Serum albumin is the strongest predictor of anti-tumor necrosis factor nonresponse in inflammatory bowel disease in resource-constrained regions lacking therapeutic drug monitoring

Background/Aims@#Evidence on predictors of primary nonresponse (PNR), and secondary loss of response (SLR) to anti-tumor necrosis factor (anti-TNF) agents in inflammatory bowel disease is scarce from Asia. We evaluated clinical/biochemical/molecular markers of PNR/SLR in ulcerative colitis (UC) and Crohn’s disease (CD). @*Methods@#Inflammatory bowel disease patients treated with anti-TNF agents (January 2005–October 2020) were ambispectively included. Data concerning clinical and biochemical predictors was retrieved from a prospectively maintained database. Immunohistochemistry for expression of oncostatin M (OSM), OSM receptor (OSM-R), and interleukin-7 receptor (IL-7R) were done on pre anti-TNF initiation mucosal biopsies. @*Results@#One-hundred eighty-six patients (118 CD, 68 UC: mean age, 34.1±13.7 years; median disease duration at anti-TNF initiation, 60 months; interquartile range, 28–100.5 months) were included. PNR was seen in 17% and 26.5% and SLR in 47% and 28% CD and UC patients, respectively. In CD, predictors of PNR were low albumin (P<0.001), postoperative recurrence (P=0.001) and high IL-7R expression (P<0.027) on univariate; and low albumin alone (hazard ratio [HR], 0.09; 95% confidence interval [CI], 0.03–0.28; P<0.001) on multivariate analysis respectively. Low albumin (HR, 0.31; 95% CI, 0.15–0.62; P=0.001) also predicted SLR. In UC, predictors of PNR were low albumin (P<0.001), and high C-reactive protein (P<0.001), OSM (P<0.04) and OSM-R (P=0.07) stromal expression on univariate; and low albumin alone (HR, 0.11; 95% CI, 0.03–0.39; P=0.001) on multivariate analysis respectively. @*Conclusions@#Low serum albumin at baseline significantly predicted PNR in UC and PNR/SLR in CD patients. Mucosal markers of PNR were high stromal OSM/OSM-R in UC and high IL-7R in CD patients.

Interferon-gamma release assay has poor diagnostic accuracy in differentiating intestinal tuberculosis from Crohn’s disease in tuberculosis endemic areas

Background/Aims@#Intestinal tuberculosis (ITB) and Crohn’s disease (CD) frequently present with a diagnostic dilemma because of similar presentation. Interferon-gamma release assay (IGRA) has been used in differentiating ITB from CD, but with sparse reports on its diagnostic accuracy in tuberculosis endemic regions and this study evaluated the same. @*Methods@#Patients with definitive diagnosis of ITB (n=59) or CD (n=49) who underwent IGRA testing (n=307) were retrospectively included at All India Institute of Medical Sciences, New Delhi (July 2014 to September 2021). CD or ITB was diagnosed as per standard criteria. IGRA was considered positive at >0.35 IU/mL.Relevant data was collected and IGRA results were compared between ITB and CD to determine its accuracy. @*Results@#Among 59 ITB patients (mean age, 32.6±13.1 years; median disease duration, 1 year; male, 59.3%), 24 were positive and 35 tested negative for IGRA. Among 49 CD patients (mean age, 37.8±14.0; median disease duration, 4 years; male, 61.2%), 12 were positive and 37 tested negative for IGRA. Hence, for diagnosing ITB, IGRA showed a sensitivity, specificity, positive and negative predictive values of 40.68%, 75.51%, 66.67%, and 51.39%, respectively. The area under the curve of IGRA for ITB diagnosis was 0.66 (95% confidence interval, 0.55–0.75). In a subset (n=64), tuberculin skin test (TST) showed sensitivity, specificity, positive and negative predictive values of 64.7%, 73.3%, 73.3%, and 64.71%, respectively. IGRA and TST were concordant in 38 (59.4%) patients with κ=0.17. @*Conclusions@#In a tuberculosis endemic region, IGRA had poor diagnostic accuracy for differentiating ITB from CD, suggesting a limited value of IGRA in this setting.

Use of thiopurines in inflammatory bowel disease: an update

Inflammatory bowel disease (IBD), once considered a disease of the Western hemisphere, has emerged as a global disease. As the disease prevalence is on a steady rise, management of IBD has come under the spotlight. 5-Aminosalicylates, corticosteroids, immunosuppressive agents and biologics are the backbone of treatment of IBD. With the advent of biologics and small molecules, the need for surgery and hospitalization has decreased. However, economic viability and acceptability is an important determinant of local prescription patterns. Nearly one-third of the patients in West receive biologics as the first/initial therapy. The scenario is different in developing countries where biologics are used only in a small proportion of patients with IBD. Increased risk of reactivation of tuberculosis and high cost of the therapy are limitations to their use. Thiopurines hence become critical for optimal management of patients with IBD in these regions. However, approximately one-third of patients are intolerant or develop adverse effects with their use. This has led to suboptimal use of thiopurines in clinical practice. This review article discusses the clinical aspects of thiopurine use in patients with IBD with the aim of optimizing their use to full therapeutic potential.

Addition of computed tomography chest increases the diagnosis rate in patients with suspected intestinal tuberculosis

Background/Aims@#Intestinal tuberculosis (ITB) is difficult to diagnose due to poor sensitivity of definitive diagnostic tests. ITB may be associated with concomitant pulmonary tuberculosis (PTB) which may remain undetected on chest X-ray. We assessed the role of contrast enhanced computed tomography (CECT) chest in detecting the prevalence of active PTB, and increasing the diagnostic yield in patients with suspected ITB. @*Methods@#Consecutive treatment naïve patients with suspected ITB (n=200) who underwent CECT chest (n=88) and had follow-up duration>1 year were recruited in this retrospective study (February 2016 to October 2018). ITB was diagnosed in the presence of caseating granuloma, positive acid fast stain or culture for Mycobacterium tuberculosis on biopsy, presence of necrotic lymph nodes (LNs) on CT enterography or positive response to anti-tubercular therapy. Evidence of active tuberculosis on CECT-chest was defined as presence of centrilobular nodules with or without consolidation/miliary nodules/thick-walled cavity/enlarged necrotic mediastinal LNs. @*Results@#Sixty-five of eighty-eight patients (mean age, 33.8±12.8 years; 47.7% of females) were finally diagnosed as ITB (4-caseating granuloma on biopsy, 12-necrotic LNs on CT enterography, 1-both, and 48-response to anti-tubercular therapy) and 23 were diagnosed as Crohn’s disease. Findings of active TB on CECT chest with or without necrotic abdominal LNs were demonstrated in 5 and 20 patients, respectively. No patient with Crohn’s disease had necrotic abdominal LNs or active PTB. Addition of CECT chest in the diagnostic algorithm improved the sensitivity of ITB diagnosis from 26.2% to 56.9%. @*Conclusions@#Addition of CECT chest significantly improves the sensitivity for definite diagnosis in a patient with suspected ITB.

Efficacy and tolerability of hyperbaric oxygen therapy in small bowel stricturing Crohn’s disease: a pilot study

Background/Aims@#Existing therapeutic options for complicated Crohn’s disease (CD) like biologics and surgery are limited by inadequate long-term efficacy, cost, and adverse effects. Tissue hypoxia is important in CD pathogenesis and may be ameliorated with hyperbaric oxygen therapy (HBOT). We assessed the efficacy and tolerability of HBOT in small bowel stricturing CD. @*Methods@#This pilot study included patients of small bowel stricturing CD (from April 2019 to January 2020) who underwent HBOT. These patients were refractory to conventional medical treatment or had multiple strictures not amenable to resection. Each session of HBOT was given for 60 minutes with a pressure of 1.5–2.5 atm. Clinical, biochemical responses and Short Inflammatory Bowel Disease (SIBD) questionnaire were evaluated at 2 and 6 months, and radiological response was evaluated at 6 months. @*Results@#Fourteen patients (mean age, 42.9±15.7 years; male, 50%) were subjected to 168 HBOT sessions. Thirteen patients (92.7%) had strictures and 1 patient had enterocutaneous fistula in addition. Median number of HBOT sessions was 11 (range, 3–20) which were administered over a median of 4 weeks. Most patients tolerated it well except 1 who had hemotympanum. At 2 and 6 months of follow-up, 64.2% of patients had a clinical response, 50% and 64.2% of patients had clinical remission respectively. Steroid-free clinical remission was seen in 8 (57%) of patients with radiological improvement in 50%. There was a significant improvement in SIBD scores at 2-month follow-up (59.4 vs. 44.5, P=0.03). @*Conclusions@#HBOT can be a safe and effective therapeutic option in patients with stricturing small bowel CD refractory to conventional medical treatment.

High mucosal cytomegalovirus DNA helps predict adverse short-term outcome in acute severe ulcerative colitis

Background/Aims@#Predictors of short-term outcome of intravenous (IV) steroid therapy in acute severe ulcerative colitis (ASUC) have been well described, but the impact of cytomegalovirus (CMV) infection as a predictor of outcome remains debatable. We investigated the role of quantitative CMV polymerase chain reaction (PCR) as a predictor of short-term outcome in patients with ASUC. @*Methods@#Consecutive patients with ASUC satisfying Truelove and Witts criteria hospitalized at All India Institute of Medical Sciences (AIIMS) from May 2016 to July 2019 were included; all received IV steroid. The primary outcome measure was steroid-failure defined as the need for rescue therapy (with ciclosporin or infliximab) or colectomy during admission. AIIMS’ index (ulcerative colitis index of severity > 6 at day 1+fecal calprotectin > 1,000 μg/g at day 3), with quantitative CMV PCR on biopsy samples obtained at initial sigmoidoscopy were correlated with the primary outcome. @*Results@#Thirty of 76 patients (39%) failed IV corticosteroids and 12 (16%) underwent surgery. Patients with steroid failure had a significantly higher mucosal CMV DNA than responders (3,454 copies/mg [0–2,700,000] vs. 116 copies/mg [0–27,220]; P 2,000 copies/mg (odds ratio [OR], 10.2; 95% confidence interval [CI], 2.6–39.7; P 2,000 copies/mg) independently predicts failure of IV corticosteroids and short-term risk of colectomy and it has an additional value to the established markers of disease severity in patients with ASUC.

Efficacy and tolerability of exclusive enteral nutrition in adult patients with complicated Crohn’s disease

Background/Aims@#Exclusive enteral nutrition (EEN), an established modality for pediatric Crohn’s disease (CD) is seldomly utilized in adults. The present study reports the outcome of EEN in adult CD patients at a tertiary care hospital in India. @*Methods@#This was a retrospective analysis of CD patients who received EEN as a sole modality/adjunct to other treatment. The primary and secondary outcomes changed in Crohn’s Disease Activity Index (CDAI), and clinical response (decline in CDAI > 70), respectively, at 4 and 8 weeks. Subgroup analysis evaluated response across different phenotypes, EEN formulations and prior treatment. Linear mixed effect model was created to assess the predictors of EEN response. @*Results@#Thirty-one CD patients received EEN over median duration of 4 weeks (range, 2–6 weeks). CDAI showed a significant improvement post EEN at 4 (baseline 290 [260–320] vs. 240 [180–280], P= 0.001) and 8 weeks (baseline 290 [260–320] vs. 186 [160–240], P= 0.001), respectively. The cumulative clinical response rates at 4 and 8 weeks were 37.3% and 80.4% respectively. The clinical response rates at 8 weeks across B1 (n = 4), B2 (n = 18) and B3 (n = 9) phenotypes were 50%, 78.8% and 100% respectively (log-rank test, P= 0.093). The response rates at 8 weeks with polymeric (n = 8) and semi-elemental diet (n = 23) were 75% and 82.6%% respectively (log-rank test, P= 0.49). Baseline CDAI (odds ratio, 1.008; 95% confidence interval, 1.002–1.017; P= 0.046) predicted response to EEN. @*Conclusions@#EEN was effective in inducing clinical response across different phenotypes of CD. Baseline disease activity remained the most important predictor of clinical response to EEN.

Prospective validation of CD4+CD25+FOXP3+ T-regulatory cells as an immunological marker to differentiate intestinal tuberculosis from Crohn’s disease

Background/Aims@#Crohn’s disease (CD) and intestinal tuberculosis (ITB) remain “difficult-to-differentiate” diseases. We have previously documented peripheral blood frequency of CD4+CD25+FOXP3+ T-regulatory cells (Treg) as a biomarker to differentiate CD and ITB. We tried to validate these results in a larger cohort of CD and ITB patients. @*Methods@#Seventy treatment naïve patients of CD (n = 23) and ITB (n = 47) (diagnosed by standard criteria) were recruited prospectively from October 2016 to May 2017. Patients with history of antitubercular therapy in the past were excluded. The frequency of Treg cells in peripheral blood was determined by flow cytometry, and compared between CD and ITB patients. @*Results@#Similar to our previous study, frequency of Treg cells in peripheral blood was significantly increased in ITB as compared to CD patients (40.9 [interquartile range, 33–50] vs. 24.9 [interquartile range, 14.4–29.6], P 31.3% had a sensitivity and specificity of 83% and 82.6% respectively, to differentiate ITB from CD. Even for the indeterminate cases (n = 33), Treg cell frequency had similar diagnostic accuracy with an AUC of 0.85 (95% confidence interval, 0.68–0.95) and a cutoff of 32.37% had sensitivity and specificity of 87% and 95% respectively, to differentiate ITB from CD. @*Conclusions@#The current findings validate that the increased frequency of CD4+CD25+FOXP3+ Treg in the peripheral blood can be used as a biomarker with high diagnostic accuracy to differentiate ITB from CD.

Efficacy and tolerability of exclusive enteral nutrition in adult patients with complicated Crohn’s disease

Background/Aims@#Exclusive enteral nutrition (EEN), an established modality for pediatric Crohn’s disease (CD) is seldomly utilized in adults. The present study reports the outcome of EEN in adult CD patients at a tertiary care hospital in India. @*Methods@#This was a retrospective analysis of CD patients who received EEN as a sole modality/adjunct to other treatment. The primary and secondary outcomes changed in Crohn’s Disease Activity Index (CDAI), and clinical response (decline in CDAI > 70), respectively, at 4 and 8 weeks. Subgroup analysis evaluated response across different phenotypes, EEN formulations and prior treatment. Linear mixed effect model was created to assess the predictors of EEN response. @*Results@#Thirty-one CD patients received EEN over median duration of 4 weeks (range, 2–6 weeks). CDAI showed a significant improvement post EEN at 4 (baseline 290 [260–320] vs. 240 [180–280], P= 0.001) and 8 weeks (baseline 290 [260–320] vs. 186 [160–240], P= 0.001), respectively. The cumulative clinical response rates at 4 and 8 weeks were 37.3% and 80.4% respectively. The clinical response rates at 8 weeks across B1 (n = 4), B2 (n = 18) and B3 (n = 9) phenotypes were 50%, 78.8% and 100% respectively (log-rank test, P= 0.093). The response rates at 8 weeks with polymeric (n = 8) and semi-elemental diet (n = 23) were 75% and 82.6%% respectively (log-rank test, P= 0.49). Baseline CDAI (odds ratio, 1.008; 95% confidence interval, 1.002–1.017; P= 0.046) predicted response to EEN. @*Conclusions@#EEN was effective in inducing clinical response across different phenotypes of CD. Baseline disease activity remained the most important predictor of clinical response to EEN.

Prospective validation of CD4+CD25+FOXP3+ T-regulatory cells as an immunological marker to differentiate intestinal tuberculosis from Crohn’s disease

Background/Aims@#Crohn’s disease (CD) and intestinal tuberculosis (ITB) remain “difficult-to-differentiate” diseases. We have previously documented peripheral blood frequency of CD4+CD25+FOXP3+ T-regulatory cells (Treg) as a biomarker to differentiate CD and ITB. We tried to validate these results in a larger cohort of CD and ITB patients. @*Methods@#Seventy treatment naïve patients of CD (n = 23) and ITB (n = 47) (diagnosed by standard criteria) were recruited prospectively from October 2016 to May 2017. Patients with history of antitubercular therapy in the past were excluded. The frequency of Treg cells in peripheral blood was determined by flow cytometry, and compared between CD and ITB patients. @*Results@#Similar to our previous study, frequency of Treg cells in peripheral blood was significantly increased in ITB as compared to CD patients (40.9 [interquartile range, 33–50] vs. 24.9 [interquartile range, 14.4–29.6], P 31.3% had a sensitivity and specificity of 83% and 82.6% respectively, to differentiate ITB from CD. Even for the indeterminate cases (n = 33), Treg cell frequency had similar diagnostic accuracy with an AUC of 0.85 (95% confidence interval, 0.68–0.95) and a cutoff of 32.37% had sensitivity and specificity of 87% and 95% respectively, to differentiate ITB from CD. @*Conclusions@#The current findings validate that the increased frequency of CD4+CD25+FOXP3+ Treg in the peripheral blood can be used as a biomarker with high diagnostic accuracy to differentiate ITB from CD.

High risk of tuberculosis during infliximab therapy despite tuberculosis screening in inflammatory bowel disease patients in India

BACKGROUND/AIMS: The data on the risk of tuberculosis (TB) reactivation with infliximab (IFX) in patients with inflammatory bowel disease (IBD) from TB endemic countries, like India, is limited. The risk of TB reactivation on IFX and its predictors in patients with IBD was assessed. METHODS: This retrospective review included consecutive patients with IBD who received IFX, and were on follow-up from January 2005 to November 2017. The data was recorded on age/disease duration, indications for IFX, screening for latent tuberculosis (LTB) before IFX, response to IFX, incidence and duration when TB developed after IFX, and type of TB (pulmonary [PTB]/extra-pulmonary [EPTB]/disseminated). RESULTS: Of 69 patients (22 ulcerative colitis/47 Crohn’s disease; mean age, 35.6±14.5 years; 50.7% males; median follow-up duration after IFX, 19 months [interquartile range, 5.5–48.7 months]), primary non-response at 8 weeks and secondary loss of response at 26 and 52 weeks were seen in 14.5%, 6% and 15% patients respectively. Prior to IFX, all patients were screened for LTB, 8 (11.6%) developed active TB (disseminated, 62.5%; EPTB, 25%; PTB, 12.5%) after a median of 19 weeks (interquartile range, 14.0–84.5 weeks) of IFX. Of these 8 patients’ none had LTB, even when 7 of 8 were additionally screened with contrast-enhanced chest tomography. Though not statistically significant, more patients with Crohn’s disease than ulcerative colitis (14.9% vs. 4.5%, P=0.21), and those with past history of TB (25% vs. 9.8%, P=0.21), developed TB. Age, gender, disease duration, or extraintestinal manifestations could not predict TB reactivation. CONCLUSIONS: There is an extremely high rate of TB with IFX in Indian patients with IBD. Current screening techniques are ineffective and it is difficult to predict TB after IFX.

A simple phenotypic classification for celiac disease

BACKGROUND/AIMS: Celiac disease is a global health problem. The presentation of celiac disease has unfolded over years and it is now known that it can manifest at different ages, has varied presentations, and is prone to develop complications, if not managed properly. Although the Oslo definitions provide consensus on the various terminologies used in literature, there is no phenotypic classification providing a composite diagnosis for the disease. METHODS: Various variables identified for phenotypic classification included age at diagnosis, age at onset of symptoms, clinical presentation, family history and complications. These were applied to the existing registry of 1,664 patients at Dayanand Medical College and Hospital, Ludhiana, India. In addition, age was evaluated as below 15 and below 18 years. Cross tabulations were used for the verification of the classification using the existing data. Expert opinion was sought from both international and national experts of varying fields. RESULTS: After empirical verification, age at diagnosis was considered appropriate in between A1 ( < 18) and A2 (≥18). The disease presentation has been classified into 3 types–P1 (classical), P2 (non-classical) and P3 (asymptomatic). Complications were considered as absent (C0) or present (C1). A single phenotypic classification based on these 3 characteristics, namely age at the diagnosis, clinical presentation, and intestinal complications (APC classification) was derived. CONCLUSIONS: APC classification (age at diagnosis, presentation, complications) is a simple disease explanatory classification for patients with celiac disease aimed at providing a composite diagnosis.

Cryptosporidium species subtypes and associated clinical manifestations in Indian patients

Aim: Present hospital based study was carried out at our tertiary care centre with an aim to study the distribution of Cryptosporidium species subtypes in patients with complaints of diarrhea

Background: Cryptosporidium species are one of the important causative agents of parasitic diarrhea, amongst which Cryptosporidium hominis [C.hominis] and Cryptosporidium parvum [C.parvum] are the two major species that are associated with human cryptosporidiosis

Methods: Four hundred and fifty [n=450] diarrheic patients complaining of different types of diarrhea were enrolled in the present study. Both microscopic and molecular diagnostic methods were used for the detection as well as for identification of Cryptosporidium species and its speciation and subtyping

Results: Forty one [n=41] and forty three [n=43] patients were positive for Cryptosporidium species by microscopy and Polymerase chain reaction [PCR] assay respectively. Of these 43 cases, 70% [30/43] were identified as C. hominis and 21% [9/43] was as C. parvum, 7% [3/43] was as Cryptosporidium felis [C.felis] and 2% [1/43] as Cryptopsoridium viatorum [C. viatorum] respectively . Upon subtyping of C. hominis and C. parvum, 16 subtypes belonging to 8 different subtype families could be identified. The frequency of different families were Ia [13%, 5/39], Ib [15%, 6/39], Id [18%, 7/39], Ie [30%, 12/39] and IIa [5%, 2/39], IIc [8%, 3/39], IId [8%, 3/39] and IIe [3%, 1/39]

Conclusion: Our study results strongly suggest and reinforces the fact that most of the human cryptosporidiosis is anthroponotic and we expect that present molecular epidemiological data will provide more insight to unravel the changing clinical paradigm of human cryptosporidiosis at large

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

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

Familial aggregation of inflammatory bowel disease in patients with ulcerative colitis

BACKGROUND/AIMS: Familial occurrence of inflammatory bowel disease (IBD) is well documented. Reports from Western countries have shown a higher familial occurrence of ulcerative colitis (UC) in first- and second-degree relatives than that in the Asian UC population. No data are currently available from the Indian subcontinent in this regard. We present our data on the familial aggregation of UC. METHODS: Records of patients with UC followed at the Inflammatory Bowel Disease Clinic at the All India Institute of Medical Sciences, New Delhi from August 2004 to January 2016 were reviewed. Details regarding the prevalence of family history and characteristics of these patients were recorded. Affected family members were contacted and disease characteristics were noted for assessment of familial aggregation. RESULTS: Of the 2,058 UC patients included in the analysis, a positive family history of IBD was confirmed in 31 patients (1.5%), 24 (77.4%) of whom had only first-degree relatives affected. All the affected relatives had UC and none had Crohn's disease. Among first-degree relatives, siblings were found to have the highest prevalence of IBD (53.3%), followed by parents (26.7%). CONCLUSIONS: The probability of occurrence of IBD in family members of affected North Indian UC patients is lower than that reported in Western populations.

Evaluation of Xpert MTB/RIF assay performance in the diagnosis of abdominal tuberculosis

BACKGROUND/AIMS: The use of genetic probes for the diagnosis of pulmonary tuberculosis (TB) has been well described. However, the role of these assays in the diagnosis of intestinal tuberculosis is unclear. We therefore assessed the diagnostic utility of the Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) assay, and estimated the prevalence of multidrug-resistant (MDR) TB in the Indian population. METHODS: Of 99 patients recruited, 37 had intestinal TB; two control groups comprised 43 with Crohn's disease (CD) and 19 with irritable bowel syndrome. Colonoscopy was performed before starting any therapy; mucosal biopsies were subjected to histopathology, acid-fast bacilli staining, Lowenstein-Jensen culture, and nucleic acid amplification testing using the Xpert MTB/RIF assay. Patients were followed up for 6 months to confirm the diagnosis and response to therapy. A composite reference standard was used for diagnosis of TB and assessment of the diagnostic utility of the Xpert MTB/RIF assay. RESULTS: Of 37 intestinal TB patients, the Xpert MTB/RIF assay was positive in three of 37 (8.1%), but none had MDR-TB. The sensitivity, specificity, positive predictive value, and negative predictive value of the Xpert MTB/RIF assay was 8.1%, 100%, 100%, and, 64.2%, respectively. CONCLUSIONS: The Xpert MTB/RIF assay has low sensitivity but high specificity for intestinal TB, and may be helpful in endemic tuberculosis areas, when clinicians are faced with difficulty differentiating TB and CD. Based on the Xpert MTB/RIF assay, the prevalence of intestinal MDR-TB is low in the Indian population.

Role of random biopsies in surveillance of dysplasia in ulcerative colitis patients with high risk of colorectal cancer

BACKGROUND/AIMS: Recent data suggest that the incidence of ulcerative colitis (UC) related colorectal cancer (CRC) in India is similar to that of West. The optimum method for surveillance is still a debate. Surveillance with random biopsies has been the standard of care, but is a tedious process. We therefore undertook this study to assess the yield of random biopsy in dysplasia surveillance. METHODS: Between March 2014 and July 2015, patients of UC attending the Inflammatory Bowel Disease clinic at the All India Institute of Medical Sciences with high risk factors for CRC like duration of disease >15 years and pancolitis, family history of CRC, primary sclerosing cholangitis underwent surveillance colonoscopy for dysplasia. Four quadrant random biopsies at 10 cm intervals were taken (33 biopsies). Two pathologists examined specimens for dysplasia, and the yield of dysplasia was calculated. RESULTS: Twenty-eight patients were included. Twenty-six of these had pancolitis with a duration of disease greater than 15 years, and two patients had associated primary sclerosing cholangis. No patient had a family history of CRC. The mean age at onset of disease was 28.89±8.73 years and the duration of disease was 19.00±8.78 years. Eighteen patients (64.28%) were males. A total of 924 biopsies were taken. None of the biopsies revealed any evidence of dysplasia, and 7/924 (0.7%) were indefinite for dysplasia. CONCLUSIONS: Random biopsy for surveillance in longstanding extensive colitis has a low yield for dysplasia and does not suffice for screening. Newer techniques such as chromoendoscopy-guided biopsies need greater adoption.