The diagnostic value of polymerase chain reaction for Mycobacterium tuberculosis to distinguish intestinal tuberculosis from crohn's disease: A meta-analysis

Deep learning model to differentiate Crohn's disease from intestinal tuberculosis using histopathological whole slide images from intestinal specimens

Crohn's disease (CD) and intestinal tuberculosis (ITB) share similar histopathological characteristics, and differential diagnosis can be a dilemma for pathologists. This study aimed to apply deep learning (DL) to analyze whole slide images (WSI) of surgical resection specimens to distinguish CD from ITB. Overall, 1973 WSI from 85 cases from 3 centers were obtained. The DL model was established in internal training and validated in external test cohort, evaluated by area under receiver operator characteristic curve (AUC). Diagnostic results of pathologists were compared with those of the DL model using DeLong's test. DL model had case level AUC of 0.886, 0.893 and slide level AUC of 0.954, 0.827 in training and test cohorts. Attention maps highlighted discriminative areas and top 10 features were extracted from CD and ITB. DL model's diagnostic efficiency (AUC = 0.886) was better than junior pathologists (*1 AUC = 0.701, P = 0.088; *2 AUC = 0.861, P = 0.788) and inferior to senior GI pathologists (*3 AUC = 0.910, P = 0.800; *4 AUC = 0.946, P = 0.507) in training cohort. In the test cohort, model (AUC = 0.893) outperformed senior non-GI pathologists (*5 AUC = 0.782, P = 0.327; *6 AUC = 0.821, P = 0.516). We developed a DL model for the classification of CD and ITB, improving pathological diagnosis accuracy effectively.

Asymptomatic intestinal tuberculosis of the terminal ileum diagnosed on colonoscopy: a case report and literature review

Objective

Colonoscopy is useful in diagnosing intestinal tuberculosis. However, the terminal ileum is generally not examined during routine colonoscopy. Therefore, even with colonoscopy, the diagnosis can be missed in patients with lesions confined to the terminal ileum. Herein, we report the case of an asymptomatic patient with intestinal tuberculosis, in whom a colonoscope insertion into the terminal ileum led to the diagnosis.

Patient

An asymptomatic 71-year-old man visited our hospital for a colonoscopy after a positive fecal occult blood test.

Results

Colonoscopy revealed diffuse edematous and erosive mucosa in the terminal ileum. Mycobacterium tuberculosis was detected by polymerase chain reaction and culture of biopsy specimens from the erosions, leading to the diagnosis of intestinal tuberculosis. The patient was treated with antitubercular agents for 6 months, and a follow-up colonoscopy revealed healing of the lesions.

Conclusion

Asymptomatic intestinal tuberculosis may occasionally be detected on colonoscopy following a positive fecal occult blood test and is sometimes confined to the terminal ileum. Therefore, clinicians should consider intestinal tuberculosis in the differential diagnosis of the causes of positive fecal occult blood test results and perform colonoscopies, including observation of the terminal ileum.

First detection of bovine tuberculosis by Ziehl-Neelsen staining and polymerase chain reaction at dairy farms in the Lekok Sub-District, Pasuruan Regency, and Surabaya region, Indonesia

Background and Aim

Bovine tuberculosis (TB) is a zoonotic disease of great public health importance, particularly in Indonesia, where control measures are limited or are not implemented. This study aimed to detect the presence of Mycobacterium pathogens in milk samples from dairy cattle in Pasuruan regency and Surabaya City, East Java, using Ziehl-Neelsen acid-fast staining and polymerase chain reaction (PCR).

Materials and Methods

Milk samples were aseptically collected from 50 cattle in the Lekok Subdistrict, Pasuruan Regency, and 44 from dairy farms in the Lakarsantri Subdistrict, Wonocolo Subdistrict, Mulyorejo Subdistrict, and Kenjeran Subdistrict, Surabaya, East Java. To detect Mycobacteria at the species level, each sample was assessed by Ziehl-Neelsen staining and PCR using the RD1 and RD4 genes.

Results

The results of PCR assay from 50 samples in Lekok Subdistrict, Pasuruan Regency showed that 30 samples (60%) were positive for Mycobacterium tuberculosis and two samples (4%) were positive for Mycobacterium bovis, although Ziehl-Neelsen staining did not show the presence of Mycobacterium spp. In the Surabaya region, 31 samples (70.45%) were positive for M. tuberculosis and three samples (6.8%) were positive for M. bovis. Six samples (13.63%) from all PCR-positive samples could be detected microscopically with Ziehl-Neelsen.

Conclusion

The presence of bovine TB in this study supports the importance of using a molecular tool alongside routine surveillance for a better understanding of the epidemiology of bovine TB in East Java.

Schaumann bodies deposited along myenteric plexus of the muscularis propria is a unique histopathological feature of Crohn's disease

AIMS

Schaumann bodies were first identified in sarcoidosis by Dr Schaumann in 1941. They were also detected in 10% of Crohn's disease (CD) cases in a study involving patients with surgically resected CD. However, the characteristics and significance of Schaumann bodies in CD have yet to be fully elucidated. This study aimed to determine the pathological features and diagnostic significance of Schaumann bodies in various bowel diseases.

METHODS

Overall, 278 bowel specimens were collected from patients with CD, intestinal tuberculosis, ulcerative colitis, intestinal schistosomiasis, diverticulosis and idiopathic mesenteric vasculopathy. The frequency, pathology and clinical features of patients with Schaumann bodies were studied.

RESULTS

Schaumann bodies were present exclusively in CD (27.0%, 38 of 141) and were not detected in other intestinal diseases within the series. In CD, Schaumann bodies were deposited along the myenteric plexus of the muscularis propria (84.2%, 32 of 38). These bodies were small (diameter: 60.3±32.7 µm) and exhibited a low density in the intestinal wall (1.1±0.4 per low-power field). The majority were located within the cytoplasm of multinucleated giant cells (84.2%, 32 of 38) and were not found within or adjacent to granulomas. Notably, the number of female patients with CD and Schaumann bodies was higher than that of males.

CONCLUSION

Schaumann bodies are common in resected CD specimens, and their characteristic deposition pattern may serve as a diagnostic indication for CD.

IBD barriers across the continents - East Asia

Inflammatory bowel diseases (IBDs) are chronic illnesses with significant morbidities and impact on patients' quality of life. There has been a rapid increase in the incidence of IBD in East Asia in recent decades. However, there is a huge unmet need in the diagnosis and management of IBD in this region. With the increasing awareness of IBD in East Asia and a persistently high rate of tuberculosis in this region, this poses a significant challenge in the diagnosis and management of IBD. In this review, we will explore the barriers to the diagnosis and management of IBD in the East Asia, hoping to provide an insight on how to improve the healthcare system in the management of this complex disease.

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.

Evidence-based approach to diagnosis and management of abdominal tuberculosis

Abdominal tuberculosis is an ancient problem with modern nuances in diagnosis and management. The two major forms are tuberculous peritonitis and gastrointestinal tuberculosis (GITB), while the less frequent forms are esophageal, gastroduodenal, pancreatic, hepatic, gallbladder and biliary tuberculosis. The clinicians need to discriminate the disease from the close mimics: peritoneal carcinomatosis closely mimics peritoneal tuberculosis, while Crohn's disease closely mimics intestinal tuberculosis. Imaging modalities (ultrasound, computed tomography, magnetic resonance imaging and occasionally positron emission tomography) guide the line of evaluation. Research in diagnostics (imaging and endoscopy) has helped in the better acquisition of tissue for histological and microbiological tests. Although point-of-care polymerase chain reaction-based tests (e.g. Xpert Mtb/Rif) may provide a quick diagnosis, these have low sensitivity. In such situations, ancillary investigations such as ascitic adenosine deaminase and histological clues (granulomas, caseating necrosis, ulcers lined by histiocytes) may provide some specificity to the diagnosis. A diagnostic trial of antitubercular therapy (ATT) may be considered if all diagnostic armamentaria fail to clinch the diagnosis, especially in TB-endemic regions. Objective evaluation with clear endpoints of response is mandatory in such situations. Early mucosal response (healing of ulcers at two months) and resolution of ascites are objective criteria for early response assessment and should be sought at two months. Biomarkers, especially fecal calprotectin for intestinal tuberculosis, have also shown promise. For most forms of abdominal tuberculosis, six months of ATT is sufficient. Sequelae of GITB may require endoscopic balloon dilatation for intestinal strictures or surgical intervention for recurrent intestinal obstruction, perforation or massive bleeding.

Clinical characteristics and diagnosis of intestinal tuberculosis in clinical practice at Thailand's largest national tertiary referral center: An 11-year retrospective review

BACKGROUND

Diagnosing intestinal tuberculosis (ITB) is challenging due to the low diagnostic sensitivity of current methods. This study aimed to assess the clinical characteristics and diagnosis of ITB at our tertiary referral center, and to explore improved methods of ITB diagnosis.

METHODS

This retrospective study included 177 patients diagnosed with ITB at Siriraj Hospital (Bangkok, Thailand) during 2009-2020.

RESULTS

The mean age was 49 years, 55.4% were male, and 42.9% were immunocompromised. Most diagnoses (108/177) were made via colonoscopy; 12 patients required more than one colonoscopy. Among those, the sensitivity of tissue acid-fast bacilli (AFB), presence of caseous necrosis, polymerase chain reaction (PCR), and culture was 40.7%, 13.9%, 25.7%, and 53.4%, respectively. Among patients with negative tissue histopathology, 4 (3.7%) and 13 (12.0%) were ITB positive on tissue PCR and culture, respectively. The overall sensitivity when all diagnostic methods were used was 63%. Seventy-six patients had stool tests for mycobacteria. The overall sensitivity of stool tests was 75.0%. However, when analyzing the 31 patients who underwent both endoscopy and stool testing, the sensitivity of stool testing when using tissue biopsy as a reference was 45.8%. Combining stool testing and tissue biopsy did not significantly increase the sensitivity compared to tissue biopsy alone (83.9% vs. 77.4%, respectively).

CONCLUSION

Despite the availability of PCR and culture for TB, the overall diagnostic sensitivity was found to be low. The sensitivity increased when the tests were used in combination. Repeated colonoscopy may be beneficial. Adding stool mycobacteria tests did not significantly increase the diagnostic yield if endoscopy was performed, but it could be beneficial if endoscopy is unfeasible.

Management and monitoring of pediatric inflammatory bowel disease in the Asia-Pacific region: A position paper by the Asian Pan-Pacific Society for Pediatric Gastroenterology, Hepatology, and Nutrition (APPSPGHAN) PIBD Working Group: Surgical management, disease monitoring, and special considerations

Disease phenotype of pediatric inflammatory bowel disease (PIBD) in children from the Asia-Pacific region differs from that of children from the West. Many parts of Asia are endemic for tuberculosis, making diagnosis and management of pediatric Crohn's disease a challenge. Current available guidelines, mainly from Europe and North America, may not be completely applicable to clinicians caring for children with PIBD in Asia due to differences in disease characteristics and regional resource constraints. This position paper is an initiative from the Asian Pan-Pacific Society for Pediatric Gastroenterology, Hepatology and Nutrition (APPSPGHAN) that aims to provide an up-to-date, evidence-based approach to PIBD in the Asia-Pacific region. A group of pediatric gastroenterologists with a special interest in PIBD performed an extensive literature search covering epidemiology, disease characteristics and natural history, management, and monitoring. Attention was paid to publications from the region with special consideration to a resource-limited setting. This current position paper deals with surgical management, disease monitoring, immunization, bone health, and nutritional issues of PIBD in Asia. A special section on differentiating pediatric Crohn's disease from tuberculosis in children is included. This position paper provides a useful guide to clinicians in the surgical management, disease monitoring, and various health issues in children with IBD in Asia-Pacific region.

ECCO Topical Review on Clinicopathological Spectrum and Differential Diagnosis of Inflammatory Bowel Disease

INTRODUCTION

Many diseases can imitate inflammatory bowel disease [IBD] clinically and pathologically. This review outlines the differential diagnosis of IBD and discusses morphological pointers and ancillary techniques that assist with the distinction between IBD and its mimics.

METHODS

European Crohn's and Colitis Organisation [ECCO] Topical Reviews are the result of an expert consensus. For this review, ECCO announced an open call to its members and formed three working groups [WGs] to study clinical aspects, pathological considerations, and the value of ancillary techniques. All WGs performed a systematic literature search.

RESULTS

Each WG produced a draft text and drew up provisional Current Practice Position [CPP] statements that highlighted the most important conclusions. Discussions and a preliminary voting round took place, with subsequent revision of CPP statements and text and a further meeting to agree on final statements.

CONCLUSIONS

Clinicians and pathologists encounter a wide variety of mimics of IBD, including infection, drug-induced disease, vascular disorders, diverticular disease, diversion proctocolitis, radiation damage, and immune disorders. Reliable distinction requires a multidisciplinary approach.

Recent advances in the diagnosis of intestinal tuberculosis

BACKGROUND

Intestinal tuberculosis still has a high incidence, especially in developing countries. The biggest challenge of this disease is the establishment of the diagnosis because the clinical features are not typical. Investigations such as culture, acid-fast bacilli (AFB) staining, and histopathology have low sensitivity, so other investigations are needed. Latest molecular-based diagnostic modalities such as GeneXpert, interferon-gamma (IFN-γ) release assays (IGRA), polymerase chain reaction (PCR), multiplex-PCR, and immunological markers are expected to help diagnose intestinal tuberculosis. This article review will examine the latest diagnostic modalities that can be used as a tool in establishing the diagnosis of intestinal tuberculosis.

RESULTS

Through a literature search, we were able to review the diagnostic values of various available diagnostic modalities as the appropriate additional test in intestinal tuberculosis. Culture as a gold standard has a sensitivity and specificity value of 9.3% and 100% with the MGIT BACTEC system as the most recommended medium. The sensitivity values of AFB staining, histopathology examination, GeneXpert, IGRA, PCR, multiplex-PCR and, immunological markers were ranged between 17.3 and 31%; 68%; 81-95.7%; 74-88%; 21.6-65%; 75.7-93.1%; and 52-87%, respectively. Meanwhile the specificity values were 100%; 77.1%; 91-100%; 74-87%; 93-100%; 96.4-100%; and 70-95%, respectively.

CONCLUSION

The combination of clinical examination, conventional examination, and the latest molecular-based examination is the best choice for establishing the diagnosis of intestinal tuberculosis. Most recent modalities such as multiplex PCR and immunological marker examinations are diagnostic tools that deserve to be used in diagnosing intestinal tuberculosis as their sensitivity and specificity values are quite high and more evidences are expected to support the application of these examinations shortly soon.

Recent updates in diagnosis of abdominal tuberculosis with emphasis on nucleic acid amplification tests

INTRODUCTION

Abdominal tuberculosis (TB) is a common epitome of extrapulmonary TB (EPTB), wherein peritoneal and intestinal TB are the most prevalent forms. Diagnosis of abdominal TB is a daunting challenge owing to variable anatomical locations, paucibacillary nature of specimens and atypical clinical presentations that mimic other abdominal diseases, such as Crohn's disease and malignancies. In this review, we made a comprehensive study on the diagnosis of abdominal TB.

AREA COVERED

Various modalities employed for abdominal TB diagnosis include clinical features, imaging, bacteriological tests (smear/culture), histopathological/cytological observations, interferon-gamma release assays and nucleic acid amplification tests (NAATs). Among NAATs, loop-mediated isothermal amplification assay, PCR, multiplex-PCR, nested PCR, real-time PCR and GeneXpert® MTB/RIF were discussed. Identification of circulating Mycobacterium tuberculosis cell-free DNA by real-time PCR within ascitic fluids is another useful approach.

EXPERT OPINION

Several novel molecular/immunological methods, such as GeneXpert Ultra, aptamer-linked immobilized sorbent assay, immuno-PCR (I-PCR) and nanoparticle-based I-PCR have recently been developed for detecting pulmonary TB and several EPTB types, which may also be explored for abdominal TB diagnosis. Precise and prompt diagnosis of abdominal TB may initiate an early therapy so as to reduce the complications, i.e. abdominal pain, ascites, abdominal distension, intestinal obstruction/perforation, etc., and avoid surgical involvement.Plain Language SummaryAbdominal tuberculosis (TB) is a manifestation of extrapulmonary TB (EPTB), where peritoneal and intestinal TB are two major forms. Diagnosis of abdominal TB is difficult owing to low bacterial load present in clinical samples and non-specific clinical presentations as it mimics other diseases such as inflammatory bowel diseases, abdominal malignancies, etc. Bacteriological tests (smear/culture) almost fail owing to poor sensitivities and it is not always possible to get representative tissue samples for histopathological and cytological observations. In recent years, molecular tests i.e. nucleic acid amplification tests (NAATs), such as PCR/multiplex-PCR (M-PCR), nested PCR and GeneXpert are widely employed. Markedly, PCR/M-PCR and nested PCR exhibited reasonable good sensitivities/specificities, while GeneXpert revealed low sensitivity in most of the studies but high specificity, thus it could assist in differential diagnosis of intestinal TB and Crohn's disease. Further, novel molecular/immunological tests employed for pulmonary TB and other EPTB types were described and those tests can also be utilized to diagnose abdominal TB. Reliable and rapid diagnosis of abdominal TB would initiate an early start of anti-tubercular therapy and reduce the severe complications.

Gastrointestinal and Abdominal Tuberculosis

Gastrointestinal (GI) tuberculosis (TB) remains a significant problem worldwide, and may involve the luminal GI tract from oral cavity to perianal area in addition to associated viscera and peritoneum. Although GI TB more commonly affects immunocompromised hosts, it can also occur in immunocompetent people. Diagnosis is difficult because it usually mimics a malignancy or inflammatory bowel disease. A high index of clinical suspicion and appropriate use of combined investigative methods help in early diagnosis, and reduce morbidity and mortality. Anti-TB therapy is the same as for pulmonary disease, and invasive and specialized interventions are reserved for selected complications.

Application value of tissue tuberculosis antigen combined with Xpert MTB/RIF detection in differential diagnoses of intestinal tuberculosis and Crohn's disease

Background

The purpose of this study was to examine the value of Xpert MTB/RIF assay and detection of additional Mycobacterium tuberculosis complex (MTBC) species antigens from intestinal tissue samples in differentiating intestinal tuberculosis (ITB) from Crohn’s disease (CD).

Methods

Several clinical specimens of intestinal tissue obtained by either endoscopic biopsy or surgical excision were used for mycobacteriologic solid cultures,Xpert MTB/RIF assays, immunohistochemistry, and histological examinations. Four antigens (38KDa, ESAT-6, MPT64, and Ag85 complex) of MTBC in the intestinal tissue were detected by immunohistochemical analysis.

Results

The study included 42 patients with ITB and 46 with CD. Perianal lesions and longitudinal ulcers were more common in patients with CD, while caseating granuloma and annular ulcers were more common in patients with ITB. The positive rate of MTBC detected by Xpert MTB/RIF in intestinal tissues of patients with ITB was 33.33%, which was significantly higher than that in patients with CD and that detected using acid-fast staining smears. It was also higher than that detected by tissue MTBC culture, but the difference was not statistically significant. The positive MPT64 expression rate in patients with ITB was 40.48%, which was significantly higher than that observed in patients with CD. The sensitivity of parallelly combined detection of tuberculosis protein MPT64 and Xpert MTB/RIF in diagnosing ITB was 50.0%.

Conclusions

The detection of Xpert MTB/RIF in intestinal tissue is a rapid and useful method for establishing an early diagnosis of ITB. The detection of MTBC using Xpert MTB/RIF and MPT64 antigen in intestinal tissues has a definitive value in the differential diagnosis ofITB and CD. The combination of these two methods can improve the detection sensitivity.

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.

Challenges in the diagnosis and management of inflammatory bowel disease in resource-limited settings in Asia

Inflammatory bowel disease (IBD) is increasing in prevalence in resource-limited settings in Asia. Although the prevalence of IBD is lower in these settings than in high-income countries, the high disease burden due to large population size is projected to overtake that of high-income countries in the near future. Unique challenges exist for diagnosing and managing IBD in Asia. On one hand, the inadequate disease awareness in physicians and the general population, the scarcity of diagnostic services, the infectious mimics of IBD (specifically intestinal tuberculosis), and the widespread use of empirical antibiotics and antitubercular therapy pose diagnostic challenges. On the other hand, the absence of a centralised health-care delivery system or universal health insurance, the high cost of therapy, limited access to biologics, and the high risk of opportunistic infections with immunosuppressive therapy present therapeutic challenges. The high probability of tuberculosis reactivation often precludes biological therapy because Asia is highly endemic for tuberculosis and has a high prevalence of latent tuberculosis. Current screening strategies are often ineffective in ruling out latent tuberculosis. Hence, management strategies are often modified according to these challenges. This Series paper discusses the challenges in the diagnosis and management of IBD in resource-limited settings in Asia.

Challenging diagnosis of gastrointestinal tuberculosis made simpler with multi-targeted loop-mediated isothermal amplification assay

BACKGROUND

Prompt and accurate diagnosis of gastrointestinal tuberculosis (GITB) is highly challenging. Current conventional techniques lack sensitivity and are time-consuming. Multi targeted loop-mediated isothermal amplification (LAMP) using two targets (IS6110 and MPB64) is a promising technique for rapid diagnosis of TB.

METHODS

LAMP test using IS6110 and MPB64 targets for M. tuberculosis complex was performed on ileocecal biopsy samples of 35 clinically suspected patients of GITB and 30 ileocecal biopsy samples of non-tuberculosis control subjects. Results of IS6110 LAMP and MPB64 LAMP were compared with IS6110 PCR and culture INFERENCE: Overall LAMP test (using any of the two targets) had a sensitivity and specificity of 100 and 100%, respectively, for confirmed GITB (five culture positive) cases and 85.71 and 100%, respectively, for clinically suspected 30 ileocecal biopsy samples of GITB. Sensitivity of IS6110 LAMP, MPB64 LAMP and IS6110 PCR for clinically suspected cases was 22 (73.33%), 24 (80%) and 21 (70%), respectively. In total 35 GITB patients, the overall sensitivity of microscopy, culture, IS6110 PCR, IS6110 LAMP, MPB64 LAMP and the multi-targeted LAMP assay (if any of the two targets were used) were 5.71, 14.28, 68.57, 74.28, 82.85 and 85.71%, respectively. Specificity of all the tests was 100%. There were three cases which were missed by IS6110 LAMP and two cases by MPB64 LAMP.

CONCLUSION

Multi-targeted LAMP is a promising technique for rapid and accurate diagnosis of GITB.

Apoptosis in peripheral blood lymphocytes in intestinal tuberculosis and Crohn's disease: Implications to diagnostic differentiation

AIM

Intestinal tuberculosis (ITb) and Crohn's disease (CD) mimic each other often leading to misdiagnosis. We evaluated the difference between ITb and CD using the extent of apoptosis in peripheral blood lymphocytes.

METHODS

CD4⁺ cells as a percentage of the lymphocytes and viable, dead, total apoptotic, early apoptotic, and late apoptotic CD4⁺ cells were assessed in the peripheral blood by flow cytometry in healthy controls and patients with confirmed active ITb and CD prior to initiating therapy. Early apoptotic and total apoptotic cells were further expressed as a proportion of the percentage of CD4⁺ cells.

RESULTS

The percentages of CD4⁺ cells (6.5 [3.0, 8.7] vs. 13.40 [10.15, 13.40]; p < 0.001), total apoptotic cells (0.13 [0.0, 0.22] vs. 0.08 [0.0, 0.21]; p = 0.045), early apoptotic (1.24 [0.55, 2.54] vs. 0.71 [0.40, 1.30]; p = 0.037), and the proportion of the latter two parameters (17.18 [5.61, 57.33] vs. 4.84 [2.71, 9.83]; p-value 0.039) and (17.18 [7.4, 67.50] vs. 5.51 [3.10, 11.03]; p-value 0.036) were significantly different between patients with ITb and CD. The best sensitivity, specificity, and positive and negative predictive values for the diagnosis of ITb were seen with the CD4⁺ cell percentage (82.6%, 82.4%, 86.4%, 77.8%, respectively) and the proportion of early apoptotic cells (73.9%, 70.6%, 77.3%, 66.7%, respectively).

CONCLUSION

CD4⁺ cells as a percentage of peripheral blood lymphocytes and the proportion of early apoptotic CD4⁺ cells show promise to diagnostic differentiation between ITb and CD.

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.

Utility of tissue Xpert-Mtb/Rif for the diagnosis of intestinal tuberculosis in patients with ileocolonic ulcers

Introduction

Data on the use of Xpert Mtb/Rif for the diagnosis of intestinal tuberculosis is sparse. We report on the utility of Xpert Mtb/Rif testing for diagnosis of intestinal tuberculosis (ITB) in patients with ileocecal ulcers.

Methodology

We performed a retrospective analysis of patients with ileocecal ulcers and suspected to have ITB and in whom testing of intestinal tissue for Xpert Mtb/Rif was performed. The patients were divided into two groups: those with a final diagnosis of intestinal tuberculosis and those with other diagnosis. These patients were compared for clinical features and presentation. The sensitivity, specificity, positive predictive value, and negative predictive value of Xpert Mtb/Rif for the diagnosis of ITB were calculated.

Results

Of the 40 patients studied, 23 were women and the mean age was 32.92 ± 12.78 years. Abdominal pain was present in 33 (88.5%) patients and diarrhea in 12 (30%). A total of 25 patients had underlying ITB whereas 15 patients had other diagnoses (Crohn's disease, amebiasis, nonspecific ileitis, etc.). The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of GeneXpert-Mtb/Rif was 32% (CI: 14.95-53.50%), 100% (78.2-100), 46.88% (40.27-53.59%), 100 & 57.50 (40.89-72.89%) respectively.

Conclusion

A positive GeneXpert-Mtb/Rif helps in the diagnosis of ITB, but the sensitivity is low.

Ten Cases of Intestinal Tuberculosis Which Were Initially Misdiagnosed as Inflammatory Bowel Disease

Objective Intestinal tuberculosis (ITB) and inflammatory bowel disease (IBD) frequently present with similar clinical, endoscopic and pathological features, therefore it is difficult to differentiate between them. The aim of this study was to elucidate the diagnostic delay and prognosis of ITB cases, initially misdiagnosed as IBD. Methods ITB cases were selected from the hospitalized patient list between April 2004 and March 2017 in a tuberculosis center in Japan. We retrospectively evaluated the initial diagnosis, clinical characteristics, endoscopic and pathological findings, bacterial examinations, treatment and prognosis. Results Among 66 ITB patients, ten patients were initially misdiagnosed as IBD. Seven patients were male and the median age was 60.5 years (23-74 years). After the diagnosis of IBD, all the patients were treated with mesalazine, in addition to corticosteroids in two patients and sequential azathioprine and infliximab in one. The median duration of diagnostic delay was 5.5 months (range 0.5-17 months). Eight patients had active pulmonary tuberculosis at the diagnosis of ITB. Acid-fast bacilli were confirmed in four of seven patients by reevaluation of the pathological specimens at the IBD diagnosis. Two patients needed intestinal resection and one with erroneous corticosteroid use for IBD died due to respiratory failure in spite of receiving appropriate treatment for tuberculosis. Conclusion ITB patients were frequently misdiagnosed and treated as IBD, thus resulting in a poor clinical outcome even after finally making a correct diagnosis and administering appropriate treatment. On diagnosis of IBD and/or treatment failure, chest radiograph and acid-fast bacilli of the pathological specimens should be carefully evaluated in order to rule out tuberculosis.

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.

Intestinal tuberculosis in a 55-year-old woman with a 30-year history of rheumatoid arthritis

Introduction

Tuberculosis (TB) is one of the endemic diseases with a challenging diagnosis in the absence of pulmonary disease. On the other hand, rheumatoid arthritis (RA) is a systemic autoimmune disease with extra-articular manifestations that occur at any age after onset, such as nodules, Sjögren's syndrome, anemia of chronic disease, and pulmonary manifestations, which are more frequently seen in patients with severe, active disease. Here we present a case of RA with intestinal TB.

Case report

A 55-year-old woman with a 30-year history of RA using prednisolone and hydroxychloroquine presented with a nonpositional hypogastric pain and a weight loss of 20 kg over 7 months. No history of biological therapy was recorded. Colonoscopy revealed an ulcerated mass that was suspicious for malignancy. The pathobiological assessments confirmed ulceration and granulation tissue formation, foci of necrotizing granulomatous inflammation in lamina propria with adjacent mild crypt regenerative changes. Also, Ziehl-Neelsen staining for acid-fast bacilli in the granulomas was positive though the polymerase chain reaction assay did not detect the Mycobacterium tuberculosis. Anti-TB medication for 2 weeks eliminated the symptoms.

Conclusions

Intestinal TB in patients with vague abdominal symptoms and relevant physical findings such as pain and palpable mass should be considered to prevent late or misdiagnosis.