A biomarker-stratified comparison of top-down versus accelerated step-up treatment strategies for patients with newly diagnosed Crohn's disease (PROFILE): a multicentre, open-label randomised controlled trial.

BACKGROUND: Management strategies and clinical outcomes vary substantially in patients newly diagnosed with Crohn's disease. We evaluated the use of a putative prognostic biomarker to guide therapy by assessing outcomes in patients randomised to either top-down (ie, early combined immunosuppression with infliximab and immunomodulator) or accelerated step-up (conventional) treatment strategies. METHODS: PROFILE (PRedicting Outcomes For Crohn's disease using a moLecular biomarker) was a multicentre, open-label, biomarker-stratified, randomised controlled trial that enrolled adults with newly diagnosed active Crohn's disease (Harvey-Bradshaw Index ≥7, either elevated C-reactive protein or faecal calprotectin or both, and endoscopic evidence of active inflammation). Potential participants had blood drawn to be tested for a prognostic biomarker derived from T-cell transcriptional signatures (PredictSURE-IBD assay). Following testing, patients were randomly assigned, via a secure online platform, to top-down or accelerated step-up treatment stratified by biomarker subgroup (IBDhi or IBDlo), endoscopic inflammation (mild, moderate, or severe), and extent (colonic or other). Blinding to biomarker status was maintained throughout the trial. The primary endpoint was sustained steroid-free and surgery-free remission to week 48. Remission was defined by a composite of symptoms and inflammatory markers at all visits. Flare required active symptoms (HBI ≥5) plus raised inflammatory markers (CRP >upper limit of normal or faecal calprotectin ≥200 µg/g, or both), while remission was the converse-ie, quiescent symptoms (HBI <5) or resolved inflammatory markers (both CRP ≤ the upper limit of normal and calprotectin <200 µg/g) or both. Analyses were done in the full analysis (intention-to-treat) population. The trial has completed and is registered (ISRCTN11808228). FINDINGS: Between Dec 29, 2017, and Jan 5, 2022, 386 patients (mean age 33·6 years [SD 13·2]; 179 [46%] female, 207 [54%] male) were randomised: 193 to the top-down group and 193 to the accelerated step-up group. Median time from diagnosis to trial enrolment was 12 days (range 0-191). Primary outcome data were available for 379 participants (189 in the top-down group; 190 in the accelerated step-up group). There was no biomarker-treatment interaction effect (absolute difference 1 percentage points, 95% CI -15 to 15; p=0·944). Sustained steroid-free and surgery-free remission was significantly more frequent in the top-down group than in the accelerated step-up group (149 [79%] of 189 patients vs 29 [15%] of 190 patients, absolute difference 64 percentage points, 95% CI 57 to 72; p<0·0001). There were fewer adverse events (including disease flares) and serious adverse events in the top-down group than in the accelerated step-up group (adverse events: 168 vs 315; serious adverse events: 15 vs 42), with fewer complications requiring abdominal surgery (one vs ten) and no difference in serious infections (three vs eight). INTERPRETATION: Top-down treatment with combination infliximab plus immunomodulator achieved substantially better outcomes at 1 year than accelerated step-up treatment. The biomarker did not show clinical utility. Top-down treatment should be considered standard of care for patients with newly diagnosed active Crohn's disease. FUNDING: Wellcome and PredictImmune Ltd.

Infliximab versus ciclosporin for steroid-resistant acute severe ulcerative colitis (CONSTRUCT): a mixed methods, open-label, pragmatic randomised trial.

BACKGROUND: Infliximab and ciclosporin are of similar efficacy in treating acute severe ulcerative colitis, but there has been no comparative evaluation of their relative clinical effectiveness and cost-effectiveness. METHODS: In this mixed methods, open-label, pragmatic randomised trial, we recruited consenting patients aged 18 years or older at 52 district general and teaching hospitals in England, Scotland, and Wales who had been admitted, unscheduled, with severe ulcerative colitis and failed to respond to intravenous hydrocortisone within about 5 days. Patients were randomly allocated (1:1) to receive either infliximab (5 mg/kg intravenous infusion given over 2 h at baseline, and again at 2 weeks and 6 weeks after the first infusion) or ciclosporin (2 mg/kg per day by continuous infusion for up to 7 days, followed by twice-daily tablets delivering 5·5 mg/kg per day for 12 weeks). Randomisation used a web-based password-protected site, with a dynamic algorithm to generate allocations on request, thus protecting against investigator preference or other subversion, while ensuring that each trial group was balanced by centre, which was the only stratification used. Local investigators and participants were aware of the treatment allocated, but the chief investigator and analysts were masked. Analysis was by treatment allocated. The primary outcome was quality-adjusted survival-ie, the area under the curve (AUC) of scores from the Crohn's and Ulcerative Colitis Questionnaire (CUCQ) completed by participants at baseline, 3 months, and 6 months, then every 6 months from 1 year to 3 years. This trial is registered with the ISRCTN Registry, number ISRCTN22663589. FINDINGS: Between June 17, 2010, and Feb 26, 2013, 270 patients were recruited. 135 patients were allocated to the infliximab group and 135 to the ciclosporin group. 121 (90%) patients in each group were included in the analysis of the primary outcome. There was no significant difference between groups in quality-adjusted survival (mean AUC 564·0 [SD 241·9] in the infliximab group vs 587·0 [226·2] in the ciclosporin group; mean adjusted difference 7·9 [95% CI -22·0 to 37·8]; p=0·603). Likewise, there were no significant differences between groups in the secondary outcomes of CUCQ scores, EQ-5D, or SF-6D scores; frequency of colectomy (55 [41%] of 135 patients in the infliximab group vs 65 [48%] of 135 patients in the ciclosporin group; p=0·223); or mean time to colectomy (811 [95% CI 707-912] days in the infliximab group vs 744 [638-850] days in the ciclosporin group; p=0·251). There were no differences in serious adverse reactions (16 reactions in 14 participants receiving infliximab vs ten in nine patients receiving ciclosporin); serious adverse events (21 in 16 patients vs 25 in 17 patients); or deaths (three in the infliximab group vs none in the ciclosporin group). INTERPRETATION: There was no significant difference between ciclosporin and infliximab in clinical effectiveness. FUNDING: NIHR Health Technology Assessment programme.

Disease status, patient quality of life and healthcare resource use for ulcerative colitis in the UK: an observational study.

BACKGROUND: Ulcerative colitis is a lifelong, chronic, relapsing-remitting disease. OBJECTIVE: To assess the relationship between ulcerative colitis disease status and patient quality of life, and to determine the impact of ulcerative colitis on healthcare costs and work productivity, in the UK. METHODS: Clinicians assessed 173 adult patients' current disease status at a single study visit using the partial Mayo (pMayo) instrument. Patients completed the Euro Quality of Life 5-dimension, 5-level (EQ-5D-5L) questionnaire, the Work Productivity and Activity Impairment (WPAI) questionnaire. Healthcare resource use was determined from questionnaires and from patients' medical charts. RESULTS: Patients in remission had a significantly higher EQ-5D-5L scores (mean (SD) 0.86 (0.15)) than patients with active disease (0.71 (0.20); p<0.001). Patients with mild disease had significantly higher mean (SD) EQ-5D-5L scores than patients with moderate/severe disease: 0.77 (0.11) and 0.66 (0.24), respectively (p<0.001). The mean percent productivity impairment was greater for patients with active disease than for patients in remission on all items of the WPAI questionnaire: 24.6% vs 1.8% for work time missed, 34.1% vs 12.9% for impairment while working, 40.8% vs 14.4% for overall work impairment and 42.7% vs 13.0% for activity impairment (p<0.001 for all comparisons). The mean (SD) total cost of healthcare for ulcerative colitis in the prior 3 months was £1211 (1588). CONCLUSIONS: When compared with patients in remission, patients with active ulcerative colitis have significantly worse quality of life and significantly more work impairment. The healthcare costs of ulcerative colitis are considerable.

The successful treatment of IgG4-positive colitis with adalimumab in a patient with IgG4-related sclerosing disease--a new subtype of aggressive colitis?

We present the case of a 16 year old girl who developed an aggressive colitis in the context of a prior biopsy proven autoimmune pancreatitis, which presented with obstructive jaundice at the age of 13 year. This history prompted prospective investigation and the discovery of compelling evidence to make a diagnosis of IgG4-related sclerosing disease with extra-pancreatic colonic involvement on the basis of raised serum IgG4 levels and a florid colonic IgG4 plasma cell infiltrate with over 20 IgG4 positive plasma cells/hpf. The colitis was resistant to conventional therapy but responded dramatically to treatment with the anti-TNFα monoclonal antibody, adalimumab. This is the first case to report both the effectiveness of adalimumab in treating IgG4 positive colitis in a patient with IgG4-related sclerosing disease, and to prospectively record resolution of an IgG4 positive colonic infiltrate with immunosuppression.

Stromelysin-1 and macrophage metalloelastase expression in the intestinal mucosa of Crohn's disease patients treated with infliximab.

BACKGROUND AND AIMS: The mechanism by which anti-tumor necrosis factor (TNF)-alpha therapy promotes rapid closure of fistulas and mucosal wound healing in Crohn's disease (CD) remains unclear. An ex-vivo model of gut T-cell mediated injury indicated that TNF-alpha blockade prevents tissue damage concomitant with matrix metalloproteinase (MMP) inhibition. We, therefore, hypothesized that the chimeric anti-TNF-alpha antibody infliximab facilitates wound healing in CD by downregulating tissue degrading MMPs. We focused on MMP-3 (stromelysin-1) and MMP-12 (macrophage metalloelastase) as these two enzymes have been linked to connective tissue destruction in CD. METHODS: Endoscopic biopsies were taken from 10 CD patients immediately before and after 10 weeks of treatment with infliximab. Before treatment, biopsies were taken from macroscopically inflamed areas, and after treatment were collected from the same locations as before treatment. The degree of mucosal damage was assessed by using a histological scoring system. MMP transcripts were detected by in-situ hybridization on paraffin sections. MMP proteins were determined by immunoblotting on mucosal homogenates. RESULTS: Six out of 10 patients had a clinical response to infliximab. MMP-3 and MMP-12 transcripts and proteins, which were highly expressed in CD inflamed mucosa, decreased after treatment in those patients who responded to infliximab. MMP-3 and MMP-12 downregulation was accompanied by a concomitant improvement of the histologic score. No change in MMP expression was found in nonresponders. CONCLUSION: The downregulation of tissue degrading MMPs in CD mucosa may explain the wound repair capacity of infliximab in healing fistulas and ulcers.

Lambda light chain revision in the human intestinal IgA response.

Revision of Ab L chains by secondary rearrangement in mature B cells has the potential to change the specific target of the immune response. In this study, we show for the first time that L chain revision is normal and widespread in the largest Ab producing population in man: intestinal IgA plasma cells (PC). Biases in the productive and non-productive repertoire of lambda L chains, identification of the circular products of rearrangement that have the characteristic biases of revision, and identification of RAG genes and protein all reflect revision during normal intestinal IgA PC development. We saw no evidence of IgH revision, probably due to inappropriately orientated recombination signal sequences, and little evidence of kappa-chain revision, probably due to locus inactivation by the kappa-deleting element. We propose that the lambda L chain locus is available and a principal modifier and diversifier of Ab specificity in intestinal IgA PCs.

Matrix metalloproteinase-3 production by gut IgG plasma cells in chronic inflammatory bowel disease.

BACKGROUND: In both ulcerative colitis (UC) and Crohn's disease (CD) there is a marked increase in mucosal IgG plasma cells (PC), although their precise role is not well established. In this study we isolated gut PCs from patients with IBD and normal controls and analyzed cytokine production, matrix metalloproteinase (MMP)-3 and tissue inhibitor of metalloproteinase (TIMP)-1 production, and PC longevity ex vivo. METHODS: Lamina propria mononuclear cells (LPMCs) were isolated from patients with CD (n = 19), UC (n = 27), and normal controls (n = 42). PCs were further selected by immunomagnetic isolation using CD138 microbeads. Cytokine, MMP-3, and TIMP-1 expression was investigated by Taqman polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), Western blotting, and confocal microscopy. PC lifespan in vitro was studied by ELISpot analysis. RESULTS: PCs from both controls and IBD patients contained high levels of transcripts for TGFbeta, whereas they did not contain significant transcripts for IL-4, IL-5, IL-10, IFNgamma, TNF, or IL-12p40. PCs from patients with CD and UC expressed significantly higher levels of MMP-3 protein and transcripts than controls (P < 0.0001). The vast majority of MMP-3-expressing PCs were IgG+ve. In culture, IgA PCs from both IBD patients and controls persisted for only a few days, but IgG PCs from IBD patients persisted for at least 3 weeks. CONCLUSIONS: We have demonstrated that IgG PCs from patients with IBD express large amounts of MMP-3 and that they appear to be long-lived. These results identify a new pathway by which IgG PCs may damage the gut.

Evidence for the role of interferon-alfa production by dendritic cells in the Th1 response in celiac disease.

BACKGROUND & AIMS: Dendritic cells (DCs) play a crucial role in immune responses by controlling the extent and type of T-cell response to antigen. Celiac disease is a condition in which T-cell immunity to gluten plays an important pathogenic role, yet information on DCs is scant. We examined mucosal DCs in celiac disease in terms of phenotype, activation/maturation state, cytokine production, and function. METHODS: Mucosal DCs from 48 celiacs and 30 controls were investigated by flow cytometry. In situ distribution of DCs was analyzed by confocal microscopy. Interferon (IFN)-alfa, interleukin (IL)-4, IL-5, IL-12p35, IL-12p40, IL-18, IL-23p19, IL-27, and transforming growth factor-beta transcripts were measured by real-time reverse-transcription polymerase chain reaction in sorted DCs. DC expression of IL-6, IL-12p40, and IL-10 was assessed by intracellular cytokine staining. The effect of IFN-alfa and IL-18 blockade on the gluten-induced IFN-gamma response in celiac biopsy specimens grown ex vivo also was investigated. RESULTS: Mucosal DCs were increased in untreated, but not treated, celiacs. The majority of them were plasmacytoid with higher levels of maturation (CD83) and activation (CD80/CD86) markers. Higher transcripts of Th1 relevant cytokines, such as IFN-alfa, IL-18, and IL-23p19, were produced by celiac DCs, but because IL-12p40 was undetectable, a role for IL-23 is unlikely. Intracellular cytokine staining of celiac DCs showed higher IL-6, but lower IL-10 expression, and confirmed the lack of IL-12p40. Blocking IFN-alfa inhibited IFN-gamma transcripts in ex vivo organ culture of celiac biopsy specimens challenged with gluten. CONCLUSIONS: These data suggest that IFN-alfa-producing DCs contribute to the Th1 response in celiac disease.

Functional modulation of Crohn's disease myofibroblasts by anti-tumor necrosis factor antibodies.

BACKGROUND & AIMS: Infliximab induces immune cell apoptosis by outside-to-inside signaling through transmembrane tumor necrosis factor-alpha (mTNF). However, in inflamed gut, myofibroblasts also produce TNF-alpha, and the affects of anti-TNF antibodies on these structural cells are unknown. We investigated the action of infliximab on apoptosis, the production of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMP)-1, and migration of Crohn's disease (CD) myofibroblasts. METHODS: Colonic myofibroblasts were isolated from patients with active CD and controls. mTNF was evaluated by Western blotting and flow cytometry. Infliximab-treated myofibroblasts were analyzed for apoptosis by Annexin V staining and caspase-3. TIMP-1 and MMPs were measured by Western blotting, and fibroblast migration was assessed by using an in vitro wound-healing scratch assay. RESULTS: CD myofibroblasts showed higher mTNF expression than control myofibroblasts. Infliximab had no effect on CD myofibroblast apoptosis, caspase-3 activation, and production of MMP-3 and MMP-12. However, infliximab induced a significant dose-dependent increase in TIMP-1 production, which was inhibited by the p38 mitogen-activated protein kinase inhibitor SB 203580. The anti-TNF agents adalimumab, etanercept, and p55 TNF-receptor-human IgG fusion protein also increased TIMP-1 production. The migration of CD myofibroblasts was enhanced significantly by infliximab and recombinant human TIMP-1, and infliximab-induced migration was inhibited by anti-TIMP-1 neutralizing antibody. Infliximab also decreased CD myofibroblast collagen production. CONCLUSIONS: Our findings show a novel therapeutic pathway for anti-TNF therapies in enhancing TIMP-1 production and myofibroblast migration, which may reduce MMP activity and facilitate the wound healing.

The pathophysiologic rationale for biological therapies in inflammatory bowel disease.

PURPOSE OF REVIEW: Inflammatory bowel disease is driven by an excessive immune response in the gut wall. This review summarises important new developments in understanding this immune response and the downstream mechanisms of intestinal injury, alongside their potential role in opening up new avenues of treatment. RECENT FINDINGS: The evidence continues to accumulate that Crohn's disease is primarily due to a T helper cell-type 1 immune response in the gut wall. IL-12 and IL-18 appear to be the cytokines primarily responsible for Th1 polarisation, but IL-21 may also be important. The p40 chain of IL-12 also associates with a novel p19 chain to form IL-23 which is also a potent Th1-inducing cytokine but the expression of IL-23 in Crohn's disease has not been reported. Progress in understanding the immunology of ulcerative colitis remains slow, but IL-13 produced by natural killer T cells may be involved. T-cell resistance to apoptosis occurs in Crohn's disease, and human and mouse studies indicate that the signalling molecule STAT3, which transduces signals from IL-6 and IL-10, is involved in mucosal T cell homeostasis. Fibroblasts and metalloproteinases continue be implicated in ulceration, fibrosis, and fistula formation. SUMMARY: Understanding the immunology of inflammatory bowel disease continues to underpin the vast majority of new therapies and identifies new targets. Novel approaches, such as exploiting the antiinflammatory role of cannabinoid receptors, may also prove productive in the future.

Immunopathogenesis of Crohn's disease.

This review highlights the huge advances made in the understanding of Crohn's disease in the last 15 years. The pathogenic immune response in the gut wall is a highly polarised T helper cell type 1 response, probably directed against antigens of the commensal flora. There is marked over-expression of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-alpha and increased production of matrix degrading enzymes by fibroblasts and macrophages, which are probably responsible for ulceration and fistula formation. Crohn's disease runs in families and the susceptibility genes identified so far are associated with innate recognition of microbial products (Nod2) or epithelial barrier function (OCTN cation transporter genes and DLG5). Endogenous healing pathways mediated by transforming growth factor (TGF)-beta1 are inhibited because mucosal inflammatory cells express Smad7, the endogenous intracellular inhibitor of TGF-beta signalling. This makes it unlikely that enteral feeds containing TFG-beta are therapeutic by means of direct anti-inflammatory effects, however TGF-beta may still be involved because it is a well known epithelial motogen and may promote mucosal healing, in synergy with changes in mucosal bacterial populations as a result of the change in the diet.

Human intestinal IgA response is generated in the organized gut-associated lymphoid tissue but not in the lamina propria.

BACKGROUND & AIMS: The intestinal lamina propria has traditionally been viewed as the effector site of mucosal immune responses. However, this view has been challenged with the identification, in the murine lamina propria, of an in situ class switch DNA recombination pathway to IgA. In this study, we tested the hypothesis that in situ class switching occurs in the human lamina propria. METHODS: Immunohistochemistry was used to analyze tissue microenvironments and RT-PCR to look for molecular evidence of Ig class switching and to track clonally related cells of B lineage. RESULTS: We found no evidence of proliferation of either lamina propria CD20+ or CD19+ cells or evidence of activation-induced cytidine deaminase mRNA expression outside the organized gut-associated lymphoid tissue, although I alpha-C alpha immunoglobulin germ-line gene transcript expression could be identified in the lamina propria. We identified clonally related cells, including IgA and IgM isotype-switched variants, in multiple samples known to be free of activation-induced cytidine deaminase, organized lymphoid tissue, or cellular proliferation. For 4 groups of cells, the patterns of somatic mutations on the rearranged IgV(H)5 gene segment were more similar between cells from distant sites than from their immediate neighbors, implying dissemination of cells from a common set of precursors. CONCLUSIONS: Our data are inconsistent with a model in which precursors of human IgA-secreting plasma cells are induced or expanded in the lamina propria. The human lamina propria is therefore likely to solely be an effector site of intestinal secretory IgA responses that originate from the organized gut-associated lymphoid tissues.

Phenotypic characterization of CD3-7+ cells in developing human intestine and an analysis of their ability to differentiate into T cells.

We have identified a large population of CD3(-)7(+) cells in human fetal gut. Three- and four-color flow cytometry revealed a distinct surface Ag profile on this population; the majority were negative for CD4 and CD8, whereas most of the remainder expressed the CD8alphaalpha homodimer. In contrast about half of CD3(+) cells expressed CD4 and half expressed CD8alpha. A large proportion of CD3(-)7(+) cells expressed CD56, CD94, and CD161, and whereas CD3(+) T cells also expressed CD161, they only rarely expressed CD56 or CD94. Further studies were conducted to determine whether the CD3(-)7(+) cells have the potential to differentiate into CD3(+) cells. About half of CD3(-)7(+) cells contain intracellular CD3epsilon. Rearranged TCR gamma-chains were detected in highly purified CD3(-)7(+) cells as an early molecular sign of T cell commitment, and the pattern of rearrangement with V regions spliced to the most 5' Jgamma segment is reminiscent of early thymocyte differentiation. In reaggregate thymic organ cultures, CD3(-)7(+) cells also gave rise to CD3(+) T cells. Thus, we demonstrate that the CD3(-)7(+) cells present in the human fetal gut display a distinct phenotype and are able to develop into CD3(+) T cells.

Microbial-gut interactions in health and disease. Immune responses.

The indigenous bacterial microflora colonize the gut at birth and remain there throughout life. Approximately 10(14) bacteria are present in the ileum and colon and they are clearly immunogenic. The evidence is strong that the vast majority of IgA plasma cells in normal human gut are responding to the antigens of the flora, and although the flora is also responsible for producing the large numbers of T cells which are present in the gut of healthy individuals, the types of T cell response which the flora elicits are less well understood. A major challenge for the immune system is to distinguish between the antigens of the flora and the antigens of pathogens. There is also a growing realization that the normal flora can also influence gene expression in antigen-presenting cells in the gut and so set the context in which T cells respond to food antigen and vaccines.