A comprehensive review and update on Crohn's disease

Crohn’s disease of esophagus, stomach and duodenum

Crohn’s disease with involvement of the esophagus, stomach and duodenum has a prevalence of 0.5% to 4% in symptomatic adult patients, but some studies have shown that these results may be underestimated, since upper gastrointestinal endoscopy is not performed routinely in the initial evaluation of the disease in adult patients, as it is in the pediatric population. In general, involvement of the upper gastrointestinal tract in Crohn’s disease occurs concomitantly with involvement of the lower gastrointestinal tract. The diagnosis depends on clinical, endoscopic, histological and radiological evaluation. The presence of aphthoid ulcers, longitudinal ulcers, bamboo-joint-like appearance, stenoses and fistulas are endoscopic findings suggestive of the disease, and it is important to exclude the presence of Helicobacter pylori infection. The primary histological findings, which facilitate the diagnosis, are the presence of a chronic inflammatory process with a predominance of lymphoplasmacytic cells and active focal gastritis. The presence of epithelioid granuloma, although less frequent, is highly suggestive of the disease in the absence of chronic granulomatous disease. Treatment should include the use of proton pump inhibitors associated with corticosteroids, immunomodulators and biological therapy according to the severity of the disease.

A comprehensive review and update on ulcerative colitis. Dis Mon 2019;65:100851. [PMID: 30837080 DOI: 10.1016/j.disamonth.2019.02.004]

Ulcerative colitis (UC) is a chronic idiopathic inflammatory bowel disorder of the colon that causes continuous mucosal inflammation extending from the rectum to the more proximal colon, with variable extents. UC is characterized by a relapsing and remitting course. UC was first described by Samuel Wilks in 1859 and it is more common than Crohn's disease worldwide. The overall incidence and prevalence of UC is reported to be 1.2-20.3 and 7.6-245 cases per 100,000 persons/year respectively. UC has a bimodal age distribution with an incidence peak in the 2nd or 3rd decades and followed by second peak between 50 and 80 years of age. The key risk factors for UC include genetics, environmental factors, autoimmunity and gut microbiota. The classic presentation of UC include bloody diarrhea with or without mucus, rectal urgency, tenesmus, and variable degrees of abdominal pain that is often relieved by defecation. UC is diagnosed based on the combination of clinical presentation, endoscopic findings, histology, and the absence of alternative diagnoses. In addition to confirming the diagnosis of UC, it is also important to define the extent and severity of inflammation, which aids in the selection of appropriate treatment and for predicting the patient's prognosis. Ileocolonoscopy with biopsy is the only way to make a definitive diagnosis of UC. A pathognomonic finding of UC is the presence of continuous colonic inflammation characterized by erythema, loss of normal vascular pattern, granularity, erosions, friability, bleeding, and ulcerations, with distinct demarcation between inflamed and non-inflamed bowel. Histopathology is the definitive tool in diagnosing UC, assessing the disease severity and identifying intraepithelial neoplasia (dysplasia) or cancer. The classical histological changes in UC include decreased crypt density, crypt architectural distortion, irregular mucosal surface and heavy diffuse transmucosal inflammation, in the absence of genuine granulomas. Abdominal computed tomographic (CT) scanning is the preferred initial radiographic imaging study in UC patients with acute abdominal symptoms. The hallmark CT finding of UC is mural thickening with a mean wall thickness of 8 mm, as opposed to a 2-3 mm mean wall thickness of the normal colon. The Mayo scoring system is a commonly used index to assess disease severity and monitor patients during therapy. The goals of treatment in UC are three fold-improve quality of life, achieve steroid free remission and minimize the risk of cancer. The choice of treatment depends on disease extent, severity and the course of the disease. For proctitis, topical 5-aminosalicylic acid (5-ASA) drugs are used as the first line agents. UC patients with more extensive or severe disease should be treated with a combination of oral and topical 5-ASA drugs +/- corticosteroids to induce remission. Patients with severe UC need to be hospitalized for treatment. The options in these patients include intravenous steroids and if refractory, calcineurin inhibitors (cyclosporine, tacrolimus) or tumor necrosis factor-α antibodies (infliximab) are utilized. Once remission is induced, patients are then continued on appropriate medications to maintain remission. Indications for emergency surgery include refractory toxic megacolon, colonic perforation, or severe colorectal bleeding.

The Use of Probiotic Therapy to Modulate the Gut Microbiota and Dendritic Cell Responses in Inflammatory Bowel Diseases

Recent investigations have shown that different conditions such as diet, the overuse of antibiotics or the colonization of pathogenic microorganisms can alter the population status of the intestinal microbiota. This modification can produce a change from homeostasis to a condition known as imbalance or dysbiosis; however, the role-played by dysbiosis and the development of inflammatory bowel diseases (IBD) has been poorly understood. It was actually not until a few years ago that studies started to develop regarding the role that dendritic cells (DC) of intestinal mucosa play in the sensing of the gut microbiota population. The latest studies have focused on describing the DC modulation, specifically on tolerance response involving T regulatory cells or on the inflammatory response involving reactive oxygen species and tissue damage. Furthermore, the latest studies have also focused on the protective and restorative effect of the population of the gut microbiota given by probiotic therapy, targeting IBD and other intestinal pathologies. In the present work, the authors propose and summarize a recently studied complex axis of interaction between the population of the gut microbiota, the sensing of the DC and its modulation towards tolerance and inflammation, the development of IBD and the protective and restorative effect of probiotics on other intestinal pathologies.

Epigenetics, DNA Organization, and Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders affecting the gastrointestinal tract. The incidence of IBD is increasing, with more cases occurring in developed countries. Multiple factors such as genetics, environmental changes, gut microbiota, and immune abnormalities have been associated with development of IBD. In recent years, it has become increasingly apparent that epigenetic modifications of chromatin and the manner in which chromatin is organized in the nucleus are additionally important elements that can influence responses induced by the factors described above, and may therefore contribute to the onset and pathogenesis of IBD. Epigenetics and chromatin organization regulate diverse functions that include maintenance of homeostasis in the intestinal epithelium, the development and differentiation of immune cells, and modulation of responses generated by the immune system to defend against potential pathogens. Furthermore, changes in epigenetic chromatin marks and in chromatin organization have now been linked to differential gene expression in IBD patient cells. Although direct evidence for a role of histone modifications in IBD is currently very limited, in this review, we summarize the links between various epigenetic modifications, the proteins that catalyze or recognize these modifications, and the development or progression of IBD in human and experimental IBD. We also discuss how epigenetics influence the organization of DNA contacts to regulate gene expression and the implications this may have for diagnosing and treating IBD.

The Super-Donor Phenomenon in Fecal Microbiota Transplantation

Fecal microbiota transplantation (FMT) has become a highly effective bacteriotherapy for recurrent Clostridium difficile infection. Meanwhile the efficacy of FMT for treating chronic diseases associated with microbial dysbiosis has so far been modest with a much higher variability in patient response. Notably, a number of studies suggest that FMT success is dependent on the microbial diversity and composition of the stool donor, leading to the proposition of the existence of FMT super-donors. The identification and subsequent characterization of super-donor gut microbiomes will inevitably advance our understanding of the microbial component of chronic diseases and allow for more targeted bacteriotherapy approaches in the future. Here, we review the evidence for super-donors in FMT and explore the concept of keystone species as predictors of FMT success. Possible effects of host-genetics and diet on FMT engraftment and maintenance are also considered. Finally, we discuss the potential long-term applicability of FMT for chronic disease and highlight how super-donors could provide the basis for dysbiosis-matched FMTs.

Importance of TLR9-IL23-IL17 axis in inflammatory bowel disease development: Gene expression profiling study

BACKGROUND AND AIMS

Mucosal gene expression have not been fully enlightened in inflammatory bowel disease (IBD). Aim of this study was to define IL23A, IL17A, IL17F and TLR9 expression in different IBD phenotypes.

METHODS

Evaluation of mRNA levels was performed in paired non-inflamed and inflamed mucosal biopsies of newly diagnosed 50 Crohn's disease (CD) and 54 ulcerative colitis (UC) patients by quantitative real-time PCR analysis.

RESULTS

IL17A and IL17F expression levels were significantly increased in inflamed IBD mucosa. Inflamed CD ileal and UC mucosa showed increased IL23A, while only inflamed CD ileal samples showed increased TLR9 mRNA level. Correlation between analysed mRNAs levels and endoscopic and clinical disease activity were found in UC, but only with clinical activity in CD.

CONCLUSION

Both CD and UC presented expression of Th17-associated genes. Nevertheless, expression profiles between different disease forms varies which should be taken into account for future research and therapeutics strategies.

Treatment of Granulomas in Patients With Ataxia Telangiectasia

Background: Ataxia telangiectasia (A-T) is a devastating multi-system disorder characterized by progressive cerebellar ataxia, growth retardation, immunodeficiency, chronic pulmonary disease and chromosomal instability. Cutaneous granulomas are a known phenomenon in A-T but extra-dermal manifestation of granulomas at bone and synovia has not been reported so far. The clinical presentation, immunological findings, the long-term course and treatment options of eight patients with severe granulomas will be reported.

Methods: From our cohort of 44 classical A-T patients, eight patients aged 2–11 years (18.2%) presented with granulomas. Immunological features of patients with and without granulomas were compared. Five patients suffered from cutaneous manifestation, in two patients we detected a bone and in one a joint involvement. Patients with significant extra-dermal involvement as well as one patient with massive skin manifestation were treated with TNF inhibitors. The patient with granulomas at his finger joint and elbow was treated with hematopoietic stem cell transplantation (HSCT).

Results: Interestingly, seven of eight patients with granulomas were total IgA deficient, but there were no differences in IgG and IgM levels. All lymphocytes subsets were equally distributed except patients with granuloma had significantly lower naïve CD8 cells. In patients without treatment, four of eight showed a slow but significant enlargement of the granuloma. Treatment success with TNF inhibitors was variable. In one patient, treatment with TNF inhibitors led to a total remission for 3 years up to now. In two patients, treatment with TNF inhibitors led to a partial regression of granulomas. Treatment interruptions caused deterioration again.

Conclusions: Granulomas in A-T progress slowly over years and can lead to significant morbidity.Treatment with TNF inhibitors was safe and in part successful in our patients. Interestingly HSCT leads to complete remission, and indicates that aberrant immune function is responsible for granulomas in A-T patients. What This Study Adds to the Field: Granulomas in A-T progress slowly over years and can lead to significant morbidity. Treatment with TNF inhibitors was safe and in part successful in our patients.

AT A GLANCE COMMENTARY:

Scientific knowledge on the subject: Little is known about the clinical presentation, course and treatment of granulomas in ataxia telangiectasia (A-T). In addition, this is the first report of extra-dermal manifestation of granulomas at bone and synovia in patients with A-T.

What This Study Adds to the Field: Granulomas in A-T progress slowly over years and can lead to significant morbidity. Treatment with TNF inhibitors was safe and in part successful in our patients.

Acute febrile neutrophilic dermatosis in a patient with Crohn's disease: case report and review of the literature

Crohn's disease is a chronic inflammatory bowel disease. The disease is characterized by acute exacerbations with diarrhea, abdominal pain, fever, anorexia, intestinal bleeding, and weight loss. Immune-mediated diseases that are frequently associated with Crohn's disease include arthritis, ankylosing spondylitis, sacroiliitis, episcleritis, uveitis, and skin lesions, such as erythema nodosum and pyoderma gangrenosum. The authors present the case of a 22-year-old female patient that was admitted to their hospital due to diarrhea, fever, arthralgias, and diffuse erythematous papules and plaques with vesicles and pustules affecting the patient's face, lips, arms, trunk, and legs. Six months prior to onset, the patient was diagnosed with terminal ileitis and Crohn's disease of the sigmoid colon. Treatment with mesalazine and budesonide had been introduced. In the diagnostic procedure, a skin biopsy was taken from the patient. Histology confirmed dense infiltration of neutrophilic polymorphonuclear leukocytes, or Sweet's syndrome. This condition is a rare manifestation of chronic inflammatory bowel diseases such as Crohn's disease and ulcerative colitis. This syndrome is thought to be a hypersensitivity reaction and may be associated with various inflammatory, infectious, or neoplastic diseases. The patient was treated with high doses of methylprednisolone (60 mg IV), which resulted in rapid improvement of Crohn's disease and skin lesions.

Advanced parametric imaging for evaluation of Crohn's disease using dual-energy computed tomography enterography

We describe a case of small bowel Crohn's disease in which dual-energy computed tomography enterography using dual-layer spectral detector scanner contributed to quantitative assessment, and provided a higher degree of confidence pertaining to the diagnosis. Dual-layer spectral detector computed tomography enables retrospective analysis including virtual monochromatic imaging, iodine mapping, and determining the effective atomic number Z with routine scan protocols. These advanced parametric dual-energy imaging holds promising potential as an imaging biomarker for diagnosis, risk-stratification, monitoring of disease progression and therapy, and outcome prediction.

Malabsorption Syndromes

Malabsorption syndrome refers to the small intestines' inability to absorb certain nutrients and fluids. There are several common associated disorders, which may present with subtle and/or overt symptoms. With subtle symptoms, it is difficult to determine the cause, making diagnosis difficult or even inaccurate. Malabsorption can originate from an immune response, an inflammatory process, or alternation of the small intestines by surgical methods. This article reviews common malabsorption disease processes of the small bowel and the resulting pathophysiology. Diagnostic studies, treatment, and prognosis of various conditions within the malabsorption disease state are discussed.