Distinctive histopathologic phenotype in resection specimens from patients with Crohn's disease receiving anti-TNF-α therapy

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.

Risk factors for surgery in stricturing small bowel Crohn's disease: A retrospective cohort study from the GETAID pédiatrique

OBJECTIVES

Previous studies have shown rates of surgical resection of up to 41% in stricturing pediatric Crohn's disease (CD). In this retrospective multicenter study, our aims were to identify clinical risk factors and magnetic resonance enterography (MRE) features of small bowel strictures associated with surgery.

METHODS

Pediatric patients with symptomatic stricturing small bowel CD (defined as obstructive symptoms or proximal dilatation on MRE) confirmed by MRE between 2010 and 2020 were recruited from 12 French tertiary hospitals. Patient characteristics were compared by surgical outcome multivariable Cox regression.

RESULTS

Fifty-six patients (61% boys) aged 12.2 ± 2.7 years at diagnosis of CD were included. Median duration of CD before diagnosis of stricture was 11.7 months (interquartile range [IQR]: 25-75: 1.2-29.9). Nineteen (34%) patients had stricturing phenotype (B2) at baseline. Treatments received  before stricture diagnosis included MODULEN-IBD (n = 31), corticosteroids (n = 35), antibiotics (n = 10), anti-TNF (n = 27), immunosuppressants (n = 28). Thirty-six patients (64%) required surgery, within 4.8 months (IQR: 25-75: 1.8-17.3) after stricture diagnosis. Parameters associated with surgical resection were antibiotic exposure before stricture diagnosis (adjusted odds ratio [aOR]: 15.62 [3.35-72.73], p = 0.0005), Crohn's disease obstructive symptoms score (CDOS) > 4 (aOR: 3.04 [1.15-8.03], p = 0.02) and dilation proximal to stricture >28 mm (aOR: 3.62 [1.17-11.20], p = 0.03).

CONCLUSION

In this study, antibiotic treatment before stricture diagnosis, intensity of obstructive symptoms, and diameter of dilation proximal to small bowel stricture on MRE were associated with risk for surgical resection.

Granuloma Presence at Initial Surgery Predicts Need for Repeat Surgery Independent of Rutgeerts Score in Crohn's Disease

BACKGROUND

Approximately half of Crohn's disease (CD) patients experience recurrence and need for repeat resections, highlighting need for prognostic biomarkers. Presence of epithelioid granuloma on surgical tissue and high Rutgeerts endoscopic score are associated with postoperative CD clinical recurrence. We sought to evaluate presence of epithelioid granuloma at first surgery and Rutgeerts score as a combined risk assessment for CD surgical recurrence.

METHODS

Our study included consented CD patients who underwent initial ileocecal resection and were prospectively followed postoperatively. From 2009 to 2019, 418 CD patients underwent initial ileocecal resection with >4 years of follow-up, including postoperative endoscopic assessment (Rutgeerts score).

RESULTS

Postoperative CD patients were grouped based on granuloma presence (30.6%; n = 128) or absence (69.4%; n = 290). Endoscopic recurrence (defined as Rutgeerts score ≥i2) was similar between the granuloma (26%) and no granuloma (25%) groups, respectively (P = .82). Patients with granuloma and CD endoscopic recurrence at first postoperative endoscopy had higher number of bowel surgeries compared with all other groups (no granuloma or CD endoscopic recurrence, P = .007; no granuloma but CD endoscopic recurrence present, P = .04; granuloma present and no CD endoscopic recurrence, P = .04). Epithelioid granuloma presence was associated with 1.65 times higher risk of subsequent surgery independently from first postoperative endoscopic recurrence Rutgeerts score.

CONCLUSIONS

Granuloma presence on initial surgical histology is immediately available and identifies high-risk CD patients who may benefit from early postoperative treatment, and these precision intervention trials are warranted.

Histopathological assessment of the microscopic activity in inflammatory bowel diseases: What are we looking for?

Advances in diagnostics of inflammatory bowel diseases (IBD) and improved treatment strategies allowed the establishment of new therapeutic endpoints. Currently, it is desirable not only to cease clinical symptoms, but mainly to achieve endoscopic remission, a macroscopic normalization of the bowel mucosa. However, up to one-third of IBD patients in remission exhibit persisting microscopic activity of the disease. The evidence suggests a better predictive value of histology for the development of clinical complications such as clinical relapse, surgical intervention, need for therapy escalation, or development of colorectal cancer. The proper assessment of microscopic inflammatory activity thus became an important part of the overall histopathological evaluation of colonic biopsies and many histopathological scoring indices have been established. Nonetheless, a majority of them have not been validated and no scoring index became a part of the routine bioptic practice. This review summarizes a predictive value of microscopic disease activity assessment for the subsequent clinical course of IBD, describes the most commonly used scoring indices for Crohn's disease and ulcerative colitis, and comments on current limitations and unresolved issues.

Histological Indices and Risk of Recurrence in Crohn's Disease: A Retrospective Study of a Cohort of Patients in Endoscopic Remission

BACKGROUND

Although histological healing is raising interest in ulcerative colitis to predict recurrence, its meaning in Crohn's disease (CD) remains unknown. We aimed to study the performances of different histological indices to predict recurrence of CD patients with mucosal healing.

METHODS

Crohn's disease patients with mucosal healing diagnosed between 2010 and 2018 were included if there was available clinical and endoscopical data. Nancy Histological index (NHI), Geboes score (GS), Robarts Histopathology index (RHI), Global Histological Disease Activity Score (GHAS), and Inflammatory Bowel Disease-Distribution Chronicity Activity score (IBD-DCA) were independently assessed by 3 pathologists.

RESULTS

Eighty-eight patients were included, of which 28 relapsed (32%) within 30.5 months. All 4 histological indices were associated with recurrence, with significant relapse risk (NHI, odds ratio [OR], 1.67; GHAS, OR, 2.33; RHI, OR, 1.19; GS, OR, 2.09; and IBD-DCA, OR, 2.14). Microscopic activity was significantly associated with relapse only with the IBD-DCA score. Predicting performances of all these scores were poor. Calibration curves indicate that the GHAS and IBD-DCA are the closest to the ideal predicted probability curve and thus could better predict recurrence than the other scores. Interobserver agreement varied from poor for GHAS (k = .39) to good for RHI (k = .68).

CONCLUSIONS

Histological scores are valuable indicators to predict recurrence. Histological assessment of activity seems insufficient to predict CD course with most of the score evaluated, highlighting the need for new indices or adaptation of actual scores to CD specificities.

Paediatric Ulcerative Colitis Is a Fibrotic Disease and Is Linked with Chronicity of Inflammation

BACKGROUND AND AIMS

Intestinal fibrosis has recently been characterised in adult ulcerative colitis and may affect motility, diarrhoea, and the symptom of urgency. We aimed to charactersze the presence of fibrosis in paediatric patients with ulcerative colitis, and its link to severity and chronicity of mucosal inflammation, as well as clinical factors of severity.

METHODS

We performed a single-centre cross-sectional study in children ages 1-18 years with ulcerative colitis, undergoing colectomy or proctocolectomy. Tissue cross-sections were derived from proximal, mid, and distal colon and rectum, and inflammation and fibrosis were graded based on previously developed scores. Clinical data were collected prospectively.

RESULTS

From 62 patients, 205 intestinal sections were evaluated. Median age at diagnosis was 13 years, 100% had extensive colitis, and all resections were done for refractory disease. The presence, chronicity, and degree of inflammation were linked with the presence of fibrosis. Thickness of the muscularis mucosa was also linked with presence and chronicity of inflammation. The overall submucosal fibrosis burden was associated with prior anti-tumour necrosis factor use.

CONCLUSIONS

Paediatric patients with ulcerative colitis exhibit colorectal submucosal fibrosis and muscularis mucosa thickening, which correlate with the presence, chronicity, and degree of mucosal inflammation. Fibrosis should be recognised as a complication of paediatric ulcerative colitis, and ulcerative colitis should be considered a progressive disease.

Histopathological Features in Colonic Biopsies at Diagnosis Predict Long-term Disease Course in Patients with Crohn's Disease

BACKGROUND AND AIMS

Crohn's disease [CD] is characterised by a heterogeneous disease course. Patient stratification at diagnosis using clinical, serological, or genetic markers does not predict disease course sufficiently to facilitate clinical decision making. The current study aimed to investigate the additive predictive value of histopathological features to discriminate between a long-term mild and severe disease course.

METHODS

Diagnostic biopsies from treatment-naïve CD patients with mild or severe disease courses in the first 10 years after diagnosis were reviewed by two gastrointestinal pathologists after developing a standardised form comprising 15 histopathological features. Multivariable logistic regression models were built to identify predictive features and compute receiver operating characteristic [ROC] curves. Models were internally validated using bootstrapping to obtain optimism-corrected performance estimates.

RESULTS

In total, 817 biopsies from 137 patients [64 mild, 73 severe cases] were included. Using clinical baseline characteristics, disease course could only moderately be predicted (area under receiver operating characteristic curve [AUROC]: 0.738 [optimism 0.018], 95% confidence interval [CI] 0.65-0.83, sensitivity 83.6%, specificity 53.1%). When adding histopathological features, in colonic biopsies a combination of [1] basal plasmacytosis, [2] severe lymphocyte infiltration in lamina propria, [3] Paneth cell metaplasia, and [4] absence of ulcers were identified and resulted in significantly better prediction of a severe course (AUROC: 0.883 [optimism 0.033], 95% CI 0.82-0.94, sensitivity 80.4%, specificity 84.2%).

CONCLUSIONS

In this first study investigating the additive predictive value of histopathological features in biopsies at CD diagnosis, we found that certain features of chronic inflammation in colonic biopsies contributed to prediction of a severe disease course, thereby presenting a novel approach to improving stratification and facilitating clinical decision making.

Bowel stiffness associated with histopathologic scoring of stenosis in patients with Crohn's disease

BACKGROUND AND AIMS

Intestinal stenosis is a common complication of Crohn's Disease (CD). Stenosis is associated with alteration of bowel mechanical properties. This study aims to quantitate the mechanical properties of the intestinal stenosis and to explore associations between histology and mechanical remodeling at stenotic intestinal sites in CD patients.

METHODS

Intestinal segments from stenotic sites were studied in vitro from 19 CD patients. A luminal catheter with a bag was used to stepwise pressurize the intestinal segments from 0-100 cmH₂O with 10 cmH₂O increments. B-mode ultrasound images were obtained at the narrowest part of the stenosis at each pressure level and morphometric parameters were obtained from ultrasound images. The mechanical behavior of the stenotic tissue were characterized by using an isotropic three dimensional strain energy function in Demiray model form, the mechanical constants were obtained by fitting the model to the recorded intraluminal pressure and the inner radius of the stenotic segment of the small bowel. Grading scores were used for histological analysis of inflammation, fibrosis, muscular hypertrophy and adipocyte proliferation in the intestinal layers. The collagen area fraction in intestinal layers was also calculated. Associations between histological and the mechanical constants (stiffness) were analyzed.

RESULTS

Chronic inflammation was mainly located in mucosa whereas fibrosis was found in submucosa. The mechanical remodeling was performed with changed mechanical constants ranged between 0.35-13.68kPa. The mechanical properties changes were associated mainly with chronic inflammation, fibrosis and combination of inflammation and fibrosis (R>0.69, P<0.001). Furthermore, the mechanical properties correlated with the collagen fraction in submucosa and muscular layers (R>0.53, P<0.05).

CONCLUSIONS

We quantitated the intestinal stenosis stiffness. Associations were found between bowel mechanical remodeling and histological changes at the stenotic site in CD patients.

STATEMENT OF SIGNIFICANCE

Although intestinal ultrasonography, CT and MRI can be used to diagnose Crohn's Disease (CD)-associated bowel strictures, these techniques may not have sufficient accuracy and resolution to differentiate predominantly inflammatory strictures from predominantly fibrotic strictures. The present study aims to quantitate the mechanical remodeling of intestinal stenosis and to explore the associations between histological parameters and mechanical properties at the intestinal stenotic sites in CD patients. For the first time, we quantitatively demonstrated that the mechanical properties of the intestinal wall in CD stenosis are associated with the chronic inflammation, fibrosis and collagen fraction in the intestinal layers. The results of this study may facilitate design and development of artificial biomaterials for gastrointestinal organs. The potential clinical implication of this study is that the histological characteristics in patients with CD can be predicted clinically by means of inflammation and fibrosis assessment in conjunction with tissue stiffness measurement.

Bowel ultrasound enhances predictive value based on clinical indicators: a scoring system for moderate-to-severe endoscopic activities in patients with ulcerative colitis

BACKGROUND AND AIM

The aim was to assess non-invasive factors among clinical features, laboratory, and bowel ultrasound (BUS) characteristics and to develop a scoring system to predict endoscopic activities for ulcerative colitis (UC) patients.

METHODS

We performed a retrospective study collecting UC patients between January 2015 to September 2020. Logistic regression was performed to predict moderate-to-severe endoscopic activities, defined as endoscopic Mayo score ⩾2. Model performance was described with discrimination and calibration ability and validated by internal and external methods.

RESULTS

A total of 103 and 29 patients were enrolled in the modeling and validation groups, respectively. Stool frequency ⩾5 times/day, hematochezia, erythrocyte sedimentation rate (ESR), and colonic wall flow in BUS were included into two predictive models for endoscopic activities, both with good discrimination ability [Area under curve (AUC) 0.879 and 0.882, p < 0.001] and a sensitivity of 76.7% and specificity of 92.3%, which showed an adequate calibration ability by using the Hosmer-Lemeshow test (p = 0.14 and 0.07). The external validation displayed consistent results with the above mentioned. Nomograms were also established for these models.

CONCLUSION

We developed predictive models for endoscopic disease activities by using noninvasive factors based on stool frequency, hematochezia, ESR, and colonic wall blood flow in BUS. These models performed well in the internal and external validation.

Serological Biomarkers of Tissue Turnover Identify Responders to Anti-TNF Therapy in Crohn's Disease: A Pilot Study

INTRODUCTION

Anti-tumor necrosis factor (TNF) therapy is effective in inducing remission in Crohn's disease in 60% of patients. No serological biomarkers are available, which can predict response to anti-TNF. We aimed to investigate serological markers of collagen turnover reflecting tissue inflammation as predictors of response to anti-TNF.

METHODS

In 2 retrospective observational cohorts, markers for matrix metalloproteinase-degraded type III and IV collagens (C3M and C4M, respectively) and for formation of type III and IV collagens (PRO-C3 and PRO-C4, respectively) were measured in serum and compared with standard C-reactive protein in patients with active Crohn's disease who started infliximab (IFX, n = 21) or adalimumab (ADA, n = 21). Disease activity was classified by the Harvey-Bradshaw index (active disease ≥5); response was defined as clinical remission.

RESULTS

Seventeen patients (81%) treated with IFX were in remission at week 14; 15 patients (71%) treated with ADA were in remission at week 8. Serum C4M at baseline was increased in nonresponders compared with responders (IFX: 35.0 ± 2.4 vs 23.2 ± 2.6, P = 0.04, ADA: 53.0 ± 3.2 vs 34.1 ± 2.8, P = 0.006). C4M levels at baseline predicted response in both cohorts (IFX: odds ratio 39 [95% confidence interval, 2.4-523.9] P = 0.02, cutoff 35.2 nmol/L; ADA: odds ratio 26 [95% confidence interval, 1.8-332.5], P = 0.01, cutoff 46.9 nmol/L). C-reactive protein was not able to predict response to anti-TNF.

DISCUSSION

Response to anti-TNF therapy within the first 14 weeks of treatment can be predicted based on baseline levels of basement membrane marker C4M. This marker could be used as biomarker for response to anti-TNF and could aid in early therapy decision making. Validation in larger well-defined cohorts is needed.

Chronic inflammation and other changes are significant components of clinically fibrotic strictures in Crohn's disease: a histological study of resected strictures clinically characterized as noninflamed

BACKGROUND

Strictures related to Crohn's disease due to fibrosis are a result of an exaggerated tissue remodelling response to inflammation, characterized by accumulation of collagen-rich extracellular matrix produced by mesenchymal cells.

OBJECTIVES

The objective of this study was to characterize histological changes seen in resected 'fibrotic' strictures to better understand individual components of intestinal stenosis.

METHODS

We identified patients undergoing surgery for ileal Crohn's disease secondary to symptomatic stricturing disease (Montreal B2) using the histopathology database at Queen Elizabeth Hospital in Birmingham, UK, between 2012 and 2017. Phenotypic data were recorded and resection specimens reviewed. Two independent pathologists applied the semiquantitative scoring system previously developed by us to the microscopic images. Data were analyzed using the possible maximum total score (%PMTS).

RESULTS

Forty-eight patients (M = 25) were included. with median disease duration of 7 years (range 0.25-39 years); nearly two-thirds had ileocolonic distribution (L3). In this cohort, despite presurgery diagnosis of noninflamed fibrosis, chronic inflammation was noted to be a prominent component of all strictures. The histological scoring showed presence of several other prominent findings such as muscular hyperplasia and volume expansion.There was statistically significant positive correlation between chronic inflammation and fibrosis and muscular hyperplasia.

CONCLUSION

The histological features of Crohn's disease-related strictures show multiple changes in multiple layers and not simply fibrosis. In our cohort, despite the observation prior to surgery that strictures were clinically considered fibrotic, the finding of chronic inflammation as a dominant component at a histological level in the resection is important. The findings might suggest that one of the main drivers of progressive fibrosis is the inflammatory component, which probably is never fully resolved.

Multiple strictures of the small intestine demanding surgical intervention as a rare consequence of graft versus host disease – case report

Background

Intestinal strictures are an extremely rare and life-threating complication in patients undergoing allogenic hematopoietic stem cell transplantation (allo-HSCT). We describe the case of a child operated for multiple strictures of the small intestine secondary to GvHD.

Case presentation

A 7-year-old girl underwent second allo-HSCT from matched unrelated donor for post-CALR-positive-ET myelofibrosis and its relapse after the first HSCT. HSCT was complicated with grade IV acute GvHD (skin and gut). The patient was treated with CsA, with methylprednisolone, and due to corticosteroid resistance subsequently with etanercept and ECP. She required parenteral nutrition due to malabsorption symptoms and anorexia for 15 months after HSCT. On day + 457, the laparotomy was performed due to increasing symptoms of mechanical bowel obstruction. Ten critical cicatricial strictures of the small intestine were revealed. Nine segmental resections of the strictured segments and 6 intestinal anastomoses were done during one surgical procedure. The postoperative period was uncomplicated, and oral feeding was gradually implemented, achieving full coverage. Pathological examination confirmed the diagnosis of overlap syndrome of acute and chronic GvHD. Therefore, the patient started therapy with ruxolitinib which was continued till 30 months after HSCT. Corticosteroids were gradually withdrawn on day + 574. Currently, 32 months after the second HSCT, no GvHD and no gastrointestinal disturbances are observed. The patient remains in hematological and molecular remission of myelofibrosis.

Conclusions

GvHD therapy is largely based on conservative treatment, but a patient presenting with occlusive symptoms due to permanent changes in the gastrointestinal wall needs to undergo surgery to ensure its efficient functioning.

Transmural Histological Scoring Systems in Crohn's Disease: A Systematic Review With Assessment of Methodological Quality and Operating Properties

BACKGROUND

The relative proportion of inflammation and fibrosis in a stricture is highly relevant in defining the clinical approach for Crohn's disease [CD] patients. Whereas transmural inflammation in CD can be accurately estimated by cross-sectional imaging, evaluating the extent and severity of fibrosis still requires surgical pathology of intestinal resection specimens. This study systematically reviewed all existing transmural histopathological scoring systems developed for the assessment of inflammation and/or fibrosis in CD.

METHODS

A systematic review of histopathological scoring systems for the assessment of transmural inflammation and/or fibrosis in CD, focusing on originally developed scoring systems. Risk of bias, methodological quality, and operating or psychometric properties [validity, reliability, responsiveness, and feasibility] of each histological scoring system were analysed.

RESULTS

A total of 29 original scoring systems were included in this review. Three scoring systems were highlighted as the most widely reproduced, one aimed at assessing inflammation only and two aimed at assessing inflammation and fibrosis. These scores were more widely reproduced probably due to their ease of application in clinical studies. Two highly comprehensive scores were identified, showing good operating properties and high methodological quality, as well as the lowest risk of bias; these should, therefore, be further validated in clinical research studies.

CONCLUSIONS

This study reviewed all existing transmural histopathological scoring systems for the assessment of inflammation and/or fibrosis in CD and identified the most reliable and accurate scores for clinical research and clinical practice settings.

Clinical significance of granulomas in Crohn's disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Epithelioid granuloma is one hallmark used to histologically diagnose Crohn's disease (CD). However, the clinical significance of granulomas in CD is unclear. Therefore, we performed a meta-analysis to compare the clinical features with CD according to the presence of granulomas.

METHODS

A literature search in PubMed, EMBASE, and Cochrane databases was performed on manuscripts published until October 2018. We included studies that met the following inclusion criteria: (i) patient: patients with CD; (ii) exposure: granulomas on the pathology; (iii) comparator: no granulomas; and (iv) outcomes: disease location, disease behavior, perianal disease, disease activity, use of biologics, and CD-associated hospitalization, surgery.

RESULTS

Nineteen studies met our inclusion criteria. Granulomas in CD patients were associated with a higher proportion of ileocolonic disease (odds ratio [OR]: 1.49, 95% confidence interval [CI]: 1.21-1.83), a higher proportion of upper gastrointestinal disease (OR: 2.25, 95% CI: 1.28-3.95), a higher proportion of penetrating behavior (OR: 1.48, 95% CI: 1.09-2.01), a higher prevalence of perianal disease (OR: 2.15, 95% CI: 1.48-3.11), and a higher severity index at presentation (standardized mean difference: 0.20, 95% CI: 0.09-0.32). In addition, the use of biologics was significantly higher in CD patients with granulomas compared with without granulomas (OR: 1.66, 95% CI: 1.07-2.59). The presence of granulomas was significantly associated with CD-associated hospitalization (OR: 3.88, 95% CI: 1.44-10.49), but not with CD-associated surgery.

CONCLUSIONS

Clinical features in CD patients were significantly different according to the presence of granulomas. It may indicate a more aggressive phenotype of CD.

Levels of Intestinal Inflammation and Fibrosis in Resection Specimens after Preoperative Anti-Tumor Necrosis Factor Alpha Treatment in Patients with Crohn's Disease: A Comparative Pilot Study

Background

Strictures are a common complication in Crohn's disease (CD), found in more than 50% of patients. They are characterized by the excessive deposition of extracellular proteins in the tissue as a result of the chronic inflammatory process. The effect of anti-tumor necrosis factor alpha (TNF-α) therapy on the development of fibrosis is not yet fully understood.

Aim

To investigate whether the degree of intestinal inflammation and fibrosis is correlated with preoperative anti-TNF-α) therapy on the development of fibrosis is not yet fully understood.

Methods

This unblinded, prospective, single tertiary center, pilot cohort study included all adult patients with CD who underwent elective, laparoscopic, or open intestinal resection. Preoperative investigations included measurement of blood TNF-α) therapy on the development of fibrosis is not yet fully understood.

Results

Histopathological specimens from 10 patients with CD who underwent ileocecal or ileocolic resections were retrieved. Four of those patients were on anti-TNF-α) therapy on the development of fibrosis is not yet fully understood. α) therapy on the development of fibrosis is not yet fully understood. α) therapy on the development of fibrosis is not yet fully understood. p=0.01). Anti-TNF-α) therapy on the development of fibrosis is not yet fully understood. α) therapy on the development of fibrosis is not yet fully understood. α) therapy on the development of fibrosis is not yet fully understood.

Conclusions

Patients who underwent preoperative anti-TNF-α treatment had a higher fibrosis score than controls.α) therapy on the development of fibrosis is not yet fully understood.

Epithelioid Granulomas Associate With Increased Severity and Progression of Crohn's Disease, Based on 6-Year Follow-Up

BACKGROUND & AIMS

Epithelioid granulomas are characteristics of a subset of patients with Crohn's disease (CD), but their significance, with regard to disease progression and severity, is unclear. We investigated the relationship between granulomas and CD severity over a 6-year time period in a large cohort of patients.

METHODS

We performed a retrospective study of patients with CD seen at the Inflammatory Bowel Disease Center at the University of Pittsburgh; data were collected from 2009 through 2014 and patients were assigned to groups with and without histologic evidence of granuloma. Demographic, clinical (including disease activity, quality of life, medication use, and healthcare utilization), and laboratory data were used in association and survival analyses. Differences between groups were evaluated using the Mann-Whitney U-test for continuous variables.

RESULTS

Of 1466 patients with CD, granulomas were identified in 187 (12.8%). In the subset of patients who underwent surgery, 21.0% had granulomas. The presence of granuloma was associated with increased serum levels of c-reactive protein (odds ratio [OR], 2.9; 95% CI, 2.078-4.208; P < .0001), younger mean age at diagnosis (23.6 ± 11.3 years in patients with granulomas vs 27.9 ± 13.3 years in patients without; P = .0005), higher rates of stricturing or penetrating disease phenotype, higher rates of steroid and narcotic use, and higher healthcare utilization. Among patients that underwent surgery, the presence of granulomas was associated with need for repeat surgery during the 6-year observation period (OR, 2.5; 95% CI, 1.54-4.02; P = .0002). Infliximab use was associated with detection of granuloma in a significantly lower proportion of surgical specimens compared to patients who had not been treated with a biologic agent (OR, 0.22; 95 CI, 0.05-0.97; P = .03).

CONCLUSIONS

Epithelioid granulomas develop in less than 13% of patients with CD, and are associated with a more aggressive disease phenotype. Patients who have undergone surgery for CD and have granulomas are at increased risk for repeat surgery within 6 years.

Smooth Muscle Hyperplasia/Hypertrophy is the Most Prominent Histological Change in Crohn's Fibrostenosing Bowel Strictures: A Semiquantitative Analysis by Using a Novel Histological Grading Scheme

BACKGROUND

The simplistically and ambiguously termed 'fibrostenosis' of bowel is a hallmark of severe Crohn's disease [CD] and a major contributor to medical treatment failure. Non-invasive imaging assessment and novel medical therapy targeting this condition are under investigation, which particularly requires a better understanding of the underlying histological basis.

METHODS

We analysed 48 patients with stricturing Crohn's ileitis or/and colitis that required surgical resection. The most representative sections of the fibrostenotic, non-stenotic and uninvolved regions were reviewed for histological analysis. For each layer of bowel wall (mucosa including muscularis mucosae [MU], submucosa [SM], muscularis propria [MP], subserosal adventitia [SS]), histological abnormalities were evaluated individually, including active and chronic inflammation, fibrosis, smooth muscle hyperplasia or hypertrophy, neuronal hypertrophy and adipocyte proliferation. A novel semiquantitative histological grading scheme was created.

RESULTS

The most significant histopathological features characterizing the stricturing intestines were smooth muscle hyperplasia of SM, hypertrophy of MP and chronic inflammation. The muscular alteration was predominant in all layers. The overall muscular hyperplasia/hypertrophy was positively correlated with chronic inflammation and negatively correlated with fibrosis, whereas SM muscular hyperplasia was also associated with MU active inflammation. Similar changes, to a lesser extent, occurred in the adjacent non-stenotic inflamed bowel as well.

CONCLUSIONS

In CD-associated 'fibrostenosis', it is the smooth muscle hyperplasia/hypertrophy that contributes most to the stricturing phenotype, whereas fibrosis is less significant. The 'inflammation-smooth muscle hyperplasia axis' may be the most important in the pathogenesis of Crohn's strictures.

Patient optimization for surgery relating to Crohn's disease

The majority of patients with Crohn's disease require abdominal surgery during their lifetime, some of whom will require multiple operations. Postoperative complications are seen more frequently in patients requiring abdominal surgery for Crohn's disease than in patients requiring abdominal surgery for other conditions. In this article, we review the evidence supporting preoperative optimization, discussing strategies that potentially improve surgical outcomes and reduce perioperative morbidity and mortality. We discuss the roles of adequate cross-sectional imaging, nutritional optimization, appropriate adjustments of medical therapy, management of preoperative abscesses and phlegmons, smoking cessation and thromboembolic prophylaxis. We also review operation-related factors, and discuss their potential implications with respect to postoperative complications. Overall, the literature suggests that preoperative management has a major effect on postoperative outcomes.

Colonic macrophage polarization in homeostasis, inflammation, and cancer

Our review focuses on the colonic macrophage, a monocyte-derived, tissue-resident macrophage, and the role it plays in health and disease, specifically in inflammatory conditions such as inflammatory bowel disease and cancer of the colon and rectum. We give special emphasis to macrophage polarization, or phenotype, in these different states. We focus on macrophages because they are one of the most numerous leukocytes in the colon, and because they normally contribute to homeostasis through an anti-inflammatory phenotype. However, in conditions such as inflammatory bowel disease, proinflammatory macrophages are increased in the colon and have been linked to disease severity and progression. In colorectal cancer, tumor cells may employ anti-inflammatory macrophages to promote tumor growth and dissemination, whereas proinflammatory macrophages may antagonize tumor growth. Given the key roles that this cell type plays in homeostasis, inflammation, and cancer, the colonic macrophage is an intriguing therapeutic target. As such, potential macrophage-targeting strategies are discussed.

Endoscopic Complete Remission of Crohn Disease After Anti-Tumor Necrosis Factor-α Therapy: CT Enterographic Findings and Their Clinical Implications

OBJECTIVE

The purpose of this study was to describe the CT enterographic (CTE) findings after endoscopic complete remission (CR) of Crohn disease in patients treated with anti-tumor necrosis factor-α (anti-TNF-α) and the clinical implications of these findings.

MATERIALS AND METHODS

The records of 27 patients with Crohn disease (14 men, 13 women; mean age, 28.4 ± 8.6 [SD] years) who achieved endoscopic (ileocolonoscopic) CR after anti-TNF-α therapy and underwent CTE both before therapy and at endoscopic CR were identified. Two readers independently assessed the frequencies and severities of mural and perienteric CTE abnormalities, generally regarded as active inflammatory findings, in the terminal ileum and colorectum in the endoscopic CR state and compared them with the corresponding findings before anti-TNF-α therapy. The association between the presence of CTE abnormalities in the face of endoscopic CR and patient outcome during subsequent follow-up was investigated.

RESULTS

CTE abnormalities were present in the face of endoscopic CR in 11-18 (26-42%) of 43 bowel sections (18 terminal ileum, 25 colorectum), the most frequent being mural hyperenhancement (21-40%) followed by mural thickening (12-16%). Both findings were mild and unaccompanied by other findings. The frequency and severity of mural and perienteric CTE abnormalities were statistically significantly reduced at endoscopic CR compared with the pre-treatment state. Patients with (n = 10) and without (n = 17) CTE abnormalities at endoscopic CR did not significantly differ with respect to Crohn disease aggravation during subsequent follow-up periods averaging 27.4 and 28.5 months (0/10 versus 2/17, p = 0.516).

CONCLUSION

More than one-fourth of bowel sections in endoscopic CR after anti-TNF-α therapy had residual CTE abnormalities, predominantly mild mural thickening or hyperenhancement. These findings may not have any clinical significance.