Epithelia Use Butyrophilin-like Molecules to Shape Organ-Specific γδ T Cell Compartments.

Many body surfaces harbor organ-specific γδ T cell compartments that contribute to tissue integrity. Thus, murine dendritic epidermal T cells (DETCs) uniquely expressing T cell receptor (TCR)-Vγ5 chains protect from cutaneous carcinogens. The DETC repertoire is shaped by Skint1, a butyrophilin-like (Btnl) gene expressed specifically by thymic epithelial cells and suprabasal keratinocytes. However, the generality of this mechanism has remained opaque, since neither Skint1 nor DETCs are evolutionarily conserved. Here, Btnl1 expressed by murine enterocytes is shown to shape the local TCR-Vγ7(+) γδ compartment. Uninfluenced by microbial or food antigens, this activity evokes the developmental selection of TCRαß(+) repertoires. Indeed, Btnl1 and Btnl6 jointly induce TCR-dependent responses specifically in intestinal Vγ7(+) cells. Likewise, human gut epithelial cells express BTNL3 and BTNL8 that jointly induce selective TCR-dependent responses of human colonic Vγ4(+) cells. Hence, a conserved mechanism emerges whereby epithelia use organ-specific BTNL/Btnl genes to shape local T cell compartments.

The γδTCR combines innate immunity with adaptive immunity by utilizing spatially distinct regions for agonist selection and antigen responsiveness.

T lymphocytes expressing γδ T cell antigen receptors (TCRs) comprise evolutionarily conserved cells with paradoxical features. On the one hand, clonally expanded γδ T cells with unique specificities typify adaptive immunity. Conversely, large compartments of γδTCR+ intraepithelial lymphocytes (γδ IELs) exhibit limited TCR diversity and effect rapid, innate-like tissue surveillance. The development of several γδ IEL compartments depends on epithelial expression of genes encoding butyrophilin-like (Btnl (mouse) or BTNL (human)) members of the B7 superfamily of T cell co-stimulators. Here we found that responsiveness to Btnl or BTNL proteins was mediated by germline-encoded motifs within the cognate TCR variable γ-chains (Vγ chains) of mouse and human γδ IELs. This was in contrast to diverse antigen recognition by clonally restricted complementarity-determining regions CDR1-CDR3 of the same γδTCRs. Hence, the γδTCR intrinsically combines innate immunity and adaptive immunity by using spatially distinct regions to discriminate non-clonal agonist-selecting elements from clone-specific ligands. The broader implications for antigen-receptor biology are considered.

Risankizumab versus Ustekinumab for Moderate-to-Severe Crohn's Disease.

BACKGROUND: The efficacy and safety of risankizumab as compared with ustekinumab in patients with Crohn's disease are unknown. METHODS: In this phase 3b, multicenter, open-label, randomized, controlled trial with blinded assessment of end points, patients with moderate-to-severe Crohn's disease who had had an inadequate response to anti-tumor necrosis factor (TNF) therapy or unacceptable side effects with such therapy were randomly assigned to receive risankizumab or ustekinumab at standard doses for 48 weeks. The two primary end points, which were tested sequentially, were clinical remission at week 24 (defined as a Crohn's Disease Activity Index score of <150 [range, 0 to 600, with higher scores indicating more severe disease activity]), which was analyzed in the first 50% of patients to complete the week 24 visit, with a noninferiority margin of 10 percentage points; and endoscopic remission at week 48 (defined as a score of ≤4, a decrease of ≥2 points from baseline, and no subscore >1 in any individual variable on the Simple Endoscopic Score for Crohn's Disease [range, 0 to 56, with higher scores indicating more severe disease]), which was analyzed for superiority in 100% of the patients. Safety was assessed in all patients who received at least one dose of risankizumab or ustekinumab. RESULTS: In the full intention-to-treat population for the efficacy analysis, 230 of 255 patients (90.2%) who received risankizumab and 193 of 265 patients (72.8%) who received ustekinumab completed all the assigned treatments. Both primary end points were met; risankizumab was noninferior to ustekinumab with respect to clinical remission at week 24 (58.6% vs. 39.5%; adjusted difference, 18.4 percentage points; 95% confidence interval [CI], 6.6 to 30.3) and superior to ustekinumab with respect to endoscopic remission at week 48 (31.8% vs. 16.2%; adjusted difference, 15.6 percentage points; 95% CI, 8.4 to 22.9; P<0.001). The incidence of adverse events appeared to be similar in the two groups. CONCLUSIONS: In this head-to-head clinical trial of risankizumab and ustekinumab involving patients with moderate-to-severe Crohn's disease who had had unacceptable side effects with anti-TNF therapy or an inadequate response to such therapy, risankizumab was noninferior to ustekinumab with respect to clinical remission at week 24 and superior with respect to endoscopic remission at week 48. (Funded by AbbVie; ClinicalTrials.gov number, NCT04524611.).

Mirikizumab as Induction and Maintenance Therapy for Ulcerative Colitis.

BACKGROUND: Mirikizumab, a p19-directed antibody against interleukin-23, showed efficacy in the treatment of ulcerative colitis in a phase 2 trial. METHODS: We conducted two phase 3, randomized, double-blind, placebo-controlled trials of mirikizumab in adults with moderately to severely active ulcerative colitis. In the induction trial, patients were randomly assigned in a 3:1 ratio to receive mirikizumab (300 mg) or placebo, administered intravenously, every 4 weeks for 12 weeks. In the maintenance trial, patients with a response to mirikizumab induction therapy were randomly assigned in a 2:1 ratio to receive mirikizumab (200 mg) or placebo, administered subcutaneously, every 4 weeks for 40 weeks. The primary end points were clinical remission at week 12 in the induction trial and at week 40 (at 52 weeks overall) in the maintenance trial. Major secondary end points included clinical response, endoscopic remission, and improvement in bowel-movement urgency. Patients who did not have a response in the induction trial were allowed to receive open-label mirikizumab during the first 12 weeks of the maintenance trial as extended induction. Safety was also assessed. RESULTS: A total of 1281 patients underwent randomization in the induction trial, and 544 patients with a response to mirikizumab underwent randomization again in the maintenance trial. Significantly higher percentages of patients in the mirikizumab group than in the placebo group had clinical remission at week 12 of the induction trial (24.2% vs. 13.3%, P<0.001) and at week 40 of the maintenance trial (49.9% vs. 25.1%, P<0.001). The criteria for all the major secondary end points were met in both trials. Adverse events of nasopharyngitis and arthralgia were reported more frequently with mirikizumab than with placebo. Among the 1217 patients treated with mirikizumab during the controlled and uncontrolled periods (including the open-label extension and maintenance periods) in the two trials, 15 had an opportunistic infection (including 6 with herpes zoster infection) and 8 had cancer (including 3 with colorectal cancer). Among the patients who received placebo in the induction trial, 1 had herpes zoster infection and none had cancer. CONCLUSIONS: Mirikizumab was more effective than placebo in inducing and maintaining clinical remission in patients with moderately to severely active ulcerative colitis. Opportunistic infection or cancer occurred in a small number of patients treated with mirikizumab. (Funded by Eli Lilly; LUCENT-1 and LUCENT-2 ClinicalTrials.gov numbers, NCT03518086 and NCT03524092, respectively.).

Efficacy and Safety of Upadacitinib for Perianal Fistulizing Crohn's Disease: A Post Hoc Analysis of 3 Phase 3 Trials.

BACKGROUND & AIMS: Efficacy of upadacitinib, an oral Janus kinase inhibitor, for moderate-to-severe Crohn's disease was demonstrated in phase 3 induction (U-EXCEL, U-EXCEED) and maintenance (U-ENDURE) trials; this post hoc analysis evaluated upadacitinib outcomes in patients with fistulizing disease in these studies. METHODS: Patients were randomized (2:1) to once daily upadacitinib 45 mg or placebo for 12 weeks. Upadacitinib 45 mg clinical responders were rerandomized (1:1:1) to upadacitinib 15 mg, upadacitinib 30 mg, or placebo for 52 weeks. In patients with fistulas (any and perianal), resolution of drainage, closure of external openings, clinical remission, endoscopic response, and safety were assessed. RESULTS: Of 1021 patients in U-EXCEL and U-EXCEED, 143 (14.0%) had any fistulas at baseline (66 draining); of these, most (n = 128) had perianal fistulas (56 draining). Greater proportions of patients receiving upadacitinib vs placebo achieved resolution of drainage of perianal fistulas at the end of induction (placebo: 5.6%, n/n = 1/18; upadacitinib 45 mg: 44.7%, n/n = 17/38; P = .003) and maintenance (placebo: 0%, n/n = 0/11; upadacitinib 15 mg: 28.6%, n/n = 4/14; P = .105; upadacitinib 30 mg: 23.1% n/n = 3/13; P = .223) and closure of perianal fistula external openings (for induction, placebo: 4.8%, n/n = 2/42; upadacitinib 45 mg: 22.1%, n/n = 19/86; P = .013; for maintenance, placebo: 0%, n/n = 0/30; upadacitinib 15 mg: 18.8%, n/n = 6/32; P = .024; upadacitinib 30 mg: 16.0%, n/n = 4/25; P = .037). CONCLUSION: Patients with fistulizing disease (primarily perianal) treated with upadacitinib achieved higher rates of resolution of drainage, closure of external openings, clinical remission, and endoscopic response vs placebo. CLINICALTRIALS: gov, Numbers: NCT03345849 (U-EXCEL), NCT03345836 (U-EXCEED), NCT03345823 (U-ENDURE).

When Perfect Is the Enemy of Good: Results of a RAND Appropriateness Panel on Treat to Target in Asymptomatic Inflammatory Bowel Disease.

BACKGROUND: A treat-to-target strategy for inflammatory bowel disease (IBD) recommends iterative treatment adjustments to achieve clinical and endoscopic remission. In asymptomatic patients with ongoing endoscopic activity, the risk/benefit balance of this approach is unclear, particularly with prior exposure to advanced therapies. METHODS: Using the RAND/University of California Los Angeles Appropriateness Method, 9 IBD specialists rated appropriateness of changing therapy in 126 scenarios of asymptomatic patients with ulcerative colitis and Crohn's disease and active endoscopic disease. Disease extent and behavior, prior treatment, prior complications, and recent disease progression were considered, as were factors that might influence decision-making, including age and pregnancy. Ratings were collected through anonymous survey, discussed at an in-person meeting, and finalized in a second anonymous survey. RESULTS: Panelists rated change in therapy as appropriate (i.e., expected benefit sufficiently outweighs potential harms from continuing therapy) in 96/126 scenarios, generally in patients with progressive, complicated, and/or extensive disease, while changing therapy was rated uncertain in 27 scenarios of mild and/or stable disease. Changing therapy was rated inappropriate in ulcerative colitis patients with mild and stable disease previously exposed to ≥3 therapies or with improved endoscopic activity, and in Crohn's disease patients with only scattered aphthous ulcers. The validated threshold for disagreement was not crossed for any scenario. Patient age older than 65 years and a plan for pregnancy in the next year might influence decision-making in some settings. DISCUSSION: Appropriateness ratings can help guide clinical decision-making about changing therapy to achieve endoscopic remission in asymptomatic patients with IBD until data from ongoing randomized studies are available.

Early recapture of response with tofacitinib 10 mg twice daily in patients with ulcerative colitis in OCTAVE Open following dose reduction or treatment interruption in OCTAVE Sustain.

BACKGROUND AND AIM: Tofacitinib is an oral Janus kinase inhibitor for the treatment of ulcerative colitis. These post hoc analyses evaluated early improvement in patient-reported outcomes with tofacitinib 10 mg twice daily (BID) in OCTAVE Open among patients with ulcerative colitis who experienced treatment failure with placebo (retreatment subpopulation) or tofacitinib 5 mg BID (dose escalation subpopulation) during maintenance. METHODS: Endpoints based on Mayo subscores (rectal bleeding improvement, stool frequency improvement, and symptomatic [both rectal bleeding and stool frequency] improvement) were analyzed overall and by prior tumor necrosis factor inhibitor (TNFi) failure status from month (M)1-M6 in OCTAVE Open. Changes from baseline in partial Mayo score, rectal bleeding subscore, and stool frequency subscore at M1 were also analyzed, by M2 clinical response status. RESULTS: At M1 of OCTAVE Open, 83.2%, 70.3%, and 64.4% of patients in the retreatment subpopulation (n = 101) had rectal bleeding improvement, stool frequency improvement, and symptomatic improvement, respectively. Corresponding values in the dose escalation subpopulation (n = 57) were 59.6%, 50.9%, and 38.6%. For both subpopulations, results were generally consistent regardless of prior TNFi failure. In the dose escalation subpopulation, mean decrease from baseline in partial Mayo score and stool frequency subscore at M1 was greater in patients with versus without a clinical response at M2. CONCLUSIONS: Rectal bleeding improvement and stool frequency improvement were achieved by M1 in many patients receiving tofacitinib 10 mg BID in both subpopulations, with no apparent difference by prior TNFi failure. Analyses were limited by small sample sizes for some subgroups.

Ustekinumab versus adalimumab for induction and maintenance therapy in biologic-naive patients with moderately to severely active Crohn's disease: a multicentre, randomised, double-blind, parallel-group, phase 3b trial.

BACKGROUND: Active-comparator trials are important to inform patient and physician choice. We aimed to evaluate the efficacy and safety of monotherapy with either ustekinumab or adalimumab in biologic-naive patients with moderately to severely active Crohn's disease. METHODS: We conducted a randomised, double-blind, parallel-group, active-comparator, phase 3b trial (SEAVUE) at 121 hospitals or private practices in 18 countries. We included biologic-naive patients aged 18 years or older with moderately to severely active Crohn's disease and a Crohn's Disease Activity Index (CDAI) score of 220-450, who had not responded to or were intolerant to conventional therapy (or were corticosteroid dependent) and had at least one ulcer of any size at baseline endoscopic evaluation. Eligible patients were randomly assigned (1:1; via an interactive web response system) to receive ustekinumab (approximately 6 mg/kg intravenously on day 0, then 90 mg subcutaneously once every 8 weeks) or adalimumab (160 mg on day 0, 80 mg at 2 weeks, then 40 mg once every 2 weeks, subcutaneously) through week 56. Study treatments were administered as monotherapy and without dose modifications. Patients, investigators, and study site personnel were masked to treatment group assignment. The primary endpoint was the proportion of patients who were in clinical remission (CDAI score <150) at week 52 in the intention-to-treat population (ie, all patients who were randomly assigned to a treatment group). This trial is registered with ClinicalTrials.gov, NCT03464136, and EudraCT, 2017-004209-41. FINDINGS: Between June 28, 2018, and Dec 12, 2019, 633 patients were assessed for eligibility and 386 were enrolled and randomly assigned to receive ustekinumab (n=191) or adalimumab (n=195). 29 (15%) of 191 patients in the ustekinumab group and 46 (24%) of 195 in the adalimumab group discontinued study treatment before week 52. There was no significant difference between the ustekinumab and adalimumab groups in the occurrence of the primary endpoint; at week 52, 124 (65%) of 191 patients in the ustekinumab group versus 119 (61%) of 195 in the adalimumab group were in clinical remission (between-group difference 4%, 95% CI -6 to 14; p=0·42). Safety for both groups was consistent with previous reports. Serious infections were reported in four (2%) of 191 patients in the ustekinumab group and five (3%) of 195 in the adalimumab group. No deaths occurred through week 52 of the study. INTERPRETATION: Both ustekinumab and adalimumab monotherapies were highly effective in this population of biologic-naive patients, with no difference in the primary outcome between the drugs. FUNDING: Janssen Scientific Affairs.

Optimizing Therapies Using Therapeutic Drug Monitoring: Current Strategies and Future Perspectives.

Therapeutic drug monitoring (TDM) has emerged as a strategy for treatment optimization in inflammatory bowel diseases to maximize benefit and to reach more stringent, objective end points. Optimal drug concentrations in inflammatory bowel disease vary according to treatment target, disease phenotype, inflammatory burden, and timing of sampling during the treatment cycle. This review provides an update on TDM with biologic and oral small molecules, evaluates the role of reactive vs proactive TDM, and identifies the gaps in current evidence. In the future, adaptations to how we use TDM may contribute further to the goal of personalized treatment in patients with IBD.

RAND appropriateness panel to determine the applicability of UK guidelines on the management of acute respiratory distress syndrome (ARDS) and other strategies in the context of the COVID-19 pandemic.

BACKGROUND: COVID-19 has become the most common cause of acute respiratory distress syndrome (ARDS) worldwide. Features of the pathophysiology and clinical presentation partially distinguish it from 'classical' ARDS. A Research and Development (RAND) analysis gauged the opinion of an expert panel about the management of ARDS with and without COVID-19 as the precipitating cause, using recent UK guidelines as a template. METHODS: An 11-person panel comprising intensive care practitioners rated the appropriateness of ARDS management options at different times during hospital admission, in the presence or absence of, or varying severity of SARS-CoV-2 infection on a scale of 1-9 (where 1-3 is inappropriate, 4-6 is uncertain and 7-9 is appropriate). A summary of the anonymised results was discussed at an online meeting moderated by an expert in RAND methodology. The modified online survey comprising 76 questions, subdivided into investigations (16), non-invasive respiratory support (18), basic intensive care unit management of ARDS (20), management of refractory hypoxaemia (8), pharmacotherapy (7) and anticoagulation (7), was completed again. RESULTS: Disagreement between experts was significant only when addressing the appropriateness of diagnostic bronchoscopy in patients with confirmed or suspected COVID-19. Adherence to existing published guidelines for the management of ARDS for relevant evidence-based interventions was recommended. Responses of the experts to the final survey suggested that the supportive management of ARDS should be the same, regardless of a COVID-19 diagnosis. For patients with ARDS with COVID-19, the panel recommended routine treatment with corticosteroids and a lower threshold for full anticoagulation based on a high index of suspicion for venous thromboembolic disease. CONCLUSION: The expert panel found no reason to deviate from the evidence-based supportive strategies for managing ARDS outlined in recent guidelines.

Regulatory T cells and immunoglobulin E: A new therapeutic link for autoimmunity?

Autoimmune diseases have a prevalence of approximately 7 to 9% and are classified as either organ-specific diseases, including type I diabetes, multiple sclerosis, inflammatory bowel disease and myasthenia gravis, or systemic diseases, including systemic lupus erythematosus, rheumatoid arthritis and Sjögren's syndrome. While many advancements have been made in understanding of the mechanisms of autoimmune disease, including the nature of self-tolerance and its breakdown, there remain unmet needs in terms of effective and highly targeted treatments. T regulatory cells (Tregs) are key mediators of peripheral tolerance and are implicated in many autoimmune diseases, either as a result of reduced numbers or altered function. Tregs may be broadly divided into those generated in the thymus (tTregs) and those generated in the periphery (pTregs). Tregs target many different immune cell subsets and tissues to suppress excessive inflammation and to support tissue repair and homeostasis: there is a fine balance between Treg cell stability and the plasticity that is required to adjust Tregs' regulatory purposes to particular immune responses. The central role of immunoglobulin E (IgE) in allergic disease is well recognized, and it is becoming increasingly apparent that this immunoglobulin also has a wider role encompassing other diseases including autoimmune disease. Anti-IgE treatment restores the capacity of plasmacytoid dendritic cells (pDCs) impaired by IgE- high-affinity IgE receptor (FcεR1) cross-linking to induce Tregs in vitro in atopic patients. The finding that anti-IgE therapy restores Treg cell homeostasis, and that this mechanism is associated with clinical improvement in asthma and chronic spontaneous urticaria suggests that anti-IgE therapy may also have a potential role in the treatment of autoimmune diseases in which Tregs are involved.

Effectiveness and Safety of Ustekinumab in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

INTRODUCTION: Ustekinumab, an interleukin-12 and interleukin-23 antagonist, is licensed for the treatment of Crohn's disease (CD) and ulcerative colitis (UC) after the phase III trial programs demonstrated efficacy over placebo. However, these findings may not be directly transferable to the real-world due to the stringent inclusion criteria of clinical trials. METHODS: We conducted a systematic review and meta-analysis of the safety and effectiveness of ustekinumab in inflammatory bowel disease (IBD). A systematic literature search was conducted via Medline and Embase from inception to April 21, 2020. Observational studies assessing ustekinumab's safety and effectiveness by reporting response, remission and/or adverse events (AE) in either CD or UC were included. Two reviewers independently assessed risk of bias and extracted study data. Random-effects meta-analysis was performed to pool rates of clinical response, remission, and safety data. RESULTS: Following deduplication, 2147 records were identified of which 41 studies (38 CD, 3 UC) comprising 4400 patients were included for quantitative analysis. Pooled clinical remission rates for CD were 34% (95% CI, 26%-42%) following induction and 31% (95% CI, 25%-38%) at one year. For UC, post-induction clinical remission rates were 39% (95% CI, 23%-56%). Serious AEs were reported in 5.6% of patients. Pregnancy outcomes were similar to the general population. One-third of patients with active baseline perianal disease responded or had fistula healing with ustekinumab. CONCLUSIONS: In the most comprehensive systematic review and meta-analysis to date, and the first to include UC, ustekinumab was shown to be effective and safe in the real-world treatment of IBD.

Appropriateness of Medical and Surgical Treatments for Chronic Pouchitis Using RAND/UCLA Appropriateness Methodology.

BACKGROUND AND AIMS: The treatment of chronic pouchitis remains a challenge due to the paucity of high-quality studies. We aimed to provide guidance for clinicians on the appropriateness of medical and surgical treatments in chronic pouchitis. METHODS: Appropriateness of medical and surgical treatments in patients with chronic pouchitis was considered in 16 scenarios incorporating presence/absence of four variables: pouchitis symptoms, response to antibiotics, significant prepouch ileitis, and Crohn's disease (CD)-like complications (i.e., stricture or fistula). Appropriateness of permanent ileostomy in patients refractory to medical treatments was considered in eight additional scenarios. Using the RAND/UCLA appropriateness method, international IBD expert panelists rated appropriateness of treatments in each scenario on a 1-9 scale. RESULTS: Chronic antibiotic therapy was rated appropriate only in asymptomatic antibiotic-dependent patients with no CD-like complications and inappropriate in all other scenarios. Ileal-release budesonide was rated appropriate in 6/16 scenarios including patients with significant prepouch ileitis but no CD-like complications. Probiotics were considered either inappropriate (14/16) or uncertain (2/16). Biologic therapy was considered appropriate in most scenarios (14/16) and uncertain in situations where significant prepouch ileitis or CD-like complications were absent (2/16). In patients who are refractory to all medications, permanent ileostomy was considered appropriate in all scenarios (7/8) except in asymptomatic patients with no CD-like complications. CONCLUSIONS: In the presence of significant prepouch ileitis or CD-like complications, chronic antibiotics and probiotics are inappropriate. Biologics are appropriate in all patients except in asymptomatic patients with no evidence of complications. Permanent ileostomy is appropriate in most medically refractory patients.

Adaptations to the current ECCO/ESPGHAN guidelines on the management of paediatric acute severe colitis in the context of the COVID-19 pandemic: a RAND appropriateness panel.

OBJECTIVE: Paediatric acute severe colitis (ASC) management during the novel SARS-CoV-2/COVID-19 pandemic is challenging due to reliance on immunosuppression and the potential for surgery. We aimed to provide COVID-19-specific guidance using the European Crohn's and Colitis Organisation/European Society for Paediatric Gastroenterology, Hepatology and Nutrition guidelines for comparison. DESIGN: We convened a RAND appropriateness panel comprising 14 paediatric gastroenterologists and paediatric experts in surgery, rheumatology, respiratory and infectious diseases. Panellists rated the appropriateness of interventions for ASC in the context of the COVID-19 pandemic. Results were discussed at a moderated meeting prior to a second survey. RESULTS: Panellists recommended patients with ASC have a SARS-CoV-2 swab and expedited biological screening on admission and should be isolated. A positive swab should trigger discussion with a COVID-19 specialist. Sigmoidoscopy was recommended prior to escalation to second-line therapy or colectomy. Methylprednisolone was considered appropriate first-line management in all, including those with symptomatic COVID-19. Thromboprophylaxis was also recommended in all. In patients requiring second-line therapy, infliximab was considered appropriate irrespective of SARS-CoV-2 status. Delaying colectomy due to SARS-CoV-2 infection was considered inappropriate. Corticosteroid tapering over 8-10 weeks was deemed appropriate for all. After successful corticosteroid rescue, thiopurine maintenance was rated appropriate in patients with negative SARS-CoV-2 swab and asymptomatic patients with positive swab but uncertain in symptomatic COVID-19. CONCLUSION: Our COVID-19-specific adaptations to paediatric ASC guidelines using a RAND panel generally support existing recommendations, particularly the use of corticosteroids and escalation to infliximab, irrespective of SARS-CoV-2 status. Consideration of routine prophylactic anticoagulation was recommended.

Infliximab is associated with attenuated immunogenicity to BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 vaccines in patients with IBD.

OBJECTIVE: Delayed second dose SARS-CoV-2 vaccination trades maximal effectiveness for a lower level of immunity across more of the population. We investigated whether patients with inflammatory bowel disease treated with infliximab have attenuated serological responses to a single dose of a SARS-CoV-2 vaccine. DESIGN: Antibody responses and seroconversion rates in infliximab-treated patients (n=865) were compared with a cohort treated with vedolizumab (n=428), a gut-selective anti-integrin α4ß7 monoclonal antibody. Our primary outcome was anti-SARS-CoV-2 spike (S) antibody concentrations, measured using the Elecsys anti-SARS-CoV-2 spike (S) antibody assay 3-10 weeks after vaccination, in patients without evidence of prior infection. Secondary outcomes were seroconversion rates (defined by a cut-off of 15 U/mL), and antibody responses following past infection or a second dose of the BNT162b2 vaccine. RESULTS: Geometric mean (SD) anti-SARS-CoV-2 antibody concentrations were lower in patients treated with infliximab than vedolizumab, following BNT162b2 (6.0 U/mL (5.9) vs 28.8 U/mL (5.4) p<0.0001) and ChAdOx1 nCoV-19 (4.7 U/mL (4.9)) vs 13.8 U/mL (5.9) p<0.0001) vaccines. In our multivariable models, antibody concentrations were lower in infliximab-treated compared with vedolizumab-treated patients who received the BNT162b2 (fold change (FC) 0.29 (95% CI 0.21 to 0.40), p<0.0001) and ChAdOx1 nCoV-19 (FC 0.39 (95% CI 0.30 to 0.51), p<0.0001) vaccines. In both models, age ≥60 years, immunomodulator use, Crohn's disease and smoking were associated with lower, while non-white ethnicity was associated with higher, anti-SARS-CoV-2 antibody concentrations. Seroconversion rates after a single dose of either vaccine were higher in patients with prior SARS-CoV-2 infection and after two doses of BNT162b2 vaccine. CONCLUSION: Infliximab is associated with attenuated immunogenicity to a single dose of the BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 vaccines. Vaccination after SARS-CoV-2 infection, or a second dose of vaccine, led to seroconversion in most patients. Delayed second dosing should be avoided in patients treated with infliximab. TRIAL REGISTRATION NUMBER: ISRCTN45176516.

Anti-SARS-CoV-2 antibody responses are attenuated in patients with IBD treated with infliximab.

OBJECTIVE: Antitumour necrosis factor (anti-TNF) drugs impair protective immunity following pneumococcal, influenza and viral hepatitis vaccination and increase the risk of serious respiratory infections. We sought to determine whether infliximab-treated patients with IBD have attenuated serological responses to SARS-CoV-2 infections. DESIGN: Antibody responses in participants treated with infliximab were compared with a reference cohort treated with vedolizumab, a gut-selective anti-integrin α4ß7 monoclonal antibody that is not associated with impaired vaccine responses or increased susceptibility to systemic infections. 6935 patients were recruited from 92 UK hospitals between 22 September and 23 December 2020. RESULTS: Rates of symptomatic and proven SARS-CoV-2 infection were similar between groups. Seroprevalence was lower in infliximab-treated than vedolizumab-treated patients (3.4% (161/4685) vs 6.0% (134/2250), p<0.0001). Multivariable logistic regression analyses confirmed that infliximab (vs vedolizumab; OR 0.66 (95% CI 0.51 to 0.87), p=0.0027) and immunomodulator use (OR 0.70 (95% CI 0.53 to 0.92), p=0.012) were independently associated with lower seropositivity. In patients with confirmed SARS-CoV-2 infection, seroconversion was observed in fewer infliximab-treated than vedolizumab-treated patients (48% (39/81) vs 83% (30/36), p=0.00044) and the magnitude of anti-SARS-CoV-2 reactivity was lower (median 0.8 cut-off index (0.2-5.6) vs 37.0 (15.2-76.1), p<0.0001). CONCLUSIONS: Infliximab is associated with attenuated serological responses to SARS-CoV-2 that were further blunted by immunomodulators used as concomitant therapy. Impaired serological responses to SARS-CoV-2 infection might have important implications for global public health policy and individual anti-TNF-treated patients. Serological testing and virus surveillance should be considered to detect suboptimal vaccine responses, persistent infection and viral evolution to inform public health policy. TRIAL REGISTRATION NUMBER: ISRCTN45176516.

Comparison of Assays for Therapeutic Monitoring of Infliximab and Adalimumab in Patients With Inflammatory Bowel Diseases.

Comparison data regarding anti-tumor necrosis factor drug concentrations in inflammatory bowel disease (IBD) between the enzyme-linked immunosorbent assay (ELISA) and the homogenous mobility shift assay (HMSA) are scarce.1-3 As decisions in clinical practice depend on the thresholds that define a therapeutic drug concentration, it is important to determine if this varies based on the type of assay used for therapeutic drug monitoring.4 We recently showed a discrepancy between a commercially available ELISA and the HMSA for both infliximab and adalimumab concentrations in patients with IBD.5 Based on the results of the study, Prometheus Laboratories (San Diego, CA) initiated a comprehensive review of their HMSA assays and found that there was an upward drift for both infliximab (from December 2017 to May 2019) and adalimumab (from August 2017 to May 2019), including when our study was performed. Prometheus Laboratories corrected the errant values and reported the revised drug concentrations to physicians (Supplementary Methods). We aimed to compare the corrected infliximab and adalimumab concentrations with the original ELISA values.

Effects of Low FODMAP Diet on Symptoms, Fecal Microbiome, and Markers of Inflammation in Patients With Quiescent Inflammatory Bowel Disease in a Randomized Trial.

BACKGROUND & AIMS: There is limited evidence that a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) reduces gut symptoms in quiescent inflammatory bowel disease (IBD). We performed a randomized, controlled trial to investigate the effects of a low FODMAP diet on persistent gut symptoms, the intestinal microbiome, and circulating markers of inflammation in patients with quiescent IBD. METHODS: We performed a single-blind trial of 52 patients with quiescent Crohn's disease or ulcerative colitis and persistent gut symptoms at 2 large gastroenterology clinics in the United Kingdom. Patients were randomly assigned to groups that followed a diet low in FODMAPs (n = 27) or a control diet (n = 25), with dietary advice, for 4 weeks. Gut symptoms and health-related quality of life were measured using validated questionnaires. Stool and blood samples were collected at baseline and end of trial. We assessed fecal microbiome composition and function using shotgun metagenomic sequencing and phenotypes of T cells in blood using flow cytometry. RESULTS: A higher proportion of patients reported adequate relief of gut symptoms following the low FODMAP diet (14/27, 52%) than the control diet (4/25, 16%, P=.007). Patients had a greater reduction in irritable bowel syndrome severity scores following the low FODMAP diet (mean reduction of 67; standard error, 78) than the control diet (mean reduction of 34; standard error, 50), although this difference was not statistically significant (P = .075). Following the low FODMAP diet, patients had higher health-related quality of life scores (81.9 ± 1.2) than patients on the control diet (78.3 ± 1.2, P = .042). A targeted analysis revealed that in stool samples collected at the end of the study period, patients on the low FODMAP diet had significantly lower abundance of Bifidobacterium adolescentis, Bifidobacterium longum, and Faecalibacterium prausnitzii than patients on control diet. However, microbiome diversity and markers of inflammation did not differ significantly between groups. CONCLUSIONS: In a trial of the low FODMAP diet vs a control diet in patients with quiescent IBD, we found no significant difference after 4 weeks in change in irritable bowel syndrome severity scores, but significant improvements in specific symptom scores and numbers reporting adequate symptom relief. The low FODMAP diet reduced fecal abundance of microbes believed to regulate the immune response, compared with the control diet, but had no significant effect on markers of inflammation. We conclude that a 4-week diet low in FODMAPs is safe and effective for managing persistent gut symptoms in patients with quiescent IBD. www.isrctn.com no.: ISRCTN17061468.

HLA-DQA1*05 Carriage Associated With Development of Anti-Drug Antibodies to Infliximab and Adalimumab in Patients With Crohn's Disease.

BACKGROUND & AIMS: Anti-tumor necrosis factor (anti-TNF) therapies are the most widely used biologic drugs for treating immune-mediated diseases, but repeated administration can induce the formation of anti-drug antibodies. The ability to identify patients at increased risk for development of anti-drug antibodies would facilitate selection of therapy and use of preventative strategies. METHODS: We performed a genome-wide association study to identify variants associated with time to development of anti-drug antibodies in a discovery cohort of 1240 biologic-naïve patients with Crohn's disease starting infliximab or adalimumab therapy. Immunogenicity was defined as an anti-drug antibody titer ≥10 AU/mL using a drug-tolerant enzyme-linked immunosorbent assay. Significant association signals were confirmed in a replication cohort of 178 patients with inflammatory bowel disease. RESULTS: The HLA-DQA1*05 allele, carried by approximately 40% of Europeans, significantly increased the rate of immunogenicity (hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.60-2.25; P = 5.88 × 10-13). The highest rates of immunogenicity, 92% at 1 year, were observed in patients treated with infliximab monotherapy who carried HLA-DQA1*05; conversely the lowest rates of immunogenicity, 10% at 1 year, were observed in patients treated with adalimumab combination therapy who did not carry HLA-DQA1*05. We confirmed this finding in the replication cohort (HR, 2.00; 95% CI, 1.35-2.98; P = 6.60 × 10-4). This association was consistent for patients treated with adalimumab (HR, 1.89; 95% CI, 1.32-2.70) or infliximab (HR, 1.92; 95% CI, 1.57-2.33), and for patients treated with anti-TNF therapy alone (HR, 1.75; 95% CI, 1.37-2.22) or in combination with an immunomodulator (HR, 2.01; 95% CI, 1.57-2.58). CONCLUSIONS: In an observational study, we found a genome-wide significant association between HLA-DQA1*05 and the development of antibodies against anti-TNF agents. A randomized controlled biomarker trial is required to determine whether pretreatment testing for HLA-DQA1*05 improves patient outcomes by helping physicians select anti-TNF and combination therapies. ClinicalTrials.gov ID: NCT03088449.

Regulatory T-cell therapy in Crohn's disease: challenges and advances.

The prevalence of IBD is rising in the Western world. Despite an increasing repertoire of therapeutic targets, a significant proportion of patients suffer chronic morbidity. Studies in mice and humans have highlighted the critical role of regulatory T cells in immune homeostasis, with defects in number and suppressive function of regulatory T cells seen in patients with Crohn's disease. We review the function of regulatory T cells and the pathways by which they exert immune tolerance in the intestinal mucosa. We explore the principles and challenges of manufacturing a cell therapy, and discuss clinical trial evidence to date for their safety and efficacy in human disease, with particular focus on the development of a regulatory T-cell therapy for Crohn's disease.