Crohn's disease and intestinal tuberculosis: challenging from every angle.

A woman in her 20s with a recent diagnosis of Crohn's disease (CD) affecting the ileocaecal valve was started on adalimumab, after routine tuberculosis (TB) tests were negative. Her abdominal symptoms got worse and she started presenting respiratory distress and fever. Tomography revealed a left pleural effusion, pneumonia and peritonitis with pelvic abscess. The diagnosis of disseminated TB with digestive involvement was suggested and sputum cultures were positive for Mycobacterium tuberculosis Treatment for TB was started and immunosuppressants discontinued, leading to respiratory improvement. Abdominal imaging was repeated, showing worsening signs of multisegmental ileal wall thickening, ileocaecal valve obstruction and a persistent pelvic abscess. She was then submitted to a laparoscopic ileocaecal resection for suspicion of worsening CD. Histopathology showed chronic ileocolitis compatible with CD and ganglionic tuberculosis, revealing the diagnosis of intestinal tuberculosis superimposed in CD. Recovery was uneventful.

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.

Enteric fever masquerading as Crohn's disease in a child with abdominal tuberculosis.

In tropical countries, like India, various types of infectious diseases like tuberculosis, enteric fever, malaria and dengue are prevalent. Disease trend over time has been gradually shifting from infective to inflammatory frame because of increasing awareness regarding hygiene and increasing immunisation coverage. This case report describes an adolescent boy having a long history of abdominal pain, bleeding per rectum and documented weight loss, presented with an acute episode of fever. But the coexisting infections and/or inflammatory conditions presented challenges to the treating physician in diagnosis and management despite of good clinical experience. In this case, a chronic gastrointestinal infection caused by Mycobacterium tuberculosis with a superadded Salmonella typhi infection was masquerading as inflammatory bowel disease (Crohn's disease). Utmost caution should be exercised to reach the correct diagnosis and take the necessary steps to manage this type of situation in tropical countries like India.

Frequency, outcomes, and need for intervention in stricturing gastrointestinal tuberculosis: a systematic review and meta-analysis.

BACKGROUND: Gastrointestinal strictures impact clinical presentation in abdominal tuberculosis and are associated with significant morbidity. AIM: To conduct a systematic review of the prevalence of stricturing disease in abdominal and gastrointestinal tuberculosis and response to antitubercular therapy (ATT). METHODS: We searched Pubmed and Embase on 13th January 2022, for papers reporting on the frequency and outcomes of stricturing gastrointestinal tuberculosis. The data were extracted, and pooled prevalence of stricturing disease was estimated in abdominal tuberculosis and gastrointestinal (intestinal) tuberculosis. The pooled clinical response and stricture resolution (endoscopic or radiologic) rates were also estimated. Publication bias was assessed using the Funnel plot and Egger test. The risk of bias assessment was done using a modified Newcastle Ottawa Scale. RESULTS: Thirty-three studies reporting about 1969 patients were included. The pooled prevalence of intestinal strictures in abdominal tuberculosis and gastrointestinal TB was 0.12 (95%CI 0.07-0.20, I2 = 89%) and 0.27 (95% CI 0.21-0.33, I2 = 85%), respectively. The pooled clinical response of stricturing gastrointestinal tuberculosis to antitubercular therapy was 0.77 (95%CI 0.65-0.86, I2 = 74%). The pooled stricture response rate (endoscopic or radiological) was 0.66 (95%CI 0.40-0.85, I2 = 91%). The pooled rate of need for surgical intervention was 0.21 (95%CI 0.13-0.32, I2 = 70%), while endoscopic dilatation was 0.14 (95%CI 0.09-0.21, I2 = 0%). CONCLUSION: Stricturing gastrointestinal tuberculosis occurs in around a quarter of patients with gastrointestinal tuberculosis, and around two-thirds of patients have a clinical response with antitubercular therapy. A subset of patients may need endoscopic or surgical intervention. The estimates for the pooled prevalence of stricturing disease and response to ATT had significant heterogeneity.

MTBDRplus and MTBDRsl for simultaneous diagnosis of gastrointestinal tuberculosis and detection of first-line and second-line drug resistance.

BACKGROUND AND AIM: Emergence of drug resistance, especially to second-line drugs, hampers tuberculosis elimination efforts. The present study aimed to evaluate MTBDRplus and MTBDRsl assays for detecting first-line and second-line drug resistance, respectively, in gastrointestinal tuberculosis (GITB). METHODS: Thirty ileocecal biopsy specimens, processed in the Department of Microbiology between 2012 and 2022, that showed growth of Mycobacterium tuberculosis on culture were included in the study. DNA, extracted from culture, was subjected to MTBDRplus and MTBDRsl (Hain Lifescience GmbH, Nehren, Germany), following manufacturer's instructions. Their performance was compared against phenotypic drug susceptibility testing (pDST) and gene sequencing. RESULTS: Out of the 30 specimens, 4 (13.33%) were mono-isoniazid resistant, 4 (13.33%) were multidrug resistant (MDR), 2 (6.67%) were pre-extensively drug resistant (pre-XDR), and 2 (6.67%) were mono-fluoroquinolone resistant. The results were 100% concordant with pDST and gene sequencing. CONCLUSIONS: In the wake of growing drug resistance in all forms of extrapulmonary tuberculosis, including GITB, MTBDRplus and MTBDRsl are reliable tools for screening of resistance to both first-line and second-line drugs.

High Accuracy of a Simplified, Practical Algorithm in Differentiating Crohn's Disease from Intestinal Tuberculosis.

BACKGROUND: The differentiation between intestinal tuberculosis (ITB) and Crohn's disease (CD) remains a challenge, particularly in areas where tuberculosis is highly prevalent. Previous studies have identified features that favour one diagnosis over the other. The aim of the study was to determine the accuracy of a standardized protocol in the initial diagnosis of CD versus ITB. METHODS: All patients with suspected ITB or CD were prospectively recruited. A standardized protocol was applied, and the diagnosis was made accordingly. The protocol consists of history and examination, ileocolonoscopy with biopsies, and tuberculosis workup. The diagnosis of probable ITB was made based on at least one positive finding. All other patients were diagnosed as probable CD. Patients were treated either with anti-tubercular therapy or steroids. Reassessment was then carried out clinically, biochemically, and endoscopically. In patients with suboptimal response, the treatment was either switched or escalated depending on the reassessment. RESULTS: 164 patients were recruited with final diagnosis of 30 (18.3%) ITB and 134 (81.7%) CD. 1 (3.3%) out of 30 patients with ITB was initially treated as CD. 16 (11.9%) out of 134 patients with CD were initially treated as ITB. The initial overall accuracy for the protocol was 147/164 (89.6%). All patients received the correct diagnosis by 12 weeks after reassessment. CONCLUSION: In our population, most patients had CD rather than ITB. The standardized protocol had a high accuracy in differentiating CD from ITB.

Intestinal and perianal tuberculosis: an uncommon clinical presentation and challenging diagnosis.

We present the case of a 40-year-old immunocompetent man with complaints of perianal abscess, diarrhea, and weight loss for 3 months. He denied respiratory symptoms. Colonoscopy revealed ulcers and histopathology showed non-necrotizing granulomas and excluded acid-fast bacilli. Initially, the clinical and histological findings favored the diagnosis of Crohn's disease, however, further investigation by performing chest radiography in the context of a pre-immunomodulatory checklist, revealed pulmonary cavitations confirmed on computed tomography scan. Further mycobacteriological studies suggested the diagnosis of active pulmonary tuberculosis. Demonstration of the presence of Mycobacterium tuberculosis in the colon was possible by RT-PCR. Complete resolution of intestinal and perianal symptoms was achieved 2 weeks after treatment with anti-bacillary agents.

Mini-laparoscopy as a diagnostic tool for abdominal tuberculosis: a retrospective series of 29 cases.

OBJECTIVES: Abdominal tuberculosis (TB) is a "great mimic," and diagnosis remains challenging even for experienced clinicians. While mini-laparoscopy has already been demonstrated to be an efficient diagnostic tool for a variety of diseases, we aimed to demonstrate the feasibility of this technique in diagnosing abdominal TB. METHODS: We retrospectively included patients who underwent mini-laparoscopy at the University Medical Center Hamburg-Eppendorf between April 2010 and January 2022 for suspected abdominal TB. Demographic, clinical, and laboratory data, radiological findings as well as macroscopic, histopathologic, and microbiologic results were analyzed by chart review. RESULTS: Out of 49 consecutive patients who underwent mini-laparoscopy for suspected abdominal TB, the diagnosis was subsequently confirmed in 29 patients (59%). Among those, the median age was 30 years (range 18-86 years) and the majority were male (n = 22, 76%). Microbiological diagnosis was established in a total of 16 patients. The remaining patients were diagnosed with abdominal TB either by histopathological detection of caseating granulomas (n = 3), or clinically by a combination of typical presentation, mini-laparoscopic findings, and good response to anti-tuberculous treatment (n = 10). Bleeding from the respective puncture site occurred in 19 patients (66%) and either resolved spontaneously or was arrested with argon plasma coagulation alone (n = 10) or in combination with fibrin glue (n = 1). Minor intestinal perforation occurred in 2 patients and was treated conservatively. CONCLUSIONS: Mini-laparoscopy is a useful and safe modality for the diagnosis of abdominal TB.

Comparative evaluation of interleukin-10, transforming growth factor-ß, and interleukin-17 in gastrointestinal tuberculosis and crohn's disease.

Background: Gastrointestinal tuberculosis (GITB) and Crohn's disease (CD) are close mimickers and difficult to discriminate. Recent work has focused on the immunological differences between GITB and CD based on cytokines related to T-regulatory cells and Th17 cells. In the present cross-sectional study, suspected cases of GITB or CD underwent extensive clinical, radiological, endoscopic, histological, and microbiological assessment. The diagnosis was based on standard criteria and response to antitubercular therapy endoscopically. Methods: Interleukin (IL)-10, transforming growth factor-ß (TGF-ß), and IL-17 were measured and compared between GITB and CD along with other parameters. Fisher's exact test and Mann-Whitney U test were used as per the data type. Results: Of the 27 patients, 11 had CD, 9 had GITB, and 7 had other conditions. Chronic diarrhea, involvement of left and long segments of the colon, and aphthous ulcers were significantly more frequent in CD; however, transverse ulcers were in GITB. IL-10 was reduced in both GITB (median-interquartile range [IQR] 9.54 [3.65-24.04]) and CD (median-IQR 13.28 [6.91-22.50]) compared to control (median-IQR 26.72 [10.34-35.43]). TGF-ß showed little variation, but IL-17 was below the detection limit in most cases. None of these cytokines were significantly different between CD and GITB. The sensitivity and specificity of multiplex Mycobacterium tuberculosis-polymerase chain reaction were 44.44% and 100%, respectively. Conclusion: Serum cytokine profiling (IL-10, IL-17, and TGF-ß) could not significantly differentiate GITB and CD. Moreover, extensive molecular, transcriptomic, chemokines, and cytokine analyses may shed light on these aspects.

Esophageal tuberculosis induced dysphagia: a case report.

BACKGROUND: Patients can present for a wide variety of etiologies for dysphagia, and it is important to consider less common causes once common etiologies have been ruled out. Extrapulmonary Mycobacterium tuberculosis (TB) presentations are rare to see in the western populations due to relative lack of TB exposure and overall less immunocompromised populations, but should be considered for at-risk patients. Gastrointestinal (GI) TB is rare, and the GI tract is considered only the sixth most frequent site of extrapulmonary TB (EPTB). CASE PRESENTATION: This is a case report of a 35-year-old Ethiopian male presenting with dysphagia and retrosternal odynophagia who was found to have infiltration of mediastinal lymphadenopathy into the esophageal wall secondary to TB. This patient underwent an upper endoscopy, which revealed a linear 2 cm full thickness mucosal defect in the middle esophagus concerning for an infiltrative process with full thickness tear. Computed tomography (CT) of the chest demonstrated a subcarinal soft tissue mass that was inseparable from the esophagus. He was referred to thoracic surgery and underwent an exploratory mediastinal dissection. A mediastinoscopy scope was inserted and the mediastinal dissection was made until the subcarinal nodes were identified and removed. Biopsy results showed necrotizing and non-necrotizing granulomas, and acid-fast bacilli (AFB) culture from the surgically removed lymph node showed Mycobacterium TB complex growth. He had no known TB exposures and did not have any TB risk factors. He then followed up in infectious disease clinic and was managed with anti-tuberculosis treatment (ATT) with complete resolution of symptoms. CONCLUSIONS: Our patient was ultimately found to have esophageal TB secondary to mediastinal invasion into the esophageal wall from lymphadenopathy associated with TB. This is an extremely rare presentation in western populations due to diminished exposure rates and overall less immunocompromised populations compared to impoverished countries with increased TB exposure and human immunodeficiency virus (HIV) infection rates. Although TB is not as commonly seen in western populations, it should be considered on the differential for any atypical presentations of GI diseases for patients with clinical or geographic risk factors.

Abdominal cyst of unclear aetiology: gastrointestinal stromal tumour or reactivation of abdominal tuberculosis.

Differential diagnosis of a new abdominal mass is broad and includes infection, malignancy and other inflammatory processes. Definitive diagnosis may be challenging without invasive biopsy, as history, physical exam and imaging may be non-specific. A 69-year-old man with a history of abdominal tuberculosis presented with a new painful abdominal cyst consistent with reactivation of tuberculosis versus new malignancy. Investigations revealed 4+ acid-fast bacilli from the aspirate suggestive of tuberculosis, but no improvement was noted on antituberculous therapy. Core needle biopsy noted c-KIT-positive spindle cells, diagnostic for a gastrointestinal stromal tumour, while cultures grew non-tuberculous mycobacteria.

Gastric Outlet Obstruction: Don't Miss Duodenal Tuberculosis.

We report a case of isolated duodenal tuberculosis (TB) in a patient who presented with features of gastric outlet obstruction. The diagnosis was made on repeat endoscopic duodenal biopsy after initial histopathology failed to reveal the diagnosis. The patient recovered with antitubercular therapy. The index of suspicion has to be high in TB endemic countries as clinical, radiological, and endoscopic features are nonspecific.

Gastrointestinal tuberculosis: A systematic review of epidemiology, presentation, diagnosis and treatment.

Tuberculosis (TB) once considered a disease of the developing world is infrequent in the developing world too. Its worldwide prevalence with a huge impact on the healthcare system both in economic and health terms has prompted the World Health Organization to make it a top priority infectious disease. Tuberculous infection of the pulmonary system is the most common form of this disease, however, extrapulmonary TB is being increasingly recognized and more often seen in immunocompromised situations. Gastrointestinal TB is a leading extrapulmonary TB manifestation that can defy diagnosis. Overlap of symptoms with other gastrointestinal diseases and limited accuracy of diagnostic tests demands more awareness of this disease. Untreated gastrointestinal TB can cause significant morbidity leading to prolonged hospitalization and surgery. Prompt diagnosis with early initiation of therapy can avoid this. This timely review discusses the epidemiology, risk factors, pathogenesis, clinical presentation, current diagnostic tools and therapy.

Management of abdominal tuberculosis in a community-based hospital in a high-income developing country.

BACKGROUND: The delayed diagnosis and management of abdominal tuberculosis increases its mortality. We aimed to study the clinical presentation, management, and outcome of patients who had abdominal tuberculosis and were treated at Al-Ain Hospital, Al-Ain City, United Arab Emirates. METHODS: All patients who had abdominal tuberculosis and were treated at Al-Ain Hospital between January 2011 and December 2018 were studied. Data were collected retrospectively using a structured protocol including demography, clinical presentation, diagnostic methods, management, and outcome. RESULTS: Twenty-four patients having a median age of 30 years were studied with an incidence of 0.6/100,000 population. The most common symptoms were abdominal pain (95.8%) and malaise (79.2%). Fever was present only in nine patients (37.5%). Laboratory investigations, except for polymerase chain reaction immunoassay, were not helpful. Chest X-ray was abnormal in three patients (12.5%). Ultrasound and abdominal CT scan were non-specific. Thirteen patients needed surgical intervention for diagnosis or therapy. Diagnosis was confirmed by histopathology in 15 patients (62.5%), immunological assays in 7 patients (29.2%), microbiological culture in 1 patient (4%), and therapeutic trial in 1 patient (4%). The most common type of abdominal tuberculosis was gastrointestinal in 13 patients (54.2%) followed by free wet peritonitis in 5 patients (20.8%). All patients had quadruple anti-tuberculous therapy for a minimum of 6 months. The median hospital stay was 6.5 days. None of our patients died. CONCLUSIONS: Diagnosis of abdominal tuberculosis remains challenging despite advances in medical technology and diagnostic tools. The limited need for diagnostic therapy in our study supports the benefit of PCR assay. Surgery was mainly indicated as the last option to reach the diagnosis or to treat 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.

Abdominal tuberculosis in a tertiary care centre in Saudi Arabia.

OBJECTIVES: Abdominal tuberculosis (ATB) is the second most common type of extra-pulmonary tuberculosis. Though it does not usually pose a significant risk of infectivity, ATB can go unidentified and progress to disseminated infection. The aim of this study is to highlight the incidence and outcome of this infection in a tertiary care centre in the Kingdom of Saudi Arabia (KSA). METHODS: In this retrospective study, we included all ATB patients admitted to our centre between January 1 st, 2010 and December 31, 2018. A total of 42 patients with a median age of 49 (range 18-83 years, 78.6% males) were identified. RESULTS: The most common presentation was abdominal pain, weight loss, and abdominal distension. All the patients were HIV negative; however, 50% had a comorbid condition, mainly diabetes mellitus, chronic renal failure, and liver cirrhosis. Tuberculous peritonitis was the predominant type of ATB. Suspicious and potentially malignant abdominal masses appeared on the abdominal CT scans of six patients. This suggest that TB should be excluded in patients from endemic area presenting with abdominal masses. All patients received standard anti-tuberculous medication for an average duration of 7.4 months. The outcome was excellent with 88%% achieving complete response. Adjunctive corticosteroids were not used, and none of the patients had a surgical complication. CONCLUSION: The diagnosis of ATB is challenging. It can mimic inflammatory bowel disease in young populations and malignancy in middle-aged and elderly population. For this reason, a high index of suspicion with prompt treatment is required to improve the prognosis and prevent complications.

Treatment of intestinal tuberculosis with small bowel perforation: a case report.

BACKGROUND: Diagnosis of intestinal tuberculosis poses a dilemma to physicians due to nonspecific symptoms like abdominal pain, fever, nausea, and a change in bowel habit. In particular, the distinction between inflammatory bowel disease and intestinal tuberculosis remains challenging. CASE PRESENTATION: A 27-year-old man from Colombia presented with fever, night sweats, and progressive lower abdominal pain. Computed tomography revealed a thickening of the bowel wall with a mesenterial lymphadenopathy, ascites ,and a pleural tumor mass. Histology of intestinal and pleural biopsy specimens showed a granulomatous inflammation. Although microscopy and polymerase chain reaction (PCR) for Mycobacterium tuberculosis (MTB) were negative, empirical MTB treatment was initiated on suspicion. Due to a massive post-stenotic atrophied intestinal bowel, MTB medications were administered parenterally in the initial phase of treatment to guarantee adequate systemic resorption. The complicated and critical further course included an intra-abdominal abscess and bowel perforation requiring a split stoma, before the patient could be discharged in good condition after 3 months of in-hospital care. CONCLUSIONS: This case highlights the clinical complexity and diagnostic challenges of intestinal MTB infection. A multidisciplinary team of physicians should be sensitized to a timely diagnosis of this disease, which often mimics inflammation similar to inflammatory bowel disease, other infections, or malignancies. In our case, radiological findings, histological results, and migratory background underpinned the suspected diagnosis and allowed early initiation of tuberculostatic treatment.

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

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

Serial measurements of faecal calprotectin may discriminate intestinal tuberculosis and Crohn's disease in patients started on antitubercular therapy.

BACKGROUND: Response to antitubercular therapy (ATT) is often used to differentiate intestinal tuberculosis (ITB) from Crohn's disease. Role of non-invasive biomarkers to predict mucosal response to ATT is unclear. MATERIALS AND METHODS: A prospective study to compare faecal calprotectin and serum C-reactive protein (CRP) levels at diagnosis, 2 and 6 months of ATT in patients with suspected ITB started on ATT was done. The patients were eventually divided into two groups: ITB or alternative diagnosis (OTH). Decline of calprotectin and CRP levels was used to compute area under the receiver operating characteristic (AUROC) to predict mucosal healing at 2 months. RESULTS: Thirty-seven patients (mean age: 34.95 ± 16.35 years, 23 males) were included and 28 (75.67%) were diagnosed as ITB while nine (24.32%) had alternative diagnosis (OTH). The median faecal calprotectin values of ITB and OTH groups at baseline, 2 months and 6 months were 216 and 282 µg/g (P = 0.466), 43 and 216 µg/g (P = 0.003), and 26 and 213 µg/g (P < 0.001), respectively. The median CRP values at baseline, 2 months and 6 months were 18 and 30 mg/L (P = 0.767), 4.7 and 15 mg/L (P = 0.025), and 3 and 10.85 mg/L (P = 0.068), respectively. The AUROC of percent decline in faecal calprotectin and serum CRP at 2 months for mucosal healing were 0.8287 [95% confidence inteval (CI) 0.6472-1] and 0.6018 (95% CI 0.4079-0.7957), respectively. CONCLUSION: Faecal calprotectin can help in assessing response to therapy in suspected ITB patients started on empirical ATT.