Stromal Cells in the Pathogenesis of Inflammatory Bowel Disease

Up till now, research on inflammatory bowel disease [IBD] has mainly been focused on the immune cells present in the gastrointestinal tract. However, recent insights indicate that stromal cells also play an important and significant role in IBD pathogenesis. Stromal cells in the intestines regulate both intestinal epithelial and immune cell homeostasis. Different subsets of stromal cells have been found to play a role in other inflammatory diseases [e.g. rheumatoid arthritis], and these various stromal subsets now appear to carry out also specific functions in the inflamed gut in IBD. Novel potential therapies for IBD utilize, as well as target, these pathogenic stromal cells. Injection of mesenchymal stromal cells [MSCs] into fistula tracts of Crohn's disease patients is already approved and used in clinical settings. In this review we discuss the current knowledge of the role of stromal cells in IBD pathogenesis. We further outline recent attempts to modify the stromal compartment in IBD with agents that target or replace the pathogenic stroma.

Foreign rectal body - Systematic review and meta-analysis

BACKGROUND

Self-inserted foreign rectal bodies are an infrequent occurrence, however they present a serious dilemma to the surgeon, due to the variety of objects, and the difficulty of extraction. The purpose of this study is to give a comprehensive review of the literature regarding the epidemiology, diagnostic tools and therapeutic approaches of foreign rectal body insertion.

METHODS

A comprehensive systematic literature review on Pubmed/ Medline and Google for 'foreign bodies' was performed on January 14th 2018. A meta-analysis was carried out to evaluate the epidemiology, diagnostics and therapeutic techniques. 1,551 abstracts were identified, of which 54 articles were included.

RESULTS

The motivation of foreign rectal body insertion is mostly sexual stimulation. Patients are typically young and predominantly male, with a male to female ratio of 6:1. Sexual devices (35.7%, n=108) and glass objects (17.5%, n=53) are the most commonly self-inserted rectal foreign bodies. Patient history should be taken sensitively after diagnostic evaluation and identification of the object. Removal was performed under general anesthesia in 45.2% (n=95) and sedation in 29.0% (n=61). The total complication rate was described to be 30.4%.

CONCLUSIONS

Diagnostics must be performed with caution in order to rule out perforation and establish a treatment algorithm. Manual transanal extraction under sedation or general anesthesia may be performed in conjunction with cautious abdominal compression. Because of the variety of objects, i.e. in form and material, each case must be treated individually. Sometimes creativity and surgeon imagination may be required, although different algorithms have been established.

The Oxysterol Synthesising Enzyme CH25H Contributes to the Development of Intestinal Fibrosis

Intestinal fibrosis and stenosis are common complications of Crohn's disease [CD], frequently requiring surgery. Anti-inflammatory strategies can only partially prevent fibrosis; hence, anti-fibrotic therapies remain an unmet clinical need. Oxysterols are oxidised cholesterol derivatives with important roles in various biological processes. The enzyme cholesterol 25-hydroxylase [CH25H] converts cholesterol to 25-hydroxycholesterol [25-HC], which modulates immune responses and oxidative stress. In human intestinal samples from CD patients, we found a strong correlation of CH25H mRNA expression with the expression of fibrosis markers. We demonstrate reduced intestinal fibrosis in mice deficient for the CH25H enzyme, using the sodium dextran sulphate [DSS]-induced chronic colitis model. Additionally, using a heterotopic transplantation model of intestinal fibrosis, we demonstrate reduced collagen deposition and lower concentrations of hydroxyproline in CH25H knockouts. In the heterotopic transplant model, CH25H was expressed in fibroblasts. Taken together, our findings indicate an involvement of oxysterol synthesis in the pathogenesis of intestinal fibrosis.

Xenotransplantation of human intestine into mouse abdomen or subcutaneous tissue: Novel platforms for the study of the human enteric nervous system

BACKGROUND

Current efforts to develop stem cell therapy as a novel treatment for neurointestinal diseases are limited by the unavailability of a model system to study cell transplantation in the human intestine. We propose that xenograft models support enteric nervous system (ENS) development in the fetal human intestine when transplanted into mice subcutaneously or intra-abdominally.

METHODS

Fetal human small and large intestine were grafted onto the small intestinal mesentery and into the subcutaneous tissue of immunodeficient mice for up to 4 months. Intestinal cytoarchitecture and ENS development were studied using immunohistochemistry.

KEY RESULTS

In both abdominal and subcutaneous grafts, the intestine developed normally with formation of mature epithelial and mesenchymal layers. The ENS was patterned in two ganglionated plexuses containing enteric neurons and glia, including cholinergic and nitrergic neuronal subtypes. c-Kit-immunoreactive interstitial cells of Cajal were present in the gut wall.

CONCLUSIONS & INFERENCES

Abdominal xenografts represent a novel model that supports the growth and development of fetal human intestine. This in vivo approach will be a useful method to study maturation of the ENS, the pathophysiology of neurointestinal diseases, and the long-term survival and functional differentiation of neuronal stem cells for the treatment of enteric neuropathies.

Genetic polymorphisms associated with smoking behaviour predict the risk of surgery in patients with Crohn's disease

BACKGROUND

Smoking is a strong environmental factor leading to adverse outcomes in Crohn's disease, but a more benign course in ulcerative colitis. Several single nucleotide polymorphisms (SNPs) are associated with smoking quantity and behaviour.

AIM

To assess whether smoking-associated SNPs interact with smoking to influence the clinical course of inflammatory bowel diseases.

METHODS

Genetic and prospectively obtained clinical data from 1434 Swiss inflammatory bowel disease cohort patients (821 Crohn's disease and 613 ulcerative colitis) were analysed. Six SNPs associated with smoking quantity and behaviour (rs588765, rs1051730, rs1329650, rs4105144, rs6474412 and rs3733829) were combined to form a risk score (range: 0-12) by adding the number of risk alleles. We calculated multivariate models for smoking, risk of surgery, fistula, Crohn's disease location and ulcerative colitis disease extent.

RESULTS

In Crohn's disease patients who smoke, the number of surgeries was associated with the genetic risk score. This translates to a predicted 3.5-fold (95% confidence interval: 2.4- to 5.7-fold, P<.0001) higher number of surgical procedures in smokers with 12 risk alleles than individuals with the lowest risk. Patients with a risk score >7 had a significantly shorter time to first intestinal surgery. The genetic risk score did not predict surgery in ulcerative colitis or occurrence of fistulae in Crohn's disease. SNP rs6265 was associated with ileal disease in Crohn's disease (P<.05) and proctitis in ulcerative colitis (P<.05).

CONCLUSIONS

SNPs associated with smoking quantity is associated with an increased risk for surgery in Crohn's disease patients who smoke. Our data provide an example of genetics interacting with the environment to influence the disease course of inflammatory bowel disease.

Uncommon case of brain metastasis in a patient with a history of heavy smoking

Primary sarcomas of the aorta are extremely uncommon. Depending on histomorphology and immunohistochemical pattern, intimal sarcomas can show angiosarcomatous differentiation. Here, we describe the case of a 60-year-old woman with a primary intimal sarcoma of the aortic arch and signs of cerebral metastatic disease as the initial manifestation. After the patient experienced the onset of severe headaches, ataxia, and left-sided weakness, magnetic resonance imaging showed several brain lesions. Histologic assessment of a brain biopsy specimen revealed a malignant tumour composed of large pleomorphic cells that were positive for pancytokeratin and CD10. Radiation to the brain did not significantly improve the patient's symptoms, and cranial computed tomography (ct) imaging revealed several metastases, indicating lack of response. Because of the patient's smoking history, the presence of central nervous system and skeletal metastases on combined positron-emission tomography and ct imaging, and the focal pan-cytokeratin positivity of the tumour, carcinoma of the lung was favoured as the primary tumour. Despite chemotherapy with cisplatin and etoposide, the patient's neurologic symptoms and general condition deteriorated rapidly, and she died within a few days. At autopsy, an undifferentiated intimal sarcoma of the aortic arch was diagnosed. The primary tumour in the aorta consisted of large pleomorphic cells. Immunohistochemical analysis of the aortic tumour and brain metastases demonstrated diffuse positivity for vimentin and p53 and focal S-100 staining. In summary, we report a challenging case of advanced intimal sarcoma of the aortic arch with brain and bone metastases at initial presentation. Our report demonstrates the difficulties in diagnosing and treating this disease, and the need for multicentre studies to accrue more patients for investigations of optimal therapy.

[Biologicals in gastroenterology: TNF-blockers]

TNF-blockers represent a well accepted therapeutic option in the treatment of inflammatory bowel disease. Though they are successfully used in many patients, they can also exert severe side effects, such as infectious diseases. Therefore, a careful review of the patient history as well as a continuous evaluation of the patient's state of health is crucial before starting an anti-TNF therapy during the therapeutic treatment. In addition, we review also the possibilities by loss of efficacy of an anti-TNF therapy, such as dose increase or re-induction therapy.