under the Curve (AUC) was calculated for each DEP.A total of 818 proteins were identified through proteomic quantification. Among them, 108 DEPs were identified to be differentiated between CD and ITB, 105 proteins between CD and PIL and 55 proteins between ITB and PIL. The proteome from the three groups was distinguishable in the PCA plot. The results revealed that 19, 12, and 10 proteins (AUC ≥ 0.95) were differentially expressed between CD and PIL, CD and ITB, and PIL and ITB, respectively. Among these DEPs, tumor necrosis factor ligand superfamily member 13 was higher in CD than in ITB and PIL. Peroxiredoxin-5, T-complex protein 1 subunit Gamma, CutA, and Fibulin-5 were increased in CD and PIL when compared with ITB. The levels of fibrinogen chains were also significantly higher in patients with PIL compared with CD.The current study demonstrated that serum proteome was distinguishable among patients with CD, PIL, and ITB. The identified proteins may assist in the clinical differentiation among them.

Intestinal tuberculosis and Crohn's disease: the importance and difficulty of a differential diagnosis

Tuberculosis (TB) is the most prevalent infection worldwide and affects one third of the population, predominantly in developing countries. Intestinal TB (ITB) is the sixth most frequent extra-pulmonary TB infection. Crohn's disease (CD) is a chronic inflammatory bowel disease that arises from the interaction of immunological, environmental and genetic factors. Due to changes in the epidemiology of both diseases, distinguishing CD from ITB is a challenge, particularly in immunocompromised patients and those from areas where TB is endemic. Furthermore, both TB and CD have a predilection for the ileocecal area. In addition, they share very similar clinical, radiological and endoscopic findings. An incorrect diagnosis and treatment may increase morbidity and mortality. Thus, a great degree of caution is required as well as a familiarity with certain characteristics of the diseases, which will aid the differentiation between the two diseases.

Imaging in discriminating intestinal tuberculosis and Crohn's disease: past, present and the future

Introduction: Intestinal tuberculosis (ITB) and Crohn's disease (CD) have similar clinical presentation, but require different treatment approaches. Despite advances in various endoscopic, imaging, microbiological, and histological techniques, the differentiation of these two entities is often difficult. Newer radiological and image acquisition modalities have now become indispensable tools for evaluation of these two diseases.Areas covered: This review summarizes the currently available literature on various radiological investigations to differentiate ITB from CD. This review also enumerates the newer modalities in image acquisition techniques and their potential role for differentiating these two diseases. At present abdominal computed tomography (CT) scan is used as a first line investigation for differentiating ITB from CD. Magnetic resonance imaging (MRI) is preferred in pediatric patients and for follow-up studies.Expert opinion: Role of newer modalities like contrast enhanced abdominal ultrasound, perfusion CT, advanced MRI and positron emission tomography (PET) is evolving and requires further exploration. Till further robust studies are available, differentiation between ITB and CD requires use of a combination of clinical, endoscopic, serological, histological, and radiological parameters rather than relying on a single test.

Indian guidelines on imaging of the small intestine in Crohn's disease: A joint Indian Society of Gastroenterology and Indian Radiology and Imaging Association consensus statement

The Indian Society of Gastroenterology (ISG) Task Force on Inflammatory Bowel Disease and the Indian Radiological and Imaging Association (IRIA) developed combined ISG-IRIA evidence-based best-practice guidelines for imaging of the small intestine in patients suspected to have or having Crohn's disease. The 29 consensus statements, developed through a modified Delphi process, are intended to serve as reference for teaching, clinical practice, and research.

Analysis of Phenotypic Variables and Differentiation Between Untypical Crohn's Disease and Untypical Intestinal Tuberculosis

BACKGROUND

The differentiation between untypical intestinal tuberculosis (UITB) and untypical Crohn's disease (UCD) is a challenge.

AIMS

To analyze phenotypic variables and propose a novel prediction model for differential diagnosis of two conditions.

METHODS

A total of 192 patients were prospectively enrolled. The clinical, laboratory, endoscopic, and radiological features were investigated and subjected to univariable and multivariable analyses. The final prediction model for differentiation between UCD and UITB was developed by logistic regression analysis and Fisher discriminant analysis on the training set. The same discriminant function was tested on the validation set.

RESULTS

Twenty-five candidates were selected from 52 phenotypic variables of typical Crohn's disease (TCD), UCD, and UITB patients. UCD's variables overlapped with both TCD and UITB. The percentages of tuberculosis history, positive PPD, and positive T-SPOT result in UCD were all significantly higher than that in TCD (11.6% vs. 0.0%, 27.9% vs. 0.0%, 25.6% vs. 4.5%, respectively, P < 0.05). The regression equations and Fisher discriminant function for discrimination between UCD and UITB were developed. In the training data, the area under the receiver operating characteristic of equations was 0.834, 0.69, and 0.648 in the clinical-laboratory, endoscopic, and radiological model, respectively. The accuracy of Fisher discriminant function for discrimination was 86% in UCD and 73% in UITB in the validation data.

CONCLUSIONS

Phenotypes of UCD patients in TB-endemic countries may be associated with TB infection history. Fisher discriminant analysis is a good choice to differentiate UCD from UITB, which is worthy of verification in clinical practice.

The potential role of CT enterography and gastrointestinal ultrasound in the evaluation of anti-tubercular therapy response of intestinal tuberculosis: a retrospective study

Background

Accurate evaluation of anti-tubercular therapy (ATT) responses is crucial for both diagnosis and treatment of intestinal tuberculosis (ITB). Little is known about the role of cross-sectional imaging techniques in ITB follow-up assessment. We aimed to investigate the accuracy of cross-sectional imaging modalities, CT enterography (CTE) and gastrointestinal ultrasound (GIUS), in the evaluation of ATT responses in ITB patients.

Methods

Patients diagnosed with ITB and followed up by CTE and/or GIUS were retrospectively searched in the databases. Clinical, imaging, laboratory and endoscopic data were collected at baseline and the first follow-up visit. Responses were graded as good, partial and no response based on protocols described in the literature and by our institution. CTE evaluation was based on changes in the lesion area, mural thickness, enhancement patterns and lymph nodes, while GIUS evaluation was based on changes in bowel wall morphology and the Limberg score. Clinical evaluation was used as the gold-standard evaluation method, which was determined by a comprehensive impression of endoscopic changes along with symptomatic improvement and laboratory tests, with imaging results masked.

Results

Twenty patients with ITB were enrolled in our study. The first follow-up time was from 2 to 12 months (average 6 months). According to the gold standard evaluation, 11 patients were evaluated as having a good ATT response, while 9 had a partial response. A total of 18 patients were followed up by CTE, while 7 were followed up by GIUS, depending on medical and/or financial considerations. The accuracy of CTE and GIUS was 83% (15/18) and 85.7% (6/7), respectively. The sensitivity, specificity, PPV and NPV of CTE were 88.9, 77.8, 80 and 87.5%, respectively. Moreover, the sensitivity, specificity, PPV and NPV of GIUS were 100, 50, 83.3 and 100%, respectively. By combining the results of CTE and GIUS results, the overall accuracy was 90%, with sensitivity and specificity of 91.7 and 87.5%, respectively.

Conclusion

To our knowledge, this is the first study exploring the accuracy of the cross-sectional imaging modalities CTE/GIUS in the evaluation of ATT responses. Our results indicated their promising application prospect in clinical practice as a non-invasive and cost-effective approach.

Electronic supplementary material

The online version of this article (10.1186/s12876-019-1030-0) contains supplementary material, which is available to authorized users.

Ileocecal thickening: Clinical approach to a common problem

Ileocecal thickening (ICT) is a common finding on radiological imaging. It can be caused by a variety of inflammatory, infectious, or neoplastic conditions, and evaluating a patient of ICT can be a challenging task. Intestinal tuberculosis (ITB), Crohn's disease (CD), and adenocarcinoma are the most common causes. Enteric bacterial infections, cytomegalovirus, histoplasmosis, amebiasis, systemic vasculitis, lymphoma, etc. should be suspected in appropriate clinical settings. However, it could often be a spurious or nonspecific finding. A thickness of more than 3 mm in a normally distended small bowel is usually considered abnormal. Detailed evaluation of imaging of the site and extent of thickening; the degree and pattern of thickening; and the associated findings, such as degree of fat stranding, fibrofatty proliferation, adjacent lymph nodes, and solid organ involvement, should be performed. Ileocolonoscopy is an important tool for diagnosing and obtaining samples for tissue diagnosis. Histopathology is usually the gold standard for diagnosis, although—not uncommonly—findings could be nonspecific, and reaching a definitive diagnosis is difficult. As such, a systematic approach with the integration of clinical, biochemical, radiological, endoscopic, histological, and other laboratory tests is the key to reaching a diagnosis. In this article, we review the causes of ICT and present a clinical approach for the management of ICT.

Development and Validation of a Novel Diagnostic Nomogram to Differentiate Between Intestinal Tuberculosis and Crohn's Disease: A 6-year Prospective Multicenter Study

OBJECTIVES

Differentiating Crohn's disease (CD) from intestinal tuberculosis (ITB) remains a diagnostic challenge. Misdiagnosis carries potential grave implications. We aimed to develop and validate a novel diagnostic nomogram for differentiating them.

METHODS

In total, 310 eligible patients were recruited from 6 tertiary inflammatory bowel disease centers. Among them, 212 consecutive patients (143 CD and 69 ITB) were used in the derivation cohort for the establishment of diagnostic equation and nomogram; 7 investigative modalities including clinical manifestations, laboratory results, endoscopic findings, computed tomography enterography features, and histology results were used to derive the diagnostic model and nomogram. Ninety-eight consecutive patients (76 CD and 22 ITB) were included for validation of the diagnostic model.

RESULTS

Eight out of total 79 parameters were identified as valuable parameters used for establishing diagnostic equations. Two regression models were built based on 7 differential variables: age, transverse ulcer, rectum involvement, skipped involvement of the small bowel, target sign, comb sign, and interferon-gamma release assays (for model 1) or purified protein derivative (for model 2), respectively. Accordingly, 2 nomograms of the above 2 models were developed for clinical practical use, respectively. Further validation test verified the efficacy of the nomogram 1 with 90.9% specificity, 86.8% sensitivity, 97.1% PPV, 66.7% negative predictive value (NPV), and 87.8% accuracy for identifying CD, and the efficacy of the nomogram 2 with 100% specificity, 84.2% sensitivity, 100% positive predictive value, 64.7% NPV, and 87.8% accuracy for diagnosing CD.

CONCLUSIONS

The derivation and validation cohorts identified and validated 2 highly accurate and practical diagnostic nomograms for differentiating CD from ITB. These diagnostic nomograms can be conveniently used to identify some difficult CD or ITB cases, allowing for decision-making in a clinical setting.

Differentiating Crohn’s disease from intestinal tuberculosis

Differentiating Crohn’s disease (CD) and intestinal tuberculosis (ITB) has remained a dilemma for most of the clinicians in the developing world, which are endemic for ITB, and where the disease burden of inflammatory bowel disease is on the rise. Although, there are certain clinical (diarrhea/hematochezia/perianal disease common in CD; fever/night sweats common in ITB), endoscopic (longitudinal/aphthous ulcers common in CD; transverse ulcers/patulous ileocaecal valve common in ITB), histologic (caseating/confluent/large granuloma common in ITB; microgranuloma common in CD), microbiologic (positive stain/culture for acid fast-bacillus in ITB), radiologic (long segment involvement/comb sign/skip lesions common in CD; necrotic lymph node/contiguous ileocaecal involvement common in ITB), and serologic differences between CD and ITB, the only exclusive features are caseation necrosis on biopsy, positive smear for acid-fast bacillus (AFB) and/or AFB culture, and necrotic lymph node on cross-sectional imaging in ITB. However, these exclusive features are limited by poor sensitivity, and this has led to the development of multiple multi-parametric predictive models. These models are also limited by complex formulae, small sample size and lack of validation across other populations. Several new parameters have come up including the latest Bayesian meta-analysis, enumeration of peripheral blood T-regulatory cells, and updated computed tomography based predictive score. However, therapeutic anti-tubercular therapy (ATT) trial, and subsequent clinical and endoscopic response to ATT is still required in a significant proportion of patients to establish the diagnosis. Therapeutic ATT trial is associated with a delay in the diagnosis of CD, and there is a need for better modalities for improved differentiation and reduction in the need for ATT trial.

Diagnostic Performance of a 5-Marker Predictive Model for Differential Diagnosis Between Intestinal Tuberculosis and Crohn's Disease

BACKGROUND

The differentiation between intestinal tuberculosis (ITB) and Crohn's disease (CD) is a challenge. The aim of this study was to investigate a predictive model for differential diagnosis between ITB and CD.

METHODS

A total of 268 patients who were suspected of having ITB or CD were prospectively recruited between January 2013 and September 2016. The clinical, laboratory, radiological, endoscopic, and histological features were investigated and subjected to univariate and multivariate analyses. The final predictive model was developed based on the regression coefficients of multivariate logistic regression. To validate the model, the same regression equation was tested on the other group.

RESULTS

A total of 239 patients had a final diagnosis, including 86 ITB and 153 CD. Five variables (perianal disease, pulmonary involvement, longitudinal ulcer, left colon, and ratio of tuberculosis-specific antigen to phytohaemagglutinin) were selected for the predictive model to discriminate between ITB and CD. In the predictive model of the training data set, the area under the receiver operating characteristic (ROC) curve, sensitivity, specificity, and accuracy, with a cutoff level of 0.29, were 0.975 (95% confidence interval [CI], 0.939-0.993), 96.7%, 90.7%, and 92.8%, respectively. Application of the predictive model to the validation data set showed similar performance in distinguishing ITB from CD. The area under the ROC curve, sensitivity, specificity, and accuracy were 0.950 (95% CI, 0.871-0.987), 88.5%, 93.5%, and 91.7%, respectively.

CONCLUSIONS

This 5-marker predictive model could be conveniently used by clinicians to draw a reliable differential diagnosis between ITB and CD in clinical practice. 10.1093/ibd/izy154_video1izy154.video15790725497001.

Atypical serious hematochezia and rare imaging feature in gastrointestinal tuberculosis

A young patient had serious hematochezia for nearly 2 months without obvious cause. Abdominal CT images showed rare features such as serious hemorrhage and multiple miliary nodules in the small bowel. The colonoscopy showed multiple lymphoid follicles in the terminal ileum. The laparotomy showed adverse adhesion in the abdominal cavity and multiple miliary noduli in the surfaces of small bowel wall. The pathology suggested tuberculosis. This patient received anti-TB therapy and the condition improved gradually. There are many variants of GI tuberculosis demonstrating uncommon and rare imaging features. It turned to be difficult in diagnosis when it showed the rare appearance, such as the great amount of intestinal bleeding and multiple noduli in our case. The reason why gastrointestinal bleeding might be attributed to the invasiveness of submucosal vessels by the tuberculosis bacteria. And the multiple noduli on the bowel wall might be the granuloma formation. Therefore, from the experience of our case, gastrointestinal tract might also be the first and only involved site, and it may cause great amount of bleeding to a life danger, even in young people.

Combination of increased visceral fat and long segment involvement: Development and validation of an updated imaging marker for differentiating Crohn's disease from intestinal tuberculosis

BACKGROUND AND AIM

Computed tomographic (CT) features (long segment, ileocaecal area involvement, and lymph nodes > 1 cm) have demonstrated good specificity but poor sensitivity, while visceral to subcutaneous fat ratio on CT (VF/SC > 0.63) has moderate sensitivity and specificity in differentiating Crohn's disease (CD) and intestinal tuberculosis (ITB). This study aims to develop and validate an updated model incorporating CT features and VF/SC to improve the diagnostic accuracy of imaging in differentiating CD/ITB.

METHODS

Computed tomographic features and VF/SC were documented in two cohorts (development [n = 59, follow-up: January 2012 to November 2014] and validation [n = 69, follow-up: December 2014 to December 2015]) of CD/ITB patients diagnosed by standard criteria. Patients with normal CT were excluded. Features significantly different between CD/ITB were incorporated into a model.

RESULTS

In both the cohorts, necrotic lymph nodes were exclusive for ITB (23.1% vs 0% and 43.3% vs 0%), while long segment involvement (57.6% vs 7.7%, P < 0.001, and 52.6% vs 16.1%, P < 0.001) and VF/SC ratio > 0.63 (72.7% vs 19.2%, P < 0.001, and 81.6% vs 25.8%, P < 0.001) were significantly more common in CD. A risk score of 2, based upon long segment involvement and VF/SC ratio > 0.63, had an excellent specificity of 100% and 100% and sensitivity of 54% and 50% for CD in development and validation cohorts, respectively. Based upon these features, in 43% patients with the diagnostic dilemma of CD/ITB, a definite diagnosis based only on imaging could be made.

CONCLUSION

Necrotic lymph nodes are exclusive for ITB, and the combination of long segment involvement and VF/SC ratio > 0.63 is exclusive for CD, and these features can make a definite diagnosis in 43% patients with a CD/ITB dilemma.

Imaging of the small intestine in Crohn's disease: Joint position statement of the Indian Society of Gastroenterology and Indian Radiological and Imaging Association

The Indian Society of Gastroenterology (ISG) Task Force on Inflammatory Bowel Disease and the Indian Radiological and Imaging Association (IRIA) developed combined ISG-IRIA evidence-based best-practice guidelines for imaging of the small intestine in patients with suspected or known Crohn's disease. These 29 position statements, developed through a modified Delphi process, are intended to serve as reference for teaching, clinical practice, and research.

Temporal trends in the misdiagnosis rates between Crohn's disease and intestinal tuberculosis

AIM

To investigate the temporal trends in the misdiagnosis rate between Crohn's disease (CD) and intestinal tuberculosis (ITB) in South Korea.

METHODS

We retrospectively reviewed the medical records of patients managed for CD or ITB at Asan Medical Center, a tertiary referral hospital, Seoul, Korea between 1996 and 2014. The temporal trends in the misdiagnosis rates between the two diseases were analyzed. The demographic and clinical characteristics were compared between CD patients who were initially misdiagnosed as ITB (final CD group) and vice versa (final ITB group). Final diagnostic criteria for ITB and medication for CD before definite diagnosis of TB were also analyzed in final ITB group.

RESULTS

In total, 2760 patients were managed for CD and 772 patients for ITB between 1996 and 2014. As well, 494 of the 2760 CD patients (17.9%) were initially misdiagnosed as ITB and 83 of the 772 ITB patients (10.8%) as CD. The temporal trend in misdiagnosing CD as ITB showed a decrease (OR = 0.89, 95%CI: 0.87-0.91, P < 0.001), whereas the temporal trend in misdiagnosing ITB as CD showed an increase (OR = 1.06, 95%CI: 1.01-1.11, P = 0.013). Age at diagnosis, presenting symptoms, and proportion of patients with active/past perianal fistula and active/inactive pulmonary tuberculosis (TB) were significantly different between final CD group and final ITB group. Forty patients (48.2%) in final ITB group were diagnosed by favorable response to empirical anti-TB treatment. Seventeen patients (20.5%) in final ITB group had inappropriately received corticosteroids and/or thiopurines due to misdiagnosis as CD. However, there were no mortalities in both groups.

CONCLUSION

Cases of CD misdiagnosed as ITB have been decreasing, whereas cases of ITB misdiagnosed as CD have been increasing over the past two decades.

Abdominal tuberculosis: Is there a role for surgery?

It is important that surgeons are familiar with the various manifestations of tuberculosis (TB). Although TB has been declining in incidence in the developed world, it remains an important problem in endemic areas of the developing world. The aim of the review was to elucidate the natural history and characteristics of abdominal TB and ascertain the indications for surgery. TB can affect the intestine as well as the peritoneum and the most important aspect of abdominal TB is to bear in mind the diagnosis and obtain histological evidence. Abdominal TB is generally responsive to medical treatment, and early diagnosis and management can prevent unnecessary surgical intervention. Due to the challenges of early diagnosis, patients should be managed in collaboration with a physician familiar with anti-tuberculous therapy. An international expert consensus should determine an algorithm for the diagnosis and multidisciplinary management of abdominal TB.

Crohn's disease

Crohn's disease is a chronic inflammatory disease of the gastrointestinal tract, with increasing incidence worldwide. Crohn's disease might result from a complex interplay between genetic susceptibility, environmental factors, and altered gut microbiota, leading to dysregulated innate and adaptive immune responses. The typical clinical scenario is a young patient presenting with abdominal pain, chronic diarrhoea, weight loss, and fatigue. Assessment of disease extent and of prognostic factors for complications is paramount to guide therapeutic decisions. Current strategies aim for deep and long-lasting remission, with the goal of preventing complications, such as surgery, and blocking disease progression. Central to these strategies is the introduction of early immunosuppression or combination therapy with biologicals in high-risk patients, combined with a tight and frequent control of inflammation, and adjustment of therapy on the basis of that assessment (treat to target strategy). The therapeutic armamentarium for Crohn's disease is expanding, and therefore the need to develop biomarkers that can predict response to therapies will become increasingly important for personalised medicine decisions in the near future. In this Seminar, we provide a physician-oriented overview of Crohn's disease in adults, ranging from epidemiology and cause to clinical diagnosis, natural history, patient stratification and clinical management, and ending with an overview of emerging therapies and future directions for research.

Accuracy of computed tomographic features in differentiating intestinal tuberculosis from Crohn's disease: a systematic review with meta-analysis

Abdominal computed tomography (CT) can noninvasively image the entire gastrointestinal tract and assess extraintestinal features that are important in differentiating Crohn's disease (CD) and intestinal tuberculosis (ITB). The present meta-analysis pooled the results of all studies on the role of CT abdomen in differentiating between CD and ITB. We searched PubMed and Embase for all publications in English that analyzed the features differentiating between CD and ITB on abdominal CT. The features included comb sign, necrotic lymph nodes, asymmetric bowel wall thickening, skip lesions, fibrofatty proliferation, mural stratification, ileocaecal area, long segment, and left colonic involvements. Sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio (DOR) were calculated for all the features. Symmetric receiver operating characteristic curve was plotted for features present in >3 studies. Heterogeneity and publication bias was assessed and sensitivity analysis was performed by excluding studies that compared features on conventional abdominal CT instead of CT enterography (CTE). We included 6 studies (4 CTE, 1 conventional abdominal CT, and 1 CTE+conventional abdominal CT) involving 417 and 195 patients with CD and ITB, respectively. Necrotic lymph nodes had the highest diagnostic accuracy (sensitivity, 23%; specificity, 100%; DOR, 30.2) for ITB diagnosis, and comb sign (sensitivity, 82%; specificity, 81%; DOR, 21.5) followed by skip lesions (sensitivity, 86%; specificity, 74%; DOR, 16.5) had the highest diagnostic accuracy for CD diagnosis. On sensitivity analysis, the diagnostic accuracy of other features excluding asymmetric bowel wall thickening remained similar. Necrotic lymph nodes and comb sign on abdominal CT had the best diagnostic accuracy in differentiating CD and ITB.

Meta-Analytic Bayesian Model For Differentiating Intestinal Tuberculosis from Crohn's Disease

OBJECTIVES

Distinguishing intestinal tuberculosis (ITB) from Crohn's disease (CD) is difficult, although studies have reported clinical, endoscopic, imaging, and laboratory findings that help to differentiate these two diseases. We aimed to produce estimates of the predictive power of these findings and construct a comprehensive model to predict the probability of ITB vs. CD.

METHODS

A systematic literature search for studies differentiating ITB from CD was conducted in MEDLINE, PUBMED, and EMBASE from inception until September 2015. Fifty-five distinct meta-analyses were performed to estimate the odds ratio of each predictive finding. Estimates with a significant difference between CD and ITB and low to moderate heterogeneity (I²<50%) were incorporated into a Bayesian prediction model incorporating the local pretest probability.

RESULTS

Thirty-eight studies comprising 2,117 CD and 1,589 ITB patients were included in the analyses. Findings in the model that significantly favored CD included male gender, hematochezia, perianal disease, intestinal obstruction, and extraintestinal manifestations; endoscopic findings of longitudinal ulcers, cobblestone appearance, luminal stricture, mucosal bridge, and rectal involvement; pathological findings of focally enhanced colitis; and computed tomographic enterography (CTE) findings of asymmetrical wall thickening, intestinal wall stratification, comb sign, and fibrofatty proliferation. Findings that significantly favored ITB included fever, night sweats, lung involvement, and ascites; endoscopic findings of transverse ulcers, patulous ileocecal valve, and cecal involvement; pathological findings of confluent or submucosal granulomas, lymphocyte cuffing, and ulcers lined by histiocytes; a CTE finding of short segmental involvement; and a positive interferon-γ release assay. The model was validated by gender, clinical manifestations, endoscopic, and pathological findings in 49 patients (27 CD, 22 ITB). The sensitivity, specificity, and accuracy for diagnosis of ITB were 90.9%, 92.6%, and 91.8%, respectively.

CONCLUSIONS

A Bayesian model based on the meta-analytic results is presented to estimate the probability of ITB and CD calibrated to local prevalence. This model can be applied to patients using a publicly available web application.

Development and validation of visceral fat quantification as a surrogate marker for differentiation of Crohn's disease and intestinal tuberculosis

BACKGROUND AND AIM

Crohn's disease (CD) and intestinal tuberculosis (ITB) have close phenotypic resemblance. Mesenteric fat (a component of visceral fat [VF]) hypertrophy and fat wrapping, which is visible radiologically as fibrofatty proliferation, is seen more commonly in CD than in ITB.

AIM

The present study was conducted to study the role of VF in differentiating CD and ITB.

METHODS

Visceral fat area and subcutaneous (SC) fat area were measured on computed tomography in two cohorts (development and validation). VF/SC ratio was also calculated for all patients. In the development cohort, retrospective data collection was carried out for 75 patients with CD and ITB who were on follow-up from January 2012 to November 2014. In the validation cohort, 82 patients were recruited prospectively from December 2014 to December 2015 and were diagnosed as CD or ITB according to standard diagnostic criteria.

RESULTS

Visceral fat area and VF/SC ratio were significantly higher in CD patients (n = 42: development, n = 46: validation) than in ITB patients (n = 33: development, n = 36: validation) in both the development (106.2 ± 63.5 vs 37.3 ± 22, P = <0.001; 1.1 ± 0.57 vs 0.43 ± 0.24, P = <0.001) and validation cohorts (102.2 ± 69.8 vs 55.8 ± 44.9, P = 0.01; 1.2 ± 0.68 vs 0.56 ± 0.33, P = <0.001). A cut-off of 0.63 for VF/SC ratio in the development cohort had a high sensitivity (82%) and specificity (81%) in differentiating CD and ITB. Similar sensitivity (81%) and specificity (78%) were seen when this cut-off was applied in the validation cohort.

CONCLUSION

The VF/SC ratio is a simple, cost-effective, non-invasive and single objective parameter with a good sensitivity and specificity to differentiate CD and ITB.

Usefulness of spectral computed tomography for evaluation of intestinal activity and severity in ileocolonic Crohn's disease

BACKGROUND

Assessment of intestinal activity and severity of Crohn's disease (CD) is crucial to guide treatment. In this study, we aimed to investigate the accuracy of spectral computed tomography (CT) in this assessment and make a comparison with conventional CT.

METHODS

A total of 50 patients with ileocolonic CD underwent spectral CT scanning. Conventional CT and spectral CT images were reconstructed. Endoscopic lesions were classified as absent, mild lesions and severe lesions. Qualitative and quantitative findings in CT images were compared in these segments. Logistic regressions were established, based on conventional and spectral CT parameters, to predict intestinal activity and severity. Comparisons were made by receiver operating characteristic (ROC) curve.

RESULTS

The results showed that bowel wall hyperenhancement, ulcers on CT images, comb sign, bowel wall thickness, normalized iodine concentration (NIC) and slope of HU curve (λ_HU) increased significantly (p < 0.01) with endoscopic severity. In predicting intestinal activity, spectral CT demonstrated higher accuracy (99.6% versus 94.7%), sensitivity (99.1% versus 93.4%) and specificity (99.9% versus 94.4%) than conventional CT. In predicting intestinal severity, spectral CT also had higher accuracy (96.5% versus 91.9%), sensitivity (96.5% versus 92.1%) and specificity (95.8% versus 89.8%) than conventional CT. Besides, both NIC and λ_HU correlated significantly with Simple Endoscopic Score for CD (r = 0.833 and r = 0.771; both p < 0.001), but their correlations with C-reactive protein (r = 0.578 and r = 0.513; both p < 0.01) and Harvey-Bradshaw Index (r = 0.545 and r = 0.522; both p < 0.01) were moderate.

CONCLUSIONS

Compared with conventional CT, spectral CT had higher accuracy in detecting intestinal activity and severity of CD, which could be an alternative choice in evaluation of CD.

Hepatic and Intra-abdominal Tuberculosis: 2016 Update

Mycobacterium tuberculosis (TB) infection affects nearly 10 million people a year and causes 1.5 million deaths. TB is common in the immunosuppressed population with 12 % of all new diagnoses occurring in human immune deficiency virus (HIV)-positive patients. Extra-pulmonary TB occurs in 12 % of patients with active TB infection of which 3.5 % is hepatobiliary and 6-38 % is intra-abdominal. Hepatobiliary and intra-abdominal TB can present with a myriad of non-specific symptoms, and therefore, diagnosis requires a high level of suspicion. Accurate and rapid diagnosis requires a multidisciplinary team (MDT) approach using radiology, interventional radiology, surgery and pathology services. Treatment of TB is predominantly medical, yet surgery plays an important role in managing the complications of hepatobiliary and intra-abdominal TB.

Increased 18F-FDG uptake of heterotopic pancreatitis in the small intestine: A CARE-compliant case report

BACKGROUD

Heterotopic pancreas (HP), a relatively uncommon congenital anomaly, is rarely noted during F-FDG positron-emission tomography/computed tomography (PET/CT) scan.

METHODS

A 60-year-old woman was referred to our hospital due to a 10-day history of abdominal pain with elevated levels of serum amylase and lipase. Abdominal CT and ultrasound examinations were negative. In order to search for the cause, an F-FDG PET/CT whole body scan was suggested to an old woman revealing the presence of F-FDG accumulating nodule in small intestine.

RESULTS

Surgical findings and pathologic results confirmed the diagnosis of small intestinal heterotopic pancreas with active chronic inflammation.

CONCLUSION

This uncommon case underscores the necessity of considering heterotopic pancreatitis in small intestine with focal F-FDG uptake as a possible differential diagnosis in intestinal tumor and tuberculosis.

Intestinal tuberculosis versus crohn's disease: Clinical and radiological recommendations

Intestinal tuberculosis is a common clinical problem in India. The clinical features of this disease are nonspecific and can be very similar to Crohn's disease. Radiological evaluation of the small bowel has undergone a paradigm shift in the last decade. This long tubular organ that has traditionally been difficult to evaluate can now be well-visualized by some innovative imaging and endoscopic techniques. This article highlights the state-of-the-art evaluation of ulceroconstrictive diseases of the bowel and provides recommendations for the differentiation of intestinal tuberculosis from Crohn's disease.

Diagnosis of inflammatory bowel disease in Asia: the results of a multinational web-based survey in the 2(nd) Asian Organization for Crohn's and Colitis (AOCC) meeting in Seoul

Background/Aims

As the number of Asian patients with inflammatory bowel disease (IBD) has increased recently, there is a growing need to improve IBD care in this region. This study is aimed at determining how Asian countries are currently dealing with their IBD patients in terms of diagnosis.

Methods

A questionnaire was designed by the organizing committee of Asian Organization for Crohn's and Colitis, for a multinational web-based survey conducted between March 2014 and May 2014.

Results

A total of 353 Asian medical doctors treating IBD patients responded to the survey (114 in China, 88 in Japan, 116 in Korea, and 35 in other Asian countries). Most of the respondents were gastroenterologists working in an academic teaching hospital. While most of the doctors from China, Japan, and Korea use their own national guidelines for IBD diagnosis, those from other Asian countries most commonly adopt the European Crohn's Colitis Organisation's guideline. Japanese doctors seldom adopt the Montreal classification for IBD. The most commonly used activity scoring system for ulcerative colitis is the Mayo score in all countries except China, whereas that for Crohn's disease (CD) is the Crohn's Disease Activity Index. The most available tool for small-bowel evaluation in CD patients differs across countries. Many physicians administer empirical anti-tuberculous medications before the diagnosis of CD.

Conclusions

The results of this survey demonstrate that Asian medical doctors have different diagnostic approaches for IBD. This knowledge would be important in establishing guidelines for improving the care of IBD patients in this region.

Intestinal tuberculosis and Crohn's disease: challenging differential diagnosis

Along with epidemiological changes in tuberculosis (TB) and an increased incidence of Crohn's disease (CD), the differential diagnosis of intestinal TB (ITB) and CD is of vital importance and has become a clinical challenge because treatment based on misdiagnosis may lead to fatal outcomes. In this study, we reviewed the similarities and differences in clinical, endoscopic, radiological and histological features of these two diseases. Concomitant pulmonary TB, ascites, night sweats, involvement of fewer than four segments of the bowel, patulous ileocecal valve, transverse ulcers, scars or pseudopolyps strongly indicate ITB. Bloody stools, perianal signs, chronic diarrhea, extraintestinal manifestations, anorectal lesions, longitudinal ulcers and a cobblestone appearance are all suggestive of CD. Significant differences in the size, number, location and patterns of granulomas in ITB and CD with regard to their histopathologic features have been noted. Immune stain of cell surface markers is also helpful. Interferon-γ release assay and polymerase chain reaction analysis have achieved satisfactory sensitivity and specificity in the diagnosis of ITB. Computed tomography enterographic findings of segmental small bowel or left colon involvement, mural stratification, the comb sign and fibrofatty proliferation are significantly more common in CD, whereas mesenteric lymph node changes (calcification or central necrosis) and focal ileocecal lesions are more frequently seen in ITB. A diagnosis should be carefully established before the initiation of the therapy. In suspicious cases, short-term empirical anti-TB therapy is quite efficient to further confirm the diagnosis.