The role of in vitro interferonγ-release assay in differentiating intestinal tuberculosis from Crohn's disease in China

Abstract Background The first visible signs of Crohn’s disease (CD) are microscopic erosions over the follicle-associated epithelium (FAE). The aim of the study was to investigate the effects of human α-defensin 5 (HD5) on adherent-invasive Escherichia coli LF82 translocation and HD5 secretion after LF82 exposure in an in vitro model of human FAE and in human FAE ex vivo. Methods An in vitro FAE-model was set up by the coculture of Raji B cells and Caco-2-cl1 cells. Ileal FAE from patients with CD and controls were mounted in Ussing chambers. The effect of HD5 on LF82 translocation was studied by LF82 exposure to the cells or tissues with or without incubation with HD5. The HD5 secretion was measured in human FAE exposed to LF82 or Salmonella typhimurium. The HD5 levels were evaluated by immunofluorescence, immunoblotting, and ELISA. Results There was an increased LF82 translocation across the FAE-model compared with Caco-2-cl1 (P < 0.05). Incubation of cell/tissues with HD5 before LF82 exposure reduced bacterial passage in both models. Human FAE showed increased LF82 translocation in CD compared with controls and attenuated passage after incubation with sublethal HD5 in both CD and controls (P < 0.05). LF82 exposure resulted in a lower HD5 secretion in CD FAE compared with controls (P < 0.05), whereas Salmonella exposure caused equal secretion on CD and controls. There were significantly lower HD5 levels in CD tissues compared with controls. Conclusions Sublethal HD5 reduces the ability of LF82 to translocate through FAE. The HD5 is secreted less in CD in response to LF82, despite a normal response to Salmonella. This further implicates the integrated role of antimicrobial factors and barrier function in CD pathogenesis.

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Extracellular vesicles package dsDNA to aggravate Crohn’s disease by activating the STING pathway

Cell Death and Disease ◽

10.1038/s41419-021-04101-z ◽

2021 ◽

Vol 12 (9) ◽

Author(s):

Fan Zhao ◽

Tao Zheng ◽

Wenbin Gong ◽

Jie Wu ◽

Haohao Xie ◽

...

Keyword(s):

Crohn’S Disease ◽

Crohn's Disease ◽

Extracellular Vesicles ◽

Intestinal Inflammation ◽

Therapeutic Effects ◽

Murine Colitis ◽

Sting Pathway ◽

Deficient Mice

AbstractCrohn’s disease (CD) is an intestinal immune-dysfunctional disease. Extracellular vesicles (EVs) are membrane-enclosed particles full of functional molecules, e.g., nuclear acids. Recently, EVs have been shown to participate in the development of CD by realizing intercellular communication among intestinal cells. However, the role of EVs carrying double-strand DNA (dsDNA) shed from sites of intestinal inflammation in CD has not been investigated. Here we isolated EVs from the plasma or colon lavage of murine colitis and CD patients. The level of exosomal dsDNA, including mtDNA and nDNA, significantly increased in murine colitis and active human CD, and was positively correlated with the disease activity. Moreover, the activation of the STING pathway was verified in CD. EVs from the plasma of active human CD triggered STING activation in macrophages in vitro. EVs from LPS-damaged colon epithelial cells were also shown to raise inflammation in macrophages via activating the STING pathway, but the effect disappeared after the removal of exosomal dsDNA. These findings were further confirmed in STING-deficient mice and macrophages. STING deficiency significantly ameliorated colitis. Besides, potential therapeutic effects of GW4869, an inhibitor of EVs release were assessed. The application of GW4869 successfully ameliorated murine colitis by inhibiting STING activation. In conclusion, exosomal dsDNA was found to promote intestinal inflammation via activating the STING pathway in macrophages and act as a potential mechanistic biomarker and therapeutic target of CD.

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Role of Colonoscopy in Differentiating Intestinal Tuberculosis from Crohn’s Disease

Journal of Digestive Endoscopy ◽

10.4103/jde.jde_13_17 ◽

2017 ◽

Vol 08 (02) ◽

pp. 072-077 ◽

Cited By ~ 1

Author(s):

P. Rajesh Prabhu ◽

Mayank Jain ◽

Piyush Bawane ◽

Joy Varghese ◽

Jayanthi Venkataraman

Keyword(s):

Crohn’S Disease ◽

Crohn's Disease ◽

Statistical Tests ◽

Intestinal Tuberculosis ◽

Aphthous Ulcer ◽

Tb Treatment ◽

Respective Treatment ◽

Skip Lesions ◽

Histological Confirmation

ABSTRACT Background: The interface between tuberculosis (TB) and Crohn’s disease (CD) is relevant as TB complicates both the diagnosis and management of CD. Aim: This study aimed to identify the distinctive characteristics of ileocaecal and colonic TB (C‑TB) and colonic CD (C‑CD) at colonoscopy and to correlate the colonoscopy findings with histology. Materials and Methods: This prospective study included consecutive patients presenting with classical symptoms of TB or CD. The colonoscopic findings were compared with histology, which was taken as gold standard. Appropriate statistical tests were applied. Results: Fifty‑eight individuals fulfilled the inclusion criteria. Nine and 16 patients with C‑TB and C‑CD, respectively, had histological confirmation of respective diagnosis. In 33 specimens, the histological diagnosis was inconclusive. The sensitivity of colonoscopy for diagnosing C‑TB was high at 88.9% (95% confidence interval [CI]: 51.8–99.7). It was 50% (95% CI: 24.7–75.4) for CD. The reverse was true for CD whose specificity was high at 71.4% (95% CI: 55.3–84.3) and low for TB at 46.9% (95% CI: 32.5–61.7). All the patients diagnosed as confirmed CD or TB responded well to respective treatment. Six of the thirty patients with failed response to anti‑TB treatment required surgery or change in treatment after 2 months. Conclusion: Colonoscopic findings of isolated ileal involvement, aphthous ulcer, cobble stoning, long‑segment strictures, skip lesions and perianal involvement favored a diagnosis of CD. Correlation of colonoscopy with histology is poor for both CD and TB. The accuracy, sensitivity and specificity of colonoscopy were better and superior for the diagnosis of CD, than in the diagnosis of TB.

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