Significance of the epithelioid granuloma in biopsies of Crohn's colitis

Definitions of Histological Abnormalities in Inflammatory Bowel Disease: an ECCO Position Paper

Histological assessment of endoscopic biopsies in inflammatory bowel disease [IBD] plays an important role in clinical management, investigative studies, and clinical trials. Scoring schemes consisting of multiple histological items and offering considerable precision are widely available. However, definitions of histological abnormalities are often inconsistent. Furthermore, interobserver variability for their recognition and assessment may be high. The European Crohn's and Colitis Organisation [ECCO] formed an expert panel to explore definitions of histological abnormalities in IBD, with the aim of improving the quality of diagnosis and facilitating development of scoring schemes. The process confirmed that the current definitions often have no evidence base and vary between sources. Using available evidence and expert knowledge, the panel produced a series of ECCO consensus position statements on histological features in IBD.

Detection Rates of Non-Cavitary Epithelioid Cell Granuloma by Gastrointestinal Biopsy in Patients with Treatment-Naïve Crohn's Disease

Introduction

Detecting non-cavitary epithelioid cell granuloma by gastrointestinal biopsy is important in the initial diagnosis of Crohn's disease (CD). In the present study, we aimed to determine the rate of granuloma detection by gastrointestinal biopsy according to the number of biopsies performed.

Methods

The present study included patients newly diagnosed with CD at our hospital between April 2017 and March 2023. During endoscopic examinations, biopsy specimens were taken from affected lesions. Initially, one section per biopsy was examined to detect granuloma. In cases where no granulomas were detected, step sections were additionally prepared and examined. The rate of granuloma detection by gastrointestinal biopsy was retrospectively examined.

Results

A total of 30 patients with a new diagnosis of CD were included in this study. In total, 284 gastrointestinal biopsies were performed in 29 cases. The rate of granuloma detection by gastrointestinal biopsy per case was 58.6% (17 out of 29 cases). The rate of granuloma detection by gastrointestinal biopsy per biopsy was 6.0% (17 out of 284 biopsies) on initial histological examination and 11.6% (33 out of 284 biopsies) following examination of step sections. The rate of granuloma detection was significantly improved by performing histological examination of step sections compared with initial examinations (p < 0.05).

Conclusion

The rate of granuloma detection per biopsy was 11.6%, even after histological examination of step sections. These results indicate that performing multiple intestinal biopsies and assessing for the presence of granuloma using multiple section examinations are required in the initial diagnosis of CD.

Additional information obtained from mucosal biopsies is limited after pan-enteric capsule endoscopy in patients with suspected Crohn's disease

Background and study aims Pan-enteric capsule endoscopy (CE) is an emerging alternative to ileo-colonoscopy for diagnosing Crohn's disease (CD). However, CE does not offer the opportunity to take biopsies to support the diagnosis. This study examined the additional information obtained with mucosal biopsies and the feasibility of CE as a single diagnostic procedure. Patients and methods This retrospective study was based on a prospective, blind multicenter trial in which patients with suspected CD were examined with ileo-colonoscopy plus segmental biopsies and CE. Histopathological findings were compared to the result of CE. Results A total of 107 patients with a complete CE were included in the analysis. CE was consistent with CD in 44 patients (41.1%) and ulcerative colitis in 10 patients (9.3%). Histopathology confirmed the result of CE in 39.3% of patients and added new diagnostic information in 6.5% of patients. A CE consistent with CD was histologically confirmed in 20.5% of patients. Biopsies most often showed non-specific inflammation (61.4%). Only one patient with a normal CE had a specific histological diagnosis (microscopic colitis). Biopsies altered the diagnosis of ulcerative colitis to CD in two patients, and in two patients with a normal CE, biopsies showed CD or ulcerative colitis. In one patient with lymphoma in the terminal ileum and cecum, CE was misinterpreted as CD. Conclusions In patients with suspected CD and an evident result of CE, the additional information obtained from biopsies is limited, and CE as a single diagnostic procedure might be feasible in selected patients. Biopsies are warranted, however, in patients with an atypical endoscopic appearance or suspected malignancy.

Risk Factors of Clinical Relapses in Pediatric Luminal Crohn's Disease: A Retrospective Cohort Study

INTRODUCTION

There is currently little knowledge on factors associated with the relapse of Crohn's disease (CD) in children. The aims of this study were to describe the risk factors associated with relapse in pediatric CD and the changes in the relapse rate over the past decade.

METHODS

Patients younger than 18 years and diagnosed between 2009 and 2019 were included in this retrospective cohort study. Clinical, endoscopic, histological, and laboratory data, as well as induction and maintenance treatments, were collected from the medical records. Survival analyses and Cox regression models were used to assess the impact of these risk factors on relapse.

RESULTS

Six hundred thirty-nine patients were included. There was a decrease in the clinical relapse rate over the past decade: 70.9% of the patients diagnosed between 2009 and 2014 relapsed as compared with 49.1% of the patients diagnosed between 2015 and 2019 (P < 0.0001). The following variables were associated with clinical relapse: female sex (adjusted hazard ratio [aHR] = 1.52, P = 0.0007), exposure to oral 5-ASA (aHR = 1.44, P = 0.04), use of immunomodulatory agents compared with tumor necrosis factor-alpha inhibitors (methotrexate aHR = 1.73, P = 0.003; thiopurines aHR = 1.63, P = 0.002), presence of granulomas (aHR = 1.34, P = 0.02) and increased eosinophils on intestinal biopsies (aHR = 1.36, P = 0.02), high levels of C-reactive protein (aHR = 1.01, P < 0.0001) and fecal calprotectin (aHR = 1.08, P < 0.0001), and low serum infliximab levels (aHR = 2.32, P = 0.001).

DISCUSSION

Relapse of pediatric CD has decreased in the past decade. The risk of relapse is significantly associated with clinical, endoscopic, histological, and laboratory variables and treatment strategies.

Granulomas in Diagnostic Biopsies Associated With High Risk of Crohn's Complications-But May Be Preventable

BACKGROUND

Granulomatous intestinal inflammation may be associated with aggressive Crohn's disease (CD) behavior. However, this has not been confirmed, and it is unknown if associated disease complications are preventable.

METHODS

This is a retrospective cohort of patients younger than 21 years at CD diagnosis (November 1, 2005 to November 11, 2015). Clinical information was abstracted, including dates of starting medications and the timing of perianal fistula or stricture development, if any. Diagnostic pathology reports were reviewed, and a subset of biopsy slides were evaluated by a blinded pathologist. Patients were excluded if perianal fistula or stricture developed within 30 days after CD diagnosis. Medications were included in analyses only if started >90 days before development of perianal fistula or stricture.

RESULTS

In total, 198 patients were included. Half (54%) had granulomas at diagnosis. Granulomas were associated with a greater than 3-fold increased risk of perianal fistula (hazard ration [HR] = 3.24; 95% confidence interval CI], 1.40-7.48). Immunomodulator and anti-tumor necrosis factor-α (anti-TNF) therapy were associated with 90% (HR, = 0.10; 95% CI, 0.03-0.42) and 98% (HR, = 0.02; 95% CI, 0.01-0.10) reduced risk of perianal fistula, respectively. Patients with granulomatous inflammation preferentially responded to anti-TNF therapy with reduced risk of perianal fistula. The presence of granulomas was not associated with risk of stricture. Immunomodulator and anti-TNF therapy were associated with 96% (HR, = 0.04; 95% CI, 0.01-0.22) and 94% (HR, = 0.06; 95% CI, 0.02-0.20) reduced risk of stricture, respectively.

CONCLUSIONS

Granulomas are associated with increased risk of perianal fistula but not stricture. Steroid sparing therapies seem to reduce the risk of both perianal fistula and stricture. For those with granulomas, anti-TNF-α therapy greatly reduced the risk of perianal fistula development, whereas immunomodulators did not.

Clinicopathological Characteristics and Etiological Factors of Granulomatous Gastritis

AIMS

To examine the clinicopathological characteristics of granulomatous gastritis (GG) among different etiologies, particularly Crohn disease (CD), and determine the contribution of H. pylori and the clinical significance of isolated GG.

METHODS/RESULTS

We identified 269 GG cases overall (0.19% prevalence): 220 had an underlying granulomatous disease (CD, sarcoidosis, tuberculosis) and only 8 of these (3.6%) had H. pylori, fewer than the 10.3% rate among non-GG biopsies (p<.001). Conversely, among 49 GG cases without known cause (foreign body, undetermined, idiopathic), 13 (26.5%) had H. pylori, more than background (p=.001). Most patients (n=185/68.8%) had CD and these were more likely male (p<.001), younger (p<.001), white (p<.001), and had single (p=.010), smaller (p=.005), antral (p=.027) granulomas, amid inflammation (p=.005), compared to non-CD GG cases; younger age was independently associated with CD (p=.003; OR=1.13, 95% CI: 1.04-1.22). Among CD patients, younger age (p=.003; OR=1.04, 95% CI: 1.01-1.07) and upper gastrointestinal (GI) symptoms (p=.017; OR=2.53, 95% CI: 1.18-5.43) were associated with new (vs. established) diagnosis, whereas multiple gastric granulomas (p=.003; OR=4.67, 95% CI: 1.67-13.04) and lack of upper GI symptoms (p<.001; OR=6.75, 95% CI: 2.94-15.49) were associated with lower GI granulomas. Of 86 isolated GG cases (i.e., no prior diagnosis or lower GI granulomas), 51 (59.3%) were eventually diagnosed with CD, and this was independently associated with younger age (p=.014; OR=1.11, 95% CI: 1.02-1.21) and upper GI symptoms (p=.033; OR=19.27, 95% CI: 1.27-293.31). The positive predictive value of finding isolated GG towards a CD diagnosis in patients <30 years-old was 91%, increasing in males (93%), with single (94%), antral (97%) granulomas, or upper GI symptoms (94%).

CONCLUSIONS

GG does not correlate with H. pylori in patients with granulomatous disease, but may be associated with the organism when such diagnosis is lacking. In CD patients with GG, younger age and upper GI symptoms are associated with a new CD diagnosis, whereas multiple gastric granulomas and lack of upper GI symptoms correlate with lower GI granulomas. GG, including in isolated cases with no prior clinical history or granuloma, likely signifies CD, particularly in younger, male patients, or those with single, antral granulomas, or upper GI symptoms.

Clinical features and monocyte/macrophage subsets characterization in granulomatous vs non-granulomatous Crohn's disease

Aims: Granuloma, mainly composed of macrophages, is a histological feature of Crohn's disease (CD). However, its significance in CD has not been investigated adequately. Our study aims to address this issue by comparing the clinical manifestations and monocyte/macrophage subtypes between granulomatous and non-granulomatous CD.Materials and methods: Demographics, symptoms, endoscopic manifestations, histopathological features, and Montreal classification of patients with and without granulomas were compared. Flow cytometry was used to determine the phagocytosis and subsets of monocytes. ELISA was used to measure the plasma levels of TNF-α, IL-6, IL-1β, IL-10, CCL22, and TGF-β1. Immunohistochemistry was performed to quantify the expression of CD68, CD163 and iNOS.Results: Of the222 CD patients enrolled, granulomas were detected in 90. Compared with non-granulomatous CD patients, those with granulomas had younger age, increased rates of diarrhea and perianal complications, along with higher endoscopic score. Intestinal stenosis and crypt abscess were more frequently observed in granulomatous CD patients. A defective phagocytosis of monocytes was observed in granulomatous CD patients. Meanwhile, higher percentages of intermediate and non-classic monocytes, with a lower percentage of classic monocyte were found in them. Besides, they had higher levels of TGF-β1 and IL-10, a lower level of TNF-α, an increased ratio of CD163⁺/CD68⁺cells, and a decreased ratio of iNOS⁺/CD68⁺ cells.Conclusions: Granulomatous CD patients exhibited different manifestations compared with their non-granulomatous counterparts. More aggressive therapy may be needed in granulomatous CD patients. Furthermore, the heterogeneity of monocyte/macrophage subsets and altered plasma cytokine may underlie the difference between those two groups.

Selective M1 macrophage polarization in granuloma-positive and granuloma-negative Crohn's disease, in comparison to intestinal tuberculosis

BACKGROUND/AIMS

Classical M1 macrophage activation exhibits an inflammatory phenotype while alternative M2 macrophage activation exhibits an anti-inflammatory phenotype. We aimed to determine whether there are discriminant patterns of macrophage polarization in Crohn's disease (CD) and intestinal tuberculosis (iTB).

METHODS

Colonic mucosal biopsies from 29 patients with iTB, 50 with CD, and 19 controls were examined. Dual colored immunohistochemistry was performed for iNOS/CD68 (an M1φ marker) and CD163/CD68 (an M2φ marker), and the ratio of M1φ to M2φ was assessed. To establish the innate nature of macrophage polarization, we analyzed the extent of mitochondrial depolarization, a key marker of inflammatory responses, in monocyte-derived macrophages obtained from CD and iTB patients, following interferon-γ treatment.

RESULTS

M1φ polarization was more prominent in CD biopsies (P=0.002) than in iTB (P=0.2) and control biopsies. In granuloma-positive biopsies, including those in CD, M1φ predominance was significant (P=0.001). In iTB, the densities of M1φ did not differ between granuloma-positive and granuloma-negative biopsies (P=0.1). Interestingly, higher M1φ polarization in CD biopsies correlated with high inflammatory response exhibited by peripheral blood-derived monocytes from these patients.

CONCLUSIONS

Proinflammatory M1φ polarization was more common in colonic mucosa of CD patients, especially in the presence of mucosal granulomas. Further characterization of the innate immune system could help in clarifying the pathology of iTB and CD.

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.

Granulomatous Upper Gastrointestinal Inflammation in Pediatric Ulcerative Colitis

OBJECTIVES

Differentiating ulcerative colitis (UC) and Crohn disease (CD) can be clinically challenging, especially in children. Granulomatous inflammation has traditionally been attributed to CD. Crypt-associated giant cells and granulomas, however, have been observed in colonic biopsies of patients with UC. This phenomenon has not been described in the upper gastrointestinal (UGI) tract with UC.

METHODS

Seven pediatric patients with UC with granulomatous UGI (gUGI) lesions were identified. Diagnosis of UC was based on symptoms, clinical course, laboratory results, imaging, and endoscopy. We compared the gUGI patients to a large cohort of pediatric patients with UC (n = 149).

RESULTS

All fully evaluated cases were associated with bloody diarrhea and moderate to severe pancolitis. Gastric and/or duodenal biopsies demonstrated giant cells or granulomas near gland destruction. Small bowel imaging did not reveal any involvement. The majority of cases responded to standard medical therapies, except for 2 patients (28.6%) who required total colectomy. Acute severe, refractory colitis (ie, colectomy within 1 month of presentation) was significantly more common in the gUGI group than the large pediatric UC group (28.6% vs 1.3%, Fisher exact P = 0.01).

CONCLUSIONS

This is the first report of pediatric UC-associated granulomatous inflammation in the UGI tract. We speculate that these lesions represent extracolonic manifestations of intense colonic disease. These atypical findings expand the diagnostic considerations that should be incorporated during the differentiation between UC and CD in the pediatric age group.

Prognostic significance of granulomas in children with Crohn's disease

OBJECTIVES

Granulomas have long been considered the histological hallmark of Crohn's disease (CD). Currently, there is considerable dispute with regards to their prognostic implications. We aimed to determine the effect of granulomas on phenotypic features and disease's long-term outcomes in a large cohort of pediatric CD patients.

MATERIALS AND METHODS

Medical records of pediatric CD patients diagnosed at the Schneider Children's Medical Center were reviewed retrospectively. Patients were categorized into two groups based on the presence or absence of granulomas at diagnosis. Baseline characteristics included anthropometric, clinical, laboratory, radiological and endoscopic data. Outcome measures included flares, hospitalizations, biological therapy and surgery.

RESULTS

Of 289 CD patients diagnosed between 2001 and 2015, 99 patients (34%) had granulomas. Median age of the entire cohort at diagnosis was 14.2 years (females, 42.6%), with a median follow-up of 8.5 years. Patients with granulomas had a significantly higher percentage (47.5% vs. 23.7%, p = .001) of upper gastrointestinal involvement and ileo-colonic disease (64.9% vs. 49.5%, p = .01). Extraintestinal manifestations were twice as common in patients without granulomas (16.3% vs. 8.1%, p = .05). Patients with granulomas were more likely to be hospitalized (HR =1.43, 95% CI: 1.0-2.0) and to receive biologic therapy (HR = 1.52, 95% CI: 1.1-2.11). Additionally, both of these disease outcomes occurred significantly earlier (p = .013 and p = .027, respectively). In contrast, patients with granulomas did not exhibit increased risk of flares or bowel resection.

CONCLUSION

Patients with granulomas exhibited a distinct phenotype at diagnosis and demonstrated a more severe disease course.

Association of granulomas in mesenteric lymph nodes in Crohn's disease with younger age and transmural inflammation

BACKGROUND AND AIMS

Mesenteric lymph nodes were usually removed during bowel resection surgery for Crohn's disease (CD). Mesenteric lymph node (MLN) granuloma predicted postoperative disease recurrence in patients with CD after ileocolic resection (ICR). This study was aimed to identify factors associated with MLN granulomas in a cohort of CD patients who underwent ICR.

METHODS

The study group consisted of 18 patients with CD who underwent the index ICR between 2004 and 2012 and had MLN granulomas. The control group included 32 cases negative for MLN granulomas, which were randomly selected from the same period. Clinicodemographic and histological features were compared in these two groups.

RESULTS

The presence of MLN granuloma was associated with younger age, perianal disease, and ileocolic disease. Gender, body mass index, smoking status, disease duration, extraintestinal manifestation, length of bowel resected, total number of nodes examined, medical treatment, and indications for surgery were not significantly different between the groups. The presence of MLN granuloma was associated with mural granuloma, transmural inflammation, mural abscess, hypertrophy of the muscularis propria, fibrosis of the muscularis propria, and serosal fibrosis in the small bowel. The multivariable analysis confirms that MLN granuloma was associated with age and transmural inflammation.

CONCLUSIONS

In CD patients who underwent the index ICR, the presence of MLN granuloma was associated with younger age and transmural inflammation. Our current results suggest that the detection of MLN granulomas may be enhanced in patients at higher risk, that is, younger patients or those with transmural inflammation on imaging or histopathology.

Genetic and environmental factors significant for the presentation and development of inflammatory bowel disease

OBJECTIVES

The aim of the study was to evaluate associations between inflammatory bowel disease (IBD) presentation and variants in NOD2, TLR4, TNF-α, IL-6, IL-1β, and IL-RN genes in order to identify possible environmental factors that may affect IBD occurrence, investigate potential predictors for surgical treatment of IBD, and correlate the presence of granulomas in biopsy specimens with clinical characteristics of Crohn's disease (CD) patients.

PATIENTS AND METHODS

We genotyped 167 IBD patients using PCR-based methodology and tested for disease genotype-phenotype associations.

RESULTS

In CD patients ileal localization of disease was more frequent in NOD2 variant carriers. Ileal CD was associated with IL-6 GC+CC genotypes, identifying C allele as a possible marker of increased risk for ileal CD. In CD patients a positive family history for IBD was related to earlier onset of disease, higher risk for CD-related surgery, and appendectomy. CD patients who are TLR4 299Gly carriers are at higher risk for surgery at onset of the disease compared with TLR4 299Asp variant carriers. The presence of granuloma in biopsy specimens was more frequent in patients in whom a diagnosis of CD was made during emergency surgery. Multivariate analysis showed that CD carriers of the 299Gly allele had a 4.6-fold higher risk for emergency surgery before CD diagnosis is established compared with noncarriers, suggesting an aggressive disease course. Granuloma in endoscopic biopsies is detected 5.4-fold more frequently in patients treated surgically at the time of diagnosis.

CONCLUSION

Genetic variants together with epidemiological and clinical data of IBD patients could potentially be used as predictors of the disease course.

Immunopathogenesis of granulomas in chronic autoinflammatory diseases

Granulomas are clusters of immune cells. These structures can be formed in reaction to infection and display signs of necrosis, such as in tuberculosis. Alternatively, in several immune disorders, such as sarcoidosis, Crohn's disease and common variable immunodeficiency, non-caseating granulomas are formed without an obvious infectious trigger. Despite advances in our understanding of the human immune system, the pathogenesis underlying these non-caseating granulomas in chronic inflammatory diseases is still poorly understood. Here, we review the current knowledge about the immunopathogenesis of granulomas, and we discuss how the involved immune cells can be targeted with novel therapeutics.

Bovine lactoferrin and Crohn's disease: a case study

A 22-year-old male suffering from abdominal pain, repeated diarrhea, and weight loss visited the Digestive Disease Department of Nagoya City University Hospital on 19 December 2011. He was hospitalized and diagnosed with Crohn's colitis. His Crohn's Disease Activity Index (CDAI) was 415. Treatment by granulocyte apheresis, mesalazine, and adalimumab was started. His CDAI was 314 on 30 December and 215 on 5 January. A colonoscopic examination on 19 January showed almost complete remission in the transverse colon and marked remission in the rectum. Mesalazine therapy was stopped on 28 February, and the patient was instructed to self-inject 40 mg of adalimumab every other week. His CDAI was 50 on 10 April, indicating clinical remission. His last self-injection of adalimumab was on 24 April 2012, and he started taking 1 g of bovine lactoferrin (bLF) daily. His CDAI was 35 on 8 January 2013. He continued taking 1 g of bLF daily without any other treatment for Crohn's disease. Laboratory blood tests on 7 September 2015 showed no sign of disease recurrence, and a colonoscopic examination on 23 October 2015 showed almost complete mucosal healing. This case indicates that ingestion of bLF to maintain Crohn's disease in a remissive state should be further explored.

How to Diagnose and Treat IBD Mimics in the Refractory IBD Patient Who Does Not Have IBD

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract and includes both Crohn's disease and ulcerative colitis. Patients with IBD often present with abdominal pain, diarrhea, and rectal bleeding but may also have a wide variety of other symptoms such as weight loss, fever, nausea, vomiting, and possibly obstruction. Given that the presentation of IBD is not specific, the differential diagnosis is broad and encompasses a wide spectrum of diseases, many of which can mimic and/or even coexist with IBD. It is important for physicians to differentiate symptoms due to refractory IBD from symptoms due to IBD mimics when a patient is not responding to standard IBD treatment. Many of the various IBD mimics include infectious etiologies (viral, bacterial, mycobacterial, fungal, protozoal, and helminthic infections), vascular causes, other immune causes including autoimmune etiologies, drug-induced processes, radiation-induced, and other etiologies such as small intestinal bacterial overgrowth, diverticulitis, and bile acid malabsorption. Thoughtful consideration and evaluation of these potential etiologies through patient history and physical examination, as well as appropriate tests, endoscopic evaluation, and cross-sectional imaging is required to evaluate any patient presenting with symptoms consistent with IBD.

Presence of Granulomas in Mesenteric Lymph Nodes Is Associated with Postoperative Recurrence in Crohn's Disease

BACKGROUND

The association between the presence of granulomas in the mesenteric lymph node (MLN) and postoperative recurrent Crohn's disease (CD) is unknown. Our aim was to assess the predictive value of the presence of granulomas in MLN as well as in bowel wall for postoperative recurrence of CD.

METHODS

Patients with CD who underwent the index ileocolonic resection between 2004 and 2012 were included. Surgical pathology reports were reviewed for the presence and location of granulomas. The status of MLN granulomas was confirmed by re-review of surgical pathology specimen from randomly sampled patients by an expert pathologist. Both univariable and multivariable analyses were performed to assess the risk factors associated with postoperative recurrent CD.

RESULTS

A total of 194 patients were included. Granulomas were detected in the MLN in 23 patients (11.9%), and in the intestinal wall in 57 (29.4%). On Kaplan-Meier curve, the presence of granulomas in MLN was found to be a risk factor for postoperative endoscopic recurrence (P = 0.015) as well as surgical recurrence (P = 0.035). In contrast, granulomas in the bowel wall, which was not found to be associated with neither endoscopic recurrence (P = 0.94) or surgical recurrence (P = 0.56). On Cox proportional hazards regression analysis, the presence of MLN granulomas was independently associated with an increased risk for both postoperative endoscopic recurrence (hazard ratio [HR] = 1.91; 95% confidence interval [CI], 1.06-3.45; P = 0.031) and surgical recurrence (HR = 3.43; 95% CI, 1.18-9.99; P = 0.023).

CONCLUSIONS

The presence of granulomas in MLN but not in intestine per se was found to be an independent risk factor for recurrence in CD patients undergoing ileocolonic resection.