A qualitative study of social accountability translation: from mission to living it.

BACKGROUND: Medical schools are increasingly adopting socially accountable mission and curricula, the realisation of which are dependent on engaging individuals to embody the mission's principles in their everyday activities as doctors. However, little is known about how graduates perceive the efforts taken by their medical school to sensitise them to social accountability values, and how they translate this into their working lives. Our aim was to explore and understand graduate perceptions of how their medical school influenced them to embody a social accountability mission in their working lives. METHODS: This was a qualitative interview study carried out with graduates/alumni [n = 51] of Christian Medical College, Vellore [CMCV], India, a school with a long-established and explicit social-accountability mission. Data coding and analysis were initially inductive and thematic using Braun and Clarke's six step framework. MacIntyre's virtue ethics theory framed secondary analysis, allowing us to consider the relationships between individual and contextual factors. RESULTS: Our participants perceived that CMCV invested heavily in selecting personal qualities aligned with the CMCV mission. They saw that these qualities were reinforced through various practices: [e.g., placements in resource limited and/or remote and rural settings]; community engagement and expectations [e.g., student self-governance]; role modelling [staff and more senior students]. Much emphasis was placed on sustaining these traditions and practices over time, creating a strong sense of identity and belonging among participants, traditions which were fostered further by the alumni network and continued engagement with CMCV post-graduation. CONCLUSIONS: Ensuring social accountable medical education depends on alignment and interactions over time between context and structures, systems and human agents. Further studies are needed to extend understanding of how students from diverse contexts experience socially accountable medical education and translate their educational experience into their thinking and practice after graduation.

An Unusual Presentation of Hemorrhagic Disease in an Infant: A Probable Case of Abetalipoproteinemia.

We report a probable case of abetalipoproteinemia in an infant who presented with unusual symptoms of late-onset vitamin K deficiency. Abetalipoproteinemia is a rare autosomal recessive disease caused by mutation of the microsomal triglyceride transfer protein gene, resulting in the absence of microsomal triglyceride transfer protein function in the small bowel. It is characterized by the absence of plasma apolipoprotein B-containing lipoproteins, fat malabsorption, hypocholesterolemia, retinitis pigmentosa, progressive neuropathy, myopathy, and acanthocytosis. A biopsy of the small intestine characteristically shows marked lipid accumulation in the villi of enterocytes. Large supplements of fat-soluble vitamins A, D, E, and K have been shown to limit neurologic and ocular manifestations. Dietary fat intake is limited to medium-chain triglycerides.

Spectrum of biopsy proven renal disease in South Asian children: Two decades at a tropical tertiary care centre.

AIM: We report findings from a large single centre paediatric renal biopsy cohort in South Asia. METHODS: We analyzed all renal biopsies performed on children aged ≤18 years between 1996 and 2015 at our centre. The clinical characteristics and histological diagnosis pertaining to each case, distribution of renal diseases in children with various clinical presentations, and changes in the pattern of kidney disease during the study period were analyzed. RESULTS: A total of 1740 paediatric kidney biopsies were performed during the study period. The mean age was 12.8 ± 4.9 years (8 months to 18 years) and the male: female ratio was 1.5:1. The most common indication for renal biopsy was nephrotic syndrome (63.2%) followed by acute nephritic syndrome (13%). Minimal change disease was the most common cause of nephrotic syndrome while endocapillary proliferative glomerulonephritis (65.7% infection related), remained the commonest cause of acute nephritic syndrome. IgA nephropathy was the commonest cause of chronic kidney disease. Contrary to trends in European paediatric cohorts, the frequency of lupus nephritis increased over the two decades of the study, while that of endocapillary proliferative glomerulonephritis did not show any appreciable decline. CONCLUSION: This study provides the largest data on biopsy proven renal disease in children from South Asia published till date and highlights important differences in the spectrum and trends of kidney disease compared to data from other regions.

Self-directed learning readiness of Indian medical students: a mixed method study.

BACKGROUND: Self-directed learning (SDL) is defined as learning on one's own initiative, with the learner having primary responsibility for planning, implementing, and evaluating the effort. Medical education institutions promote SDL, since physicians need to be self-directed learners to maintain lifelong learning in the ever-changing world of medicine and to obtain essential knowledge for professional growth. The purpose of the study was to measure the self-directed learning readiness of medical students across the training years, to determine the perceptions of students and faculty on factors that promote and deter SDL and to identify the role of culture and curriculum on SDL at the Christian Medical College, Vellore, India. METHODS: Guglielmino's SDL Readiness Scale (SDLRS) was administered in 2015 to six student cohorts (452 students) at admission, end of 1st, 2nd, 3rd and 4th year of training, and at the beginning of internship in the undergraduate medicine (MBBS) program. Analysis of variance (ANOVA) was used to compare SDL scores between years of training. 5 student focus groups and 7 interviews with instructors captured perceptions of self-direction. Transcripts were coded and analyzed thematically. RESULTS: The overall mean SDLRS score was 212.91. There was no significant effect of gender and age on SDLR scores. There was a significant drop in SDLRS scores on comparing students at admission with students at subsequent years of training. Qualitative analysis showed the prominent role of culture and curriculum on SDL readiness. CONCLUSIONS: Given the importance of SDL in medicine, the current curriculum may require an increase in learning activities that promote SDL. Strategies to change the learning environment that facilitates SDL have to be considered.

Prevalence of Adult Celiac Disease in India: Regional Variations and Associations.

OBJECTIVES: Although celiac disease (CeD) affects 1% of people in the northern part of India, it is believed to be uncommon in the southern and northeastern parts because of significant differences in dietary pattern and ethnicity. We estimated the prevalence of CeD in these three populations. In a subset, we also investigated differences in the prevalence of HLA-DQ 2/8 allelotype and dietary grain consumption. METHODS: A total of 23,331 healthy adults were sampled from three regions of India-northern (n=6207), northeastern (n=8149), and southern (n=8973)-and screened for CeD using IgA anti-tissue transglutaminase antibody. Positive tests were reconfirmed using a second ELISA. CeD was diagnosed if the second test was positive and these participants were further investigated. A subsample of participants was tested for HLA-DQ2/-DQ8 and underwent detailed dietary evaluation. RESULTS: Age-adjusted prevalence of celiac autoantibodies was 1.23% in northern, 0.87% in northeastern, and 0.10% in southern India (P<0.0001). Prevalence of CeD and latent CeD, respectively, was 8.53/1,000 and 3.70/1,000 in northern, 4.66/1,000 and 3.92/1,000 in northeastern, and 0.11/1,000 and 1.22/1,000 in the southern part. The population prevalence of genes determining HLA-DQ2 and/or -DQ8 expression was 38.1% in northern, 31.4% in northeastern, and 36.4% in southern India. Mean daily wheat intake was highest in northern (455 g) compared with northeastern (37 g) or southern part (25 g), whereas daily rice intake showed an inverse pattern. CONCLUSIONS: CeD and latent CeD were most prevalent in northern India and were the least in southern India. The prevalence correlated with wheat intake and did not reflect differences in the genetic background.

Duodenal villous morphology assessed using magnification narrow band imaging correlates well with histology in patients with suspected malabsorption syndrome.

BACKGROUND AND AIM: Narrow band imaging with magnification enables detailed assessment of duodenal villi and may be useful in predicting the presence of villous atrophy or normal villi. We aimed to assess the morphology of duodenal villi using magnification narrow band imaging and correlate it with histology findings in patients with clinically suspected malabsorption syndrome. METHODS: Patients with clinical suspicion of malabsorption presenting at a tertiary care center were prospectively recruited in this diagnostic intervention study. Patients underwent upper gastrointestinal endoscopy using magnification narrow band imaging. The villous morphology in the second part of the duodenum was assessed independently by two endoscopists and the presence of normal or atrophic villi was recorded. Biopsy specimen was obtained from the same area and was examined by two pathologists together. The sensitivity and specificity of magnification narrow band imaging in detecting the presence of duodenal villous atrophy was calculated and compared to the histology. RESULTS: One hundred patients with clinically suspected malabsorption were included in this study. Sixteen patients had histologically confirmed villous atrophy. The sensitivity and specificity of narrow band imaging in predicting villous atrophy was 87.5% and 95.2%, respectively, for one endoscopist. The corresponding figures for the second endoscopist were 81.3% and 92.9%, respectively. The interobserver agreement was very good with a kappa value of 0.87. CONCLUSION: Magnification narrow band imaging performed very well in predicting duodenal villous morphology. This may help in carrying out targeted biopsies and avoiding unnecessary biopsies in patients with suspected malabsorption.

Gastroesophageal reflux following per-oral endoscopic myotomy: Can we improve outcomes?

This editorial is an analysis the review article by Nabi et al recently published in this journal. Achalasia Cardia is a disease whose pathophysiology is still unclear. It is known that there is inflammation of unknown aetiology leading to loss of ganglion cells in the muscularis propria. The end result is lower oesophageal sphincter spasm, loss of receptive relaxation, decreased oesophageal peristalsis, all leading on to varying degrees of dysphagia. The treatment of this condition is palliative in nature, performed by myotomy of the lower oesophagus either surgically or endoscopically. Gastroesophageal reflux disease (GERD) has been associated with the myotomy performed, particularly with the Peroral Endoscopic Myotomy (POEM) procedure. Nabi et al have provided an excellent overview of the latest developments in predicting, preventing, evaluating, and managing GERD subsequent to POEM. Based on this theme, this review article explores the concept of using histology of the oesophageal muscle layer, to grade the disease and thereby help tailoring the length/type of myotomy performed during the POEM procedure. In the future, will a histology based algorithm available preoperatively, help modify the POEM procedure, thereby decreasing the incidence of GERD associated with POEM?

Hydroxychloroquine-Induced Phospholipidosis - A Forgotten Complication of a Common Drug.

Hydroxychloroquine (HCQ) has immunomodulatory and immunosuppressive properties and is used in many rheumatological conditions like systemic lupus erythematosus, rheumatoid arthritis, and Sjogren's syndrome. It is usually a widely used and well-tolerated DMARD (Disease Modifying Anti Rheumatic Drugs). Its most feared toxicities include retinopathy and, rarely, cardiomyopathy. Among its other reported side effects is drug-induced phospholipidosis. Here, we report two cases of HCQ-induced phospholipidosis based on renal biopsy electron microscopy. HCQ-induced phospholipidosis, although uncommon, must be considered as one of the differentials in a patient with persistent proteinuria.

Granulomatous inflammation is less common in delayed-onset Crohn's disease.

Crohn's disease (CD) usually affects younger individuals but delayed-onset disease is not uncommon. We studied the epidemiology, demographic profile, and clinical characteristics of patients with delayed-onset CD (disease onset >50 years) and compared them with CD in younger individuals (disease onset 20-40 years) in a tertiary care center in India. The presenting symptoms, site of involvement, and treatment profile were similar, except for weight loss, which was more often noted in young-onset CD. However, granulomatous inflammation on mucosal biopsy was twice as common in young-onset compared to delayed-onset CD. As it is thus seen less often in delayed-onset CD, this may lead to a potential delay in diagnosis and treatment.

Primary adenocarcinoma of colon: A clinicopathological study with the prevalence and correlation of CDX2 biomarker expression - A tertiary care center experience.

BACKGROUND: Colorectal cancer is one of the alarming health problems worldwide. Prognostic biomarkers are the key for risk stratification in patients with colon cancer and the decision to recommend adjuvant chemotherapy. It has been difficult to identify a single prognostic biomarker for colon cancer. Currently, tumor stage, tumor grade, and microsatellite instability remain the most important prognostic variables that aid in the treatment of patients with colon cancer. Some studies highlighted that CDX2 immunohistochemistry negativity is an independent prognostic factor and indicates a worse survival rate. Our aim was to study the prevalence of CDX2 biomarker expression in patients diagnosed with primary adenocarcinoma and to correlate this with the clinical profile and pathological features. METHODS: Endoscopic mucosal biopsies and resection specimens of 148 patients diagnosed with colonic adenocarcinoma were analyzed. CDX2 immunohistochemistry was performed, and the result was correlated with clinicopathological features. The results were presented as mean, frequencies, and percentages. Pearson's Chi-square test was used to assess the associations between clinicopathological parameters and CDX2 immunohistochemistry negativity. RESULTS: The prevalence of CDX2 expression by immunohistochemistry in colon cancer was found to be 92%. CDX2 biomarker negativity was found to be higher in left-sided colon cancers, poorly differentiated adenocarcinoma, mucinous carcinoma, and higher TNM stages. CONCLUSION: CDX2-negative tumors are often associated with several adverse prognostic variables (e.g., advanced stage, poor differentiation, and metastasis). Thus, sub-classification of colon cancer based on the CDX2 biomarker aids to separate them into prognostically relevant categories.

Lack of Association of Helicobacter pylori in Laryngeal Pathologies.

To study the association of Helicobacter pylori (H. pylori) in patients with laryngeal pathologies. Study design: prospective observational study. Tertiary care teaching hospital. One hundred consecutive patients with laryngeal lesions scheduled for microlaryngoscopy were enrolled in the study. Laryngopharyngeal reflux was assessed using the reflux symptom index and reflux finding score. Tissue samples from the laryngeal lesions were taken under general anaesthesia and were screened for the presence of H. pylori using real time polymerase chain reaction (PCR) for ureA genes and histopathological examination. Of the 100 patients, 14 had a significant reflux symptom index score and 35 had significant reflux finding score. The lesions in the study subjects included both benign and malignant laryngeal pathologies. Vocal cord polyps formed more than half of the laryngeal pathology (57%) studied. Our study could not detect H. pylori in any laryngeal lesions by PCR analysis and histopathological examination. H. pylori may not be associated with laryngeal pathologies.

Comparison of Magnetic Resonance Enterography Global Score (MEGS) with indices of Crohn's disease activity in South Asian population.

PURPOSE: Assessment of disease activity in Crohn's helps predict important clinical outcomes. Among the various modalities available to assess disease activity, magnetic resonance enterography (MRE) is considered a safe and reliable imaging option. Various MRE-based scoring systems have been developed to measure disease activity, one of which being the MRE global score (MEGS). We aimed to correlate MEGS with some of the important indices of Crohn's disease activity. METHODOLOGY: Crohn's disease patients referred for MRE were included in the study. Along with demographic profile and relevant investigations, MRE parameters related to MEGS were also assessed. RESULT: A total of 47 patients were recruited for the study. Their median age was 34 years (range 18-68 years), and male:female ratio was 16:31. There was modest positive correlation between MEGS and faecal calprotectin (r = 0.3, p = 0.04), CRP level (r = 0.34, p = 0.02) and Harvey Bradshaw index (r = 0.3, p = 0.043), respectively. However, there was strong correlation between segmental MEGS and Simple Endoscopic Score in those with terminal ileal disease (r = 0.81, p < 0.001). Mural thickness was the only MRE parameter that correlated with active disease (OR - 1.35, 95% CI 1.01, 1.81, p = 0.041) on multivariate analysis. There was moderate inter-observer agreement (Lin's r = 0.78, p < 0.001). CONCLUSION: MEGS showed modest correlation with indices of Crohn's disease activity which corroborates the complementary role of MRE in management of such patients.

Comparison of primary follicular lymphoma of gastrointestinal tract and secondary involvement: A study from South India.

Primary follicular lymphoma of the gut (PFL-GI) is a rare entity. This study aims to compare the clinicopathologic features of PFL-GI with cases of gastrointestinal involvement by disseminated nodal follicular lymphoma. This is a retrospective study with 6 cases of primary follicular lymphoma and 8 cases of secondary involvement of the gut, over a period of 9 years. The slides and blocks were retrieved and reviewed. Clinical data was obtained from hospital records. Clinicopathologic features were compared. PFL-GI cases had a slightly higher median age group (p value 0.23) and no gender predilection when compared to cases with secondary involvement which showed a female preponderance. Para-aortic lymphadenopathy was seen in all secondary cases whereas none of the primary cases showed significant lymphadenopathy. The only microscopic feature that was different was the presence of hollowed out pattern of immunostaining for follicular dendritic cells seen in all cases of PFL-GI but in none of the secondary cases.

Common polymorphisms of protein tyrosine phosphate non-receptor type 2 gene are not associated with risk of Crohn's disease in Indian.

BACKGROUND: Multiple genetic risk factors for Crohn's disease (CD) have been identified. However, these observations are not consistent across different populations. The protein tyrosine phosphate non-receptor type 2 (PTPN2) gene plays a role in various aspects of host defense including epithelial barrier function, autophagy, and innate and adaptive immune response. Two common polymorphisms in the PTPN2 gene (rs2542151 and rs7234029) have been associated with risk of CD in Western countries. AIM: To evaluate the association of PTPN2 gene polymorphisms with risk of CD in Indian population. METHODS: We conducted a prospective case-control study. Patients with CD were recruited, and their clinical and investigation details were noted. Controls were patients without organic gastrointestinal disease or other comorbid illnesses. Two common polymorphisms in the PTPN2 gene (rs2542151 and rs7234029) were assessed. DNA was extracted from peripheral blood samples of cases and controls and target DNA was amplified using specific sets of primers. The amplified fragments were digested with restriction enzymes and the presence of polymorphism was detected by restriction fragment length polymorphism. The frequency of alleles was determined. The frequencies of genotypes and alleles were compared between cases and controls to look for significant differences. RESULTS: A total of 108 patients with CD (mean age 37.5 ± 12.7 years, females 42.6%) and 100 controls (mean age 39.9 ± 13.5 years, females 37%) were recruited. For the single nucleotide polymorphism (SNP) rs7234029, the overall frequency of G variant genotype (AG or GG) was noted to be significantly lower in the cases compared to controls (35.2% vs 50%, P = 0.05). For the SNP rs2542151, the overall frequency of G variant genotype (GT or GG) was noted to be similar in cases compared to controls (43.6% vs 47%, P = 0.73). There were no significant differences in minor allele (G) frequency for both polymorphisms between the cases and controls. Both the SNPs had no significant association with age of onset of illness, gender, disease location, disease behaviour, perianal disease, or extraintestinal manifestations of CD. CONCLUSION: Unlike observation form the West, polymorphisms in the PTPN2 gene (rs7234029 and rs2542151) are not associated with an increased risk of developing CD in Indian patients.

Image-enhanced endoscopy for real-time differentiation between hyperplastic and fundic gland polyps in the stomach.

BACKGROUND: Fundic gland polyps (FGP) of stomach are benign, while some hyperplastic polyps (HP) may harbor dysplasia or malignancy. Conventional white light endoscopy (WLE) cannot reliably distinguish FGP from HP. We investigated the role of image-enhanced endoscopy in differentiating FGP from HP. METHODS: Patients with gastric polyps were recruited prospectively. The characteristics of the polyps were assessed using WLE and magnification narrow band imaging (mNBI). The microsurface, intervening space (IS), and microvascular (V) features of polyps were evaluated on mNBI. The pattern characteristic of FGP and HP were determined. Histopathology of polyps was the gold standard for diagnosis. Finally, in the validation phase, five endoscopists applied the characteristic features identified in this study to predict the type of gastric polyp and their performance was assessed. RESULTS: Forty-five patients with a total of 70 gastric polyps (HP-46, FGP-24) were included in this study. On mNBI, the pattern characteristic of HP included peripheral curved type of white structures forming large circular/villous loops (microsurface), enlarged intervening space, and microvessels appearing as dark patches in the intervening space (p<0.001 vs. FGP). These were noted in 95.7% HP. In contrast, 95.8% FGP had a pattern characterized by dotted/elliptical/tubular white structures (microsurface), normal width of intervening space, and microvessels surrounding the white structures in a network pattern. This IS-V pattern classification had an accuracy of >90% in the validation phase with intra-class correlation coefficient of 0.95. The accuracy of mNBI was higher than WLE (97.1% vs. 67%) in predicting the type of gastric polyp. CONCLUSIONS: Image-enhanced endoscopy with mNBI (IS-V pattern) performs very well in differentiating HP from FGP.

Best practices of handling, processing, and interpretation of small intestinal biopsies for the diagnosis and management of celiac disease: A joint consensus of Indian association of pathologists and microbiologists and Indian society of gastroenterology.

The Indian Association of Pathologists and Microbiologists (IAPM) and Indian Society of Gastroenterology (ISG) decided to make a joint consensus recommendation for handling, processing, and interpretation of SI biopsies for the diagnosis and management of celiac disease (CD) recognizing the inhomogeneous practice of biopsy sampling, orientation, processing, and interpretation. A modified Delphi process was used to develop this consensus document containing a total of 42 statements and recommendations, which were generated by sharing the document draft, incorporating expert's opinion, followed by three cycles of electronic voting as well as a full-day face-to-face virtual ZOOM meeting and review of supporting literature. Of the 42 statements, 7 statements are on small intestinal (SI) biopsy in suspected patients of CD, site and the number of biopsies; 7 on handling, fixative, orientation, processing, and sectioning in pathology laboratories; 2 on histological orientation; 13 statements on histological interpretation and histological grading; 3 on the assessment of follow-up biopsies; 2 statements on gluten-free diet (GFD)-nonresponsive CD; 4 on challenges in the diagnosis of CD; 2 statements each on pathology reporting protocol and training and infrastructure in this area. The goal of this guideline document is to formulate a uniform protocol agreed upon both by the experienced pathologists and gastroenterologists to standardize the practice, improve the yield of small bowel biopsy interpretation, patients' compliance, overall management in CD, and generate unified data for patient care and research in the related field.

Retinoid metabolism in the small intestine during development of liver cirrhosis.

BACKGROUND AND AIMS: Retinoids are important mediators of cellular differentiation and proliferation in various epithelia of the body including the small intestine. Though alterations in intestinal epithelial cell proliferation have been noted in liver cirrhosis, mechanisms involved in the process are not well understood. This study examined the levels of various retinoids and retinoid-metabolizing enzymes in the small intestine during development of liver cirrhosis. METHODS: Four groups of animals were used (control, phenobarbitone control, thioacetamide and carbon tetrachloride treatment). Twice-weekly intragastric or i.p. administration of carbon tetrachloride or thioacetamide, respectively, produced liver cirrhosis after 3 months, which was confirmed through histology and serum markers. Retinoid levels were measured by high-performance liquid chromatography. RESULTS: A decrease in the levels of retinal, retinoic acid and retinol was evident in the intestine by 3 months, when cirrhosis was evident histologically, and these remained low until 6 months. A decrease in the activities of retinaldehyde oxidase, retinaldehyde reductase and retinol dehydrogenase was also seen in intestine from cirrhotic rats. CONCLUSION: These results suggest that altered retinoid metabolism in the intestine of cirrhotic rats might have an influence on changes in intestinal epithelial cell differentiation, seen in liver cirrhosis.

Concerns with regard to an article.

We have read with interest and concern the article titled "Consultations on human infection studies in India: Do people's voices really count" by Sandhya Srinivasan and Veena Johari. The article expresses the opinions of 2 persons who have not visited CMC, nor have spoken to anyone concerned, to ascertain the authenticity of the information published or with regard to the purported research in CMC.

Microsatellite instability in young patients with mucinous colorectal cancers - characterization using molecular testing, immunohistochemistry, and histological features.

CONTEXT: The incidence of colorectal cancers (CRCs) in young Indian patients is higher than the international average. CRCs in young patients are commonly of mucinous type and show microsatellite instability (MSI). AIMS: To ascertain the MSI status of mucinous CRCs in patients ≤40 years of age by molecular testing and to correlate this with immunohistochemical (IHC) analysis and tumor histology. SUBJECTS AND METHODS: Archived formalin-fixed paraffin embedded tissue blocks of 30 young mucinous CRC patients were retrieved. MSI testing was done using two mononucleotide markers - BAT26 and NR24. IHC analysis was done using MLH1, MSH2, and MSH6. Histological features of all cases were studied. Data were analyzed using the SPSS software and the Pearson's chi-square test and Fisher's exact test. RESULTS: Eight out of 30 cases (26.7%) showed MSI by molecular testing. IHC identified seven of these cases. Histological features showing a statistically significant association with MSI were the presence of a well-differentiated adenocarcinoma component (P = 0.003), peritumoral lymphocytes (P = 0.002) and tumor budding (P = 0.021). CONCLUSION: The detection of defective mismatch repair (MMR) proteins using IHC for MLH1, MSH2, and MSH6 and molecular testing using BAT26 and NR24 appears to be a good protocol to detect CRCs with MSI. Histology could be useful in identifying cases that require screening for presence of MMR protein defects.

In situ PCR for Mycobacterium tuberculosis in endoscopic mucosal biopsy specimens of intestinal tuberculosis and Crohn disease.

Tuberculosis and Crohn disease are granulomatous disorders affecting the intestinal tract with similar clinical manifestations and pathologic features. We evaluated the use of in situ polymerase chain reaction (PCR) using Mycobacterium tuberculosis complex-specific primers for IS 6110 to differentiate these 2 disorders in archival mucosal biopsy specimens. In situ PCR was positive in 6 of 20 tuberculosis biopsy specimens and 1 of 20 Crohn disease biopsy specimens. Staining was localized to a site of granulomatous inflammation in 3 of the tuberculosis specimens and in the Crohn disease specimen. In the other tuberculosis biopsy specimens, positive staining was localized to inflammatory granulation tissue and to a focus of intact mucosa without granulomatous inflammation. The presence of M tuberculosis DNA in Crohn disease could be due to coexisting latent tuberculosis or indicate a role for these bacteria in triggering an abnormal immune response. Therefore, in situ PCR is potentially useful to differentiate intestinal tuberculosis from Crohn disease, if the sensitivity is improved.