Antibody decay, T cell immunity and breakthrough infections following two SARS-CoV-2 vaccine doses in inflammatory bowel disease patients treated with infliximab and vedolizumab.

Anti tumour necrosis factor (anti-TNF) drugs increase the risk of serious respiratory infection and impair protective immunity following pneumococcal and influenza vaccination. Here we report SARS-CoV-2 vaccine-induced immune responses and breakthrough infections in patients with inflammatory bowel disease, who are treated either with the anti-TNF antibody, infliximab, or with vedolizumab targeting a gut-specific anti-integrin that does not impair systemic immunity. Geometric mean [SD] anti-S RBD antibody concentrations are lower and half-lives shorter in patients treated with infliximab than vedolizumab, following two doses of BNT162b2 (566.7 U/mL [6.2] vs 4555.3 U/mL [5.4], p <0.0001; 26.8 days [95% CI 26.2 - 27.5] vs 47.6 days [45.5 - 49.8], p <0.0001); similar results are also observed with ChAdOx1 nCoV-19 vaccination (184.7 U/mL [5.0] vs 784.0 U/mL [3.5], p <0.0001; 35.9 days [34.9 - 36.8] vs 58.0 days [55.0 - 61.3], p value < 0.0001). One fifth of patients fail to mount a T cell response in both treatment groups. Breakthrough SARS-CoV-2 infections are more frequent (5.8% (201/3441) vs 3.9% (66/1682), p = 0.0039) in patients treated with infliximab than vedolizumab, and the risk of breakthrough SARS-CoV-2 infection is predicted by peak anti-S RBD antibody concentration after two vaccine doses. Irrespective of the treatments, higher, more sustained antibody levels are observed in patients with a history of SARS-CoV-2 infection prior to vaccination. Our results thus suggest that adapted vaccination schedules may be required to induce immunity in at-risk, anti-TNF-treated patients.

The Relationship Between Mucosal Microbiota, Colitis, and Systemic Inflammation in Chronic Granulomatous Disorder.

PURPOSE: Chronic granulomatous disorder (CGD) is a primary immunodeficiency which is frequently complicated by inflammatory colitis and is associated with systemic inflammation. Herein, we aimed to investigate the role of the microbiome in the pathogenesis of colitis and systemic inflammation. METHODS: We performed 16S rDNA sequencing on mucosal biopsy samples from each segment of 10 CGD patients' colons and conducted compositional and functional pathway prediction analyses. RESULTS: The microbiota in samples from colitis patients demonstrated reduced taxonomic alpha-diversity compared to unaffected patients, even in apparently normal bowel segments. Functional pathway richness was similar between the colitic and non-colitic mucosa, although metabolic pathways involved in butyrate biosynthesis or utilization were enriched in patients with colitis and correlated positively with fecal calprotectin levels. One patient with very severe colitis was dominated by Enterococcus spp., while among other patients Bacteroides spp. abundance correlated with colitis severity measured by fecal calprotectin and an endoscopic severity score. In contrast, Blautia abundance is associated with low severity scores and mucosal health. Several taxa and functional pathways correlated with concentrations of inflammatory cytokines in blood but not with colitis severity. Notably, dividing patients into "high" and "low" systemic inflammation groups demonstrated clearer separation than on the basis of colitis status in beta-diversity analyses. CONCLUSION: The microbiome is abnormal in CGD-associated colitis and altered functional characteristics probably contribute to pathogenesis. Furthermore, the relationship between the mucosal microbiome and systemic inflammation, independent of colitis status, implies that the microbiome in CGD can influence the inflammatory phenotype of the condition.

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.

Magnetic resonance enterography compared with ultrasonography in newly diagnosed and relapsing Crohn's disease patients: the METRIC diagnostic accuracy study.

BACKGROUND: Magnetic resonance enterography and enteric ultrasonography are used to image Crohn's disease patients. Their diagnostic accuracy for presence, extent and activity of enteric Crohn's disease was compared. OBJECTIVE: To compare diagnostic accuracy, observer variability, acceptability, diagnostic impact and cost-effectiveness of magnetic resonance enterography and ultrasonography in newly diagnosed or relapsing Crohn's disease. DESIGN: Prospective multicentre cohort study. SETTING: Eight NHS hospitals. PARTICIPANTS: Consecutive participants aged ≥ 16 years, newly diagnosed with Crohn's disease or with established Crohn's disease and suspected relapse. INTERVENTIONS: Magnetic resonance enterography and ultrasonography. MAIN OUTCOME MEASURES: The primary outcome was per-participant sensitivity difference between magnetic resonance enterography and ultrasonography for small bowel Crohn's disease extent. Secondary outcomes included sensitivity and specificity for small bowel Crohn's disease and colonic Crohn's disease extent, and sensitivity and specificity for small bowel Crohn's disease and colonic Crohn's disease presence; identification of active disease; interobserver variation; participant acceptability; diagnostic impact; and cost-effectiveness. RESULTS: Out of the 518 participants assessed, 335 entered the trial, with 51 excluded, giving a final cohort of 284 (133 and 151 in new diagnosis and suspected relapse cohorts, respectively). Across the whole cohort, for small bowel Crohn's disease extent, magnetic resonance enterography sensitivity [80%, 95% confidence interval (CI) 72% to 86%] was significantly greater than ultrasonography sensitivity (70%, 95% CI 62% to 78%), with a 10% difference (95% CI 1% to 18%; p = 0.027). For small bowel Crohn's disease extent, magnetic resonance enterography specificity (95%, 95% CI 85% to 98%) was significantly greater than ultrasonography specificity (81%, 95% CI 64% to 91%), with a 14% difference (95% CI 1% to 27%). For small bowel Crohn's disease presence, magnetic resonance enterography sensitivity (97%, 95% CI 91% to 99%) was significantly greater than ultrasonography sensitivity (92%, 95% CI 84% to 96%), with a 5% difference (95% CI 1% to 9%). For small bowel Crohn's disease presence, magnetic resonance enterography specificity was 96% (95% CI 86% to 99%) and ultrasonography specificity was 84% (95% CI 65% to 94%), with a 12% difference (95% CI 0% to 25%). Test sensitivities for small bowel Crohn's disease presence and extent were similar in the two cohorts. For colonic Crohn's disease presence in newly diagnosed participants, ultrasonography sensitivity (67%, 95% CI 49% to 81%) was significantly greater than magnetic resonance enterography sensitivity (47%, 95% CI 31% to 64%), with a 20% difference (95% CI 1% to 39%). For active small bowel Crohn's disease, magnetic resonance enterography sensitivity (96%, 95% CI 92% to 99%) was significantly greater than ultrasonography sensitivity (90%, 95% CI 82% to 95%), with a 6% difference (95% CI 2% to 11%). There was some disagreement between readers for both tests. A total of 88% of participants rated magnetic resonance enterography as very or fairly acceptable, which is significantly lower than the percentage (99%) of participants who did so for ultrasonography. Therapeutic decisions based on magnetic resonance enterography alone and ultrasonography alone agreed with the final decision in 122 out of 158 (77%) cases and 124 out of 158 (78%) cases, respectively. There were no differences in costs or quality-adjusted life-years between tests. LIMITATIONS: Magnetic resonance enterography and ultrasonography scans were interpreted by practitioners blinded to clinical data (but not participant cohort), which does not reflect use in clinical practice. CONCLUSIONS: Magnetic resonance enterography has higher accuracy for detecting the presence, extent and activity of small bowel Crohn's disease than ultrasonography does. Both tests have variable interobserver agreement and are broadly acceptable to participants, although ultrasonography produces less participant burden. Diagnostic impact and cost-effectiveness are similar. Recommendations for future work include investigation of the comparative utility of magnetic resonance enterography and ultrasonography for treatment response assessment and investigation of non-specific abdominal symptoms to confirm or refute Crohn's disease. TRIAL REGISTRATION: Current Controlled Trials ISRCTN03982913. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 42. See the NIHR Journals Library website for further project information.

Crohn's disease is a waxing and waning lifelong inflammatory condition that affects the colon (large bowel) and small bowel. Treatment relies on accurately determining disease extent and underlying inflammation. Colonoscopy is very good for examining the colon, but it is invasive and, at best, can only visualise a few centimetres of the small bowel, so radiological imaging is very important. Magnetic resonance enterography (a type of magnetic resonance imaging scan) and ultrasonography are both radiological tests commonly performed in the NHS, and it is unclear which method is better. We performed a study to compare the accuracy of magnetic resonance enterography and ultrasonography for determining the extent of Crohn's disease in the bowel of participants newly diagnosed and in those participants with established Crohn's disease but with suspected deterioration. We also investigated how often radiologists agree with each other during test interpretation, the participant experience of undergoing the tests and their cost-effectiveness. We compared the tests in 284 participants (133 newly diagnosed and 151 with suspected deterioration). We found that both tests were accurate for detecting the presence (97% for magnetic resonance enterography and 92% for ultrasonography) and location (80% for magnetic resonance enterography and 70% for ultrasonography) of disease in the small bowel, but magnetic resonance enterography was better than ultrasonography for both (correctly classifying disease extent in 107 more participants for every 1000 participants with Crohn's disease). Magnetic resonance enterography was similarly better than ultrasonography at determining if the bowel was inflamed. The results were similar in newly diagnosed participants and those participants with suspected deterioration. Agreement between radiologists interpreting the same images was, at best, moderate for both tests. A total of 88% of participants tolerated magnetic resonance enterography well or fairly well, which was less than the percentage (99%) of participants who tolerated ultrasonography well or fairly well. Both tests had a similar effect on the treatment decisions made by doctors. Both tests were also similar in their value for money for the NHS.

Chronic Granulomatous Disorder-Associated Colitis Can Be Accurately Evaluated with MRI Scans and Fecal Calprotectin Level.

PURPOSE: Colitis is a common and serious complication of chronic granulomatous disorder (CGD) and requires assessment. Colonoscopy is invasive and carries risks of serious complication. We therefore assessed non-invasive monitoring via magnetic resonance imaging (MRI). We also evaluated fecal calprotectin (FCP), the Harvey-Bradshaw index (HBI) clinical score, and serum cytokines. METHODS: We recruited 10 patients with CGD (8 males, mean age 29.6 years), scored a modified HBI, and obtained stool for FCP. The following day we took blood for cytokine measurement via Luminex, performed MR enterography (scored by two independent radiologists using three systems: London score, CDMI, and MaRIA) followed by colonoscopy with disease activity measurement via ulcerative colitis endoscopic index of severity (UCEIS). We assessed patient experience after each investigation and overall preference with follow-up questionnaires. RESULTS: MRI scores correlated well with colonoscopic gold standard (for London score R2 0.91, p < 0.0001; for CDMI R2 0.83, p = 0.0006; for MaRIA R2 0.89, p = 0.0002). MRI was better tolerated and generally preferred, quicker, and visualized the entire large bowel whereas colonoscopy did not reach the terminal ileum in 3 participants. Elevated FCP accurately differentiated patients with colitis from those without, and log(calprotectin) correlated well with disease activity (R2 0.71, p = 0.009). Serum interleukin (IL)-12 concentration correlated with colitis activity but IL-1ß and TNF did not. Harvey-Bradshaw index did not correlate with colitis activity. CONCLUSIONS: MRI and fecal calprotectin are useful methods for monitoring CGD colitis and should reduce the need for colonoscopy in these patients. IL-12 may represent an appropriate target for treatment.

Diagnostic accuracy of magnetic resonance enterography and small bowel ultrasound for the extent and activity of newly diagnosed and relapsed Crohn's disease (METRIC): a multicentre trial.

BACKGROUND: Magnetic resonance enterography (MRE) and ultrasound are used to image Crohn's disease, but their comparative accuracy for assessing disease extent and activity is not known with certainty. Therefore, we did a multicentre trial to address this issue. METHODS: We recruited patients from eight UK hospitals. Eligible patients were 16 years or older, with newly diagnosed Crohn's disease or with established disease and suspected relapse. Consecutive patients had MRE and ultrasound in addition to standard investigations. Discrepancy between MRE and ultrasound for the presence of small bowel disease triggered an additional investigation, if not already available. The primary outcome was difference in per-patient sensitivity for small bowel disease extent (correct identification and segmental localisation) against a construct reference standard (panel diagnosis). This trial is registered with the International Standard Randomised Controlled Trial, number ISRCTN03982913, and has been completed. FINDINGS: 284 patients completed the trial (133 in the newly diagnosed group, 151 in the relapse group). Based on the reference standard, 233 (82%) patients had small bowel Crohn's disease. The sensitivity of MRE for small bowel disease extent (80% [95% CI 72-86]) and presence (97% [91-99]) were significantly greater than that of ultrasound (70% [62-78] for disease extent, 92% [84-96] for disease presence); a 10% (95% CI 1-18; p=0·027) difference for extent, and 5% (1-9; p=0·025) difference for presence. The specificity of MRE for small bowel disease extent (95% [85-98]) was significantly greater than that of ultrasound (81% [64-91]); a difference of 14% (1-27; p=0·039). The specificity for small bowel disease presence was 96% (95% CI 86-99) with MRE and 84% (65-94) with ultrasound (difference 12% [0-25]; p=0·054). There were no serious adverse events. INTERPRETATION: Both MRE and ultrasound have high sensitivity for detecting small bowel disease presence and both are valid first-line investigations, and viable alternatives to ileocolonoscopy. However, in a national health service setting, MRE is generally the preferred radiological investigation when available because its sensitivity and specificity exceed ultrasound significantly. FUNDING: National Institute of Health and Research Health Technology Assessment.

The effect of different macronutrient infusions on appetite, ghrelin and peptide YY in parenterally fed patients.

BACKGROUND & AIMS: Patients receiving parenteral nutrition (PN) still feel hungry despite adequate provision of calories intravenously. It is not known whether PN or its constituent macronutrients acutely affect appetite and to what degree this may be mediated by ghrelin and peptide YY (PYY). METHODS: Six medically stable patients (four men) with intestinal failure receiving PN received an isocaloric 200 kcal infusion on three separate occasions following a 12 h fast. The infusions consisted of either carbohydrate (10% dextrose), fat (10% intralipid) or mixed protein/carbohydrate (PN). Changes in ghrelin and peptide YY levels and changes in subjective symptoms of hunger, satiety and nausea during each macronutrient infusion were assessed. RESULTS: None of the three infusions acutely affected subjective symptoms of hunger, satiety and nausea (P>0.05 ANOVA). Ghrelin levels decreased significantly during dextrose [-19.1 (-35.9, -12.4), regression coefficient (95% CI), P<0.001] and parenteral nutrition infusions [-18.2 (-26.8, -9.6), P<0.001]. Lipid infusion had no effect on ghrelin levels but led to a significant decrease in PYY [-0.076 (-0.0123, -0.028), P=0.004]. Dextrose and PN infusion had no significant effect on PYY levels. CONCLUSIONS: Dextrose and PN infusions decrease ghrelin levels. Lipid infusion does not affect ghrelin levels but in contrast to oral nutrients leads to a significant decrease in PYY. Despite these changes, in patients receiving PN, macronutrient infusions do no acutely affect appetite.

Prokineticin-2, motilin, ghrelin and metoclopramide: prokinetic utility in mouse stomach and colon.

The ability of agents described as gastrointestinal prokinetics (prokineticin-2, [Nle(13)]-motilin, ghrelin), to modulate nerve-mediated contractions of mouse isolated stomach and colon was determined and compared with the prokinetic and 5-HT(4) receptor agonist, metoclopramide. Circular muscle preparations were electrically field-stimulated (EFS) to evoke cholinergically mediated contractions. Metoclopramide 10-100 microM facilitated EFS-evoked contractions in forestomach (n = 5-11, P < 0.05); 1 mM inhibited. Metoclopramide had no effects in colon, apart from 100 microM which reduced contractions. Prokineticin-2 0.001 nM-0.1 microM (n = 3-7) or [Nle(13)]-motilin 0.1 nM-1 microM (n = 4-8) had no effects in forestomach or colon. Ghrelin 0.01-1 microM facilitated EFS-evoked contractions in forestomach (n = 5-7, P < 0.05) but not in colon (n = 5-8). We conclude that ghrelin and metoclopramide facilitate excitatory nerve activity because neither affected inhibitory responses to EFS in the presence of atropine, or contractions to carbachol. Further, prokineticin-2 and [Nle(13)]-motilin are unlikely to exert gastric prokinetic activity in this species, the inactivity of the latter being consistent with an absence of the motilin receptor in rodents.

Ghrelin for the gastroenterologist: history and potential.

Ghrelin, a novel 28-amino acid orexigenic peptide discovered in 1999, has given us further insights into the control of energy homeostasis and growth hormone secretion. As a natural endogenous ligand of the growth hormone secretagogue receptor, it potently stimulates growth hormone release but is also implicated in many other homeostatic mechanisms. Released from the stomach, it stimulates lactotroph and corticotroph secretion, increases appetite and adiposity, has beneficial hemodynamic effects, has prokinetic and gastric acid secretory functions in the stomach, and may even be implicated in sleep. As advances in the understanding of appetite and obesity are made, it is timely to review the possibly central role of ghrelin in these physiological and pathophysiological states. This review will discuss the recent literature concerning this exciting novel neuropeptide and discuss the possible therapeutic possibilities it may open up to us.