Frequency and Predictors of Dysplasia in Pseudopolyp-like Colorectal Lesions in Patients with Long-Standing Inflammatory Bowel Disease.

Current endoscopic surveillance programs do not consider inflammatory bowel disease (IBD)-associated post-inflammatory polyps (pseudopolyps) per se clinically relevant, even though their presence seems to increase the risk of colorectal cancer (CRC). However, it remains unclear whether the link between pseudopolyps and CRC is indirect or whether some subsets of pseudopolyp-like lesions might eventually undergo neoplastic transformation. This study aimed to assess the frequency and predictors of dysplasia in pseudopolyp-like lesions in a population with long-standing colonic IBD. This was a retrospective, single-center study including patients with a colonic IBD (median disease duration of 192 months) and at least a pseudopolyp-like lesion biopsied or resected in the period from April 2021 to November 2022. One hundred and five pseudopolyps were identified in 105 patients (80 with ulcerative colitis and 25 with Crohn's disease). Twenty-three out of 105 pseudopolyp samples (22%) had dysplastic foci, and half of the dysplastic lesions were hyperplastic. Multivariate analysis showed that the age of the patients (odds ratio (OR) 1.1; p = 0.0012), size (OR 1.39; p = 0.0005), and right colonic location (OR 5.32; p = 0.04) were independent predictors of dysplasia, while previous exposure to immunosuppressors/biologics and left colonic location of the lesions were inversely correlated to dysplasia (OR 0.11; p = 0.005, and OR 0.09; p = 0.0008, respectively). No differences were seen between ulcerative colitis and Crohn's disease patients. Lesions with a size greater than 5 mm had a sensitivity of 87% and a specificity of 63% to be dysplastic. These data show that one-fourth of pseudopolyp-like lesions evident during surveillance colonoscopy in patients with longstanding IBD bear dysplastic foci and suggest treating such lesions properly.

Echopattern parameter as an aid to profile Crohn's disease patients.

BACKGROUND: Intestinal ultrasonography (US) allows for the characterization of the intestinal lesions and provides information on transmural inflammation. The aim of the study was to assess the clinical relevance of echopattern and correlation with Crohn's disease (CD) behavior and activity. METHODS: We performed a prospective study including CD patients assessed by intestinal US. The echopattern was classified as hypoechoic, hyperechoic and stratified. Color-doppler US was also performed in the thickest segment. RESULTS: One hundred CD patients were enrolled. The hypoechoic echopattern was significantly correlated with penetrating behavior (r = 0.44, p<0.0001), active disease (r = 0.21, p = 0.034), C-reactive protein/Fecal Calprotectin (r = 0.31, p = 0.004; r = 0.34, p = 0.031, respectively) and steroids (r = 0.33, p = 0.0008). Hypoechoic echopattern was associated with younger age than stratified (p = 0.046) and hyperechoic (p = 0.018) echopatterns. Bowel wall thickness was greater in the hypoechoic group than in the hyperechoic/stratified groups (p = 0.011 and p<0.0001, respectively). Hypoechoic echopattern was associated with fistulas (r = 0.52, p<0.0001) and increased vascularization (r = 0.32, p = 0.001). The hyperechoic echopattern showed a significant correlation with stricturing disease and an inverse correlation with fistulas. During a follow up period of 6 months, patients with hypoechoic echopattern had an increased risk of biological therapy need or surgery. CONCLUSIONS: The characterization of bowel wall echopattern allows for the identification of different CD behaviors.

Ultrasonographic Transmural Healing in Crohn's Disease.

Therapeutic targets in Crohn's disease (CD) have evolved greatly over the past several decades to include endoscopic improvement along with clinical remission. Yet CD is characterized by transmural damage, and there is increasing evidence of improved outcomes associated with transmural healing. Intestinal ultrasonography is a noninvasive, highly accurate imaging modality that provides real-time results and can assess for transmural healing in CD. In this review, we present the definition of transmural healing by ultrasonography, its comparison with other imaging modalities and with endoscopy, the efficacy of diverse therapies on achieving transmural healing, and data on patient outcomes in those achieving transmural healing. This review can guide clinicians who care for patients with inflammatory bowel disease on the added value of achieving transmural healing and its eventual incorporation as a target of therapy.

Endoscopic Predictors of Neoplastic Lesions in Inflammatory Bowel Diseases Patients Undergoing Chromoendoscopy.

Dye-based chromoendoscopy (DCE) with targeted biopsies is recommended for surveillance of patients with long-standing inflammatory bowel diseases (IBD), but endoscopic features that predict dysplasia are not fully clarified. We here aimed at identifying predictive factors of dysplastic/neoplastic lesions in IBD patients undergoing DCE. Two-hundred-and-nineteen patients were consecutively and prospectively enrolled from October 2019 to March 2022. One-hundred-and-forty-five out of 219 patients underwent DCE, and 148 lesions were detected in 79/145 (54%) patients. Thirty-nine lesions (26%) were dysplastic and one of them contained a CRC. Among these lesions, 7 (17.9%) had Kudo pit pattern I-II and 32 (82.1%) had a neoplastic pit pattern (Kudo III-IV). Multivariate analysis showed that neoplastic lesions Kudo III-IV (OR: 5.8, 95% CI: 2.3−14.6; p = 0.0002), lesion's size (OR 1.16, 95% CI: 1.06−1.26; p = 0.0009), and polypoid lesions according to Paris Classification (OR 7.4, 95% CI: 2.7−20.2; p = 0.0001) were independent predictors of dysplasia. A cut-off of lesion's size > 7 mm was identified as the best predictor of dysplasia. Among such features, Kudo pit pattern III-IV had the highest sensitivity and specificity to predict dysplasia (79% and 80%, respectively). Lesions with all three endoscopic features had a sensitivity of 90% and specificity of 100% to predict dysplasia. In contrast, non-polypoid lesions were inversely associated with dysplasia (OR 0.13, 95% CI: 0.05−0.36; p = 0.0001). These findings indicate that, in IBD patients, DCE-evidenced polypoid lesions with Kudo pit pattern III-IV and size > 7 mm are frequently dysplastic.

Ultrasonography Tight Control and Monitoring in Crohn's Disease During Different Biological Therapies: A Multicenter Study.

BACKGROUND & AIMS: Bowel ultrasonography (BUS) is a noninvasive tool for evaluating bowel activity in Crohn's disease (CD) patients. Aim of our multicenter study was to assess whether BUS helps to monitor intestinal activity improvement/resolution following different biological therapies. METHODS: Adult CD patients were prospectively enrolled at 16 sites in Italy. Changes in BUS parameters [i.e. bowel wall thickening (BWT), lesion length, echo pattern, blood flow changes and transmural healing (TH: normalization of all BUS parameters)] were analyzed at baseline and after 3, 6 and 12 months of different biological therapies. RESULTS: One hundred eighty-eight out of 201 CD patients were enrolled and analyzed (116 males [62%]; median age 36 years). Fifty-five percent of patients were treated with adalimumab, 16% with infliximab, 13% with vedolizumab and 16% with ustekinumab. TH rates at 12 months were 27.5% with an NNT of 3.6. TH at 12 months after adalimumab was 26.8%, 37% after infliximab, 27.2% after vedolizumab and 20% after ustekinumab. Mean BWT improvement from baseline was statistically significant at 3 and 12 months (P < .0001). Median Harvey-Bradshaw index, C-reactive protein and fecal calprotectin decreased after 12 months from baseline (P < .0001). Logistic regression analysis showed colonic lesion was associated with a higher risk of TH at 3 months and a greater BWT at baseline was associated with a lower risk of TH at 3 months [P = .03 (OR 0.70, 95% CI 0.50-0.97)] and 12 months [P = .01 (OR 0.58, 95% CI 0.38-0.89)]. At 3 months therapy optimization during the study was the only independent factor associated with a higher risk of no ultrasonographic response [P = .02 (OR 3.34, 95% CI 1.18-9.47)] and at 12 months disease duration [P = .02 (OR 3.03, 95% CI 1.15-7.94)]. CONCLUSIONS: Data indicate that BUS is useful to monitor biologics-induced bowel activity improvement/resolution in CD.

High Smad7 in the early post-operative recurrence of Crohn's disease.

BACKGROUND: In Crohn's disease (CD), one of the major inflammatory bowel disease (IBD) in human beings, there is over-expression of Smad7, an intracellular inhibitor of the suppressive cytokine TGF-ß1. The aim of this study was to assess whether Smad7 over-expression occurs in the early and/or late phases of CD. METHODS: Mucosal samples were taken from the neo-terminal ileum of CD patients undergoing ileocolonic resection, with or without (early CD) post-operative endoscopic recurrence, and terminal ileum of CD patients with long-standing disease undergoing intestinal resection (late CD). Smad7 was examined by immunohistochemistry and cytokine expression was analysed by flow-cytometry. RESULTS: Before the appearance of endoscopic lesions, the mucosa of the neo-terminal ileum contained high number of Smad7-expressing cells in both the epithelial and lamina propria compartments. Transition from this stage to endoscopic recurrence was marked by persistence of high number of Smad7-positive cells, which reduced significantly in the late stages of the disease, where Smad7 expression remained, however, greater than that seen in normal controls. In samples with early lesions, Smad7 expression positively correlated with the number of interferon-γ-secreting cells. CONCLUSIONS: Smad7 induction is an early event in the inflammatory sequence occurring in CD, thus suggesting that knockdown of Smad7 can help prevent post-operative recurrence.

Response Assessed by Ultrasonography as Target of Biological Treatment for Crohn's Disease.

BACKGROUND & AIMS: Mucosal healing, determined by ileocolonoscopy, is a goal for treatment of Crohn's disease (CD), but this is an invasive assessment procedure. We investigated whether response to tumor necrosis factor (TNF) antagonists, determined by small-intestine contrast ultrasonography, associates with long-term outcomes. METHODS: We performed observational study of 80 patients with CD treated with anti-TNF agents for at least 1 year who underwent serial small intestine contrast ultrasonography (SICUS) at the University of Rome, in Italy. SICUS was used to evaluate disease site (based on bowel wall thickness), extent of lesions, and presence of complications. Inclusion criteria required pre-therapy SICUS with follow-up SICUS after 18 months. At second SICUS, patients were assigned to categories of complete or partial responder or non-responder. CD-related outcomes (corticosteroid need, hospitalization, and surgery) were assessed at 1 year from the second SICUS, using multivariate models, and were analyzed after long term follow up (5 years) using Kaplan-Meier survival analysis. RESULTS: Based on SICUS, after a median of 18 months, 36 patients (51%) were complete responders, 30 were partial responders (34%), and 13 were non-responders (15%). At 1 year from the second SICUS, no patients with a complete response, based on ultrasonography, underwent surgery, in comparison to partial responders (P = .0003) or non-responders (P = .001). Complete responders used smaller amounts of corticosteroids than partial responders (P = .0001) or non-responders (P < .0001). Complete responders required fewer hospitalizations than non-responders (P = .001). Kaplan-Meier survival analysis of long-term follow up data demonstrated a lower cumulative probability of need for surgery, hospitalization, and need for steroids among SICUS-categorized complete responders (P < .0001, P = .003 and P = .0001 respectively) than SICUS-categorized non-responders. CONCLUSIONS: In patients with CD, response to anti-TNF agents, determined by SICUS, is associated with better long-term outcomes than partial or no response. Ultrasonographic assessment therefore provides a relatively non-invasive method for monitoring response to treatment in patients with CD.

Real-time Interobserver Agreement in Bowel Ultrasonography for Diagnostic Assessment in Patients With Crohn's Disease: An International Multicenter Study.

BACKGROUND: The unavailability of standardized parameters in bowel ultrasonography (US) commonly used in Crohn's disease (CD) and the shortage of skilled ultrasonographers are 2 limiting factors in the use of this imaging modality around the world. The aim of this study is to evaluate interobserver agreement among experienced sonographers in the evaluation of bowel US parameters in order to improve standardization in imaging reporting and interpretation. METHODS: Fifteen patients with an established diagnosis of CD underwent blinded bowel US performed by 6 experienced sonographers. Prior to the evaluation, the sonographers and clinical and radiological IBD experts met to formally define the US parameters. Interobserver agreement was tested with the Quatto method (s). RESULTS: All operators agreed on the presence/absence of CD lesions and distinguished absence of/mild activity or moderate/severe lesions in all patients. S values were moderate for bowel wall thickness (s = 0.48, P = n.s.), bowel wall pattern (s = 0.41, P = n.s.), vascularization (s = 0.52, P = n.s.), and presence of lymphnodes (s = 0.61, P = n.s.). Agreement was substantial for lesion location (s = 0.68, P = n.s.), fistula (s = 0.74, P = n.s.), phlegmon (s = 0.78, P = 0.04), and was almost perfect for abscess (s = 0.95, P = 0.02). Poor agreement was observed for mesenteric adipose tissue alteration, lesion extent, stenosis, and prestenotic dilation. CONCLUSIONS: In this study, the majority of the US parameters used in CD showed moderate/substantial agreement. The development of shared US imaging interpretation patterns among sonographers will lead to improved comparability of US results among centers and facilitate the development of multicenter studies and the spread of bowel US training, thereby allowing a wider adoption of this useful technique.

Sodium chloride-enriched Diet Enhanced Inflammatory Cytokine Production and Exacerbated Experimental Colitis in Mice.

BACKGROUND AND AIM: Environmental factors are supposed to play a decisive role in the pathogenesis of inflammatory bowel diseases [IBDs]. Increased dietary salt intake has been linked with the development of autoimmune diseases, but the impact of a salt-enriched diet on the course of IBD remains unknown. In this study, we examined whether high salt intake alters mucosal cytokine production and exacerbates colitis. METHODS: Normal intestinal lamina propria mononuclear cells [LPMCs] were activated with anti-CD3/CD28 in the presence or absence of increasing concentrations of sodium chloride [NaCl] and/or SB202190, a specific inhibitor of p38/MAP Kinase. For in vivo experiments, a high dose of NaCl was administered to mice 15 days before induction of trinitrobenzene-sulfonic acid [TNBS]-colitis or dextran sulfate sodium [DSS]-colitis. In parallel, mice were given SB202190 before induction of TNBS-colitis. Transcription factors and effector cytokines were evaluated by flow-cytometry and real-time PCR. RESULTS: IL-17A, IL-23R, TNF-α, and Ror-γT were significantly increased in human LPMCs following NaCl exposure, while there was no significant change in IFN-γ, T-bet or Foxp3. Pharmacologic inhibition of p38/MAPK abrogated the NaCl-inducing effect on LPMC-derived cytokines. Mice receiving the high-salt diet developed a more severe colitis than control mice, and this effect was preventable by SB202190. CONCLUSIONS: Our data indicated that exposure of intestinal mononuclear cells to a high-NaCl diet enhanced effector cytokine production and contributed to the exacerbation of experimental colitis in mice.

Bowel Ultrasonography in the Management of Crohn's Disease. A Review with Recommendations of an International Panel of Experts.

BACKGROUND: Bowel ultrasonography (US) is considered a useful technique for assessing mural inflammation and complications in Crohn's disease (CD). The aim of this review is to appraise the evidence on the accuracy of bowel US for CD. In addition, we aim to provide recommendations for its optimal use. METHODS: Publications were identified by literature search from 1992 to 2014 and selected based on predefined criteria: 15 or more patients; bowel US for diagnosing CD, complications, postoperative recurrence, activity; adequate reference standards; prospective study design; data reported to allow calculation of sensitivity, specificity, agreement, or correlation values; articles published in English. RESULTS: The search yielded 655 articles, of which 63 were found to be eligible and retrieved as full-text articles for analysis. Bowel US showed 79.7% sensitivity and 96.7% specificity for the diagnosis of suspected CD, and 89% sensitivity and 94.3% specificity for initial assessment in established patients with CD. Bowel US identified ileal CD with 92.7% sensitivity, 88.2% specificity, and colon CD with 81.8% sensitivity, 95.3% specificity, with lower accuracy for detecting proximal lesions. The oral contrast agent improves the sensitivity and specificity in determining CD lesions and in assessing sites and extent. CONCLUSIONS: Bowel US is a tool for evaluation of CD lesions in terms of complications, postoperative recurrence, and monitoring response to medical therapy; it reliably detects postoperative recurrence and complications, as well as offers the possibility of monitoring disease progression.

Smad7 Knockdown Restores Aryl Hydrocarbon Receptor-mediated Protective Signals in the Gut.

BACKGROUND AND AIM: In Crohn's disease [CD], the pathological process is driven by an excessive immune response that is poorly counterbalanced by regulatory mechanisms. One such a mechanism involves aryl hydrocarbon receptor [AhR], a transcription factor that delivers protective signals in the gut. Expression of AhR is reduced in CD lamina propria mononuclear cells [LPMC] even though factors accounting for such a defect remain unknown. Since CD LPMC express elevated levels of Smad7, an inhibitor of transforming growth factor beta 1 [TGF-ß1] activity, and TGF-ß1 regulates AhR in other systems, we examined the link between AhR and Smad7 in the gut. METHODS: AhR and interleukin [IL]-22 were evaluated in normal LPMC stimulated with TGF-ß1 and 6-formylindolo[3,2-b]carbazole [Ficz], an activator of AhR, and in CD LPMC incubated with a Smad7 antisense oligonucleotide and then stimulated with Ficz and TGF-ß1. AhR and IL-22 expression was evaluated in LPMC of Smad7-transgenic mice. Finally, we evaluated the protective effect of Ficz on colitis in RAG1 mice injected with naïve or Smad7-overexpressing T cells. RESULTS: In normal LPMC, TGF-ß1 induced AhR and this event was associated with increased production of IL-22 following stimulation with Ficz. Treatment of CD LPMC with Smad7 antisense oligonucleotide enabled TGF-ß1 to enhance AhR expression. Consistently, AhR expression and Ficz-induced IL-22 production were markedly reduced in T cells of Smad7-transgenic mice. In RAG1 mice, Ficz ameliorated colitis induced by wild type T cells but did not affect colitis induced by transfer of Smad7-overexpressing T cells. CONCLUSIONS: The inverse correlation between Smad7 and AhR expression helps to propagate inflammatory signals in the gut.

Aryl hydrocarbon receptor-driven signals inhibit collagen synthesis in the gut.

Fibrostrictures (FS) are a major complication of Crohn's disease (CD). Pathogenesis of FS is not fully understood, but activation of fibroblasts and excessive collagen deposition are crucial in the development of FS. Here, we investigated the role of aryl hydrocarbon receptor (AhR) in intestinal fibrosis. AhR RNA and protein expression were evaluated in intestinal fibroblasts of CD patients and controls. CD fibroblasts were stimulated with TGF-ß1 or TNF-α in the presence or absence of the AhR activator Ficz, an AhR antagonist CH223191, or a specific AhR-silencing RNA. In CD fibroblasts, TGF-ß1 and TNF-α increased Col1A1, Col3A1 and α-SMA transcripts and collagen secretion and this effect was reduced by Ficz and upregulated by CH22319. TGF-ß1 or TNF-α induced activation of p38 and ERK1/2 MAP kinases was decreased by Ficz and increased by CH223191. The inhibitory effect of Ficz on Map kinase activation and collagen induction was abolished by AhR silencing. To assess the role of AhR in vivo, mice with trinitrobenzene-sulfonic-acid induced colonic fibrosis were given Ficz or CH223191. Mice given either Ficz or CH223191 produced less or more collagen respectively as compared with control mice. Our results indicate that AhR is a negative regulator of profibrotic signals in the gut.

Frequency and Cause of Persistent Symptoms in Celiac Disease Patients on a Long-term Gluten-free Diet.

GOALS: To estimate the frequency and cause of nonresponsive celiac disease (CD). BACKGROUND: Treatment of CD is based on life-long adherence to a gluten-free diet (GFD). Some celiac patients experience persistence of symptoms despite a GFD. This condition is defined as nonresponsive CD. STUDY: Celiac patients on a GFD for at least 12 months underwent diet compliance assessment, laboratory tests, breath tests, endoscopic, and histologic evaluations according to the symptoms/signs reported. RESULTS: Seventy of 321 (21.8%) patients had persistent or recurrent symptoms/signs. The cause of symptom persistence was evaluated in 56 of 70 patients. Thirteen of 56 (23%) patients were antiendomysial antibody positive. Among the patients with negative serology, 1 had fibromyalgia, and 3 had evidence that disproved the diagnosis of CD. The remaining 39 patients with negative serology underwent duodenal biopsy sampling, which evidenced histologic alterations in 24 patients. Among the 15 patients with normal histology 3 were lactose intolerant, 9 had irritable bowel syndrome, 2 had gastroesophageal reflux disease, and in 1 patient a cause for the persistent symptom was not identified. In patients with confirmed diagnosis of CD, exposure to dietary gluten was the main cause of persistence of symptoms/signs, and consistently after dietary modification, symptoms resolved in 63% of the patients at later time points during follow-up. CONCLUSION: Nonresponsive CD occurs in nearly one fifth of celiac patients on GFD and its occurrence suggests further investigations to optimize the management of celiac patients.

Pathogenic aspects and therapeutic avenues of intestinal fibrosis in Crohn's disease.

In Crohn's disease, one of the two major forms of inflammatory bowel diseases in human beings, persistent and chronic inflammation promotes fibrotic processes thereby facilitating formation of strictures, the most common indication for surgical intervention in this disorder. The pathogenesis of Crohn's disease-associated fibrosis is not fully understood, but variants of genes involved in the recognition of microbial components/products [e.g. CARD15 (caspase-activating recruitment domain 15) and ATG16L1 (autophagy-related 16-like 1)] are associated with this phenotype, and experimental evidence suggests that intestinal fibrosis results from an altered balance between deposition of ECM (extracellular matrix) and degradation of ECM by proteases. Studies have also contributed to identify the main phenotypic and functional alterations of cells involved in the fibrogenic process, as well as molecules that stimulate such cells to produce elevated amounts of collagen and other ECM-related proteins. In the present review, we assess the current knowledge about cellular and molecular mediators of intestinal fibrosis and describe results of recent studies aimed at testing the preventive/therapeutic effect of compounds in experimental models of intestinal fibrosis.

A sonographic lesion index for Crohn's disease helps monitor changes in transmural bowel damage during therapy.

BACKGROUND & AIMS: Therapeutic antibodies against tumor necrosis factor α (anti-TNF) are effective in patients with Crohn's disease (CD). Mucosal healing is a surrogate marker of efficacy, but little is known about the effects of anti-TNF agents on structural damage in the intestine. Small-intestine contrast ultrasonography (SICUS) is a valuable tool for assessing CD lesions. A new sonographic quantitative index (the sonographic lesion index for CD [SLIC]) was developed to quantify changes in CD lesions detected by SICUS. We explored whether the SLIC can be used to monitor transmural bowel damage in CD patients during anti-TNF therapy. METHODS: We performed a prospective study of 29 patients with ileal or ileocolonic CD treated with anti-TNF agents; patients underwent SICUS before and after scheduled induction and maintenance therapy. To determine whether changes that can be detected by SICUS occur independently of anti-TNF therapy, 7 patients with ileal CD treated with mesalamine were enrolled as controls. A clinical response was defined as steroid-free remission, with CD activity index scores less than 150. RESULTS: We observed significant improvements in SLIC scores and subscores after induction and maintenance therapy with anti-TNFs, compared with before therapy. SLIC scores and subscores and index classes were improved significantly in patients with vs without clinical responses. Controls had no improvements in terms of CD activity index or SLIC scores, or index classes. CONCLUSIONS: Sonographic assessment using the quantitative index SLIC can be used to monitor changes in transmural bowel damage during anti-TNF therapy for CD.

A family study of asymptomatic small bowel Crohn's disease.

BACKGROUND: Discrepancies between severity of lesions and symptoms may be observed in Crohn's disease. We prospectively assessed whether Crohn's disease may be diagnosed among asymptomatic relatives of patients, using Small Bowel Contrast Ultrasonography. METHODS: Diagnosis of asymptomatic Crohn's disease relatives was defined ultrasonographically as: bowel wall thickness >3mm, bowel dilation/stricture, lumen diameter >2.5 cm. Diagnosis was confirmed by ileocolonoscopy. Subjects were also screened for the Leu3020insC mutation. RESULTS: Consent was given by 35 asymptomatic first-degree relatives of 18 Crohn's disease patients. Ultrasonography indicated increased bowel wall thickness (5mm) compatible with ileal Crohn's disease in 1 relative (2.8%), a 42 year-old male. Ileocolonoscopy, histology, and radiology confirmed the diagnosis of stricturing ileal Crohn's disease. Gallbladder stones were detected in 7/35 (20%) relatives and Leu3020insC mutation in 3/35 (8.5%). CONCLUSIONS: Small Bowel Contrast Ultrasonography may be a useful tool to diagnose asymptomatic small bowel Crohn's disease among first-degree relatives of patients.

Lesional accumulation of CD163-expressing cells in the gut of patients with inflammatory bowel disease.

Monocytes/macrophages displaying different markers of activation/differentiation infiltrate the inflamed gut of patients with inflammatory bowel diseases (IBD), but the role that each monocyte/macrophage subpopulation plays in the pathogenesis of IBD is not fully understood. The hemoglobin scavenger receptor CD163, a specific marker of monocytes/macrophages, has been associated with either anti-inflammatory or inflammatory functions of macrophages in several pathologies. In this study we examined the tissue distribution and function of CD163-expressing monocytes/macrophages in IBD. CD163 RNA and protein expression was more pronounced in IBD in comparison to normal controls, with no significant difference between Crohn's disease and Ulcerative colitis. In IBD, over-expression of CD163 was restricted to areas with active inflammation and not influenced by current therapy. Immunohistochemical analysis confirmed the accumulation of CD163-expressing cells in IBD, mostly around and inside blood vessels, thus suggesting that these cells are partly recruited from the systemic circulation. Indeed, FACS analysis of circulating mononuclear cells showed that the fractions of CD163-positive monocytes were increased in IBD patients as compared to controls. Functionally, interleukin-6 up-regulated CD163 expression in lamina propria mononuclear cells and mucosal explants of normal subjects. In IBD blood and mucosal cell cultures, cross-linking of CD163 with a specific monoclonal anti-CD163 antibody enhanced tumor necrosis factor-α synthesis. These findings indicate that IBD mucosa is abundantly infiltrated with CD163-positive cells, which could contribute to amplify the inflammatory cytokine response.

Bowel ultrasonography as an aid for diagnosis of intestinal acute graft-versus-host-disease after allogeneic haematopoietic stem cell transplantation.

OBJECTIVE: Aim of our prospective study was to investigate accuracy of bowel ultrasonography in detecting gastrointestinal acute graft versus host disease (GVHD), when using clinical assessment as gold standard. In a subgroup of patients, bowel ultrasonography was compared with colonoscopy and histology in diagnosing of gastrointestinal acute GVHD. METHODS: Fifty-two patients underwent allogeneic hematopoietic stem cell transplantation and developed gastrointestinal symptoms. RESULTS: Clinical assessment lead to a diagnosis of gastrointestinal acute GVHD in 17/52 patients, no gastrointestinal acute GVHD was detected in 20/52 patients, while 15 patients were not able to complete the study. Bowel ultrasonography detected either bowel wall thickness of the ileum and the colon or dilation in 16/17 patients and showed 94% sensitivity (95% CI 0.69-0.99), 95% specificity (95% CI 0.73-0.99), and 94.5% accuracy. Colonoscopy was performed in 13/52 patients, showing gastrointestinal acute GVHD in 11/13. In these 11 patients, histology confirmed the diagnosis of gastrointestinal acute GVHD, and bowel ultrasonography detected findings compatible with gastrointestinal acute GVHD in all 11 patients, and was negative in the 2 patients with no gastrointestinal acute GVHD. CONCLUSION: Bowel ultrasonography can be considered a valuable tool to add to clinical assessment for patients with suspected gastrointestinal acute GVHD for addressing a prompt and appropriate treatment.