The analysis of clinico-pathologic characteristics in patients who underwent surgery due to stricturing and non-perineal fistulizing forms of Crohn's disease: a retrospective cohort study

Relationship between histopathological findings, clinical severity and the need for surgery in patients with Crohn's disease

INTRODUCTION

Defining histological variables that make it possible to establish the activity of Crohn's disease (CD) and predict the patients who may present a higher risk of clinical complications and surgical interventions could lead to timely adjustments in medical therapy and elective surgeries that represent a lower risk of complications. The purpose of the study is to determine the relation between the histopathological findings using the Naini and Cortina (N&C) score, the clinical severity, and the indication for surgery in a group of patients with CD.

MATERIALS AND METHODS

Descriptive, retrospective, cross-sectional study of 44 patients diagnosed with CD, treated at the San Vicente Fundación University Hospital in Medellín, Colombia, between 2010 and 2022.

RESULTS

Of the 44 patients, 36 ileum samples and 34 colon samples were obtained. Of the patients with inflammatory behavior, 87.5% did not have surgical intervention (P=.022), a value that remained significant in the ileum subgroup (P=.0058). 91.3% of the patients with ileal involvement did not develop perianal disease (P=.01). Granulomas only occurred in two patients with a colon sample (5.8%). In the histological score of N&C both in the ileum and in the colon, no statistically significant differences were obtained in relation to the surgical outcome (P=.34 and P=.054, respectively).

CONCLUSION

The histological index of N&C was not a predictor in Crohn's disease (CD) related to the surgical outcome.

A Combination of Pathological Features Identifies Crohn's Disease in Surgical Bowel Resection Specimens

BACKGROUND

Diagnosis of Crohn's disease is challenging. This study aims to compare the histological features of Crohn's disease and non-Crohn's disease (other intestinal inflammatory diseases) in surgical specimens to identify a set of histologic features distinguishing Crohn's disease from non-Crohn's disease.

METHODS

Patients with Crohn's disease (N = 171) and patients with non-Crohn's disease (N = 215) diagnosed between 2010 and 2015 who had surgical bowel resection were identified. The frequency of histological features in surgical resection specimens was compared between these two groups.

RESULTS

Univariate analysis revealed that transmural inflammation, subserosal lymphoid aggregates, fissures or sinus-like structures, granulomas or granuloma-like nodules, abnormalities of the enteric nervous system, and mucosa structure alterations (muscularis mucosa thickening or mucosal atrophy with pseudopyloric gland metaplasia) were more frequent in Crohn's disease than non-Crohn's disease cases (p < 0.001 for all). Some of the above histologic features were further grouped as chronic inflammatory change which includes granulomas or granuloma-like nodules, lymphoid aggregates in the muscularis propria or subserosa, fissures or sinus-like structures, and architectural abnormality which is defined as the presence of abnormal enteric nervous system and/or mucosa structural alterations (muscularis mucosa thickening or mucosal atrophy with pseudopyloric gland metaplasia). A combination of transmural inflammation, chronic inflammatory change, and architectural abnormality had a sensitivity of 92.4% and a specificity of 97.7% for Crohn's disease.

CONCLUSIONS

In surgical bowel resection specimens, a combination of transmural inflammation, chronic inflammatory change, and architectural abnormality help diagnose Crohn's disease.

IFNγ-Treated Macrophages Induce EMT through the WNT Pathway: Relevance in Crohn’s Disease

Background: Fibrosis is a common complication of Crohn’s disease (CD) in which macrophages play a central role. Epithelial-mesenchymal transition (EMT) and the WNT pathway have been associated with fibrosis. We aim to analyse the relevance of the tissue microenvironment in macrophage phenotype and the EMT process. Methods: Intestinal surgical resections are obtained from control and CD patients with stenotic or penetrating behaviour. Cytokine’s expression, macrophage phenotype, EMT markers and WNT signalling pathway are determined by WB, RT-PCR, ELISA or Cytometry. U937 cells are treated with IFNγ, TNFα, IL1β, IL4 or IL10 and co-cultured with HT29 cells and, in some cases, are treated with XAV939 or miFZD4. The expression of macrophage, EMT and WNT pathway markers in U937 or HT29 cells is analysed by WB or RT-PCR. Results: IFNγ, WNT6, CD16 and CD86 are increased in the intestinal tissue of CD patients. IFNγ-treated U937 activated the EMT process and WNT pathway in HT29 cells, and the EMT process is mediated by FZD4. Conclusions: An IFNγ-rich microenvironment polarises macrophages, which induces EMT through the WNT pathway.

WNT2b Activates Epithelial-mesenchymal Transition Through FZD4: Relevance in Penetrating Crohn´s Disease

BACKGROUND AND AIMS

Epithelial-mesenchymal transition [EMT] has been related to fibrosis and fistula formation, common complications associated with Crohn´s disease [CD]. The WNT signalling pathway mediates EMT, and specific WNT/FZD interactions have been related to the activation of this process in several diseases. We aim to analyse the relevance of EMT and WNT ligands and receptors in the penetrating behaviour of CD.

METHODS

Intestinal surgical resections were obtained from control and CD patients with a stenotic or penetrating behaviour. Fibrosis was determined by the histological analysis of collagen deposition and EMT by confocal microscopy. The expression of WNT ligands, inhibitors, and FZD receptors was analysed by RT-PCR, WB, IH, and IF studies. The effects of WNT2b and the role of FZD4 in EMT were analysed in HT29 epithelial cells.

RESULTS

Fibrosis and expression of EMT markers were detected in samples from CD patients irrespective of the clinical behaviour. However, an increased colocalisation of E-CADHERIN and VIMENTIN, an increased number of cells expressing WNT2b, and a higher expression of FZD4 and WNT2b/FZD4 interaction, were detected in intestinal tissue from the penetrating compared with the stenotic CD behaviour. WNT2b induced EMT in HT29 cells through FZD4 activation.

CONCLUSIONS

An increased EMT, associated with increased WNT2b/FZD4 interaction, was detected in intestinal tissue from CD patients with a penetrating behaviour. WNT2b, through FZD4 activation, induces EMT in vitro which points to a novel pharmacological target to prevent intestinal penetrating complications of CD.

Histopathology Scoring Systems of Stenosis Associated With Small Bowel Crohn's Disease: A Systematic Review

BACKGROUND & AIMS

Stenosis is a common complication of Crohn's disease (CD) that has no effective medical therapy. Development of antifibrotic agents will require testing in randomized controlled trials. Computed tomography enterography- and magnetic resonance enterography-based technologies might be used to measure outcomes in these trials. These approaches have been validated in studies of patients with symptomatic strictures who underwent imaging evaluations followed by resection with histopathologic grading of the intestinal tissue for inflammation and/or fibrosis (the reference standard). Imaging findings have correlated with findings from quantitative or semiquantitative histologic evaluation of the degree of fibromuscular stenosis and/or inflammation on the resection specimen. However, it is not clear whether histologic findings are an accurate reference standard. We performed a systematic review of all published histologic scoring systems used to assess stenosing CD.

METHODS

We performed a comprehensive search of Embase and MEDLINE of studies through March 13, 2019, that used a histologic scoring system to characterize small bowel CD and assessed inflammatory and fibrotic alterations within the same adult individual. All scores fitting the criteria were included in our analysis, independent of the presence of stricturing disease, as long as inflammation and fibrosis were evaluated separately but in the same scoring system.

RESULTS

We observed substantial heterogeneity among the scoring systems, which were not derived from modern principles for evaluative index development. None had undergone formal validity or reliability testing. None of the existing indices had been constructed according to accepted methods for the development of evaluative indices. Basic knowledge regarding their operating properties were lacking. Specific indices for evaluating the important pathologic component of myofibroblast hypertrophy or hyperplasia have not been proposed.

CONCLUSIONS

In a systematic review of publications, we found a lack of validated histopathologic scoring systems for assessment of fibromuscular stenosis. Data that describe the operating properties of existing cross-sectional imaging techniques for stenosing CD should be questioned. Development and validation of a histopathology index is an important research priority.

ANALYSIS OF RISK FACTORS AND POSTOPERATIVE COMPLICATIONS IN PATIENTS WITH CROHN'S DISEASE

BACKGROUND

The post-operative complications rate is greater in patients with Crohn's disease than in other abdominal surgeries due to other benign conditions. Prevention and management of such complications are important factors in the care of these patients.

OBJECTIVE

The objectives of this research are to analyze the rate of postoperative complications and the major risk factors in patients with Crohn's disease.

METHODS

A descriptive and retrospective study based on analysis of medical records of patients with Crohn's disease undergoing ileal and/or colonic resection, which analyzed the main surgical complications and their major risk factors.

RESULTS

Forty-four surgical procedures and thirty-seven patients were analyzed. Most were female (56.7%). Postoperative complications were observed in 18 (40.9%) surgeries. The disease duration (P=0.04), the penetrating behavior (P=0.013), the time between diagnosis and the first surgery (P=0.04), malnutrition with low body mass index (BMI), duration of surgery (P=0.016), and the size of the removed specimen (P=0.014) were associated with higher rates of complications. The use of drugs blocking tumor necrosis factor up to eight weeks before surgery was not significantly associated with higher complications rates or increased need for reoperation.

CONCLUSION

The complication rate observed in this study is similar to published data. The duration of the disease, the penetrating behavior, the size of the removed specimen, the duration of the surgery, and BMI are important risk factors for perioperative complications in Crohn's disease.

Total flavone of Abelmoschus manihot suppresses epithelial-mesenchymal transition via interfering transforming growth factor-β1 signaling in Crohn’s disease intestinal fibrosis

AIM

To explore the role and mechanism of total flavone of Abelmoschus manihot (TFA) on epithelial-mesenchymal transition (EMT) progress of Crohn’s disease (CD) intestinal fibrosis.

METHODS

First, CCK-8 assay was performed to assess TFA on the viability of intestinal epithelial (IEC-6) cells and select the optimal concentrations of TFA for our further studies. Then cell morphology, wound healing and transwell assays were performed to examine the effect of TFA on morphology, migration and invasion of IEC-6 cells treated with TGF-β1. In addition, immunofluorescence, real-time PCR analysis (qRT-PCR) and western blotting assays were carried out to detect the impact of TFA on EMT progress. Moreover, western blotting assay was performed to evaluate the function of TFA on the Smad and MAPK signaling pathways. Further, the role of co-treatment of TFA and si-Smad or MAPK inhibitors has been examined by qRT-PCR, western blotting, morphology, wound healing and transwell assays.

RESULTS

In this study, TFA promoted transforming growth factor-β1 (TGF-β1)-induced (IEC-6) morphological change, migration and invasion, and increased the expression of epithelial markers and reduced the levels of mesenchymal markers, along with the inactivation of Smad and MAPK signaling pathways. Moreover, we revealed that si-Smad and MAPK inhibitors effectively attenuated TGF-β1-induced EMT in IEC-6 cells. Importantly, co-treatment of TFA and si-Smad or MAPK inhibitors had better inhibitory effects on TGF-β1-induced EMT in IEC-6 cells than either one of them.

CONCLUSION

These findings could provide new insight into the molecular mechanisms of TFA on TGF-β1-induced EMT in IEC-6 cells and TFA is expected to advance as a new therapy to treat CD intestinal fibrosis.