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

Significance of Epidemiological Background in Preventing the Misdiagnosis of Intestinal Tuberculosis as Crohn's Disease

The misdiagnosis of intestinal tuberculosis (ITB), such as Crohn's disease (CD), and subsequent treatment with immunosuppressive therapies can lead to severe outcomes. However, the differential diagnosis between these two conditions can be challenging. We herein report a patient from Myanmar who was initially diagnosed with CD due to the presence of non-caseating granulomas. The patient's symptoms were aggravated with steroid treatment, eventually leading to a diagnosis of ITB. In the international medical community, we encounter patients from countries, such as Myanmar, where tuberculosis is endemic. Therefore, it is necessary to understand the epidemiological background of each country to accurately distinguish between CD and ITB.

Discrimination of pediatric cryptogenic multifocal ulcerous stenosing enteritis from small bowel Crohn's disease and gastrointestinal tuberculosis: A retrospective study (with videos)

INTRODUCTION

Cryptogenic multifocal ulcerous stenosing enteritis (CMUSE) is a rare entity that mimics various inflammatory strictures of the small intestine. Pediatric literature is scarce. We analyzed the clinical, radiological, endoscopic and histopathological features of children with CMUSE that differentiate it from small bowel Crohn's disease (SBCD) and gastrointestinal tuberculosis (GITB).

METHODS

CMUSE was diagnosed by the following criteria: (1) unexplained small bowel strictures with superficial ulcers, (2) chronic/relapsing ulcers of small bowel after resection, (3) no signs of systemic inflammation, (4) absence of other known etiologies of small bowel ulcers. SBCD and GITB were diagnosed based on standard criteria. The clinical features, laboratory parameters, radioimaging, endoscopy (including video capsule endoscopy [VCE], intra-operative endoscopy), histopathological features and treatment outcome were noted.

RESULTS

Out of 48, CMUSE was diagnosed in 13 (27%) isolated small bowel and ileocecal strictures, while GITB and SBCD accounted for 41% and 21% cases, respectively. Common presentations were sub-acute obstruction (46%), obscure gastrointestinal bleeding (38%) and protein-losing enteropathy (38%). CMUSE patients had significantly longer disease duration compared to SBCD and GITB (p < 0.001). SBCD (90.0%) and GITB (85%) cases had elevated C-reactive protein (CRP), none with CMUSE had elevated CRP (p < 0.001). The disease was localized in jejunum (100%) and proximal ileum (56%) in CMUSE, ileocecal region (85%) in GITB, but evenly distributed in small intestine in SBCD. Endoscopy showed evenly placed, superficial, circumferential ulcers with strictures in CMUSE, deep linear ulcers in SBCD and circumferential ulcers in GITB. Upfront immunosuppression was given in four; three (75%) of them relapsed. Only surgery was done in three with one (25%) having relapse. Upfront surgery followed by immunosuppression was used in six, but all relapsed and two required repeat surgery.

CONCLUSION

CMUSE is important but underdiagnosed in children. Lack of constitutional symptoms, normal inflammatory parameters and characteristic ulcers with strictures helped in differentiating CMUSE from GITB and SBCD.

Diagnostic Value of Ileal Lesions Found during Colonoscopy with Reference to Endoscopic Indications and Findings

The diagnostic value of ileoscopy is not well established, and its routine practice is controversial. We aimed to investigate the diagnostic value of biopsy for macroscopically abnormal lesions in the terminal ileum and to identify the association between endoscopic indications and findings and the presence of significant disease. This retrospective study included 551 patients who underwent biopsy of abnormal lesions in the terminal ileum (TI) during colonoscopy between February 2000 and June 2019. Biopsy results were analyzed in relation to the endoscopic indications and gross findings. Significant disease was defined as a case in which a specific disease was suspected or confirmed by the biopsy results, requiring additional examination or treatment. Among the 551 biopsies from macroscopically abnormal lesions in the TI, 44 (8.0%) had significant diseases. The frequency of significant disease was high in patients with clinically suspected inflammatory bowel disease (IBD) (50.0%), anemia (31.6%), right lower quadrant (RLQ) pain (28.6%), and radiological abnormalities in the TI (27.5%). The frequency of Crohn's disease (CD) was high in patients with clinically suspected IBD. A concurrent abnormality in the ileocecal valve (ICV) (14.3%) and the presence of an ulcer (14.2%), mass, or polyp (25.4%) correlated with a high incidence of significant disease, particularly CD. In cases of suspected IBD, anemia, RLQ pain, and radiologic abnormalities in the TI, there is a high possibility of significant disease. Ulcers, masses, polyps, and concurrent abnormalities in the ICV were also associated with significant disease.

Use of shear wave imaging with intestinal ultrasonography in patients with chronic diarrhea

OBJECTIVE

A retrospective study was designed to determine the role of shear wave elastography (SWE) and intestinal ultrasonography to differentiate between inflammatory and fibrotic bowel strictures by determining Young's modulus (E) and shear wave dispersion (SWD) and to compare its role with contrast-enhanced computed tomography (CECT) in patients with chronic diarrhea and pain abdomen.

METHODS

Seventy-six patients who had increased small bowel thickness (SBWT) >3 mm, and large bowel wall thickness (LBWT) >4 mm on intestinal ultrasonography (IUS) were evaluated in a two-step manner. The first step involved classifying patients with increased SBWT >3 mm and LBWT >4 mm by use of SWE and dispersion into three groups that is group I (fibrotic), group II (inflammatory) thickening, and group III (mixed-fibrosis and inflammatory) wall thickening. In the second step, etiological classification was done using six gray scale features of IUS that is length and degree of bowel thickening, presence of bowel stratification, Limberg grade of vascularity, status of mesenteric fat, juxta bowel status-nodes, fluid, and fistula formation to reach to a definitive diagnosis. These findings were compared with findings on CECT. Twenty-three patients had diagnosis confirmed by biopsy while 18 underwent surgery with histologic confirmation of operative findings. The sensitivity, specificity and AUROC for both modalities were compared.

RESULTS

Group I that is fibrotic group had 33 patients with fibrotic strictures of which fibrotic Crohn's disease (CD)and tuberculosis of the bowel were the dominant types followed by neoplastic and infective causes. In Group II that is inflammatory there were 32 patients with predominantly infective ileo-colitis, and ulcerative colitis patients while 11 patients were present in group III that is (mixed fibrotic and inflammatory) type of bowel wall thickening and were patients of inflammatory CD, infective ileo-colitis. The presence of length of bowel involvement, Limberg grade, mesenteric fat proliferation, and SBWT>9 mm were the statistically significant parameters on IUS which helped to reach to final diagnosis. The sensitivity and specificity of combined SWE with SWD and IUS were 100% and 99% while that of CECT was 78% and 96% respectively with AUROC of 100% and 64%.

CONCLUSION

SWI combined with IUS in a two-step manner is an accurate way to evaluate patients with chronic diarrhea who have increased SBWT and is not only able to differentiate inflammatory from fibrotic bowel wall thickening but also helps to form an etiological diagnosis.

Diagnostic utility of CT enterography in the evaluation of ileocecal mucosal lesions of uncertain diagnosis on ileocolonoscopy

Purpose

Ileocolonoscopy aids in the diagnosis of ileocecal region pathologies when typical mucosal lesions are seen. However, in many cases the mucosal lesions of the ileocaecal region are atypical, rendering themselves to diagnostic dilemma. The present study aimed to study the role of computed tomography (CT) enterography in the evaluation of symptomatic patients who demonstrated ileocecal mucosal lesions of uncertain diagnosis on ileocolonoscopy.

Material and methods

Symptomatic patients who had ileocolonoscopy documented ileocecal mucosal lesions of uncertain diagnosis were enrolled. Patients were subjected to CT enterography within 10 days of ileocolonoscopy. On CT enterography a diagnosis of Crohn's disease (CD) or ileocaecal tuberculosis (ITB) was made. The diagnosis obtained by CT enterography was correlated with the final diagnosis obtained from histopathology. Using descriptive statistics, the diagnostic performance of CT enterography was evaluated.

Results

A total of 153 cases were enrolled in the study. CT enterography findings were present in 147 cases, resulting in a diagnostic yield of 96%. Out of these, 58.16% (89/153) had CD, 26.14% (40/153) had ITB, 6.5% (10/153) had infectious ileitis, and 9.15% (14/153) were indeterminate on histopathology. CT enterography correctly identified 78.65% (70/89) of CD and 75% (30/40) of ITB. CT enterography had a sensitivity of 78.65% and 75%, specificity of 67.19% and 87.61%, positive predictive value of 76.92% and 68.18%, and diagnostic accuracy of 73.86% and 84.31% for diagnosing CD and ITB, respectively.

Conclusions

CT enterography provided a high diagnostic yield in ileocaecal mucosal lesions of uncertain significance on endoscopy. CD and ITB were the predominant diseases detected in these individuals. CT enterography had a good diagnostic performance in the detection of these 2 disorders.

Disseminated Miliary and Intestinal Tuberculosis Mimicking Inflammatory Bowel Disease

The hematogenous dissemination of Mycobacterium tuberculosis (M. tb) is commonly via the pulmonary system. Less commonly, ingestion of M. tb can lead to primary intestinal tuberculosis (TB), often misdiagnosed as inflammatory bowel disease (IBD). In extremely rare cases, the dissemination can involve cardiac infiltration/tuberculoma. One such case involves a 21-year-old man from Guatemala who spoke a rare dialect of Spanish with nonspecific complaints and an abdominal CT scan showing terminal ileum thickening suggestive of Crohn's disease (CD). A colonoscopy revealed ileitis and tissue biopsy showed granulomatous inflammation with a positive acid-fast bacillus (AFB) stain and positive blood cultures isolated for TB. Chest CT angiography (CTA) also revealed miliary nodules and a right atrial mass was confirmed with cardiac MRI. Viral serology revealed chronic hepatitis B virus (HBV) co-infection, but the patient was HIV-negative. Anti-tubercular therapy (ATT) with rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE), in addition to tenofovir, was initiated, followed by a complicated hospital stay including rifampin-induced bone marrow suppression. Ultimately, he was discharged on isoniazid, pyrazinamide, ethambutol, levofloxacin, and entecavir. Intestinal TB can be misdiagnosed as IBD with the administration of steroids, potentially worsening infection. A systemic approach to clinical investigation with a thorough history using medical translators can lead to early diagnosis and treatment of intestinal and disseminated TB.

Revised Algorithmic Approach to Differentiate Between Nonspecific and Specific Etiologies of Chronic Terminal Ileitis

INTRODUCTION

Chronic isolated terminal ileitis (TI) may be seen in Crohn's disease (CD) and intestinal tuberculosis (ITB) in addition to other etiologies that may be managed symptomatically. We developed a revised algorithm to distinguish patients with a specific etiology from a nonspecific etiology.

METHODS

Patients with chronic isolated TI followed up from 2007 to 2022 were retrospectively reviewed. A specific (ITB or CD) diagnosis was made based on standardized criteria, and other relevant data were collected. Using this cohort, validation of a previously suggested algorithm was conducted. Furthermore, based on the results of a univariate analysis, a multivariate analysis with bootstrap validation was used to develop a revised algorithm.

RESULTS

We included 153 patients (mean age 36.9 ± 14.6 years, males-70%, median duration-1.5 years, range: 0-20 years) with chronic isolated TI of whom 109 (71.2%) received a specific diagnosis (CD-69, ITB-40). On multivariate regression and validation statistics with a combination of clinical, laboratory, radiological, and colonoscopic findings, an optimism corrected c-statistic of 0.975 and 0.958 was obtained with and without histopathological findings, respectively. Revised algorithm, based on these, showed sensitivity, specificity, positive and negative predictive values, and overall accuracy of 98.2% (95% CI: 93.5-99.8), 75.0% (95% CI: 59.7-86.8), 90.7% (95% CI: 85.4-94.2), 94.3% (95% CI: 80.5-98.5) and 91.5%(95% CI:85.9-95.4), respectively. This was more sensitive and specific than the previous algorithm (accuracy 83.9%, sensitivity 95.5%, and specificity 54.6%).

DISCUSSION

We developed a revised algorithm and a multimodality approach to stratify patients with chronic isolated TI into specific and nonspecific etiologies with an excellent diagnostic accuracy, which could potentially avoid missed diagnosis and unnecessary side effects of 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.

Perfusion Computed Tomography May Help in Discriminating Gastrointestinal Tuberculosis and Crohn’s Disease

Gastrointestinal tuberculosis (GITB) and Crohn’s disease (CD) are close mimics. This prospective study aimed to evaluate the diagnostic performance of perfusion computed tomography (CT) in differentiating GITB from CD. Consecutive patients with ileocaecal thickening underwent perfusion CT of the ileocaecal region between January 2019 and July 2020. Two radiologists (blinded to the final diagnosis) independently assessed blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability at perfusion CT. These parameters were compared among the patients with GITB as well as active and inactive CD. Receiver operating characteristic curves were utilized for determining the diagnostic performance of perfusion CT. Interclass correlation coefficient and Bland–Altman analysis were performed to compare the observations of the two radiologists. During the study period, 34 patients underwent perfusion CT. Eight patients had diagnoses other than intestinal tuberculosis or CD. Thus, 26 patients (mean age 36 ± 14 years, 18 males) with GITB (n = 11), active CD (n = 6), and inactive CD (n = 9) were evaluated. BF, MTT, and permeability showed significant differences among the groups, while BV did not differ significantly among the groups. BF and permeability had 100% sensitivity and 100% specificity, while MTT had 61.5–100% sensitivity and 70–100% specificity for differentiating GITB from active CD and active from inactive CD. The interclass correlation coefficient for perfusion CT parameters was 0.88–1. Perfusion CT is a novel imaging technique that can improve the diagnostic performance of differentiating tuberculosis from CD.

Diffusion-weighted magnetic resonance imaging of abdominal tuberculosis: a new take on an old disease

Abdominal tuberculosis is a major cause of mortality and morbidity in developing countries also re-emerging in western world due to the AIDS epidemic and population migration. Large proportion of the patients are young and hence radiation exposure is of concern. In addition, in some patients, contrast may be contraindicated or repeat studies may be required, where MR especially DWI may be useful. The aim of the study is to describe MRI features in abdominal tuberculosis including DWI in the involved bowel, lymphadenopathy, omental, and peritoneal thickening. Nodes being especially easy to appreciate on DWI, thus DWI in conjunction with routine noncontrast MR sequence can be useful technique to identify abdominal tubercular lesions in patients with contraindication to contrast.

Applying logistic LASSO regression for the diagnosis of atypical Crohn's disease

In countries with a high incidence of tuberculosis, the typical clinical features of Crohn's disease (CD) may be covered up after tuberculosis infection, and the identification of atypical Crohn's disease and intestinal tuberculosis (ITB) is still a dilemma for clinicians. Least absolute shrinkage and selection operator (LASSO) regression has been applied to select variables in disease diagnosis. However, its value in discriminating ITB and atypical Crohn's disease remains unknown. A total of 400 patients were enrolled from January 2014 to January 2019 in second Xiangya hospital Central South University.Among them, 57 indicators including clinical manifestations, laboratory results, endoscopic findings, computed tomography enterography features were collected for further analysis. R software version 3.6.1 (glmnet package) was used to perform the LASSO logistic regression analysis. SPSS 20.0 was used to perform Pearson chi-square test and binary logistic regression analysis. In the variable selection step, LASSO regression and Pearson chi-square test were applied to select the most valuable variables as candidates for further logistic regression analysis. Secondly, variables identified from step 1 were applied to construct binary logistic regression analysis. Receiver operating characteristic (ROC) curve analysis was performed on these models to assess the ability and the optimal cutoff value for diagnosis. The area under the ROC curve (AUC), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy rate, together with their 95% confidence and intervals (CIs) were calculated. MedCalc software (Version 16.8) was applied to analyze the ROC curves of models. 332 patients were eventually enrolled to build a binary logistic regression model to discriminate CD (including comprehensive CD and tuberculosis infected CD) and ITB. However, we did not get a satisfactory diagnostic value via applying the binary logistic regression model of comprehensive CD and ITB to predict tuberculosis infected CD and ITB (accuracy rate:79.2%VS 65.1%). Therefore, we further established a binary logistic regression model to discriminate atypical CD from ITB, based on Pearsonchi-square test (model1) and LASSO regression (model 2). Model 1 showed 89.9% specificity, 65.9% sensitivity, 88.5% PPV, 68.9% NPV, 76.9% diagnostic accuracy, and an AUC value of 0.811, and model 2 showed 80.6% specificity, 84.4% sensitivity, 82.3% PPV, 82.9% NPV, 82.6% diagnostic accuracy, and an AUC value of 0.887. The comparison of AUCs between model1 and model2 was statistically different (P < 0.05). Tuberculosis infection increases the difficulty of discriminating CD from ITB. LASSO regression showed a more efficient ability than Pearson chi-square test based logistic regression on differential diagnosing atypical CD and ITB.

Gastrointestinal tuberculosis presenting as acute abdomen: a case report

Intestinal tuberculosis (ITB) represents an important diagnostic challenge in the clinical setting, as it generally can occur as a chronic condition often mimicking other diseases such as Crohn’s disease (CD), and can present itself with acute onset, which can be life-threatening. A 29-years-old Chinese woman coming to ER with abdominal pain, fever and weight loss. Computed tomography and colonoscopy images were not diagnostic. Despite medical therapy, the patient progressively worsened developing sepsis requiring emergency surgery. Pathological and microbiological examination of the colon both pointed towards gastrointestinal tuberculosis involvement. Although ITB is generally a chronic-wasting condition, it can also occur as acute abdomen representing an absolute surgical emergency. Although caseation and necrosis in granulomas can be used for diagnosis of ITB, preoperative diagnosis is still challenging. Endoscopic biopsies targeted to ulcerous lesions could be an essential diagnostic tool, contrary to those targeted to the ulcers’ edges as performed in CD.

Intestinal Tuberculosis Presenting with Gastrointestinal Bleeding in Patient on Warfarin Therapy

Background

Intestinal tuberculosis (ITB) constitutes less than 5% of overall cases of extrapulmonary disease and mostly affects the ileocecal region. The presentation and radiologic findings in enteric tuberculosis can mimic Crohn's disease (CD). Case Presentation. We present a case report of an African woman who presented to a Kenyan hospital with lower gastrointestinal bleeding while on anticoagulation for valvular atrial fibrillation, and was diagnosed with intestinal tuberculosis after colonoscopy, biopsy, and positive staining for tuberculous bacilli.

Conclusion

Intestinal tuberculosis causing gastrointestinal bleeding is rare but should be suspected in patients living in TB endemic regions.

Tuberculosis of abdominal lymph nodes, peritoneum, and GI tract: a malignancy mimic

OBJECTIVE

The purpose is to discuss abdominal tuberculosis mimicking malignancy involving the lymph nodes, peritoneum, and the GI tract.

CONCLUSION

Awareness of the pathophysiology and imaging appearance on various modalities of abdominal tuberculosis involving the lymph nodes, peritoneum, and the GI tract that may simulate malignancy can aid differentiation, diagnosis, and therapy, particularly in areas where tuberculosis is endemic.

Multidetector computed tomography: a corner stone imaging modality in evaluation of acute small bowel diseases

Background

The diagnosis of acute small bowel diseases is one of the challenging issues that confronted by the radiologists so accurate diagnosis is essential to determine the appropriate way of management. CT has become the preferred imaging tool to evaluate acute small bowel diseases. Our study aimed to assess the role of MDCT in evaluation of acute abdomen secondary to small bowel origin by identification and differentiation between different acute small bowel pathologies.

Results

Thirty-eight patients presented with acute abdomen of small bowel origin from June 2019 to September 2019. The mean age of incidence was 48 ± 19 years ranged from 4 to 88 years. Males represented by 23 patients (60.5%). Acute exacerbation of inflammatory bowel diseases (Crohn’s disease) represented by (34.2%), small bowel obstruction (31.6%), ischemic bowel diseases (21.1%), small bowel perforation (10.5%) and infectious (TB enteritis) small bowel disease (2.6%). MDCT had an overall high sensitivity (97.3%) in assessment of acute small bowel diseases in correlation with post-operative data and follow-up response to management.

Conclusions

MDCT is a reliable diagnostic imaging tool for assessment of patients with acute abdomen secondary to small bowel origin with high-efficiency in differentiation between different pathological entities that causing acute abdomen.

Differential prevalence of pathobionts and host gene polymorphisms in chronic inflammatory intestinal diseases: Crohn's disease and intestinal tuberculosis

BACKGROUND AND OBJECTIVES

Crohn's disease (CD) and Intestinal tuberculosis (ITB) are chronic inflammatory ulcero-constrictive intestinal diseases with similar phenotype. Although both are disease models of chronic inflammation and their clinical presentations, imaging, histological and endoscopic findings are very similar, yet their etiologies are diverse. Hence, we aimed to look at differences in the prevalence of pathobionts like adherent-invasive Escherichia coli (AIEC), Listeria monocytogenes, Campylobacter jejuni and Yersinia enterocolitica in CD and ITB as well as their associations with host-associated genetic polymorphisms in genes majorly involved in pathways of microbial handling and immune responses.

METHODS

The study cohort included 142 subjects (69 patients with CD, 32 with ITB and 41 controls). RT- PCR amplification was used to detect the presence of AIEC, L. monocytogenes, C. jejuni, and Y. enterocolitica DNA in colonic mucosal biopsies. Additionally, we tested three SNPs in IRGM (rs13361189, rs10065172, and rs4958847), one SNP in ATG16L1 (rs2241880) and one SNP in TNFRSF1A (rs4149570) by real-time PCR with SYBR green from peripheral blood samples in this cohort.

RESULTS

In patients with CD, AIEC was most frequently present (16/ 69, 23.19%) followed by L. monocytogenes (14/69, 20.29%), C. jejuni (9/69, 13.04%), and Y. enterocolitica (7/69, 10.14%). Among them, L. monocytogenes and Y. enterocolitica were significantly associated with CD (p = 0.02). In addition, we identified all the three SNPs in IRGM (rs13361189, rs10065172, and rs4958847), one SNP in ATG16L1 (rs2241880) and TNFRSF1A (rs4149570) with a significant difference in frequency in patients with CD compared with ITB and controls (p<0.05).

CONCLUSION

Higher prevalence of host gene polymorphisms, as well as the presence of pathobionts, was seen in the colonic mucosa of patients with CD as compared to ITB, although both are disease models of chronic inflammation.

Accuracy of High Resolution Multidetector Computed Tomography in the Local Staging of Rectal Cancer

Background Magnetic resonance imaging (MRI) is the gold standard for local staging of rectal cancer. Advanced computed tomography (CT) machines are now capable of high-resolution images of rectal cancer and utilized for CT perfusion. The possibility of local staging of rectal cancer by CT needs to be explored.

Purpose The aim of the study is to evaluate accuracy of high-resolution CT for local rectal cancer staging.

Methods A high-resolution CT was performed for local staging of rectal cancer in our study group of 93 patients, where 64 underwent primary surgery and 29 underwent surgery post neoadjuvant chemoradiotherapy (NACRT).

Results In differentiating stages T2-and-less than T2 from T3–T4 rectal cancer, accuracy, sensitivity, specificity, and kappa score in overall patients were 91%, 87%, 94%, and 0.8; in primary surgery group were 89%, 76%, 94%, and 0.7; in NACRT group were 97%, 100%, 94%, and 0.9; in low rectal group were 94%, 89%, 97%, and 0.82, respectively.

Conclusion High resolution CT is an accurate tool for local staging of rectal cancer.

Inflammatory bowel disease: An Indian perspective

Inflammatory bowel disease (IBD) in recent times is causing a significant healthcare burden as both ulcerative colitis and Crohn's disease (CD) require lifelong therapy and constant monitoring. The current review highlights the concerns in a country like India with special reference to the changing trends of IBD, risk attribution and the financial issues. Indian immigrants behave like residential Indians, whereas their children show IBD prevalence similar to the West, highlighting the role of environmental triggers. However, the environmental and genetic factors in Indians with IBD are not well understood. Men appear to be more frequently affected than women in India. The disease severity is milder in the patients, both males and females, but the risk for colorectal cancer (CRC) is similar to the West. The incidence of paediatric IBD is on the rise. The major burden of IBD in the Indian subcontinent at present is in children, adolescents and teens. Cost towards the management of complications, non-adherence to treatment, differentiating tuberculosis from CD and finally screening for CRC in patients with IBD are the points to ponder in the Indian scenario.

A Comprehensive Review of Infectious Granulomatous Diseases of the Gastrointestinal Tract

A granuloma is defined as a localized inflammatory reaction or a hypersensitive response to a nondegradable product leading to an organized collection of epithelioid histiocytes. Etiologies of granulomatous disorders can be divided into two broad categories: infectious and noninfectious (autoimmune conditions, toxins, etc.) causes. The endless list of causalities may prove challenging for gastroenterologists and pathologists to formulate a list of clearly defined differentials. This is true when distinguishing these etiologies based on various clinical presentations and endoscopic and histological findings. We aim to provide a comprehensive review of some of the frequent and rare infectious granulomatous diseases of the gastrointestinal tract documented in the literature to date. We provide an overview of each infectious pathology with an emphasis on epidemiology, clinical presentation, and endoscopic and histologic findings, in addition to treatment.

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.

Comparison of virtual computed tomography enteroscopy using carbon dioxide with small-bowel enteroclysis and capsule endoscopy in patients with small-bowel tuberculosis

OBJECTIVE

Comparison of virtual CT enteroscopy (VCTE) using carbon dioxide with small-bowel enteroclysis (SBE) and capsule endoscopy (CE) in small-bowel tuberculosis (SBTB).

METHODS

This prospective study comprised consecutive patients suspected to have SBTB. VCTE and SBE were performed on the same day and evaluated by independent radiologists. CE was performed within 2 weeks. VCTE was performed following insufflation of carbon dioxide via catheters in the jejunum and anorectum. A contrast-enhanced CT was followed by a delayed non-contrast CT. Image processing was done using virtual colonoscopy software. Findings on VCTE, SBE, and CE were compared. The final diagnosis of SBTB was based on either histopathological or cytological findings, response to antitubercular treatment, or a combination of these.

RESULTS

Of the 55 patients in whom VCTE was performed, complete data was available in 52 patients. A final diagnosis of SBTB was established in 37 patients. All patients had VCTE and SBE. CE was performed in 34 patients. Adequate luminal distension was achieved in all patients with SBE and 35 patients with VCTE. SBE showed more strictures in jejunum (10.8%) and ileum (75.7%) compared with VCTE (jejunum, 8.1%, and ileum, 64.9%) and CE (jejunum, 5.9%, and ileum, 61.8%). However, difference was not statistically significant. VCTE revealed a greater length of strictures in both the jejunum and ileum compared with SBE and CE.

CONCLUSION

VCTE allows adequate evaluation of the bowel in most patients with SBTB. It allows detection of greater length of abnormality in jejunum and ileum compared with SBE and CE.

KEY POINTS

• The use of VCTE using CO₂ bowel insufflation in patients with SBTB should be considered. • VCTE allows detection of a greater length of abnormality in the jejunum and ileum.

Clinical Features and Outcomes of Tuberculosis in Inflammatory Bowel Disease Patients Treated with Anti-tumor Necrosis Factor Therapy

Background/Aims

Anti-tumor necrosis factor (TNF) therapy is used widely for the treatment of inflammatory bowel disease (IBD). In the present study, the characteristics and outcomes of tuberculosis (TB) in IBD patients treated with anti-TNF therapy were compared with those of non-IBD TB patients.

Methods

Twenty-five IBD patients who initially developed TB during anti-TNF therapy were enrolled in this study. Seventy-five ageand gender-matched non-IBD TB patients were selected as controls in a 1:3 ratio.

Results

The proportion of non-respiratory symptoms was higher in the IBD patients than in the non-IBD patients (12 [48.0%] in the IBD patients vs. 15 [20.0%] in the non-IBD patients; p=0.009). Eight (32.0%) IBD patients and 19 (25.3%) non-IBD patients had extra- pulmonary lesions (p=0.516). The frequency of positive smear results for acid-fast bacilli (AFB) was significantly higher in the non-IBD patients than in the IBD patients (three [12.0%] IBD patients vs. 27 [36.0%] non-IBD patients; p=0.023). Active TB was cured in 24 (96.0%) patients in the IBD group and in 70 (93.3%) patients in the non-IBD group (p=0.409). The TB-related mortality rates were 4.0% and 1.3% in the IBD patients and non-IBD patients, respectively (p=0.439).

Conclusions

The rate of extrapulmonary involvement, side effects of anti-TB medications, and clinical outcomes did not differ between the IBD patients who initially developed TB during anti-TNF therapy and non-IBD patients with TB. On the other hand, the IBD patients had a lower rate of AFB smear positivity and a higher proportion of non-respiratory symptoms.

Extrapulmonary Tuberculosis: Pathophysiology and Imaging Findings

Extrapulmonary tuberculosis (TB) represents approximately 15% of all TB infections. It is difficult to diagnose on the basis of imaging characteristics and clinical symptoms, and biopsy is required in many cases. Radiologists must be aware of the imaging findings of extrapulmonary TB to identify the condition in high-risk patients, even in the absence of active pulmonary infection. In extrapulmonary TB, the lymphatic system is most frequently affected. The presence of necrotic lymph nodes and other organ-specific imaging features increases the diagnostic probability of extrapulmonary TB. Disseminated infection and central nervous system involvement are the most frequent manifestations in immunosuppressed patients. Renal disease can occur in immunocompetent patients with very long latency periods between the primary pulmonary infection and genitourinary involvement. In several cases, gastrointestinal, solid-organ, and peritoneal TB show nonspecific imaging findings. Tuberculous spondylitis is the most frequent musculoskeletal manifestation. It is usually diagnosed late and affects multiple vertebral segments with extensive paraspinal abscess. Articular disease is the second most frequent musculoskeletal manifestation, and synovitis is its predominant imaging finding.^©RSNA, 2019.

Mesenchymal stem cells offer a drug-tolerant and immune-privileged niche to Mycobacterium tuberculosis

Anti-tuberculosis (TB) drugs, while being highly potent in vitro, require prolonged treatment to control Mycobacterium tuberculosis (Mtb) infections in vivo. We report here that mesenchymal stem cells (MSCs) shelter Mtb to help tolerate anti-TB drugs. MSCs readily take up Mtb and allow unabated mycobacterial growth despite having a functional innate pathway of phagosome maturation. Unlike macrophage-resident ones, MSC-resident Mtb tolerates anti-TB drugs remarkably well, a phenomenon requiring proteins ABCC1, ABCG2 and vacuolar-type H⁺ATPases. Additionally, the classic pro-inflammatory cytokines IFNγ and TNFα aid mycobacterial growth within MSCs. Mechanistically, evading drugs and inflammatory cytokines by MSC-resident Mtb is dependent on elevated PGE2 signaling, which we verify in vivo analyzing sorted CD45^-Sca1⁺CD73⁺-MSCs from lungs of infected mice. Moreover, MSCs are observed in and around human tuberculosis granulomas, harboring Mtb bacilli. We therefore propose, targeting the unique immune-privileged niche, provided by MSCs to Mtb, can have a major impact on tuberculosis prevention and cure.

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.

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.

Imaging in Pediatric Extra-Pulmonary Tuberculosis

Extrapulmonary tuberculosis in children tends to be more severe than the adults. It can affect almost any organ system of the body. The clinical manifestations are often non-specific. Imaging findings are also not always very specific. This article describes the imaging spectrum of pediatric extrapulmonary tuberculosis.

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.

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.

Small Bowel Lesions Mimicking Crohn's Disease

PURPOSE OF REVIEW

Not all injuries of the terminal ileum are Crohn's disease. It is the purpose of this review to consider the differential diagnosis of other acute and chronic ileal lesions.

RECENT FINDINGS

The recognition of a granulomatous disease of the terminal ileum, distinct from tuberculosis, dates back over 85 years and perhaps much farther, but over the past decades, many other clinical pathologic entities have been described that are neither tuberculosis nor Crohn's eponymous regional enteritis. In recent years, the catalog of lesions mimicking Crohn's disease of the small bowel and proposals for differential diagnosis and treatment have expanded to include newly reported appendiceal pathology, primary cancers and lymphomas of the intestine, unexpected metastases from distant organs, unusual infections, vasculitides and other ischemic conditions, Behçet's disease, endometriosis, and drug reactions. A diagnosis of Crohn's disease should not be a reflex action in the face of small bowel structural or inflammatory lesions without consideration of pathology in adjacent organs, primary and metastatic lesions of the small intestine, infections, vascular diseases, infiltrative diseases, drug injury, or other "idiopathic" conditions.

MAP1981c, a Putative Nucleic Acid-Binding Protein, Produced by Mycobacterium avium subsp. paratuberculosis, Induces Maturation of Dendritic Cells and Th1-Polarization

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative pathogen of chronic granulomatous enteropathy (Johne's disease) in animals, and has been focused on its association with various autoimmune diseases in humans, including Crohn's disease. The discovery of novel mycobacterial antigens and exploring their role in host immunity can contribute to the advancement of effective defense strategies including vaccines and diagnostic tools. In a preliminary study, we identified cellular extract proteins of MAP that strongly react with the blood of patients with Crohn's disease. In particular, MAP1981c, a putative nucleic acid-binding protein, showed high expression levels and strong reactivity to IgG and IgM in the sera of patients. Here, we investigated the immunological features of MAP1981c and focused on its interaction with dendritic cells (DCs), confirming its immunomodulatory ability. MAP1981c was shown to recognize Toll-like receptor (TLR) 4, and induce DC maturation and activation by increasing the expression of co-stimulatory (CD80 and CD86) and MHC class I/II molecules and the secretion of pro-inflammatory cytokines (IL-6, IL-1β, and TNF-α) in DCs. This DC activation by MAP1981c was mediated by downstream signaling of TLR4 via MyD88- and TRIF-, MAP kinase-, and NF-κB-dependent signaling pathways. In addition, MAP1981c-treated DCs activated naïve T cells and induced the differentiation of CD4⁺ and CD8⁺ T cells to express T-bet, IFN-γ, and/or IL-2, but not GATA-3 and IL-4, thus indicating that MAP1981c contributes to Th1-type immune responses both in vitro and in vivo. Taken together, these results suggest that MAP1981c is a novel immunocompetent antigen that induces DC maturation and a Th1-biased response upon DC activation, suggesting that MAP1981c can be an effective vaccine and diagnostic target.

Kaleidoscopic View of Bowel Tuberculosis on Multi- Detector Computed Tomography (CT) Enterography - A Novel Technique Unfolding an Archaic Disease

Gastrointestinal tuberculosis (GI TB) is an important manifestation of abdominal tuberculosis (TB), an extra-pulmonary form of the disease. GI TB commonly affects the small bowel but is difficult to diagnose due to the challenge of evaluating the entire length of overlapping small bowel loops with traditional diagnostic methods like Barium meal follow through, abdominal computed tomography (CT), and endoscopy. New techniques of CT/MR enteroclysis/enterography are now available which specifically image the small bowel. MDCT enterography (MDCTE) is a non-invasive, simple to perform, modified abdominal CT imaging technique permitting reasonably accurate evaluation of the small bowel lumen, wall, perienteric tissues, and solid organs within the abdomen. As GI TB can cause morphological alterations in and around the small bowel, MDCTE seems to be an attractive modality for patients suspected of abdominal or GI TB. As scarce literature is available on MDCTE on tuberculosis, we present a pictorial review on MDCTE findings in patients with GI tuberculosis proved on FNAC and clinical and/or imaging follow-up.

Differentiation Between Crohn Disease and Intestinal Tuberculosis in Children

OBJECTIVES

The aim of the study was to evaluate clinical, endoscopic, radiologic, and histopathological features helpful in differentiating Crohn disease (CD) from intestinal tuberculosis (ITB) in children.

METHODS

Patients diagnosed to have CD or ITB based on standard recommended criteria were enrolled. Children with inflammatory bowel disease unclassified or suspected ITB or CD with incomplete work-up or lost to follow-up were excluded. The clinical and laboratory (radiology, endoscopy, and histology) details of children were analyzed.

RESULTS

Twenty cases of ITB (14 [3-17] years) and 23 of CD (11 [1-17] years) were enrolled. Presentation with chronic diarrhea (82% vs 40%; P = 0.006) and blood in stool (74% vs 10%; P = 0.001) favored CD, whereas subacute intestinal obstruction (20% vs 0%; P = 0.04) and ascites (30% vs 0%; P = 0.005) favored ITB. Presence of deep ulcers (61% vs 30%; P = 0.04), longitudinal ulcers (48% vs 15%; P = 0.02), involvement of multiple colonic segments (70% vs 35%; P = 0.02), left-sided colon (87% vs 40%; P = 0.003), extraintestinal manifestations (21.7% vs 0%; P = 0.02), and higher platelet count (3.9 vs 2.6 × 10/mm; P = 0.02) favored CD. Isolated ileocecal involvement (40% vs 8.7%; P = 0.03) was a feature of ITB. TB bacilli were demonstrated in 40% ITB cases (colon-6, ascites-1, abdominal lymph node-1). On multivariate analysis, presence of blood in stool (odds ratio: 37.5 [confidence interval: 3.85-365.72], P = 0.002) and left-sided colonic involvement (odds ratio: 16.2 [confidence interval: 1.63-161.98], P = 0.02) were independent predictors of CD.

CONCLUSIONS

Microbiologic confirmation of tuberculosis is possible in 40% ITB cases. Presence of blood in stool and left-sided colonic involvement are the most important features favoring CD.