Does Crohn's disease need differentiation from tuberculosis?

Endoscopic Monitoring of Treatment of Indeterminate Intestinal Lesions in a Prospective "Real-Life" Cohort in Eastern India Where Tuberculosis Remains Endemic: Distinguishing Intestinal Tuberculosis From Crohn's Disease

Introduction It is sometimes difficult to differentiate between intestinal tuberculosis (ITB) and Crohn's disease (CD) in India, as both conditions may mimic each other. The aim was to differentiate ITB from CD in indeterminate intestinal lesions with a therapeutic trial of anti-tubercular therapy (ATT) and follow-up to find out the clinical, endoscopic, radiological, and histological predictors for differentiation between ITB and CD. Methods A prospective observational cohort study of patients diagnosed with ITB and CD according to the Asia-Pacific Guidelines in a "real-life" clinical setting was conducted. ITB was diagnosed by Paustian criteria with Logan's modification. CD was diagnosed according to European Crohn's and Colitis Organization (ECCO) guidelines. We put the patients with a definite diagnosis of ITB and those with an indeterminate diagnosis on ATT and followed them up clinically, endoscopically, and radiologically. Patients were reassessed clinically, endoscopically, and histologically eight weeks after the start of therapy. They were again evaluated endoscopically and radiologically after completion of six months of ATT. The CD patients continued anti-inflammatory, immunomodulator, biological, and/or steroid treatments. Results We conducted this prospective study on consecutive Indian patients who had 21 definite diagnoses of ITB, 26 definite diagnoses of CD, and 42 indeterminate diagnoses. We diagnosed 49 with ITB and 28 (57%) after a therapeutic trial. Ultimately, 40 patients received a CD diagnosis, with 14 (35%) not responding to the ATT therapeutic trial. In patients with ITB, symptomatic improvement after eight weeks of ATT is correlated with endoscopic healing, especially for ulcers but not necessarily for nodularity or strictures. In 50% of these patients, minimal nodularity/pseudopolypii as well as residual scarring was seen on endoscopy even after completion of therapy. Strictures in ITB patients persisted on endoscopy in 40% despite six months of ATT. GI bleeding (64% vs. 10%; p < 0.0001), chronic diarrhea (71% vs. 35%; P = 0.02), fistula or sinuses (21% vs. 0%; p < 0.01), and multiple site involvement of the intestine (73% vs. 6%; p < 0.0001) were significantly more common in CD than in patients with ITB. Fever (82% vs. 50%; p < 0.01) and positive tuberculin tests were more common in ITB patients. PCR positivity and the presence of AFB in smear and culture could be demonstrated in only a small percentage of ITB patients. Conclusion Therapeutic trials in indeterminate intestinal lesions can distinguish ITB from CD without significant adverse effects. Strictures in patients with ITB do not resolve in all patients. GI bleeding, chronic diarrhea, fistulas or sinuses, multiple sites of involvement, and fever have the highest accuracy in differentiating ITB from CD.

Comparison of small bowel findings using capsule endoscopy between Crohn's disease and intestinal tuberculosis in Korea

Background

Little is known about capsule endoscopy (CE) findings in patients with intestinal tuberculosis who exhibit small bowel lesions. The aim of the present study was to distinguish between Crohn’s disease (CD) and intestinal tuberculosis based on CE findings.

Methods

Findings from 55 patients, who underwent CE using PillCam SB CE (Given Imaging, Yoqneam, Israel) between February 2003 and June 2015, were retrospectively analyzed.

Results

CE revealed small bowel lesions in 35 of the 55 patients: 19 with CD and 16 with intestinal tuberculosis. The median age at diagnosis for patients with CD was 26 years and 36 years for those with intestinal tuberculosis. On CE, three parameters, ≥10 ulcers, >3 involved segments and aphthous ulcers, were more common in patients with CD than in those intestinal tuberculosis. Cobblestoning was observed in five patients with CD and in none with intestinal tuberculosis. The authors hypothesized that a diagnosis of small bowel CD could be made when the number of parameters in CD patients was higher than that for intestinal tuberculosis. The authors calculated that the diagnosis of either CD or intestinal tuberculosis would have been made in 34 of the 35 patients (97%).

Conclusion

The number of ulcers and involved segments, and the presence of aphthous ulcers, were significantly higher and more common, respectively, in patients with CD than in those with intestinal tuberculosis. Cobblestoning in the small bowel may highly favor a diagnosis of CD on CE.

Clinical and laboratory features of intestinal tuberculosis

Background/aims

As increasing numbers of Crohn's disease (CD) cases are being recognized in India, so the differential diagnosis of CD and gastrointestinal tuberculosis (GITB) is becoming increasingly important. If patients are misdiagnosed with GITB, toxicity may result from unnecessary anti-TB therapy and treatment of the primary disease (ie, CD) gets delayed. We therefore aimed to assess the accuracy of various parameters that can be used to predict GITB diagnosis at index evaluation.

Materials and methods

This was a prospective, unicentric, observational study carried out in the gastroenterology department of a tertiary care hospital between August 2011 and January 2013. Patients who presented to our hospital and were suspected of having GITB were included in our study. Patients were then followed up over a 6-month period.

Statistical analysis

Chi-square test was used to analyze the data.

Results

Of the 69 patients with GITB, 49 (71.01%) had thickening of the involved part of the colon and 33 (47.83%) had abdominal lymphadenopathy. The ileocecal valve was involved in 58 patients (84.05%) Histological detection of granulomas had 78.95% specificity, 36.23% sensitivity, and 51.40% accuracy. Tuberculosis polymerase chain reaction was found to have 78.95% specificity, 71.01% sensitivity, and 73.83% accuracy. BACTEC-MGIT culture was found to have 100% specificity, 20.29% sensitivity, and 48.60% accuracy.

Conclusion

Although histology is helpful in ruling out other conditions, TB-specific findings such as caseating granuloma and acid-fast bacilli are rarely seen. Instead, tuberculosis polymerase chain reaction has the highest diagnostic accuracy followed by BACTEC culture.

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.

Efficacy of thalidomide therapy in pediatric Crohn’s disease with evidence of tuberculosis

AIM

To evaluate the efficacy of thalidomide for treating troublesome cases of pediatric Crohn’s disease (CD) with tuberculosis infection.

METHODS

A retrospective study of clinical outcome among children treated with thalidomide was conducted. All patients had evidence of tuberculosis infection with a failure of anti-tuberculosis treatment for more than one year, and were subsequently diagnosed with CD. All the patients received thalidomide treatment with a starting dose of 1.2-2.5 mg/kg per day. Remission was defined as pediatric CD activity index less than or equal to 10.

RESULTS

Ten patients with CD were treated with thalidomide at an average age of 7.2 years and followed up for a median of 22.2 mo. Clinical remission rate was 60% after 9-12 mo of thalidomide treatment. One patient with no response had an interleukin-10 receptor alpha gene mutation. Erythrocyte sedimentation rate, C-reactive protein and platelet count showed a dramatic decrease; hemoglobin level and weight improved significantly after thalidomide treatment when compared with the baseline values.

CONCLUSION

Thalidomide is an effective and safe drug for remission of CD in pediatric patients who have been treated for tuberculosis.

Approach to a Child with Colitis

In this review, the authors discuss the etiology, pathogenesis, and clinical presentations of colitis in children, and provide current recommendations for the approach to a child with colitis. In addition, they discuss in detail one of the important and emerging causes of chronic colitis in children; inflammatory bowel disease (IBD). Diagnostic and management approaches to colitis in children vary considerably based on several factors, including if the colitis is acute in onset or chronic, the age of the child, and the geographical region of the affected child. Broader classification or differential diagnosis of colitis falls under infectious, inflammatory, allergic, and less commonly, immune-mediated and ischemic colitis. Recent epidemiologic reports have elucidated a shift in our understanding of ethnicities and geographic regions affected by IBD. The incidence and prevalence of IBD has been steadily increasing in developing countries, including South-East Asia/India. Also, the risk of developing IBD among the second-generation South-Asians immigrants has greatly increased, with rates approaching those in the Western country to which they immigrated. Current research is focusing on genetic, environmental, and dietary factors to understand the increased incidence of IBD in developing countries and immigrants from developing nations.

Differential diagnosis of Crohn's disease versus ileal tuberculosis

Both intestinal tuberculosis and Crohn's disease are chronic granulomatous inflammatory diseases of the bowel having overlap of clinical, endoscopic, radiological, and histological features. Differentiating between the two disorders is relevant not only in Asian countries but also in the West. In spite of diagnostic criteria for both diseases being available, still the dilemma of segregating the two diseases remains. Nearly one third of the patients with Crohn's disease may receive anti-tuberculosis treatment also. Diagnosis should be based on the combination of all disease-specific and corroborative evidences.

CFP10 and ESAT6 aptamers as effective Mycobacterial antigen diagnostic reagents

The development of effective Mycobacterial antigen diagnostic reagents remains a high priority. The 6-kDa early secreted antigenic target (ESAT6) and 10-kDa culture filtrate protein (CFP10) are secreted early by virulent Mycobacterium tuberculosis (M. tb) and are not present in the non-virulent Bacillus Calmette-Guerin (BCG). In this study, we used a Systematic Evolution of Ligands by Exponential Enrichment (SELEX) technique to screen for a functional ssDNA aptamer "antibody" that specifically bound to ESAT6-CFP10 (CE) protein. The selected single ssDNA aptamers (CE24 and CE15) demonstrated the highest specificity and binding affinity to CFP10 (CE24: Kd = 3.75 × 10(-7) M) and ESAT6 (CE15: Kd = 1.6 × 10(-7) M). We further detected CFP10 and ESAT6 proteins in serum samples from active pulmonary tuberculosis (TB) patients, extrapulmonary TB patients and healthy donors by using an enzyme-linked oligonucleotide assay (ELONA). The results showed that the sensitivity and specificity were 100% and 94.1% (using CE24 aptamer-based ELONA) and 89.6% and 94.1% (using CE15 aptamer-based ELONA), respectively. A good correlation was observed between aptamer-based ELONA and T-SPOT TB assay. Thus, our study suggests that CE24 and CE15 have potentially broad applications as early antigen diagnostic agents not only for active pulmonary TB, extrapulmonary TB, but also possibly for latent TB infection and TB with immune-deficiency.

Comparative study of intestinal tuberculosis and primary small intestinal lymphoma

AIM: To characterize the clinical, radiological, endoscopic and pathological features of intestinal tuberculosis (ITB) and primary small intestinal lymphoma (PSIL).

METHODS: This was a retrospective study from February 2005 to October 2012 of patients with a diagnosis of ITB (n = 41) or PSIL (n = 37). All patients with ITB or PSIL underwent computed tomography (CT) and pathological examination. Thirty-five patients with ITB and 32 patients with PSIL underwent endoscopy. These patients were followed for a further 18 mo to ascertain that the diagnosis had not changed. Clinical, endoscopic, CT and pathological features were compared between ITB and PSIL patients.

RESULTS: Night sweating, fever, pulmonary TB and ascites were discovered significantly more often in ITB than in PSIL patients (P < 0.05), however, abdominal mass, hematochezia and intestinal perforation were found significantly more frequently in PSIL than in ITB patients (P < 0.05). Ring-like and rodent-like ulcers occurred significantly more often in ITB than in PSIL patients (P < 0.05), however, enterorrhagia and raised lesions were significantly more frequent in PSIL than in ITB patients (P < 0.05). The rate of granuloma was significantly higher in ITB than in PSIL patients (87.8% vs 13.5%, χ² = 43.050, P < 0.05), and the incidence of confluent granulomas with caseous necrosis was significantly higher in ITB than in PSIL patients (47.2% vs 0.0%, χ² = 4.034, P < 0.05). Multi-segmental lesions, mural stratification, mural gas sign, and intestinal stricture were more frequent in ITB than in PSIL patients (P < 0.05), however, a single-layer thickening of bowel wall, single segmental lesions, and intussusception were more common in PSIL than in ITB patients (P < 0.05). Necrotic lymph nodes, comb sign and inflammatory mass were more frequent in ITB than in PSIL patients (P < 0.05). The bowel wall enhancement in ITB patients was greater than that in PSIL patients (P < 0.05), while the thickening and lymph node enlargement in PSIL patients were higher than those in ITB patients (P < 0.05).

CONCLUSION: Combined evaluation of clinical, radiological, endoscopic and pathological features is the key to differentiation between ITB and PSIL.

Utility of in vitro interferon-γ release assay in differential diagnosis between intestinal tuberculosis and Crohn's disease

OBJECTIVE

To evaluate the diagnostic utility of interferon-γ release assay (T-SPOT.TB) for the differential diagnosis between Crohn's disease (CD) and intestinal tuberculosis (ITB).

METHODS

A total of 103 CD and 88 ITB patients, confirmed by histology and anti-tuberculosis treatment response from 2003 to 2011, were included. Their characteristics and clinical features were recorded. Mycobacterium tuberculosis (MTB) polymerase chain reaction (PCR) of IS6110, in vitro T-SPOT.TB, tuberculin skin test (TST), immunoglobulin G (IgG) antibody to MTB (protein chip), serum anti-Saccharomyces cerevisiae antibodies (ASCA IgG, chronic inflammatory bowel disease profile) and acid-fast staining of biopsied colonic tissue specimens were performed. Statistical analysis was conducted to determine their concordance with the diagnosis and its sensitivity, specificity, positive (PPV) and negative predictive value (NPV).

RESULTS

Abnormal pulmonary X-ray, ascites and lesions of both cecum and ascending colon were more associated with ITB, while intestinal surgery and lesions of both ileum and adjacent colon were more commonly seen in CD. Significant diagnostic concordance was found using T-SPOT.TB (κ = 0.786) by consistency test. The sensitivity, specificity, PPV and NPV of T-SPOT.TB were 86%, 93%, 88% and 91%, respectively, and the sensitivity and NPV were significantly higher than other examinations (P < 0.05).

CONCLUSION

T-SPOT.TB is a valuable assay in differentiating ITB from CD, particularly in the diagnostic exclusion of ITB based on its high specificity and NPV.

Prospective evaluation of the clinical utility of interferon-γ assay in the differential diagnosis of intestinal tuberculosis and Crohn's disease

BACKGROUND

Distinguishing intestinal tuberculosis (ITB) from Crohn's disease (CD) is challenging. This study prospectively evaluated the clinical utility of the QuantiFERON-TB gold test (QFT) in the differential diagnosis of ITB and CD, and compared it with the clinical utility of the tuberculin skin test (TST).

METHODS

Patients with suspected ITB or CD on colonoscopic findings were enrolled from 13 hospitals in Korea between June 2007 and November 2008. A QFT and TST were performed. When the initial diagnosis was not confirmed, 2-3 months of empiric antituberculous therapy was administered.

RESULTS

In all, 128 patients were analyzed; 64 patients had ITB and 64 patients had CD. The median age of patients with ITB was greater than the patients with CD (47 years versus 31 years, P < 0.001). The positive rate for the QFT and TST (≥10 mm) in patients with ITB was significantly higher than patients with CD (67% versus 9% and 69% versus 16%, respectively; P < 0.001). The QFT and TST had good agreement (κ = 0.724, P < 0.001). The diagnostic validity of QFT in ITB had a 67% sensitivity, 90% specificity, 87% positive predictive value, and 73% negative predictive value. There was no difference in these parameters between the QFT and TST. The likelihood ratio for a positive QFT was higher than a positive TST in the diagnosis of ITB (7.1 and 4.4, respectively).

CONCLUSIONS

The QFT is a limited but useful diagnostic aid in combination with the TST in the diagnosis of ITB.

Diagnostic utility of anti-Saccharomyces cerevisiae antibody (ASCA) and Interferon-γ assay in the differential diagnosis of Crohn's disease and intestinal tuberculosis

BACKGROUND

Differential diagnosis of Crohn's disease (CD) from intestinal tuberculosis (ITB) is challenging. Anti-Saccharomyces cerevisiae antibody (ASCA) is a specific serological marker for CD and INF-gamma assay (QuantiFERON-TB gold test, QFT) is a good supplementary diagnostic tool for ITB. We evaluated the clinical usefulness of ASCA and QFT for differential diagnosis of CD from ITB in Korean adults.

METHODS

A total of 147 patients suspected to have ITB or CD were prospectively enrolled from 13 hospitals. ASCA IgG and IgA serum titers were measured by ELISA, and the QFT test was also performed.

RESULTS

Thirty-two of 72 (44.4%) patients with CD were ASCA positive (titer >25U) compared to 10 of 75 ITB patients (13.3%) and 3 of 20 healthy controls (15%) (p<0.01). The QFT test was positive in 7 patients with CD (9.7%) and 50 patients with ITB (66.6%) (p<0.01). In cases which ASCA positive/QFT negative, the sensitivity, specificity, positive predictive value, and negative predictive value for the diagnosis of CD were 44.4%, 96.0%, 91.4%, and 64.3%, respectively.

CONCLUSION

ASCA is a useful diagnostic tool for CD in Korea, where ITB is prevalent. In particular, when ASCA is combined with QFT, effective differential diagnosis of CD from ITB is possible.

Predictors of clinical and endoscopic findings in differentiating Crohn's disease from intestinal tuberculosis

BACKGROUND

There are many similarities and overlaps in clinical manifestations and ileocolonoscopic features between Crohn's disease (CD) and intestinal tuberculosis (ITB). Differentiation between CD and ITB is of great importance.

AIM

To investigate the values of clinical and endoscopic findings in differential diagnosis between CD and ITB.

METHODS

Clinical and endoscopic features of a cohort of 130 cases of CD and 122 cases of ITB from June 2003 to February 2009 were retrospectively reviewed following predetermined criteria. Parameters were screened by logistic regression analysis. Furthermore, the diagnostic efficacy of screened parameters was analyzed by regression equation (mathematical model) and receiver operating characteristic curve (ROC curve).

RESULTS

The clinical features helpful in differentiating CD from ITB are hematochezia, intestinal surgery, perianal diseases, pulmonary tuberculosis, ascites, and positive of PPD skin test; the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of regression mathematical model established by clinical features were 90.3, 76.8, 83.8, 80.7, and 88.0%, respectively. The endoscopic features helpful in differentiating CD from ITB were rectum involved lesions, longitudinal ulcer, cobblestone appearance, fixed-open ileocecal valve, transverse ulcer, and rodent ulcer; the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of regression mathematical model established by endoscopic features were 82.9, 82.0, 82.5, 82.9, and 82.0%, respectively.

CONCLUSIONS

It was proposed that a diagnostic algorithm based on available clinical and endoscopic regression equation could improve the current sensitivity, specificity, and accuracy in differentiating between CD from ITB.

Clinical, endoscopic, and histological differentiations between Crohn's disease and intestinal tuberculosis

OBJECTIVES

The clinical, endoscopic, and histological features of Crohn's disease (CD) and intestinal tuberculosis mimic each other so much that it becomes difficult to differentiate between them. The aim was to find out clinical, endoscopic, and histological predictor features for differentiation between CD and intestinal tuberculosis.

METHODS

We recruited 106 patients, 53 each with CD and intestinal tuberculosis, in this study. The clinical, histological, and endoscopic features were subjected to univariate, bivariate, and multivariate analyses. On the basis of regression coefficients of the final multivariate logistic model, a score to discriminate between CD and intestinal tuberculosis was devised. For the validation of the score, the same model was tested on 20 new patients, each with CD and intestinal tuberculosis.

RESULTS

On univariate analysis, although longer duration of disease, chronic diarrhea, blood in stool, perianal disease, extra-intestinal manifestations, involvement of left colon, skip lesions, aphthous ulcers, cobblestoning, longitudinal ulcers, focally enhanced colitis, and microgranulomas were significantly more common in CD, partial intestinal obstruction, constipation, presence of nodular lesions, higher number, and larger granulomas were significantly more common in intestinal tuberculosis. On multivariate analysis, blood in stool (odds ratio (OR) 0.1 (confidence interval (CI) 0.04-0.5)), weight loss (OR 9.8 (CI 2.2-43.9)), histologically focally enhanced colitis (OR 0.1 (CI 0.03-0.5)), and involvement of sigmoid colon (OR 0.07(0.01-0.3)) were independent predictors of intestinal tuberculosis. On the basis of regression coefficients of the final multivariate logistic model, a score that varied from 0.3 to 9.3 was devised. Higher score predicted more likelihood of intestinal tuberculosis. Once the cutoff was set at 5.1, then the sensitivity, specificity, and ability to correctly classify the two diseases were 83.0, 79.2, and 81.1%, respectively. Area under the curve for receiver-operating characteristic (ROC) to assess the ability of these features to discriminate between CD and intestinal tuberculosis was 0.9089. The area under ROC in the validation data set was 89.2% (95% CI 0.79-0.99). With a similar cutoff score of 5.1, sensitivity and specificity in the validation model were 90% (95% CI 66.9-98.2) and 60% (95% CI 36.4-80.0), respectively.

CONCLUSIONS

Blood in stool, weight loss, focally enhanced colitis, and involvement of the sigmoid colon were the most important features in differentiating CD from intestinal tuberculosis.

Differentiating intestinal tuberculosis from Crohn's disease: a diagnostic challenge

With the changing epidemiology of Crohn's disease (CD) and intestinal tuberculosis (ITB), we are in an era where the difficulty facing physicians in discriminating between the two diseases has increased, and the morbidity and mortality resulting from a delayed diagnosis or misdiagnosis is considerably high. In this article, we examine the changing trends in the epidemiology of CD and ITB, in addition to clinical features that aid in the differentiation of both diseases. The value of various laboratory, serological, and the tuberculin skin tests are reviewed as well. The use of an interferon-gamma-release assay, QuantiFERON-TB Gold, in the workup of these patients and its value in populations where the bacillus Calmette-Guérin vaccine is still administered is discussed. Different radiological, endoscopic, and pathological similarities and features that can aid the clinician in reaching a rapid diagnosis are reviewed as well. The association between mycobacteria and CD, the concerns with the practice of antituberculosis medication trials in areas where tuberculosis (TB) is endemic, as well as extrapulmonary TB induced by the use of antitumor necrosis factor-alpha agents are delineated in this article. Furthermore, we propose an algorithm for the investigation of patients in whom the differential diagnosis encompasses CD and ITB.

Distinguishing tuberculosis and Crohn's disease in developing countries: how certain can you be of the diagnosis?

Distinguishing tuberculosis and Crohn's disease in patients presenting with chronic abdominal pain and diarrhea is a huge diagnostic challenge, particularly in tuberculosis endemic countries. A large number of patients with Crohn's disease are initially misclassified as having Intestinal tuberculosis in places where tuberculosis is endemic before they are treated for Crohn's disease. Although a variety of endoscopic, radiological and histological criteria have been recommended for the differentiation, it often proves difficult in routine clinical practice. Future prospective studies are required in patients with granulomatous colitis to prevent unnecessary inappropriate anti tuberculous therapy for patients with Crohn's disease and appropriate early treatment for a patient with tuberculosis.

Ano-perianal tuberculosis--solving a clinical dilemma

BACKGROUND

Tuberculosis is one of the causes of granulomatous disease within the anorectal region. The clinical features, which include symptoms and signs of anal pain or discharge, multiple or recurrent fistula in ano and inguinal lymphadinopathy, are not characteristically distinct from other anal lesions. It is also difficult to distinguish it from other granulomatous diseases involving the same area.

MATERIALS AND METHODS

A Medline database was used to perform a literature search for articles relating to the term 'anal', 'tuberculosis' and 'Koch's'.

CONCLUSION

Analysis of the available literature shows that Koch's lesion in and around the anus is not uncommon. The presentation is varied in nature and tuberculosis should be suspected in lesions not responding to the conventional approaches. The treatment is two-fold: surgical for the suppuration and medical for the tuberculosis.

The usefulness of angiotensin converting enzyme in the differential diagnosis of Crohn's disease and intestinal tuberculosis

BACKGROUND

Since the pathologic findings of Crohn's disease (CD) and intestinal tuberculosis (IT) overlap to a large degree, the development of other biomarkers will be of great help for making the differential diagnosis of these 2 diseases. The aim of the present study is to examine the clinical efficacy of using the tissue angiotensin converting enzyme (ACE) assay in making the differential diagnosis between CD and IT.

METHODS

Tissue specimens were obtained from 36 patients who were diagnosed with CD or IT by the colonoscopic biopsy, as well as by the clinical findings. The expression of tissue ACE was detected by immunohistochemical staining. The optimal cut-off value of the immunoreactive scoring (IRS) system we used to differentiate CD from IT was determined by analysis of the ROC curve and AUROC.

RESULTS

Granuloma was present in 15 of 19 patients with CD (78.9%) and in 15 of 17 patients with IT (88.2%). ACE was present in the cytoplasm of the epithelioid cells in the granulomas from 13 of 15 patients with CD and in 14 of 15 patients with IT. The IRS scores of ACE were greater in the patients with CD than that of the patients with IT (8.07 +/- 4.38 vs. 4.13 +/- 2.47, respectively, p = 0.006). In differentiating CD from IT, the AUROC curve for the IRS of ACE was 0.767 with a sensitivity of 66.7%, a specificity of 93.3% and the cut-off point was 7.5.

CONCLUSIONS

The results of our study suggest that the assessment of the tissue ACE expression can be helpful for making the differential diagnosis between CD and IT.

Anti-Saccharomyces cerevisiae antibody does not differentiate between Crohn's disease and intestinal tuberculosis

The clinical, morphological, and histological features of intestinal tuberculosis (IT) and Crohn's disease (CD) mimic so much, that it becomes difficult to differentiate between them. The sensitivity of anti-Saccharomyces cerevisiae antibody (ASCA) IgG and ASCA IgA in CD is 60%-80%, whereas the specificity is almost 90%. There are no reports of study of ASCA in patients with IT, nor has it ever been used to differentiate CD from IT. Patients with ulcerative colitis (UC; n=25), CD (n=59), and IT (n=30) and 21 healthy controls were included in this study. The location and behavior of CD were classified according to the Modified Montreal classification. Five milliliters of blood was taken from them and serum was stored at -70 degrees C. ASCA antibodies (both IgG and IgA) were estimated using commercially available ELISA kits (AESKU Diagnostics, Germany). Anti-neutrophilic cytoplasmic antibody was measured by indirect immunofluorescence test. ASCA IgA was positive in 4.7%, 28%, 33.9%, and 43.3% and ASCA IgG was positive in 4.7%, 24%, 50.8%, and 46.6% of healthy controls and patients with UC, CD, and IT, respectively. Either ASCA IgG or ASCA IgA was positive in 9.5%, 40%, 61% and 66.6% of healthy controls, UC, CD, and IT, respectively. ANCA was positive in 0%, 32%, 10.1%, and 6.6% of healthy controls, UC, CD, and IT, respectively. ASCA IgG was positive in a significantly higher number of patients with CD (P<0.0001) and IT (P<0.0001) in comparison to healthy controls. ASCA IgA was positive in a significantly higher number of patients with UC (P<0.04), CD (P<0.013), and IT (P<0.006) in comparison to healthy controls. In comparisons between diseases, ASCA IgG was positive in significantly more patients with CD (P<0.001) and IT (P<0.001) in comparison to UC. There was no significant difference in ASCA IgA (33.9% vs. 43.3%), ASCA IgG (50.86% vs. 46.6%), or ANCA (10.7%, 7.4%) in patients with CD and IT, respectively. There was no correlation between ASCA and duration, location and behavior of CD, and IT. We conclude that ASCA IgG and ASCA IgA do not help to differentiate between IT and CD.

Role of colonoscopic biopsy in distinguishing between Crohn's disease and intestinal tuberculosis

BACKGROUND

The histological differential diagnosis of Crohn's disease and intestinal tuberculosis can be very challenging, as both are chronic granulomatous disorders with overlapping histological features.

AIM

To evaluate selected clinical and histological parameters in colonic biopsy specimens for their ability to discriminate between Crohn's disease and intestinal tuberculosis.

METHODS

25 patients with Crohn's disease and 18 patients with intestinal tuberculosis were selected for this study on the basis of established clinical, radiological and histological criteria. Clinical data and selected histological parameters in colonoscopic biopsy specimens were assessed retrospectively. A total of 103 and 41 biopsy sites were evaluated in patients with Crohn's disease and intestinal tuberculosis, respectively.

RESULTS

Clinical parameters helpful in differentiating intestinal tuberculosis from Crohn's disease included chest radiographic features of tuberculosis (56% v 0%), perianal fistulae (0% v 40%) and extraintestinal manifestations of Crohn's disease (0% v 40%). Histopathological features that seemed to reliably differentiate between intestinal tuberculosis and Crohn's disease included confluent granulomas, > or =10 granulomas per biopsy site and caseous necrosis (in biopsy samples of 50%, 33% and 22% of patients with intestinal tuberculosis, respectively, v 0% of patients with Crohn's disease). Features that were observed more often in patients with intestinal tuberculosis than in those with Crohn's disease included granulomas exceeding 0.05 mm(2) (67% v 8%), ulcers lined by conglomerate epithelioid histiocytes (61% v 8%) and disproportionate submucosal inflammation (67% v 10%).

CONCLUSION

Clinical features and selected histological parameters in colonoscopic biopsy specimens can help in differentiating between Crohn's disease and intestinal tuberculosis.

Differential diagnosis between Crohn's disease and intestinal tuberculosis in China

To evaluate the values of clinical findings in differential diagnosis between Crohn's disease (CD) and intestinal tuberculosis (ITb), so that better diagnosis strategies could be found, we analysed the records of 30 patients with ITb and 30 patients with CD retrospectively. We reviewed the cardinal symptomatic and physical, radiological, colonoscopic, pathological findings in the patients. Some cardinal symptomatic and physical, radiographic and colonscopic features of CD and ITb were positive correlation. Its Pearson correlation coefficients were 0.976, 0.953 and 0.961, respectively (p = 0.000, 0.003 and 0.000). Some histological features of CD and ITb had no correlation. Its Pearson correlation coefficient was 0.140 (p = 0.765). It is difficult to differentiate CD from ITb in clinical practice. The differential diagnosis depends largely upon colonoscopy and histopathology.

Tuberculous anal sepsis: report of clinical features in 20 cases

INTRODUCTION

Tuberculosis is a neglected cause of anal sepsis, often is not recognized, and therefore is not treated properly.

METHOD

All patients were reviewed who had tuberculous anal sepsis diagnosed by histology reports of fistulectomy specimens or abscess scrapings from January 1990 to April 1999.

RESULTS

Twenty patients (median age, 53 years; 18 males) with anal tuberculous sepsis were identified. They presented with abscesses (n = 2), abscesses and fistulas (n = 6), or fistulas (n = 12). All patients had a long history of anal complaints (3 months to 20 years), for which 15 patients were operated on previously. Nearly all fistulas (17/18) were complex, and secondary tracks or additional complicating features were common, even at first presentation. Eight patients had active concurrent pulmonary tuberculosis, and six showed evidence of previous pulmonary tuberculosis. Six patients had no signs of concurrent or previous tuberculosis elsewhere. Recurrence was observed only in cases where tuberculosis was initially not recognized, and antitubercular treatment therefore was not started.

CONCLUSION

Contrary to views held previously, anal tubercular sepsis seems to have characteristic clinical features. It should be considered in cases of known pulmonary or extrapulmonary tuberculosis or if anal sepsis is persistent, recurrent, or complex in nature.

Tuberculous colitis mimicking Crohn's disease

Intestinal tuberculosis is a rare disease in western countries and may mimic a variety of gastrointestinal disorders. Here, we report the case of a 63-yr-old patient who presented with profuse bleeding from a deep rectal ulcer. Similar lesions were found in different parts of the colon. Multilocular colorectal carcinoma was suspected based on the macroscopic appearance. Histology, however, suggested Crohn's disease. Intestinal tuberculosis was initially ruled out by negative staining for acid-fast bacilli, mycobacterial culture, and polymerase chain reaction analysis. A treatment for Crohn's disease was started. Endoscopic reexamination revealed progressive disease with extensive ulcerations of the terminal ileum. Histopathological examination then revealed acid-fast bacilli in the colonic mucosa typical for mycobacterium tuberculosis infection. This case emphasizes the need to include intestinal tuberculosis in the initial differential diagnosis of ulcerative colorectal lesions also in the western population.

TB or not TB?

These 3 cases illustrate what we believe to be unusual presentations of tuberculosis. In no case was there conclusive proof of infection with Mycobacterium tuberculosis using histological, microbiological or radiological techniques. All were treated empirically with anti-tuberculous medication, with complete recovery. With the re-emergence of tuberculosis, there may be a rise in such cases, and the importance of their recognition and empirical treatment is discussed.