non-IBD Control Patients Research Articles

Longitudinal DNA methylation profiling of the rectal mucosa identifies cell-specific signatures of disease status, severity and clinical outcomes in ulcerative colitis cell-specific DNA methylation signatures of UC

BackgroundIn peripheral blood, DNA methylation (DNAm) patterns in inflammatory bowel disease patients reflect inflammatory status rather than disease status. Here, we examined DNAm in diseased rectal mucosa from ulcerative colitis (UC) patients, focusing on constituent cell types with the goal of identifying therapeutic targets for UC other than the immune system. We profiled DNAm of rectal mucosal biopsies of pediatric UC at diagnosis (n = 211) and non-IBD control (n = 85) patients and performed epigenome-wide association studies (EWAS) of specific cell types to understand DNAm changes in epithelial, immune and fibroblast cells across disease states, course, and clinical outcomes. We also examined longitudinal analysis on follow-up samples (n = 73), and comparisons were made among patients with clinical outcomes including those undergoing colectomy versus those who did not. Additionally, we included RNA-seq from the same subjects to assess the impact of CpG sites on the transcription of nearby genes during the disease course.ResultsAt diagnosis, UC rectal mucosa exhibited a lower proportion of epithelial cells and fibroblasts, and higher proportion of immune cells, in conjunction with variation in the DNAm pattern. While treatment had significant effects on the methylation signature of immune cells, its effects on fibroblasts and epithelial cells were attenuated. Individuals who required colectomy exhibited cell composition and DNAm patterns at follow-up more similar to disease onset than patients who did not require colectomy. Combining these results with gene expression profiles, we identify CpG sites whose methylation patterns are most consistent with a contribution to poor disease outcomes and could thus be potential therapeutic targets.ConclusionsCell-specific epigenetic changes in the rectal mucosa in UC are associated with disease severity and outcome. Current therapeutics may more effectively target the immune than the epithelial and fibroblast compartments.Graphical abstract

Inflammatory bowel disease-associated adherent-invasive Escherichia coli have elevated host-defense peptide resistance.

Adherent-invasive Escherichia coli (AIEC) are isolated from inflammatory bowel disease (IBD) patients at a higher rate than from control patients. Using a collection of E. coli strains collected from Crohn's disease (CD), ulcerative colitis (UC), or non-IBD control patients, antibiotic and resistance to the antimicrobial peptides HBD-3 and LL-37 was assessed. Carriage of bacterial-encoded omptin protease genes was assessed by PCR and omptin protease activity was measured using a whole-cell based fluorescence assay. Elevated resistance to antibiotics and host defense peptides in IBD-associated AIEC were observed. IBD-associated strains showed increased (but statistically non-significant) antibiotic resistance. CD-associated strains showed greater (but statistically non-significant) resistance to HBD3-mediated killing while UC-associated strains showed statistically greater resistance to LL-37 mediated killing. High-level resistance to LL-37 was associated with carriage of omptin protease genes and with increased omptin protease activity. Antimicrobial host defense peptide resistance may be an adaptive feature of AIEC leading to enhanced pathogenesis during the initiation or progression of IBD.

P155 Incidence and significance of vitamin D deficiency at Inflammatory Bowel Disease inception in the COVID era

Abstract Background Vitamin D, a key regulator of immune response, is known to be lower in Inflammatory Bowel Disease (IBD) patients than the general population. Disparity in the incidence of deficiency between ethnic groups has previously been demonstrated. We measured vitamin D in a unique multi-ethnic inception cohort to correlate this with traditional IBD scores and patient reported outcome measures including the ‘IBD Disk’. Methods Data regarding demographics, ethnicity, faecal calprotectin (FCAL) and baseline blood results including Vitamin D was collected prospectively from January-October 2021, from adults presenting with suspected IBD. Montreal classification, Harvey-Bradshaw Index or Partial Mayo score, endoscopic disease severity indices and IBD Disk score were documented in those with confirmed diagnosis at endoscopy. Vitamin D deficiency was defined as <50nmol/l. Results 179 patients had a Vitamin D level recorded; 58 Ulcerative colitis (UC), 58 Crohn’s disease (CD), 53 non-IBD controls and 10 still awaiting diagnosis. 44(76%) CD, 32(55%) UC and 28(53%) non-IBD control patients were Vitamin D deficient at first presentation. Median levels were lowest in CD, with a significant difference between CD and non-IBD (median 35nmol/l; IQR 24.05 vs. median 48.9nmol/l; IQR 49.1; p=0.004). Regression analysis demonstrated patients with Crohn’s disease were four times more likely to have Vitamin D deficiency compared to UC (OR 4.08; 95% CI 1.35–12.36) at diagnosis. No correlation was seen between absolute vitamin D levels or vitamin deficiency state and faecal calprotectin when controlled for various factors regardless of the IBD subtype. The cohort distributions are demonstrated in Figure 1. Within the IBD cohort, Vitamin D levels were significantly lower in Black or Asian patients vs White patients (median 28.5; IQR 20.85 vs median 43.3; IQR 33.95; p=0.004). Figure 2 provides an overview of the cohort distributions. Vitamin D levels at presentation, as demonstrated in Table 1, did not correlate with Disease activity markers (DAMS) whereas baseline haemoglobin did, albeit weakly. Interestingly, Vitamin D and Haemoglobin correlated without reaching statistical significance (Spearman’s rho 0.149; p=0.08). Conclusion Our inception dataset demonstrates high rates of Vitamin D deficiency comparable to prior studies in IBD patients. Both CD and Black or Asian ethnicity were strongly associated with Vitamin D deficiency. Baseline Vitamin D did not correlate with disease activity markers whereas anaemia showed consistent weak association. Our study demonstrates the problem of hypovitaminosis D and the importance of measurement and supplementation, particularly in Black and Asian CD patients, from diagnosis.

Associations between Cellular Energy and Pediatric Inflammatory Bowel Disease Patient Response to Treatment.

Inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis, are chronic diseases of the gastrointestinal tract, with an unknown etiology, that affect over 6.8 million people worldwide. To characterize disease pathogenesis, proteomic and bioinformatic analyses were performed on colon biopsies collected during diagnostic endoscopy from 119 treatment-naïve pediatric patients, including from 78 IBD patients and 41 non-IBD patients who served as controls. Due to the presence of noninflamed and/or inflamed regions in IBD patients, up to two biopsies were obtained from IBD patients as compared to a single noninflamed biopsy from non-IBD pediatric control patients. Additional biopsies were obtained and analyzed from 33 of the IBD patients after IBD-directed therapeutic intervention for comparison of pre- and post-treatment proteomes. SuperSILAC was utilized to perform quantitative analysis of homogenized tissues, which were processed by filter-aided sample preparation. Hierarchical clustering and principal component analyses revealed proteomic patterns that distinguished inflamed from noninflamed tissues independent of therapy. Gene ontology revealed that proteins downregulated in inflammation are associated with metabolism, whereas upregulated proteins contribute to protein processing. A comparison of pre- and post-treatment proteomes from CD patients identified over 100 proteins that are significantly different between patients who responded and those who did not respond to therapy, including creatine kinase B and basigin.

S0832 Characterization of Intestinal Subepithelial PDGFRα(high), DLL1+, F3+ Cells in Ulcerative Colitis

INTRODUCTION: A deeper understanding of the cellular features of disease represents an important step in unlocking the pathogenesis of ulcerative colitis (UC). We recently characterized a novel cell type in the human fetal gut located in the subepithelial compartment adjacent to the epithelium expressing a unique combination of genes and niche factors. Due to their gene expression, we refer to these cells as intestinal, Subepithelial, PDGFR-αHI, DLL1+, F3+ (iSPαD3). Data suggests iSPαD3 cells are involved in intestinal development and maintenance of the stem cell niche. We aimed to determine if these cells are present in the adult colon, and if they play a role in the pathogenesis of inflammation in UC. METHODS: Primary human colonic tissues from non-IBD control and UC patients were obtained via surgical resection. Patients provided informed consent and this study was approved by the University of Michigan Institutional Review Board. Tissues were formalin fixed and paraffin embedded. Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) were performed. Further, we analyzed publicly available single cell RNA sequencing data and performed differential expression analysis on an iSPαD3 population. Data were queried for gene ontology term enrichment using the DAVID database. RESULTS: A population analogous to human fetal small intestinal iSPαD3 cells are present in the adult colon. In health iSPαD3 cells encircle crypts with a high degree of proximity and continuity. There are fewer cells that exhibit morphological changes in inflammation (Figures 1 and 2). In healthy colon iSPαD3 cells are enriched for genes involved in Wnt and NOTCH signaling, immune response to bacteria, B-cell regulation, TGFβ signaling, and cell growth. In inflammation they are enriched for genes related to apoptotic pathways, neutrophil chemotaxis, extracellular matrix, and regulation of IL-6, tumor necrosis factor, and JAK-STAT (Figure 3). CONCLUSION: iSPαD3 cells appear to have an important supportive role in the intestinal epithelium and are involved in the pathogenesis of inflammation in UC. Our study suggests that iSPαD3 cells function in homeostatic maintenance and containment of luminal microbiota in health. In contrast, inflammation is associated with loss of iSPαD3 homeostatic functions and in favor of apoptotic and inflammatory pathways, implicating these cells as important modulators in colonic inflammation from UC. More work is needed to elucidate a potential role for iSPαD3 cells in inflammatory bowel disease.Figure 1Figure 2Figure 3

P148 COLONIC SPROUTY2 IS ELEVATED IN INFLAMMATORY BOWEL DISEASE PATIENTS

Abstract Background The intestinal epithelium plays a central role in protecting against the development of colitis, and is disrupted in inflammatory bowel disease (IBD). It serves as the physical barrier that, when breached, allows luminal contents (i.e. bacteria, antigens) to stimulate inflammatory responses. Sprouty2 (SPRY2) is an intracellular regulator of growth factor receptor signaling that is downregulated in a compensatory response to inflammatory stimuli in cell lines and a mouse model of colitis. Additionally, mice with intestine-specific Spry2 deletion are protected against colitis and have elevated tuft and goblet cell numbers, cell types thought to protect the intestinal epithelium. This may represent a feedback mechanism to reinforce the intestinal epithelium during the initial stages of injury. However, the regulation of SPRY2 in IBD patients is unknown. We hypothesized that SPRY2 expression might be dysregulated in patients with IBD. Methods SPRY2 levels were measured by quantitative PCR analysis of human colonic tissue from endoscopic biopsies and surgical resection specimens from pediatric IBD and non-IBD patients. Human colonoids (primary cultures of colonic epithelium) were grown from surgical resection specimens of non-IBD control patients. SPRY2 expression was measured via qPCR in response to treatment with TNF for 24 hrs. Results SPRY2 expression decreased by an average of 24.41% (p = 0.0002, n =4) in colonoids from non-IBD patients treated with tumor necrosis factor (TNF) 10 ng/mL and 18.13% (p = 0.0016) for 100 ng/mL. However, SPRY2 expression in endoscopic biopsies from IBD patients was 2.325 ± 0.9846 fold higher in ulcerative colitis (UC) patients (p= 0.0242, n =8) and 9.825 ± 2.800 fold higher in Crohn’s disease patients (p= 0.0014, n=6) compared to non-IBD controls (n=27). In surgical specimens, SPRY2 levels were 37.10 ± 21.96 (p= 0.0459) fold higher in IBD (n=6) vs. non-IBD (n=4) patients. Furthermore, data mining of Gene Expression Omnibus dataset GDS3268 (biopsies from UC patients) revealed a significant negative correlation between SPRY2 and the protective tuft cell markers DCLK1 and TRPM5. Conclusion Acute TNF signaling repressed SPRY2 expression in a human colonoid model. In contrast, SPRY2 levels appear to be increased in human IBD and negatively correlate with tuft cell markers. Together these data suggest that, while acute inflammation can downregulate SPRY2 to drive increased numbers of protective secretory cells, in chronic disease this response either does not occur or is lost. A failure to down-regulate SPRY2 in response to early mucosal damage may be a factor in the development of IBD.

Dynamics of metatranscription in the inflammatory bowel disease gut microbiome.

Inflammatory bowel disease (IBD) is a group of chronic diseases of the digestive tract affecting millions of people worldwide. Genetic, environmental and microbial factors have been implicated in onset and exacerbation of IBD. However, the mechanisms associating gut microbial dysbioses and aberrant immune responses remain largely unknown. The integrative Human Microbiome Project (iHMP) seeks to close these gaps by examining the dynamics of microbiome functionality in disease by profiling the gut microbiomes of more than 100 individuals sampled over a one year period. Here, we present the first results based on 78 paired fecal metagenomes/metatranscriptomes and 222 additional metagenomes from 59 Crohn’s disease (CD), 34 ulcerative colitis (UC), and 24 non-IBD control patients. We demonstrate several cases in which measures of microbial gene expression in the inflamed gut can be informative relative to metagenomic profiles of functional potential. First, while many microbial organisms exhibited concordant DNA and RNA abundances, we also detected species-specific biases in transcriptional activity, revealing predominant transcription of pathways by individual microbes per host (e.g. by Faecalibacterium prausnitzii). Therefore, a loss of these organisms in disease may have more far-reaching consequences than suggested by their genomic abundances. Further, we identified organisms that were metagenomically abundant but inactive or dormant in the gut with little or no expression (e.g. Dialister invisus). Lastly, certain disease-specific microbial characteristics were more pronounced or only detectable at the transcript level, such as pathways predominantly expressed by different organisms in IBD patients (e.g. Bacteroides vulgatus and Alistipes putredinis). This provides potential insights into gut microbial pathway transcription that can vary over time, inducing phenotypic changes complementary to those linked to metagenomic abundances. The study’s results highlight the strength of analyzing both the activity and presence of gut microbes to provide insight into the role of the microbiome in IBD.

Hallmarks of epithelial to mesenchymal transition are detectable in Crohn's disease associated intestinal fibrosis.

BackgroundIntestinal fibrosis and subsequent stricture formation represent frequent complications of Crohn’s disease (CD). In many organs, fibrosis develops as a result of epithelial to mesenchymal transition (EMT). Recent studies suggested that EMT could be involved in intestinal fibrosis as a result of chronic inflammation. Here, we investigated whether EMT might be involved in stricture formation in CD patients.MethodsHuman colonic tissue specimens from fibrotic areas of 18 CD and 10 non-IBD control patients were studied. Immunohistochemical staining of CD68 (marker for monocytes/macrophages), transforming growth factor-β1 (TGFβ1), β-catenin, SLUG, E-.cadherin, α-smooth muscle actin and fibroblast activation protein (FAP) were performed using standard techniques.ResultsIn fibrotic areas in the intestine of CD patients, a large number of CD68-positive mononuclear cells was detectable suggesting an inflammatory character of the fibrosis. We found stronger expression of TGFβ1, the most powerful driving force for EMT, in and around the fibrotic lesions of CD patients than in non-IBD control patients. In CD patients membrane staining of β-catenin was generally weaker than in control patients and more cells featured nuclear staining indicating transcriptionally active β-catenin, in fibrotic areas. In these regions we also detected nuclear localisation of the transcription factor, SLUG, which has also been implicated in EMT pathogenesis. Adjacent to the fibrotic tissue regions, we observed high levels of FAP, a marker of reactive fibroblasts.ConclusionsWe demonstrate the presence of EMT-associated molecules in fibrotic lesions of CD patients. These findings support the hypothesis that EMT might play a role for the development of CD-associated intestinal fibrosis.Electronic supplementary materialThe online version of this article (doi:10.1186/s40169-015-0046-5) contains supplementary material, which is available to authorized users.

DOP067 Low FODMAP diet reduces irritable bowel symptoms and improves quality of life in patients with inflammatory bowel disease in a randomized controlled trial

University/Hospital. Data were expressed as median and range and differences between groups assessed by the T test. Results: Dermatological assessment was performed in 188 IBD patients (85 F, age 45.5 yrs, range 18 85; IBD duration 9 yrs, range 1 46). Among these 188 patients, there were 72 UC (35 M, age 47, range 23 85; UC duration 6 yrs, range 1 40; UC extent: distal 26, left 11, extensive 31, ileal pouch 3, ileostomy 1) and 116 CD (69 M, age 44, range 18 80; CD duration 10 yrs, range 1 46; CD colitis 8, ileo-colitis 24, ileitis 34, neo-terminal ileum 45, ileostomy 2, jejunum 1, distal ileum + jejunum 2). NonIBD C included 50 patients (31 M, age 47, range 18 75). Among the 188 IBD patients, psoriasis was detected in 48 (26%; 28 CD, 20 UC). In the IBD group, the median age and IBD duration were comparable in patients with or without psoriasis (age 50.5 range 23 72 vs 44 range 18 85; IBD duration 8 yrs range 1 45 vs 9 yrs range 1 41; p = ns for both). Mild psoriasis was detected in a higher proportion of IBD patients (40/48; 83%) than nonIBD C (28/50; 56%; p < 0.001). Scalp psoriasis and sebopsoriasis were the more common psoriasis phenotype in IBD (16/48; 33%), followed by inverse psoriasis (7/48; 15%) and by palmoplantar psoriasis (5/48; 10%). Psoriatic arthritis was detected in 9/50 (18%) non-IBD C and in 4/48 (8%) IBD patients (p = n.s.). In 4/48 (12%) IBD patients, psoriasis developed after anti-TNFs (palmo-palmar 3, sebopsoriasis 1). Conclusions: Results from a cohort of IBD patients matched with non-IBD control patients suggest that specific phenotypes of psoriasis may be associated with IBD.

The Role for Dickkopf-Homolog-1 in the Pathogenesis of Crohn’s Disease-Associated Fistulae

BackgroundOne of the most challenging conditions in Crohn’s disease (CD) patients is the treatment of perianal fistulae. We have recently shown that epithelial-to-mesenchymal transition (EMT) plays a crucial role during CD-fistulae development. Dickkopf-homolog 1 (DKK-1) is known to play a key role during EMT. Here, we investigated a role for DKK-1 in the pathogenesis of CD-associated fistulae.MethodsDkk-1 protein expression in CD-fistula specimens were investigated by immunohistochemistry. Colonic lamina propria fibroblasts (CLPF) were obtained from either non-IBD control patients or patients with fistulizing CD. HT-29 intestinal epithelial cells (IEC) were either grown as monolayers or spheroids. Cells were treated with either TNF-α, TGF-β or IL-13. Knock-down of DKK-1 or β-Catenin was induced in HT-29-IEC by siRNA technique. mRNA expression was determined by real-time-PCR.ResultsDkk-1 protein was specifically expressed in transitional cells lining the fistula tracts. TGF-β induced DKK-1 mRNA expression in HT-29-IEC, but decreased it in fistula CLPF. On a functional level, DKK-1 knock-down prevented TGF-β-induced IL-13 mRNA expression in HT-29-IEC. Further, loss of β-Catenin was accompanied by reduced levels of DKK-1 and, again, IL-13 in IEC in response to TGF-β. In turn, treatment of HT-29-IEC as well as fistula CLPF with IL-13 resulted in decreased levels of DKK-1 mRNA. Treatment with TNF-α or the bacterial wall component, muramyl-dipeptide, decreased DKK-1 mRNA levels in HT-29-IEC, but enhanced it in fistula CLPF.DiscussionWe demonstrate that DKK-1 is strongly expressed in cells lining the CD-fistula tracts and regulates factors involved in EMT initiation. These data provide evidence for a role of DKK-1 in the pathogenesis of CD-associated perianal fistulae.

Crohnʼs disease-associated polymorphism within the PTPN2 gene affects muramyl-dipeptide-induced cytokine secretion and autophagy

The single nucleotide polymorphism (SNP) rs2542151 within the gene locus region encoding protein tyrosine phosphatase non-receptor type 2 (PTPN2) has been associated with Crohn's disease (CD), ulcerative colitis (UC), type-I diabetes, and rheumatoid arthritis. We have previously shown that PTPN2 regulates mitogen-activated protein kinase (MAPK) signaling and cytokine secretion in human THP-1 monocytes and intestinal epithelial cells (IEC). Here, we studied whether intronic PTPN2 SNP rs1893217 regulates immune responses to the nucleotide-oligomerization domain 2 (NOD2) ligand, muramyl-dipeptide (MDP). Genomic DNA samples from 343 CD and 663 non-IBD control patients (male and female) from a combined German, Swiss, and Polish cohort were genotyped for the presence of the PTPN2 SNPs, rs2542151, and rs1893217. PTPN2-variant rs1893217 was introduced into T(84) IEC or THP-1 cells using a lentiviral vector. We identified a novel association between the genetic variant, rs1893217, located in intron 7 of the PTPN2 gene and CD. Human THP-1 monocytes carrying this variant revealed increased MAPK activation as well as elevated mRNA expression of T-bet transcription factor and secretion of interferon-γ in response to the bacterial wall component, MDP. In contrast, secretion of interleukin-8 and tumor necrosis factor were reduced. In both, T(84) IEC and THP-1 monocytes, autophagosome formation was impaired. We identified a novel CD-associated PTPN2 variant that modulates innate immune responses to bacterial antigens. These findings not only provide key insights into the effects of a functional mutation on a clinically relevant gene, but also reveal how such a mutation could contribute to the onset of disease.

Protein Tyrosine Phosphatase Nonreceptor Type 2 Regulates Autophagosome Formation in Human Intestinal Cells

Autophagy is a process of central importance for maintaining cell homeostasis, survival, and the regulation of inflammation. Recent studies associated variants within the gene loci, encoding protein tyrosine phosphatase nonreceptor type 2 (PTPN2), and autophagy genes, such as autophagy-related 16-like 1 (ATG16L1), with chronic inflammatory disorders, such as Crohn's disease (CD). We show that PTPN2 regulates autophagy in human intestinal epithelial cells (IEC) and primary colonic lamina propria fibroblasts (CLPF). Protein analysis in IEC and CLPF was performed by western blotting. Autophagososme formation was assessed by LC3B immunofluorescence or immunohistochemistry. Human intestinal tissue samples were obtained from noninflammatory bowel disease (IBD) control or from CD patients and genotyped for disease-associated PTPN2 or ATG16L1 variations. Knockdown of PTPN2 causes impaired autophagosome formation and dysfunctional autophagy resulted in increased levels of intracellular Listeria monocytogenes (LM) and elevated IEC apoptosis in response to tumor necrosis factor (TNF) and interferon gamma (IFN-γ). Similar findings were observed in primary CLPF derived from CD patients carrying the CD-associated PTPN2 variant. Presence of the ATG16L1 variant prevented the cytokine-induced rise in PTPN2 protein, finally resulting in impaired LC3B-II levels in IEC. Actively inflamed intestinal biopsies from CD patients carrying either ATG16L1 or PTPN2 genetic variants revealed aberrant LC3B expression patterns when compared with samples from non-IBD control patients. Our results demonstrate that PTPN2 regulates autophagosome formation in human intestinal cells. We provide a model of how a dysfunction of the CD susceptibility genes, PTPN2 and/or ATG16L1, may contribute to the onset and perpetuation of chronic intestinal inflammation.

Lymphocytic esophagitis: A possible manifestation of pediatric upper gastrointestinal Crohnʼs disease

Lymphocytic esophagitis (LE) is histologically defined by marked esophageal lymphocytosis with no or only rare intraepithelial granulocytes. This study was performed to investigate the association between LE and pediatric Crohn's disease (CD). Blinded retrospective morphologic analysis was performed on gastrointestinal biopsies from pediatric patients with an established diagnosis of CD (n = 60) and ulcerative colitis (UC; n = 30), as well as a spectrum of non-inflammatory bowel disease (IBD) patients (n = 38). The highest density of intraepithelial lymphocytes (IEL), neutrophils (IEN), and eosinophils (IEE) per high power field (hpf; 40×) were counted. LE was defined as >50 IEL/hpf and a ratio of >50:1 IEL to intraepithelial granulocytes (IEG). LE was identified in 17/60 patients with CD, and only 2/30 patients with UC and 1/38 non-IBD control patients; P = 0.0263 (CD versus UC) and P = 0.0002 (CD versus non-CD). In all, 6/60 CD patients had esophagitis with granulomas and three of these met the diagnostic criteria for LE. There was no difference in the incidence of upper gastrointestinal (UGI) symptoms between the CD patients with LE (7/17, 41%) and CD patients with esophagitis with granulomas (3/6; P = 1.0). The histologic diagnosis of LE is associated with pediatric CD and was found in 28% of CD patients. If LE is identified in pediatric CD, it is likely a manifestation of UGI-CD rather than esophagitis due to other etiologies or a variant of normal.

Effect of fish oil enriched enteral diet on inflammatory bowel disease tissues in organ culture: Differential effects on ulcerative colitis and Crohn’s disease

To investigate the influence of fish oil enriched enteral diet on intestinal tissues taken from Crohn's disease (CD), ulcerative colitis (UC) and non-inflamed non-IBD control patients in vitro. Colonoscopic biopsies from patients with active CD (n = 4), active UC (n = 7), and non-inflamed non-IBD control patients (n = 4) were incubated (three dilutions of 1:20, 1:10, and 1:5) with Waymouth's culture medium and enteral elemental diet (EO28, SHS, Liverpool, UK) modified in the fatty acid composition with fish oil (EF) in an organ culture system for 24 h. In each experimental set-up, incubation with Waymouth's medium alone as control was included. Tissue viability was assessed by adding bromodeoxyuridine (BrdU) to the culture fluid and immunohistochemically staining for BrdU uptake. Cytokine ratio of IL-1ra/IL-1beta (low ratio indicative of inflammation) and production of those cytokines as a percentage of medium control were assayed in the culture supernatant. Incubation of CD-affected tissue with EF (1:20, 1:10, and 1:5) modestly and non-significantly increased IL-1ra/IL-1beta ratio as compared with medium control (CD 39.1+/-16.1; 26.5+/-7.8, 47.1+/-16.8 vs control 13.0+/-2.2), but incubation of UC-affected tissues increased IL-1ra/IL-1beta ratio significantly in all three dilutions (UC 69.1+/-32.2, P<0.05; 76.1+/-36.4, P = 0.05; 84.5+/-37.3, P<0.02; vs control 10.2+/-3.7). Incubation of non-inflamed non-IBD control tissue did not increase the IL-1ra/IL-1beta ratio in any dilution compared to medium control (69.3+/-47.0, 54.1+/-30.6, 79.4+/-34.0 vs control 76.1+/-37.3). Average percentage production of IL-1beta indexed against medium control was significantly less in UC after EF incubation as compared with CD (UC 24.0+/-4.8 vs CD 51.8+/-8.1; P<0.05). Average percentage production of IL-1ra was markedly higher in UC (135.9+/-3.4) than that in control patients (36.5+/-4.3) (P<0.0001). IBD tissues, after incubation with elemental diet modified in its fatty acid composition with fish oil, show an increase in IL-1ra/IL-1beta cytokine ratio. This effect of omega-3 fatty acid modulation is significantly more marked in UC compared with CD and is accompanied by both a reduction of IL-1beta and increase of IL-1ra. The positive direct anti-inflammatory effect of elemental diet with fish oil in tissue affected with UC suggests dietary treatment of UC may be possible.

Oral iron therapy in inflammatory bowel disease: usage, tolerance, and efficacy.

Iron deficiency is common in inflammatory bowel disease (IBD). Anecdotal evidence suggests that oral iron is poorly tolerated and may exacerbate disease activity in patients with IBD. AIM The aim of this study was to retrospectively compare usage, tolerance, and efficacy of oral iron therapy in patients with IBD and noninflammatory causes of iron deficiency. Case records of 277 patients with IBD and 24 non-IBD iron-deficient control patients covering a 4-year period were retrospectively analyzed. Fifty-three of 277 (19%) of the patients with IBD studied had received oral iron. In only 40% of the patients who had IBD and 63% of the patients who did not (p = not significant) was iron deficiency formally confirmed before treatment. Intolerance to iron was reported in only 25% of the patients who had IBD and 17% of the patients who did not (p = not significant). In only two of eight adequately monitored iron-intolerant patients with IBD was iron therapy associated with an increase in inflammatory markers. When formally checked, iron repletion was successfully achieved as frequently in patients who had IBD (59%) as in patients who did not (45%). Iron therapy is often used without a formal diagnosis of iron deficiency having been made, at least in part because of the difficulty in making this diagnosis using ferritin, an acute-phase protein. Patients with IBD are no more intolerant of oral iron than other patients and have similar rates of repletion.