Whole gut lavage fluid interleukin-1beta and interleukin-8 in smokers and non-smokers with Crohn's disease in clinical remission

The controversial effect of smoking and nicotine in SARS-CoV-2 infection

The effects of nicotine and cigarette smoke in many diseases, notably COVID-19 infection, are being debated more frequently. The current basic data for COVID-19 is increasing and indicating the higher risk of COVID-19 infections in smokers due to the overexpression of corresponding host receptors to viral entry. However, current multi-national epidemiological reports indicate a lower incidence of COVID-19 disease in smokers. Current data indicates that smokers are more susceptible to some diseases and more protective of some other. Interestingly, nicotine is also reported to play a dual role, being both inflammatory and anti-inflammatory. In the present study, we tried to investigate the effect of pure nicotine on various cells involved in COVID-19 infection. We followed an organ-based systematic approach to decipher the effect of nicotine in damaged organs corresponding to COVID-19 pathogenesis (12 related diseases). Considering that the effects of nicotine and cigarette smoke are different from each other, it is necessary to be careful in generalizing the effects of nicotine and cigarette to each other in the conducted researches. The generalization and the undifferentiation of nicotine from smoke is a significant bias. Moreover, different doses of nicotine stimulate different effects (dose-dependent response). In addition to further assessing the role of nicotine in COVID-19 infection and any other cases, a clever assessment of underlying diseases should also be considered to achieve a guideline for health providers and a personalized approach to treatment.

Making sense of the cause of Crohn's - a new look at an old disease

The cause of Crohn’s disease (CD) has posed a conundrum for at least a century. A large body of work coupled with recent technological advances in genome research have at last started to provide some of the answers. Initially this review seeks to explain and to differentiate between bowel inflammation in the primary immunodeficiencies that generally lead to very early onset diffuse bowel inflammation in humans and in animal models, and the real syndrome of CD. In the latter, a trigger, almost certainly enteric infection by one of a multitude of organisms, allows the faeces access to the tissues, at which stage the response of individuals predisposed to CD is abnormal. Direct investigation of patients’ inflammatory response together with genome-wide association studies (GWAS) and DNA sequencing indicate that in CD the failure of acute inflammation and the clearance of bacteria from the tissues, and from within cells, is defective. The retained faecal products result in the characteristic chronic granulomatous inflammation and adaptive immune response. In this review I will examine the contemporary evidence that has led to this understanding, and look for explanations for the recent dramatic increase in the incidence of this disease.

Making sense of the cause of Crohn's - a new look at an old disease

The cause of Crohn's disease (CD) has posed a conundrum for at least a century. A large body of work coupled with recent technological advances in genome research have at last started to provide some of the answers. Initially this review seeks to explain and to differentiate between bowel inflammation in the primary immunodeficiencies that generally lead to very early onset diffuse bowel inflammation in humans and in animal models, and the real syndrome of CD. In the latter, a trigger, almost certainly enteric infection by one of a multitude of organisms, allows the faeces access to the tissues, at which stage the response of individuals predisposed to CD is abnormal. Direct investigation of patients' inflammatory response together with genome-wide association studies (GWAS) and DNA sequencing indicate that in CD the failure of acute inflammation and the clearance of bacteria from the tissues, and from within cells, is defective. The retained faecal products result in the characteristic chronic granulomatous inflammation and adaptive immune response. In this review I will examine the contemporary evidence that has led to this understanding, and look for explanations for the recent dramatic increase in the incidence of this disease.

Cigarette smoking alters epithelial apoptosis and immune composition in murine GALT

Smokers have a twofold increased risk to develop Crohn's disease (CD). However, little is known about the mechanisms through which smoking affects CD pathogenesis. Especially Crohn's ileitis is negatively influenced by smoking. Interestingly, the ileum and, more in particular, the Peyer's patches in the terminal ileum are also the sites where the first CD lesions are found. Several chemokines are implicated in the pathogenesis, among which is the CCL20-CCR6 pathway. Here, we studied the gut-associated lymphoid tissue in C57BL/6 wild-type mice and in CCR6-deficient mice after exposure to air or cigarette smoke for 24 weeks. Apoptotic index of the follicle-associated epithelium overlying the Peyer's patches was evaluated. We found that chronic smoke exposure induced apoptosis in the follicle-associated epithelium. Furthermore, immune cell numbers and differentiation along with chemokine expression were determined in Peyer's patches. Important changes in immune cell composition were observed: total dendritic cells, CD4+ T cells (including regulatory T cells) and CD8+ T cells increased significantly after smoke exposure. The CD11b+ dendritic cell subset almost doubled. Interestingly, these changes were accompanied by an upregulated mRNA expression of the chemokines CCL9 and CCL20. However, no differences in the increase of dendritic cells were observed between wild-type and CCR6-deficient mice. Our results show that cigarette smoke exposure increases apoptosis in the follicle-associated epithelium and is associated with immune cell accumulation in Peyer's patches.

(E)-metanicotine hemigalactarate (TC-2403-12) inhibits IL-8 production in cells of the inflamed mucosa

BACKGROUND

Nicotine is of therapeutic value in ulcerative colitis, but its administration is connected with adverse events. Nicotine derivatives are currently being tested to maintain the therapeutic effects and minimize adverse events. TC-2403-12 is a (E)-metanicotine hemigalactarate. The aim of this study was to determine the effectiveness of TC-2403-12 in the inhibition of TNF- and lipopolysaccharide (LPS)-induced cell activation.

METHODS

Colonic epithelial cells (CEC), monocytes (MM6), granulocytes, and the intestinal epithelial cell line HT-29 were stimulated with TNF and LPS and treated with TC-2403-12. IL-8 secretion in the cell supernatants and NF-kappaB activation were determined by ELISA. Apoptosis was quantified by flow cytometry.

RESULTS

In MM6 cells, IL-8 secretion was significantly decreased to 30% of control after TC-2403-12 treatment, with best results after pretreatment for 24 h. This decrease in cell activation was not due to apoptosis and was not mediated by inhibition of NF-kappaB activation. IL-8 production in neutrophils and primary CEC also tended to be decreased after TC-2403-12 treatment. TC-2403-12 had no influence on IL-8 secretion of HT-29 cells.

CONCLUSION

TC-2403-12 effectively inhibited TNF- and LPS-induced IL-8 production in different cell types. No toxic effects occurred at the concentrations used. Preincubation of cells with TC-2403-12 showed the best effects.

Long-term outcome of endoscopic pneumatic dilatation in Crohn's disease

BACKGROUND

To avoid multiple surgeries in stenosing Crohn's disease, pneumatic endoscopic dilatation has been introduced. The present study evaluated the long-term clinical outcome in Crohn's disease patients after endoscopic dilatation for ileal or neoileal strictures.

PATIENTS AND METHODS

All Crohn's disease patients who underwent pneumatic dilatation of ileal or ileo-colonic strictures between January 1988 and December 2001 were invited to return for a clinical check-up in June 2002. Clinical, endoscopic and radiological reports were reviewed. Symptomatic relief from sub-occlusive symptoms without requiring surgery was considered as a positive outcome, whereas the requirement of surgery was regarded as an unfavourable outcome. Possible predictors of favourable outcome were analysed.

RESULTS

Endoscopic dilatation was technically successful in 34/43 (79%) Crohn's disease patients, with a mean number of dilatations per patient of 3 +/- 3.13. During a mean follow-up of 63.7 +/- 44.6 months, a positive long-term outcome was observed in 18 (52.9%) patients, whereas surgery was necessary in the remaining 16 cases. The risk of surgery was distinctly higher within 2 years post-dilatation than in the next 2 years (26.4% versus 8.3%, respectively; P = 0.078). No clear clinical, endoscopic or radiological predictive factors for a successful outcome were identified.

CONCLUSIONS

Endoscopic pneumatic dilatation is an effective and safe procedure to be applied to patients with stenosing Crohn's disease, offering a very long-term benefit in a sub-group of patients.

Role of faecal calprotectin as non-invasive marker of intestinal inflammation

BACKGROUND/AIM

Faecal calprotectin, a neutrophil granulocyte cytosol protein, is considered a promising marker of intestinal inflammation. We assessed and compared the faecal calprotectin concentration in patients with organic and functional chronic intestinal disorders.

PATIENTS AND METHODS

The study was carried out, using a commercially available ELISA test, measuring calprotectin in stool samples collected from 131 patients with inflammatory bowel diseases, 26 with intestinal neoplasms, 48 with irritable bowel syndrome and 34 healthy subjects.

RESULTS

Median faecal calprotectin was significantly increased in Crohn's disease (231 microg/g, 95% confidence interval (CI) 110-353 microg/g), ulcerative colitis (167 microg/g, 95% CI 59-276 microg/g), and neoplasms (105 microg/g, 95% CI 0-272 microg/g), whereas normal values were found in patients with irritable bowel syndrome (22 microg/g, 95% CI 9-35 microg/g) and in healthy subjects (11 microg/g, 95% CI 3-18 microg/g). A positive correlation was observed with clinical activity scores in Crohn's disease and ulcerative colitis. In both groups, patients with clinically active disease showed higher calprotectin levels than those observed in patients with quiescent disease (405 microg/g, 95% CI 200-610 microg/g vs. 213 microg/g, 95% CI 85-341 microg/g in CD patients, p<0.05, and 327 microg/g, 95% CI 104-550 microg/g vs. 123 microg/g, 95% CI 40-206 microg/g in UC patients, p<0.001).

CONCLUSIONS

Faecal calprotectin appears to be a promising and non-invasive biomarker of intestinal inflammation. If these findings are confirmed, it may provide a useful test for the diagnosis and follow up of inflammatory bowel diseases.