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PubMed2003

Glucocorticoid resistance in inflammatory bowel disease.

Glucocorticoids are potent inhibitors of T cell activation and proinflammatory cytokines and are highly effective treatment for active inflammatory bowel disease (IBD). However, failure to respond, acutely or chronically, to glucocorticoid therapy is a common indication for surgery in IBD, with as many as 50% of patients with Crohn's disease (CD) and approximately 20% of patients with ulcerative colitis (UC) requiring surgery in their lifetime as a result of poor response to glucocorticoids. Studies report that approximately one-third of patients with CD are steroid dependent and one-fifth are steroid resistant while approximately one-quarter of patients with UC are steroid dependent and one-sixth are steroid resistant. While the molecular basis of glucocorticoid resistance has been widely assessed in other inflammatory conditions, the pathophysiology of the glucocorticoid resistance in IBD is poorly understood. Research in IBD suggests that the phenomenon of glucocorticoid resistance is compartmentalised to T-lymphocytes and possibly other target inflammatory cells. This review focuses on three key molecular mechanisms of glucocorticoid resistance in IBD: (i) decreased cytoplasmic glucocorticoid concentration secondary to increased P-glycoprotein-mediated efflux of glucocorticoid from target cells due to overexpression of the multidrug resistance gene (MDR1); (ii) impaired glucocorticoid signaling because of dysfunction at the level of the glucocorticoid receptor; and (iii) constitutive epithelial activation of proinflammatory mediators, including nuclear factor kappa B, resulting in inhibition of glucocorticoid receptor transcriptional activity. In addition, the impact of disease heterogeneity on glucocorticoid responsiveness and recent advances in IBD pharmacogenetics are discussed.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMedDate not supplied

Immune cell populations in the duodenal mucosa of cats with inflammatory bowel disease.

The aim of this study was to characterize the phenotype of leukocytes infiltrating the duodenal mucosa of cats with inflammatory bowel disease (IBD) by using immunohistochemistry and computer-aided morphometry to assess whether immunologic markers would aid in characterization of IBD. Frozen and formalin-fixed duodenal biopsies were collected from cats referred for investigation of chronic vomiting, diarrhea, or both (n = 34). Reference ranges were previously established by using duodenal samples from healthy cats (n = 16). No significant difference was found in the number of immunoglobulin G+ (IgG+) or IgA+ in either the villous lamina propria or the crypt lamina propria between cats with IBD and control cats. T cells (CD3+) increased in number from crypt to the tip of the villi in biopsies from both diseased (mean +/- SD for each group was 18.8 +/- 6.6 and 17.7 +/- 4.2 cells/ 10,000 m2 in cryptal areas to 25.2 +/- 9.5 and 29.1 +/- 13.3 cells/10,000m2 in villous areas) and healthy animals (17.9 +/- 3.9 cells/10,000 microm2 in cryptal areas to 24.1 +/- 9.3 cells/10,000 microm2 in villous areas) and no significant difference was found between diseased and control cats. By contrast, major histocompatibility complex (MHC) class II expression by leukocytes with dendritic cell or macrophage morphology in the lamina propria was significantly greater in cats with IBD (13.3 +/- 4.2 cells/10,000 microm2 in cryptal area; P = .016) than in healthy cats (11.9 +/- 3.0 cells/10,000 microm2) and MHC class II expression by enterocytes also was more pronounced in these cats showing an overall intensity of expression of 7.1 +/- 4.0 cells/10,000 microm2 in cats with IBD as opposed to 0.0 +/- 0.0 cells/10,000 microm2 to 0.3 +/- 0.7 cells/10,000 microm2 in healthy cats. These findings suggest that a subtle immunologic dysregulation occurs in spontaneously arising feline IBD.

Animals↗

PubMedDate not supplied

Pharmacokinetics and clinical efficacy of cyclosporine treatment of dogs with steroid-refractory inflammatory bowel disease.

The usual treatment of dogs with inflammatory bowel disease (IBD) consists of administration of immunosuppressive doses of steroids. However, some dogs are refractory to steroid treatment and pose a significant challenge to the veterinarian. Because cyclosporine A (cyA) has been shown to be effective in steroid-resistant IBD in humans, the purpose of this study was to investigate the pharmacokinetics and clinical efficacy of PO cyA treatment in dogs with steroid-refractory IBD (n = 14). All dogs were treated with cyA 5 mg/kg PO q24h for a period of 10 weeks. A clinical activity score was assigned to assess severity of clinical signs before and after treatment. The total number of infiltrating lymphocytes and T cells in duodenal biopsies were assessed before and after treatment in 9 dogs. In addition, serum concentration of cyA was measured in 8 dogs over a 24-hour period. Pharmacokinetic profiles in dogs with IBD were similar to those of healthy dogs. Improvement of clinical signs was observed in 12 of 14 dogs with IBD. Median clinical activity score after treatment with cyA was significantly reduced from a median score of 9 to a median score of 5 (P = 0.001). T cell numbers in duodenal biopsies were significantly decreased after treatment from a median +/- 95% range in the villous region of 28 (19-30) cells/10,000 microm2 before versus 7 (0-10)/10,000 microm2 after treatment, P = 0.01; and from a median +/- 95% range number in the crypt region of 15 (6-23) cells/10,000 microm2 before versus 4 (0-9)/10,000 microm2 after treatment, P = 0.02, implying T cell lysis as a possible mechanism of action. In conclusion, based on this small study, cyA appears to be an effective alternative drug in dogs with IBD that are refractory to immunosuppressive doses of steroids.

Adrenal Cortex Hormones↗

PubMed2001

Partial characterization of retroviruses from boid snakes with inclusion body disease.

OBJECTIVE: To characterize retroviruses isolated from boid snakes with inclusion body disease (IBD). ANIMALS: 2 boa constrictors with IBD and 1 boa exposed to an affected snake. PROCEDURE: Snakes were euthanatized, and tissue specimens and blood samples were submitted for virus isolation. Tissue specimens were cultured with or without commercially available viper heart cells and examined by use of transmission electron microscopy (TEM) for evidence of viral replication. Reverse transcriptase activ ty was determined in sucrose gradient-purified virus. Western blotting was performed, using polyclonal antibodies against 1 of the isolated viruses. Specificity of the rabbit anti-virus antibody was evaluated, using an immunogold-labeling TEM technique. RESULTS: 3 viruses (RV-1, RV-2, and RV-3) were isolated. The isolates were morphologically comparable to members of the Retroviridae family. Reverse transcriptase activity was high in sucrose gradient fractions that were rich in virus. Polyclonal antibody against RV-1 reacted with proteins of similar relative mobility in RV-1 and RV-2. By use of immunogold labeling, this antibody also recognized virions of both RV-1 and RV-2. CONCLUSIONS AND CLINICAL RELEVANCE: A retrovirus was isolated from boid snakes with IBD or exposed to IBD. Western blot analysis of viral proteins indicated that viruses isolated from the different snakes were similar. Whether this virus represents the causative agent of IBD is yet to be determined. The isolation of retroviruses from boid snakes with IBD is an important step n the process of identifying the causative agent of this disease.

Animals↗

PubMed1988

The diagnostic value of colonoscopy compared with rectosigmoidoscopy in children and adolescents with symptoms of chronic inflammatory bowel disease of the colon.

Seventy-eight young patients with symptoms of chronic inflammatory bowel disease (IBD) of the colon have been investigated to determine to what degree colonoscopy adds important information for the diagnosis of IBD in addition to results of the routine procedures, including rectosigmoidoscopy carried out at the same time. After colonoscopy IBD was established in 4 of 12 patients classified as non-IBD after the routine procedures. Eleven of 18 patients with the routine diagnosis indeterminate colitis (IC) could after colonoscopy be differentiated into UC or probable CC. In 30 of 31 cases classified as UC the routine diagnosis was confirmed by colonoscopy. Routine diagnosis as probable CC was changed to definite CC in 3 of 10 cases. In all cases but one with previously established IBD it was possible to confirm the diagnosis. Thirty-seven of 70 patients with established IBD of the colon had no radiologic evidence of colitis.

Adolescent↗

PubMed1994

A prospective study of first attacks of inflammatory bowel disease and infectious colitis. Histologic course during the 1st year after presentation.

To investigate the possibilities of differentiating between inflammatory bowel disease (IBD) and infectious colitis on histologic grounds, a prospective histologic study of 105 patients with a first attack of colitis was undertaken. Rectal biopsies were performed on four occasions during 1 year. The strongest predictor of IBD was basal plasmacytosis, followed by more than two vertical crypt branches per medium-power field, crypt distortion, villous mucosa, and mucosal atrophy. These signs were rarely found among patients with infectious colitis. Their frequency increased with the interval between initial symptoms and the first biopsy. To study the development of histologic features in the absence of treatment, the IBD patients were divided into groups depending on this interval. Focal or diffuse basal plasmacytosis increased from 38% in the group with an interval of 1-15 days to 89% in those who presented in 121-300 days, and crypt distortion from 0% to 78%, whereas absence of signs indicating IBD decreased from 62% to 11%. The presence of focal basal plasmacytosis seems to be the earliest sign of IBD. The frequency of histologic signs indicating IBD was maximal (88%) at the 1-week biopsy. After recovery, the basal plasmacytosis and villous mucosa decreased, whereas crypt distortion and mucosal atrophy remained unchanged. Early treatment did not prevent the appearance of any feature.

Adult↗

PubMed1997

Hepatobiliary and coexisting pancreatic duct abnormalities in patients with inflammatory bowel disease.

BACKGROUND: We performed a cross-sectional study to evaluate the prevalence of hepatobiliary disease in unselected patients with inflammatory bowel disease (IBD), to estimate the frequency of coexisting cholangiographic and pancreatographic duct abnormalities, and to correlate the findings with clinical, endoscopic, and histologic variables. METHODS: We screened 237 IBD patients for increased liver function values. Further, hepatobiliary evaluation consisted of transabdominal ultrasonography, endoscopic retrograde cholangiopancreatography (ERCP), and a liver biopsy. In addition, we evaluated the ERCP findings of patients with abnormal pancreatic screening tests (pancreatic enzymes or para-aminobenzoic acid excretion). RESULTS: Laboratory signs of hepatobiliary disease were found in 37 (16%) of our IBD patients. Abnormal liver test results were commoner in patients with Crohn's disease (CD) than in patients with ulcerative colitis (UC) (30.4% versus 11.2%, P < 0.05), and a similar trend was observed in the frequency of primary sclerosing cholangitis (PSC) in the respective groups of IBD patients. When the ERCP findings were combined with liver histology, 26 (11% of the whole study group) patients with PSC were found, with small-duct disease included. In 23 (10% of the whole study group) patients, definite cholangiographic changes consistent with PSC were found. Eleven (48%) of these showed coexisting pancreatic duct abnormalities. The prevalence of coexisting cholangiographic and pancreatographic duct changes in the whole study group was 4.6%. CONCLUSION: Hepatobiliary disease is at least equally common in patients with UC and CD. Coexisting cholangiographic and pancreatographic duct abnormalities in patients with IBD are relatively frequent and are considered extraintestinal manifestations of IBD.

Adult↗

PubMed1997

Inflammatory bowel disease and osteoporosis.

The relation between inflammatory bowel disease (IBD) and osteoporosis has received increasing attention during the past decade. The prevalence of low bone mass in patients with IBD has been reported to be more than 50%. The development of a quick non-invasive method to diagnose osteoporosis (dual-energy X-ray absorptiometry) provides a practical tool to identify the patient who needs special attention. The aetiology of the bone disease in patients with IBD has still not been elucidated, but corticosteroids may play a major role. Studies on the prevention/treatment of IBD-related osteoporosis are scarce. In a single uncontrolled study hormone replacement therapy proved effective in preventing bone loss in peri- and post-menopausal women with IBD. A placebo-controlled study showed that supplementation with calcium and vitamin D prevents bone loss in patients with Crohn's disease. The present paper reviews our current knowledge on the mechanisms and epidemiology of IBD-related bone disease.

Bone Density↗

PubMed1982

Increased severity and new symptoms of infectious bursal disease during aflatoxicosis in broiler chickens.

A factorial design for the presence and absence of infection with a mild strain of infectious bursal disease (IBD) virus and graded levels of dietary aflatoxin (0, .625, 1.25, 2.5, 5.0, and 10.0 microgram/g of diet) in young broiler chickens revealed several interactions which greatly changed and character of the IBD infection. An infection that was essentially free of mortality became lethal to about half the birds. A coagulopathy as indicated by prolonged prothrombin times and by the occurrence of slight hemorrhages in skeletal muscles, a hypoproteinemia, a hypocalcemia, and a markedly enlarged kidney were observed in combined aflatoxicosis and IBD, but not in IBD alone. The size of the bursa of Fabricius following an initial hypertrophy was atrophied 4 days after inoculation and the spleen was enlarged. The effects of aflatoxin and IBD on these two glands were additive. Packed blood cell volume and hemoglobin values were decreased by aflatoxin only. Thus, aflatoxin had the effects of making IBD a much more severe disease and of changing the symptoms.

Aflatoxins↗

PubMed1982

Field trials with an oil emulsion infectious bursal disease vaccine in broiler breeder pullets.

Two independent field trials were undertaken with commercial broiler companies in separate sections of Alabama in order to test the efficacy of an experimental commercially prepared oil emulsion infectious bursal disease (IBD) vaccine in broiler breeder pullets. The IBD vaccine was tested both for safety and the production of neutralizing antibodies in pullets and their progeny as well as its ability to prevent early field exposure to virulent IBD virus (IBDV) in broiler progeny that may lead to immunosuppression resulting in poor performance. The following was demonstrated in both trials: 1) the IBD vaccine had no adverse effect on breeder performance, 2) the IBD antibody titers in breeders peaked at 10 weeks postvaccination (PV) and remained about 1.5 to 4 times higher than nonvaccinated breeders through 25 weeks (PV), 3) 1-day IBDV maternal titers in broilers were related to the parental titers, 4) the IBD vaccination in pullets prevented early infection to field IBDV in progeny as determined by antibody titers and various performance parameters.

Animals↗

PubMed2026

Gut microbiota-derived metabolites target C5AR1/KDM2A/HCAR3 axis in inflammatory bowel disease: a multi-machine learning algorithms and molecular docking study.

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic recurrent disorder. Gut microbiota-derived metabolites regulate intestinal homeostasis, but their molecular mechanisms in IBD remain unclear. Current studies lack systematic "microbiota-metabolite-target" network mining with multi-method validation. This study integrates network pharmacology, three machine learning algorithms, and molecular docking to construct this regulatory network in IBD. METHODS: Transcriptome data were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified using limma (p < 0.05, |log2FC| > 0.5). Weighted gene co-expression network analysis (WGCNA) with an optimal soft threshold of β = 7 was performed to identify key module genes. Candidate genes were obtained by intersecting DEGs, gut microbiota-associated genes from the gutMGene database, and WGCNA module genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted to explore the functional roles of candidate genes. Core genes were identified using three machine learning algorithms (LASSO, Boruta, and SVM-RFE), followed by protein-protein interaction (PPI) network analysis. Molecular docking was performed to assess the binding affinities between hub proteins and gut microbiota-derived metabolites. RESULTS: A total of 885 DEGs were identified between the IBD and control groups, including 463 upregulated and 422 downregulated genes. WGCNA identified 280 key module genes from the purple and yellow modules. The intersection of DEGs, gut microbiota-associated genes, and WGCNA module genes yielded 19 core candidate genes. PPI network analysis combined with three machine learning algorithms jointly identified C5AR1, KDM2A, and HCAR3 as core hub genes. ROC curve analysis demonstrated that all three hub genes achieved AUC values greater than 0.7 in both the training and validation sets, indicating excellent diagnostic performance for IBD. Enrichment analysis revealed significant associations with the TNF, NF-κB, and IL-17 signaling pathways. Molecular docking confirmed stable binding of C5AR1 with 1,3-Diphenylpropan-2-Ol (-7.87 ± 0.83 kcal·mol-¹) and HCAR3 with 3-Indolepropionic Acid (-6.35 ± 0.70 kcal·mol-¹), both below -5.0 kcal·mol-¹. CONCLUSION: This study first constructs a "gut microbiota-metabolite-hub gene" axis in IBD, providing a computational framework for microbiota-targeted precision therapy, and identifying C5AR1/KDM2A/HCAR3 as computationally predicted diagnostic biomarkers and 1,3-Diphenylpropan-2-Ol/3-Indolepropionic Acid as candidate intervention molecules that warrant further experimental validation.

Molecular Docking Simulation↗

PubMed2005

Association of Fas-670 gene polymorphism with inflammatory bowel disease in Chinese patients.

AIM: Recent studies suggest that Fas-mediated apoptosis is involved in the pathogenesis of inflammatory bowel disease (IBD). It has been hypothesized that either increased apoptosis of intestinal epithelium or decreased apoptosis of lamina propria lymphocytes may induce inflammation of gut. The aim of this study was to determine whether the Fas gene promoter polymorphism at position-670 was associated with IBD in Chinese patients. METHODS: Fifty unrelated Chinese patients with IBD (38 patients with ulcerative colitis and 12 with Crohn's disease) and 124 healthy controls were genotyped for the Fas-670 polymorphism by PCR-restriction fragment length polymorphism method. The PCR product was digested by Mva I restriction enzyme. RESULTS: Distribution of the Fas-670 gene polymorphism was 33% for the AA genotype, 52% for the AG genotype and 15% for the GG genotype in 124 healthy subjects. In patients with IBD, 30% was for the AA genotype, 42% for the AG genotype and 28% for the GG genotype respectively. However, there was no significant difference in the genotype (P = 0.1498), allele frequencies (P = 0.3198) and carriage frequencies (P = 0.4133) between healthy controls and IBD patients. Furthermore, we did not find any difference between the left-sided colitis and total colitis (P = 0.8242). CONCLUSION: Fas-670 polymorphism is not associated with IBD in Chinese patients.

Adult↗

PubMed2005

Impact of antithrombin III on hepatic and intestinal microcirculation in experimental liver cirrhosis and bowel inflammation: an in vivo analysis.

AIM: To analyze the hepatic and intestinal microcirculation in an animal model of liver cirrhosis and inflammatory bowel disease (IBD) and to characterize the anti-inflammatory action of antithrombin III (ATIII) on leukocyte kinetics and liver damage. METHODS: Hepatic and intestinal microcirculation was investigated by intravital videomicroscopy. Standardized models of experimental chronic liver cirrhosis and bowel inflammation were employed. Animals were divided into four groups (n = 6/group): controls, animals with cirrhosis, animals with cirrhosis and IBD, animals with cirrhosis and IBD treated with ATIII. RESULTS: Cirrhosis facilitated leukocyte rolling and sticking in hepatic sinusoids (1.91+/-0.28 sticker/microm vs 0.5+/-0.5 sticker/microm in controls, P<0.05). The effect enhanced in animals with cirrhosis and IBD (5.4+/-1.65 sticker/microm), but reversed after ATIII application (3.97+/-1.04 sticker/microm, P<0.05). Mucosal blood flow showed no differences in cirrhotic animals and controls (5.3+/-0.31 nL/min vs 5.4+/-0.25 nL/min) and was attenuated in animals with cirrhosis and IBD significantly (3.49+/-0.6 nL/min). This effect was normalized in the treatment group (5.13+/-0.4 nL/min, P<0.05). Enzyme values rose during development of cirrhosis and bowel inflammation, and reduced after ATIII application (P<0.05). CONCLUSION: Liver cirrhosis in the presence of IBD leads to a significant reduction in mucosal blood flow and an increase in hepatic leukocyte adherence with consecutive liver injury, which can be prevented by administration of ATIII.

Animals↗

PubMed2005

Internet-based data inclusion in a population-based European collaborative follow-up study of inflammatory bowel disease patients: description of methods used and analysis of factors influencing response rates.

AIM: To describe an Internet-based data acquisition facility for a European 10-year clinical follow-up study project of a population-based cohort of inflammatory bowel disease (IBD) patients and to investigate the influence of demographic and disease related patient characteristics on response rates. METHODS: Thirteen years ago, the European Collaborative study group of IBD (EC-IBD) initiated a population-based prospective inception cohort of 2 201 uniformly diagnosed IBD patients within 20 well-described geographical areas in 11 European countries and Israel. For the 10-year follow-up of this cohort, an electronic patient questionnaire (ePQ) and electronic physician per patient follow-up form (ePpPFU) were designed as two separate data collecting instruments and made available through an Internet-based website. Independent demographic and clinical determinants of ePQ participation were analyzed using multivariate logistic regression. RESULTS: In 958 (316 CD and 642 UC) out of a total number of 1 505 (64%) available IBD patients, originating from 13 participating centers from nine different countries, both ePQ and ePpPFU were completed. Patients older than 40 years at ePQ completion (OR: 1.53 (95%CI: 1.14-2.05)) and those with active disease during the 3 mo previous to ePQ completion (OR: 3.32 (95%CI: 1.57-7.03)) were significantly more likely to respond. CONCLUSION: An Internet-based data acquisition tool appeared successful in sustaining a unique Western-European and Israelian multi-center 10-year clinical follow-up study project in patients afflicted with IBD.

Adult↗

PubMed2006

Elevated plasma cryofibrinogen in patients with active inflammatory bowel disease is morbigenous.

AIM: To investigate the role of cryofibrinogen (CF) in active inflammatory bowel disease (IBD). METHODS: CF was assayed in 284 subjects: 61 with active and 63 with inactive ulcerative colitis (UC), 45 who had proctocolectomy, 35 with active and 20 with inactive Crohn's disease (CD), 40 with other diseases and 20 healthy controls. Trypsin inhibitor (TI) and TI antibody (TI-Ab) were measured in plasma and CF complex by ELISA. RESULTS: CF in active UC was strikingly high compared with all other groups (c2<0.001). Similarly, CF was significantly higher in active CD than in inactive CD or in controls (c2<0.01). In UC, high CF and TI-Ab were associated with the need for operations. Further, high CF, CF/fibrinogen ratio, low TI and high TI-Ab in plasma were associated with disease activity or refractoriness to medication. Elevated CF was not associated with acute reactants like C-reactive protein and white blood cell counts except for erythrocyte sedimentation rate, suggesting that elevated CF was not a consequence of acute inflammation. CONCLUSION: Elevated CF in active IBD appears to be morbigenous. CF promotes IBD via two main mechanisms, quenching of TI (an anti-inflammatory substance) and impairing microvascular perfusion by forming protein aggregates. CF may also serve as a biomarker of chronic IBD. Additional studies are warranted to fully evaluate the role of CF in IBD and the outcome should contribute to a better understanding of the pathogenesis of IBD.

Adolescent↗

PubMed1997

Increased eosinophil granule proteins in gut lavage fluid from patients with inflammatory bowel disease.

OBJECTIVE: To explore the potential role of eosinophils in the pathogenesis of inflammatory bowel disease (IBD). DESIGN: We measured the concentrations of eosinophil granule proteins-namely, major basic protein, eosinophil peroxidase, eosinophil cationic protein, and eosinophil-derived neurotoxin-in gut lavage fluid. MATERIAL AND METHODS: Ten healthy persons and 17 patients with IBD (9 with Crohn's disease and 8 with ulcerative colitis) underwent gut lavage. Each study subject submitted an early specimen when lavage effluent became liquid and a late specimen when the output became clear. The concentrations of the granule proteins were measured by immunoassay. RESULTS: The median concentrations of eosinophil-derived neurotoxin and eosinophil cationic protein were significantly higher in patients with IBD than in control subjects for both early and late lavage specimens. Excretion of eosinophil peroxidase was also significantly higher in patients with IBD than in the healthy control subjects, but only in the early specimens. No differences were noted in the concentrations of any of the proteins between patients with ulcerative colitis and those with Crohn's disease. CONCLUSION: Concentrations of eosinophil granule proteins were increased in whole gut lavage fluid from patients with IBD in comparison with healthy control subjects. These results encourage further studies of the role of eosinophils in the pathogenesis of IBD.

Adult↗

PubMed2026

Microbial and functional shifts between flare and remission in a single-center cohort of children with inflammatory bowel disease.

BACKGROUND: Gut microbial dysbiosis is central to the pathogenesis of inflammatory bowel disease (IBD). While gut microbiome differences between patients with and without IBD are well established, microbiome changes associated with disease activity and remission remain limited, particularly in paediatric populations. AIM: To examine intra-individual taxonomic and functional gut microbiome changes during transition from active flare to remission under maintenance immunosuppression in a pilot single-center Singapore cohort of children with IBD. METHODS: Paired stool samples and clinical data were collected from seven patients with paediatric IBD [5 Crohn's disease (CD), 2 ulcerative colitis; ≤ 18 years] during active disease/flare (visit 1; Pediatric CD Activity Index/Pediatric Ulcerative Colitis Activity Index ≥ 10) and subsequent clinical remission (visit 2; Pediatric CD Activity Index/Pediatric Ulcerative Colitis Activity Index < 10). Samples underwent shotgun metagenomic sequencing for high-resolution taxonomic profiling and functional annotation of Kyoto Encyclopaedia of Genes and Genomes pathways. RESULTS: Gut microbial diversity was reduced during flare compared to remission, with Actinobacteria abundance significantly higher in remission. Two distinct microbial clusters differentiated flare and remission states: The remission cluster was enriched with Bifidobacterium adolescentis, Bifidobacterium dentium, Lactobacillus gasseri, Faecalibacterium prausnitzii, while the flare state showed increased Klebsiella pneumoniae. Remission was further characterized by a downregulation of pathogenic microbes and an upregulation of beneficial microbes including a higher abundance of the butyrate producer Anaerostipes hadrus (P = 0.046). Microbial functional genes enriched in remission were predominantly associated with metabolic pathways including vitamin and cofactor biosynthesis, as well as carbohydrate, amino acid, and lipid metabolism. CONCLUSION: The transition from flare to remission in Singaporean children with IBD is characterized by functional remodeling of the gut microbiome, which may contribute to recovery processes related to intestinal barrier integrity, cellular maintenance, and tissue repair. Targeted modulation of the gut microbiome may help sustain remission in paediatric IBD.

Functional shift↗

PubMed1999

CD44 variant isoforms on blood leukocytes in chronic inflammatory bowel disease and other systemic autoimmune diseases.

We have described recently that TNBS-induced colitis, an animal model of chronic inflammatory bowel disease (IBD), can be cured by treatment with anti-CD44v7. This finding led us to evaluate whether CD44v7 may be of functional importance in patients with IBD. Expression of CD44 variant isoforms (CD44v) has been evaluated on PBMC of 46 patients with IBD, 43 patients with autoimmune diseases not affecting the gastrointestinal tract, 26 patients with nonautoimmune disease, and 24 healthy donors. In all groups, expression of CD44v on freshly harvested PBMC was not above or was borderline above background levels. After in vitro stimulation, expression of CD44 standard (CD44s) and CD44v6 was strongly up-regulated. Exclusively on PBMC of patients with autoimmune disease, high expression of CD44v3 and CD44v7 was observed. CD44v3 and CD44v7 were mainly expressed on subsets of CD4+ lymphocytes, B cells, and monocytes; CD44v6 was predominantly detected on CD4+ and CD8+ cells. Considering functional activity, CD44v7 apparently exerted a dual effect. After culturing PBMC in the presence of anti-CD44v7, a higher percentage of cells produced IL-10. This was irrespective of whether the PBMC were derived from healthy donors or from patients with autoimmune disease or IBD. On the other hand, PBMC of all donors proliferated upon cross-linking of CD3 and CD44s or CD3 and CD44v6. Instead, costimulatory activity of CD44v7 was seen only in PBMC of patients with autoimmune disease and IBD. Because expression and function of CD44v7 in patients with systemic autoimmune disease and IBD have been much like the ones in mice suffering of TNBS-induced colitis, it is tempting to speculate that blockade of CD44v7 could also be of therapeutic relevance in the human diseases.

Adult↗