Antibody secretion by human intestinal mononuclear cells from normal controls and inflammatory bowel disease patients

Helicobacter pylori infection and inflammatory bowel disease: a 2-sample Mendelian randomization study

Introduction

Observational studies have discovered a contradictory phenomenon between Helicobacter pylori (H. pylori) infection and inflammatory bowel disease (IBD). The study aimed to confirm the causal association between H. pylori and IBD, including ulcerative colitis (UC) and Crohn's disease (CD).

Methods

We conducted a Mendelian randomization (MR) study with two sample Genome-Wide Association Studies (GWAS) to determine whether there is a causal relationship between H. pylori infection and IBD, as well as the possible pathogenic factors that may be involved. The reliability of the main MR assumptions was examined through a series of sensitivity analyses.

Results

Two genetic variants (SNPs) previously identified were employed as instrumental variables (IVs) for H. pylori infection. GWAS data for IBD, UC, and CD were obtained from the recent DF10 release10 of the FinnGen study. Our findings indicated a significant association between H. pylori seropositivity and an increased risk of IBD and UC (IBD: OR: 1.16, 95% CI, 1.03-1.31, P < 0.05; UC: OR: 1.22, 95% CI, 1.08-1.37, P < 0.001) while no causal relationship with CD (P > 0.05). Analysis of the main virulence pathogenic factors revealed a causal relationship between cytotoxin-associated protein A (CagA) and IBD and UC (IBD: OR: 1. 06, 95% CI, 1.001-1.11, P < 0.05; UC: OR: 1.07, 95% CI, 1.004-1.14, P < 0.05), while no correlation was found for vacuolar cytotoxin A (VacA) (P > 0.05). After applying the False Discovery Rate (FDR) correction, the causal relationship between CagA and the risk of IBD or UC was no longer statistically significant.

Conclusion

This study suggests a potential causal relationship between H. pylori infection and IBD, particularly UC. The effect may be more pronounced in individuals with previous H. pylori infections.

Cytomegalovirus Pneumonia in Inflammatory Bowel Disease: Literature Review and Clinical Recommendations

Aim

The objective was to elucidate the correlation between CMVP and immunosuppressive therapy in IBD patients, we hope this review could expand on the significance of CMV as an opportunistic pathogen and the potential impact on morbidity and mortality in IBD patients.

Methods

Records and clinical trajectories linked to CMVP in IBD patients were extracted from the PubMed database, irrespective of language barriers. The reference lists incorporated in these studies were manually inspected. Conclusions were generated using straightforward descriptive analysis.

Results

In total, 18 IBD patients, including Crohn's disease (CD, 67%) and Ulcerative Colitis (UC, 33%), affected by CMVP were identified from 17 published articles. A minority of these patients (17%) exhibited active disease, whereas the majority (83%) presented with quiescent disease. Fever (100%) and dyspnea (44%) emerged as the most prevalent clinical symptoms. All the patients had undergone immunosuppressive therapy. A significant proportion, up to 89%, had received thiopurine treatment prior to the CMVP diagnosis. Interestingly, none of the patients were subjected to biological therapy. Half of the patients manifested with Hemophagocytic Lymphohistiocytosis (HLH). Almost all patients (94%) were administered antiviral treatment and a substantial 83% experienced full recovery. Immunosuppressive agents were either tapered or discontinued altogether. A subset of patients, 17%, suffered fatal outcomes.

Conclusion

Our findings underscore the need for heightened suspicion of CMVP in IBD patients who exhibit symptoms such as fever and dyspnea. During the COVID-19 pandemic, CMVP should be considered a potential differential diagnosis. It was observed that CMVP primarily transpires during CD remission. Azathioprine emerged as the predominant immunosuppressant linked to CMV reactivation. The prompt application of effective antiviral therapy can substantially enhance patient outcomes. CMV vaccine might serve as a viable prevention strategy.

Pulmonary Crohn's Disease or Crohn's Disease with Lung Sarcoidosis? A Case Report and Literature Review

BACKGROUND

Crohn's disease and ulcerative hemorrhagic colitis are forms of granulomatous inflammatory intestinal disease, which usually affects the gastrointestinal tract. There are also reported rare localizations at the skin, kidney, joints, liver and eye level. Pulmonary involvement is relatively rare, and it is most commonly reported in suppuration with bronchiectasis. On the other hand, sarcoidosis is, in principle, a thoracic localization of a granulomatosis disease, although bowel, skin and intestinal disorders are described. There is not a clear line to separate Crohn's disease from sarcoidosis with, possibly because they are, in fact, considered to have the same inflammatory granulomatosis disease pathology. The diagnoses of the two entities, sarcoidosis and Crohn's disease, are based on non-pathognomonic, inclusive clinical and paraclinical criteria, without elements of the mutual exclusion of typical locations.

CASE REPORT

We present a very rare case of a young male, already diagnosed with small-bowel Crohn's disease. Granulomatous lung disease with major hemoptysis requires emergency surgery. An intraoperative assessment revealed a necrotic hemorrhagic lesion located in the left lower lobe and a lobectomy was performed. The final pathological report showed the presence of non-caseous granulomatous inflammation, with the identification of specific multinucleated giant cells.

CONCLUSIONS

The identical diagnostic principles of Crohn's disease and sarcoidosis, Crohn's disease as a predecessor to pulmonary lesions, the clinical picture and the necrotico-hemorrhagic appearance of the unilateral pulmonary lesion, which are similar to aggressive necrotico-hemorrhagic or perforating intestinal forms, are arguments in favor of the diagnosis of pulmonary Crohn's disease and not pulmonary sarcoidosis. At the same time, in general, the two diseases have overlapping elements, suggesting they are, in fact, not the same disease with different facets.

Crohn's Disease with Atypical Extra-Intestinal Manifestations Developing Under Treatment with Vedolizumab

Crohn's disease is a chronic inflammatory bowel disease that can affect any part of the GI tract, which is frequently associated with extra-intestinal manifestations. Pulmonary parenchymal disease is very uncommon and usually considered to be debilitating and harder to diagnose. Pulmonary granulomas are rarely described in the literature as a complication of Crohn's disease. Here, we present a patient with Crohn's disease exacerbation who developed granulomatous lung disease under treatment with vedolizumab. Our case may add evidence to the emerging theory that gut-selective biologic agents could lead to upregulation of some pro-inflammatory factors leading to the evolution of pulmonary disease.

LEARNING POINTS

Pulmonary parenchymal diseases are rare in Crohn's disease but they can be debilitating and life-threatening as they are usually tardily diagnosed; awareness of this association is of high value and could potentially shorten the time to a definite diagnosis.Pulmonary manifestations of Crohn's disease could be subclinical without any respiratory complaints and not diagnosed with conventional imaging modalities such as chest x-ray.Gut-selective biologic agents could lead to the emergence of extra-intestinal manifestations due to upregulation of multiple pro-inflammatory cytokines.

The intestinal microbiome, barrier function, and immune system in inflammatory bowel disease: a tripartite pathophysiological circuit with implications for new therapeutic directions

We discuss the tripartite pathophysiological circuit of inflammatory bowel disease (IBD), involving the intestinal microbiota, barrier function, and immune system. Dysfunction in each of these physiological components (dysbiosis, leaky gut, and inflammation) contributes in a mutually interdependent manner to IBD onset and exacerbation. Genetic and environmental risk factors lead to disruption of gut homeostasis: genetic risks predominantly affect the immune system, environmental risks predominantly affect the microbiota, and both affect barrier function. Multiple genetic and environmental 'hits' are likely necessary to establish and exacerbate disease. Most conventional IBD therapies currently target only one component of the pathophysiological circuit, inflammation; however, many patients with IBD do not respond to immune-modulating therapies. Hope lies in new classes of therapies that target the microbiota and barrier function.

Immunopathogenesis of IBD: current state of the art

IBD is a chronic inflammatory condition of the gastrointestinal tract encompassing two main clinical entities: Crohn's disease and ulcerative colitis. Although Crohn's disease and ulcerative colitis have historically been studied together because they share common features (such as symptoms, structural damage and therapy), it is now clear that they represent two distinct pathophysiological entities. Both Crohn's disease and ulcerative colitis are associated with multiple pathogenic factors including environmental changes, an array of susceptibility gene variants, a qualitatively and quantitatively abnormal gut microbiota and a broadly dysregulated immune response. In spite of this realization and the identification of seemingly pertinent environmental, genetic, microbial and immune factors, a full understanding of IBD pathogenesis is still out of reach and, consequently, treatment is far from optimal. An important reason for this unsatisfactory situation is the currently limited comprehension of what are the truly relevant components of IBD immunopathogenesis. This article will comprehensively review current knowledge of the classic immune components and will expand the concept of IBD immunopathogenesis to include various cells, mediators and pathways that have not been traditionally associated with disease mechanisms, but that profoundly affect the overall intestinal inflammatory process.

Tracheobronchitis with dyspnea in a patient with ulcerative colitis

We herein report the case of a 42-year-old man with a one-year history of ulcerative colitis who presented with exacerbated bloody diarrhea, a productive cough and increasing breathing difficulties. Colonoscopy revealed typical deep ulcers in the rectosigmoid colon and atypical multiple sucker-like ulcers in the transverse colon, and computed tomography of the chest demonstrated wall thickening of the trachea and bronchi. In addition, bronchoscopy showed ulcers in the trachea, and histopathology disclosed findings of necrosis and inflammation of the subepithelial tissue of the trachea. Based on these findings, the patient's respiratory symptoms were strongly suspected to be due to ulcerative colitis-related tracheobronchitis. Treatment with systemic corticosteroids subsequently resulted in a rapid clinical improvement.

Methylation of TNFRSF13B and TNFRSF13C in duodenal mucosa in canine inflammatory bowel disease and its association with decreased mucosal IgA expression

Although decreased intestinal IgA expression has been reported in dogs with inflammatory bowel disease (IBD), the mechanism underlying this decrease is unknown. Transmembrane activator and calcium-modulating cyclophilin-ligand interactor (TACI) and B cell-activating factor of the TNF family (BAFF) receptor (BAFF-R) are key receptors for T cell-independent IgA class switching by the binding of IgA-inducing cytokine a proliferation-inducing ligand (APRIL) and BAFF. Here we show decreased TACI and BAFF-R mRNA expression and hypermethylation of their corresponding genes TNFRSF13B and TNFRSF13C, respectively in the duodenal mucosa of dogs with IBD. To examine whether DNA methylation of the TNFRSF13B and TNFRSF13C influences the mRNA expression of TACI and BAFF-R, respectively, we first analyzed methylation and mRNA expression levels in vitro using 2 canine B lymphoid cell lines, GL-1 and CLBL-1. Methylation profiles in the cells were examined by bisulfite sequencing and methylation-specific PCR (MSP) with primer pairs specific to methylated or unmethylated sequences. These methylation analyses revealed hypermethylation of the CpG islands of both TNFRSF13B and TNFRSF13C in GL-1, but not in CLBL-1 cells. The mRNA expression levels of TACI and BAFF-R were significantly lower in GL-1 than in CLBL-1 cells. Treatment with 5-aza-2'-deoxycytidine significantly increased TACI and BAFF-R mRNA expression in GL-1 cells through demethylation of TNFRSF13B and TNFRSF13C, respectively. These results suggest that the mRNA expression of TACI and BAFF-R is regulated through methylation of their genes in canine B cells. Quantitative real-time MSP showed significant hypermethylation of the CpG islands of TNFRSF13B and TNFRSF13C in the duodenal mucosa of dogs with IBD. Furthermore, duodenal mRNA expression levels of TACI and BAFF-R were significantly lower in dogs with IBD than in healthy controls. The mRNA expression levels of TACI positively correlated with intestinal IgA expression, whereas the methylation level of its gene (TNFRSF13B) negatively correlated with IgA expression. The present results suggest the role of TACI in the regulation of mucosal IgA expression through epigenetic modifications.

Pulmonary manifestations of Crohn’s disease

Crohn’s disease (CD) is a systemic illness with a constellation of extraintestinal manifestations affecting various organs. Of these extraintestinal manifestations of CD, those involving the lung are relatively rare. However, there is a wide array of lung manifestations, ranging from subclinical alterations, airway diseases and lung parenchymal diseases to pleural diseases and drug-related diseases. The most frequent manifestation is bronchial inflammation and suppuration with or without bronchiectasis. Bronchoalveolar lavage findings show an increased percentage of neutrophils. Drug-related pulmonary abnormalities include disorders which are directly induced by sulfasalazine, mesalamine and methotrexate, and opportunistic lung infections due to immunosuppressive treatment. In most patients, the development of pulmonary disease parallels that of intestinal disease activity. Although infrequent, clinicians dealing with CD must be aware of these, sometimes life-threatening, conditions to avoid further impairment of health status and to alleviate patient symptoms by prompt recognition and treatment. The treatment of CD-related respiratory disorders depends on the specific pattern of involvement, and in most patients, steroids are required in the initial management.

Decreased immunoglobulin A concentrations in feces, duodenum, and peripheral blood mononuclear cells of dogs with inflammatory bowel disease

BACKGROUND

Although immunoglobulin A (IgA) plays a key role in regulating gut homeostasis, its role in canine inflammatory bowel disease (IBD) is unknown.

HYPOTHESIS

IgA expression may be altered in dogs with IBD, unlike that observed in healthy dogs and dogs with other gastrointestinal diseases.

ANIMALS

Thirty-seven dogs with IBD, 10 dogs with intestinal lymphoma, and 20 healthy dogs.

METHODS

Prospective study. IgA and IgG concentrations in serum, feces, and duodenal samples were measured by ELISA. IgA(+) cells in duodenal lamina propria and IgA(+) CD21(+) peripheral blood mononuclear cells (PBMCs) were examined by immunohistochemistry and flow cytometry, respectively. Duodenal expression of the IgA-inducing cytokine transforming growth factor β (TGF-β), B cell activating factor (BAFF), and a proliferation-inducing ligand (APRIL) was quantified by real-time RT-PCR.

RESULTS

Compared to healthy dogs, dogs with IBD had significantly decreased concentrations of IgA in fecal and duodenal samples. The number of IgA(+) CD21(+) PBMCs and IgA(+) cells in duodenal lamina propria was significantly lower in dogs with IBD than in healthy dogs or dogs with intestinal lymphoma. Duodenal BAFF and APRIL mRNA expression was significantly higher in IBD dogs than in the healthy controls. Duodenal TGF-β mRNA expression was significantly lower in dogs with IBD than in healthy dogs and dogs with intestinal lymphoma.

CONCLUSIONS AND CLINICAL IMPORTANCE

IBD dogs have decreased IgA concentrations in feces and duodenum and fewer IgA(+) PBMCs, which might contribute to development of chronic enteritis in dogs with IBD.

Pulmonary diseases associated with inflammatory bowel diseases

Among the extra-intestinal manifestations of inflammatory bowel diseases, those involving the lung are relatively rare. However, there is a wide array of such manifestations, spanning from drug-related pathologies to airway disease, fistulas, granulomatous diseases, autoimmune and thromboembolic disorders. Although infrequent, people dealing with inflammatory bowel diseases must be aware of these conditions, sometimes life-threatening, to avoid further impairment of the health status of the patients and to alleviate their symptoms by prompt recognition and treatment.

Pulmonary manifestations of inflammatory bowel disease

Extraintestinal manifestations of both Crohn's disease and ulcerative colitis (UC) have been well described, although pulmonary findings are often overlooked. We summarize the experience of more than 400 cases of pulmonary manifestations of inflammatory bowel disease (IBD). These manifestations will be categorized by disease mechanism into drug-induced disease, anatomic disease, over-lap syndromes, autoimmune disease, physiologic consequences of IBD, pulmonary function test abnormalities, and nonspecific lung disease. We intend to provide the clinician with a practical working update on the spectrum of pulmonary dysfunction associated with IBD.

Recent advances in inflammatory bowel disease

The last decade has seen tremendous advances in our knowledge, which has led to genuine improvements in our understanding of the pathogenesis and management of inflammatory bowel disease (IBD). The combined power of cellular and molecular biology has begun to unveil the enigmas of IBD, and, consequently, substantial gains have been made in the treatment of IBD. Refinements in drug formulation have provided the ability to target distinct sites of delivery, while enhancing the safety and efficacy of older agents. Simultaneous progress in biotechnology has fostered the development of new agents that strategically target pivotal processes in disease pathogenesis. This article addresses our current understanding of the pathogenesis of IBD, including the latest developments in animal models and covers agents currently used in the treatment of IBD as well as emerging therapies.

Distal proctocolitis and n-3 polyunsaturated fatty acids (n-3 PUFAs): the mucosal effect in situ

It has been postulated that patients with ulcerative colitis (UC) have altered reactivity of gut-associated lymphoid tissue. In such cases there is intense infiltration of the mucosa with immune competent cells and associated tissue damage. We have shown previously that the dietary supplementation with the n-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) results in significant systemic immune suppression. The aim of this study, therefore, was to evaluate the in situ effect of n-3 PUFAs on distal proctocolitis. Each patient received either fish oil extract (EPA 3.2 g, DHA 2.4 g) (n = 9) or sunflower oil (n = 9) daily in a double blind manner for six months. Monthly assessment included: (1) disease activity using clinical, sigmoidoscopic, and histological scores and (2) immunohistochemical analysis (immunoglobulins, CD profiles) of rectal biopsy specimens (before and after six months supplementation) using monoclonal antibodies and quantitative computer-assisted video image analysis. Prior to receiving supplementation, patients with proctocolitis (n = 18) showed significantly higher numbers of cells expressing CD3 (pan T cells) and HLA-DR and IgM containing cells compared with non-colitic controls (n = 8). Six months supplementation with n-3 PUFAs resulted in significant reduction in the number of cells expressing CD3 and HLA and the percentage of cells containing IgM. There was no significant change in the CD20 nor the percentage of IgG or IgA containing cells in either group of patients with procto-colitis. In patients receiving n-3 PUFA supplementation, there was improvement in the disease activity and histological scores, compared with pretreatment evaluation. This study has demonstrated both evidence of suppression of in situ immune reactivity and concurrent reduction in disease activity in patients with proctocolitis receiving n-3 PUFA supplementation. This may have important implication for therapy in patients with ulcerative colitis.

Decreased mucosal IgA levels in ileum of patients with chronic ulcerative colitis

Patients with chronic ulcerative colitis (CUC) are known to have decreased spontaneous IgA secretion by colonic mononuclear cells. The aim of this study was to determine whether a similar alteration exists in the apparently healthy ileum of patients with CUC. The concentration of IgA was measured in the supernatant from homogenized mucosal ileal biopsies using a sandwich-type ELISA. The concentration of IgA was significantly (P = 0.025) decreased in the ileum of patients with CUC (N = 24) in comparison to normal ileum (N = 10). The number of mucosal IgA-containing mononuclear cells (MNC) was also determined using an avidin-biotin-immunoperoxidase technique on paraffin-embedded ileal sections. Although reduced, the number of positive cells and their distribution was not significantly different in the ileum of patients with CUC (N = 20) when compared to normal ileum (N = 10). We suggest that decreased mucosal IgA levels are a panintestinal condition in CUC and that this is a primary alteration rather than a secondary response to the inflammatory process. Considering the role of IgA, we propose that decreased mucosal IgA levels in CUC may predispose to the disease by a reduction of the immune-mediated exclusion mechanism and/or by an impairment of the down-regulation of the inflammatory response.

Salivary antimicrobial proteins in patients with Crohn's disease

The aim was to study the level of salivary proteins with antimicrobial properties in persons with Crohn's disease. Twenty-five patients were recruited, 13 with ongoing symptoms (acute group) and 12 free of clinical signs of the disease at the time of the investigation (nonacute group). A control group matched to the nonacute group was also included in the study. Unstimulated and stimulated whole saliva samples were collected, and the secretion rates estimated. Unstimulated saliva was analyzed for concentrations of total protein, peroxidase, thiocyanate, slgA, lactoferrin, lysozyme, and for specific bacteria aggregation ability. Numbers of mutans streptococci and lactobacilli in saliva were determined, and dental caries status was examined. No differences were found among the groups regarding salivary flow rate, total protein, or any of the antimicrobial proteins. However, three patients with Crohn's disease had no detectable slgA in saliva compared with none in the control group. The lactobacillus count and the number of decayed tooth surfaces were higher in the nonacute group than in the control group.