Fungal sensing by dectin-1 directs the non-pathogenic polarization of TH17 cells through balanced type I IFN responses in human DCs.

The non-pathogenic TH17 subset of helper T cells clears fungal infections, whereas pathogenic TH17 cells cause inflammation and tissue damage; however, the mechanisms controlling these distinct responses remain unclear. Here we found that fungi sensing by the C-type lectin dectin-1 in human dendritic cells (DCs) directed the polarization of non-pathogenic TH17 cells. Dectin-1 signaling triggered transient and intermediate expression of interferon (IFN)-ß in DCs, which was mediated by the opposed activities of transcription factors IRF1 and IRF5. IFN-ß-induced signaling led to integrin αvß8 expression directly and to the release of the active form of the cytokine transforming growth factor (TGF)-ß indirectly. Uncontrolled IFN-ß responses as a result of IRF1 deficiency induced high expression of the IFN-stimulated gene BST2 in DCs and restrained TGF-ß activation. Active TGF-ß was required for polarization of non-pathogenic TH17 cells, whereas pathogenic TH17 cells developed in the absence of active TGF-ß. Thus, dectin-1-mediated modulation of type I IFN responses allowed TGF-ß activation and non-pathogenic TH17 cell development during fungal infections in humans.

Clinical and humoral response after SARS-CoV-2 breakthrough infection in patients receiving immunosuppressant therapy.

BACKGROUND: Despite impaired humoral response in patients treated with immunosuppressants (ISPs), recent studies found similar severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) breakthrough infection compared to controls. One potential explanation is the rapid generation of humoral response on infection, but evidence is lacking. OBJECTIVES: We investigated the longitudinal dynamics of the SARS-CoV-2 antibody repertoire after SARS-CoV-2 delta and omicron breakthrough infection in patients with immune-mediated inflammatory diseases (IMIDs) receiving ISP therapy and controls. METHODS: As a prospective substudy of the national Target-to-B! (T2B!) consortium, we included IMID patients receiving ISPs therapy and controls who reported SARS-CoV-2 breakthrough infection between July 1, 2021, and April 1, 2022. To get an impression of the dynamics of the antibody repertoire, 3 antibody titers of wild-type RBD, wild-type S, and omicron RBD were measured at 4 time points after SARS-CoV-2 breakthrough infection. RESULTS: We included 302 IMID patients receiving ISPs and 178 controls. Antibody titers increased up to 28 days after breakthrough infection in both groups. However, in IMID patients receiving therapy with anti-CD20 and sphingosine-1 phosphate receptor modulators, antibody titers were considerably lower compared to controls. In the anti-TNF group, we observed slightly lower antibody titers in the early stages and a faster decline of antibodies after infection compared to controls. Breakthrough infections were mostly mild, and hospitalization was required in less than 1% of cases. CONCLUSIONS: Most ISPs do not influence the dynamics of the SARS-CoV-2 antibody repertoire and exhibit a rapid recall response with cross-reactive antibody clones toward new virus variants. However, in patients treated with anti-CD20 therapy or sphingosine-1 phosphate receptor modulators, the dynamics were greatly impaired, and to a lesser extent in those who received anti-TNF. Nevertheless, only a few severe breakthrough cases were reported.

External validation of the MAGNIFI-CD index in patients with complex perianal fistulising Crohn's disease.

BACKGROUND: There is an increasing need for objective treatment monitoring in perianal fistulising Crohn's disease (pfCD). Therefore, the magnetic resonance novel index for fistula imaging in CD (MAGNIFI-CD) index has been designed and internally validated on the ADMIRE-CD trial cohort. The aim of this study was to externally validate the MAGNIFI-CD index to monitor response to medical and surgical treatment regimens in pfCD. METHODS: A retrospective longitudinal cohort was established of consecutive patients with complex pfCD treated with surgical and/or medical therapy and a baseline and follow-up MRI between January 2007 and May 2021. The MAGNIFI-CD index was scored by two independent, abdominal radiologists blinded for time points and clinical outcomes. Responsiveness, reliability, and test accuracy regarding clinically important improvement were assessed. Cut-offs for response and remission were selected classified on fistula drainage assessment and physician global assessment. RESULTS: A total of 65 patients (51% female, median age 32 years) were included. A clinically relevant responsiveness of the MAGNIFI-CD was shown, with a significant decrease in clinical remitters and responders with a median MAGNIFI-CD of 18.0 [7.5-20.0] to 9.0 [0.8-16.0] (p < 0.001) and non-significant change in non-responders with a median MAGNIFI-CD of 20.0 [12.0-23.0] to 18.0 [13.0-21.0] (p = 0.22). There was an 'almost perfect' interobserver agreement (ICC = 0.87; 95% CI 0.80-0.92) for the MAGNIFI-CD index. An optimal cut-off value was defined as a decrease of 2 points for clinical response, and a MAGNIFI-CD ≤ 6 for remission at follow-up MRI. CONCLUSION: The MAGNIFI-CD index is a responsive and reliable MRI scoring instrument for treatment monitoring in perianal fistulising Crohn's disease. CLINICAL RELEVANCE STATEMENT: The MAGNIFI-CD index is a well-structured, responsive scoring instrument to assess fistula severity and activity that allows quantitative detection of changes in therapy response in patients with perianal fistulising Crohn's disease, thereby facilitating endpoints in clinical trials. KEY POINTS: Well-defined cut-offs for response and remission are needed for objective treatment monitoring of perianal fistulising Crohn's disease (pfCD). Cut-off values for remission and for response at 6 months follow-up were defined. Interobserver agreement was good. The MAGNIFI-CD index is responsive and reliable for treatment monitoring and is suitable for use in clinical trials.

Anti-drug antibodies against anti-TNF in patients with inflammatory bowel disease: an evaluation of possible strategies.

OBJECTIVE: Immunogenicity against anti-TNF antibodies usually leads to loss of response. We aimed to evaluate the efficacy of clinical strategies to improve clinical remission and pharmacokinetics upon detection of anti-drug antibodies (ADA). METHODS: Inflammatory bowel disease (IBD) patients with ADA against infliximab or adalimumab were identified through a single centre database search covering 2004-2022. Criteria for successful intervention upon ADA detection (baseline) were clinical remission after 1 year without further change in strategy. RESULTS: Two-hundred-and-fifty-five IBD patients (206 Crohn's disease) were identified. At baseline, median ADA level was 77 AU/ml; 50.2% of patients were in clinical remission. Implemented strategies were: (1) 81/255 (32%) conservative management, (2) 102/255 (40%) anti-TNF optimisation, (3) 72/255 (28%) switch within or out of class. Switching was the most successful strategy for clinical remission (from 19% at baseline to 69% at 1 year, p < 0.001). Patients that continued the same dose anti-TNF or discontinued biological therapy were often in clinical remission, but deteriorated significantly (-22.7%, p = 0.004). Anti-TNF dose intensification with immunomodulator optimisation was the fastest (median 3.0 months, p = 0.009) and most effective (65% ADA suppression, p < 0.001) strategy to suppress ADA compared to solely anti-TNF or immunomodulator optimisation. CONCLUSIONS: Switching therapy, within or out of class, is the most successful strategy to regain and maintain clinical remission upon immunogenicity. When switching to another anti-TNF, concomitant immunomodulatory therapy should be started or continued to prevent repeated immunogenic loss of response. Anti-TNF dose escalation with concomitant immunomodulator optimisation is the fastest and most effective strategy to suppress ADA.

Immunogenicity against anti-TNF antibodies is associated with loss of response in patients with inflammatory bowel diseases and remains a clinical challenge. We investigated potential therapeutic strategies in a retrospective patient cohort focusing on clinical efficacy and pharmacokinetics.

Intestinal Ultrasound Is Accurate to Determine Endoscopic Response and Remission in Patients With Moderate to Severe Ulcerative Colitis: A Longitudinal Prospective Cohort Study.

BACKGROUND & AIMS: Intestinal ultrasound (IUS) is noninvasive, cost-effective, and accurate to determine disease activity in ulcerative colitis (UC). In this study, we prospectively evaluated IUS for treatment response in a longitudinal cohort by using endoscopy and histology as gold standards. METHODS: Consecutive patients with moderate to severe UC (endoscopic Mayo score [EMS] ≥2) starting tofacitinib treatment were included. Patients were evaluated at baseline and after 8 weeks of tofacitinib induction by means of clinical, biochemical, endoscopic (EMS and UC endoscopic index for severity), histologic (Robarts Histopathologic Index) and IUS assessments. Readers of IUS, endoscopy, and histology were blinded for all other outcomes. The primary outcome was difference in bowel wall thickness (BWT) for endoscopic improvement vs no endoscopic improvement. Endoscopic remission was defined as EMS = 0, improvement as EMS ≤1, and response as a decrease of EMS ≥1. RESULTS: Thirty patients were included, with 27 patients completing follow-up. BWT correlated with EMS (ρ = 0.68, P < .0001), UC endoscopic index for severity (ρ = 0.73, P < .0001) and Robarts Histopathologic Index (ρ = 0.49, P = .002) at both time points. BWT in the sigmoid was lower in patients with endoscopic remission (1.4 mm vs 4.0 mm, P = .016), endoscopic improvement (1.8 mm vs 4.5 mm, P < .0001) and decrease in BWT was more pronounced in patients with endoscopic response (-58.1% vs -13.4%, P = .018). The most accurate cutoff values for BWT were 2.8 mm (area under the curve [AUC] 0.87) for endoscopic remission, 3.9 mm (AUC 0.92) for improvement, and decrease of 32% (AUC 0.87) for response. The submucosa was the most responsive wall layer. CONCLUSION: IUS, importantly BWT as the single most important parameter, is highly accurate to detect treatment response when evaluated against endoscopic outcomes.

Guselkumab for the Treatment of Crohn's Disease: Induction Results From the Phase 2 GALAXI-1 Study.

BACKGROUND & AIMS: Guselkumab, a selective p19 interleukin-23 antagonist, is approved for the treatment of plaque psoriasis and psoriatic arthritis. This study evaluated the efficacy and safety of guselkumab in patients with moderately to severely active Crohn's disease with inadequate response or intolerance to conventional or biologic therapy. METHODS: GALAXI-1, a phase 2, double-blind, placebo-controlled study, randomized patients 1:1:1:1:1 to intravenous guselkumab 200 mg, 600 mg, or 1200 mg at weeks 0, 4, and 8; intravenous ustekinumab approximately 6 mg/kg at week 0 and 90 mg subcutaneously at week 8; or placebo. Change from baseline in Crohn's Disease Activity Index score (primary end point), clinical remission, clinical response, Patient Reported Outcomes-2 remission, clinical-biomarker response, endoscopic response (major secondary end points), and safety in guselkumab-treated patients vs placebo were evaluated through week 12. Ustekinumab was a reference arm. RESULTS: Of 309 patients evaluated, approximately 50% had disease refractory to prior biologic therapy. At week 12, significantly greater reductions in Crohn's Disease Activity Index from baseline (least squares means: 200 mg: -160.4, 600 mg: -138.9, and 1200 mg: -144.9 vs placebo: -36.2; all, P < .05) and significantly greater proportions of patients achieved clinical remission in each guselkumab group vs placebo (Crohn's Disease Activity Index <150; 57.4%, 55.6%, and 45.9% vs 16.4%; all, P < .05). Greater proportions of patients receiving guselkumab achieved clinical response, Patient Reported Outcomes-2 remission, clinical-biomarker response, and endoscopic response at week 12 vs placebo. Efficacy of ustekinumab vs placebo was also demonstrated. Safety event rates were generally similar across treatment groups. CONCLUSIONS: At week 12, all 3 dose regimens of guselkumab induced greater clinical and endoscopic improvements vs placebo, with a favorable safety profile. CLINICALTRIALS: gov, Number: NCT03466411.

Higher vs Standard Adalimumab Induction Dosing Regimens and Two Maintenance Strategies: Randomized SERENE CD Trial Results.

BACKGROUND & AIMS: Dose-optimization strategies for biologic therapies in Crohn's disease (CD) are not well established. The SERENE CD (Study of a Novel Approach to Induction and Maintenance Dosing With Adalimumab in Patients With Moderate to Severe Crohn's Disease) trial evaluated higher vs standard adalimumab induction dosing and clinically adjusted (CA) vs therapeutic drug monitoring (TDM) maintenance strategies in patients with moderately to severely active CD. METHODS: In this phase 3, randomized, double-blind, multicenter trial, eligible adults (Crohn's Disease Activity Index score of 220-450, endoscopic evidence of mucosal inflammation, and previous failure of standard therapies) were randomized to higher induction regimen (adalimumab 160 mg at weeks 0, 1, 2, and 3; n = 308) or standard induction regimen (adalimumab 160 mg at week 0 and 80 mg at week 2; n = 206) followed by 40 mg every other week from week 4 onward. Co-primary end points included clinical remission at week 4 and endoscopic response at week 12. At week 12, patients were re-randomized to maintenance therapy optimized by Crohn's Disease Activity Index and C-reactive protein (CA; n = 92) or serum adalimumab concentrations and/or clinical criteria (TDM; n = 92); exploratory end points were evaluated at week 56. RESULTS: Similar proportions of patients receiving higher induction regimen and standard induction regimen achieved clinical remission at week 4 (44% in both; P = .939) and endoscopic response at week 12 (43% vs 39%, respectively, P = .462). Week 56 efficacy was similar between CA and TDM. Safety profiles were comparable between dosing regimens. CONCLUSIONS: Higher induction regimen was not superior to standard induction regimen, and CA and TDM maintenance strategies were similarly efficacious. Adalimumab therapy was well tolerated, and no new safety concerns were identified. (ClinicalTrials.gov, Number: NCT02065570).

Standardizing Scoring Conventions for Crohn's Disease Endoscopy: An International RAND/UCLA Appropriateness Study.

BACKGROUND AND AIMS: Endoscopic assessment of disease activity is integral for evaluating treatment response in patients with Crohn's disease (CD). We aimed to define appropriate items for evaluating endoscopic activity and conventions for consistent endoscopic scoring rules in CD. METHODS: A 2-round modified RAND/University of California at Los Angeles Appropriateness Method study was conducted. A panel of 15 gastroenterologists used a 9-point Likert scale to rate the appropriateness of statements pertaining to the Simple Endoscopic Score for CD, Crohn's Disease Endoscopic Index of Severity, and additional items relevant to endoscopy scoring in CD. Each statement was voted as appropriate, uncertain, or inappropriate based on the median panel rating and presence of disagreement. RESULTS: Panelists voted that it is appropriate for all ulcers to contribute to endoscopic scoring in CD, including aphthous ulcers, ulcerations at a surgical anastomosis, and anal canal ulcers (scored in the rectum). Endoscopic healing should reflect an absence of ulcers. Narrowing should be defined as a clear decrease in luminal diameter; stenosis should be defined by an impassable narrowing, and if occurring at the junction of 2 segments, scored in the distal segment. Scarring and inflammatory polyps were considered inappropriate for including in the affected area score. The optimal method for defining ulcer depth remains uncertain. CONCLUSIONS: We outlined scoring conventions for the Simple Endoscopic Score for CD and Crohn's Disease Endoscopic Index of Severity, noting that both scores have limitations. Therefore, we identified priorities for future research and steps for developing and validating a more representative endoscopic index in CD.

Multicenter Cohort Study of Infliximab Pharmacokinetics and Therapy Response in Pediatric Acute Severe Ulcerative Colitis.

BACKGROUND & AIMS: We aimed to model infliximab (IFX) pharmacokinetics (PK) in pediatric acute severe ulcerative colitis (ASUC) and assess the association between PK parameters, including drug exposure, and clinical response. METHODS: We studied a multicenter prospective cohort of hospitalized children initiating IFX for ASUC or IBD-unclassified. Serial IFX serum concentrations over 26 weeks were used to develop a PK model. We tested the association of PK parameter estimates with day 7 clinical response, week 8 clinical remission, week 26 corticosteroid-free clinical remission (CSF-CR) (using the Pediatric Ulcerative Colitis Activity Index), and colectomy-free survival. RESULTS: Thirty-eight participants received IFX (median initial dose, 9.9 mg/kg). Day 7 clinical response, week 8 clinical remission, and week 26 CSF-CR occurred in 71%, 55%, and 43%, respectively. Albumin, C-reactive protein, white blood cell count, platelets, weight, and antibodies to IFX were significant covariates incorporated into a PK model. Week 26 non-remitters exhibited faster IFX clearance than remitters (P = .013). However, cumulative IFX exposure did not differ between clinical response groups. One (2.7%) and 4 (10.8%) participants underwent colectomy by week 26 and 2 years, respectively. Day 3 IFX clearance >0.02 L/h was associated with colectomy (hazard ratio, 58.2; 95% confidence interval, 6.0-568.6; P < .001). CONCLUSIONS: At median higher-than-label IFX dosing for pediatric ASUC, baseline faster IFX CL was associated with colectomy and at week 26 with lack of CSF-CR. IFX exposure was not predictive of clinical outcomes. Higher IFX dosing may sufficiently optimize early outcomes in pediatric ASUC. Larger studies are warranted to determine whether sustained intensification can overcome rapid clearance and improve later outcomes. CLINICALTRIALS: gov identifier: NCT02799615.

Higher vs Standard Adalimumab Induction and Maintenance Dosing Regimens for Treatment of Ulcerative Colitis: SERENE UC Trial Results.

BACKGROUND & AIMS: SERENE UC (Study of a Novel Approach to Induction and Maintenance Dosing With Adalimumab in Patients With Moderate to Severe Ulcerative Colitis) evaluated the efficacy of higher adalimumab induction and maintenance dose regimens in patients with ulcerative colitis. METHODS: This phase 3, double-blind, randomized trial included induction and maintenance studies, with a main study (ex-Japan) and Japan substudy. Eligible patients (18-75 years, full Mayo score 6-12, centrally read endoscopy subscore 2-3) were randomized 3:2 to higher induction regimen (adalimumab 160 mg at weeks 0, 1, 2, and 3) or standard induction regimen (160 mg at week 0 and 80 mg at week 2); all received 40 mg at weeks 4 and 6. At week 8, all patients were rerandomized 2:2:1 (main study) to 40 mg every week (ew), 40 mg every other week (eow), or exploratory therapeutic drug monitoring; or 1:1 (Japan substudy) to 40 mg ew or 40 mg eow maintenance regimens. RESULTS: In the main study, 13.3% vs 10.9% of patients receiving the higher induction regimen vs standard induction regimen achieved clinical remission (full Mayo score ≤2 with no subscore >1) at week 8 (induction primary end point; P = .265); among week-8 responders, 39.5% vs 29.0% receiving 40 mg ew vs 40 mg eow achieved clinical remission at week 52 (maintenance primary end point; P = .069). In the integrated (main + Japan) population, 41.1% vs 30.1% of week-8 responders receiving 40 mg ew vs 40 mg eow achieved clinical remission at week 52 (nominal P = .045). Safety profiles were comparable between dosing regimens. CONCLUSION: Although primary end points were not met, a >10% absolute difference in clinical remission was demonstrated with higher adalimumab maintenance dosing. Higher dosing regimens were generally well tolerated and consistent with the known safety profile of adalimumab in ulcerative colitis. CLINICALTRIALS: gov, Number: NCT002209456.

CORE-IBD: A Multidisciplinary International Consensus Initiative to Develop a Core Outcome Set for Randomized Controlled Trials in Inflammatory Bowel Disease.

BACKGROUND & AIMS: End points to determine the efficacy and safety of medical therapies for Crohn's disease (CD) and ulcerative colitis (UC) are evolving. Given the heterogeneity in current outcome measures, harmonizing end points in a core outcome set for randomized controlled trials is a priority for drug development in inflammatory bowel disease. METHODS: Candidate outcome domains and outcome measures were generated from systematic literature reviews and patient engagement surveys and interviews. An iterative Delphi process was conducted to establish consensus: panelists anonymously voted on items using a 9-point Likert scale, and feedback was incorporated between rounds to refine statements. Consensus meetings were held to ratify the outcome domains and core outcome measures. Stakeholders were recruited internationally, and included gastroenterologists, colorectal surgeons, methodologists, and clinical trialists. RESULTS: A total of 235 patients and 53 experts participated. Patient-reported outcomes, quality of life, endoscopy, biomarkers, and safety were considered core domains; histopathology was an additional domain for UC. In CD, there was consensus to use the 2-item patient-reported outcome (ie, abdominal pain and stool frequency), Crohn's Disease Activity Index, Simple Endoscopic Score for Crohn's Disease, C-reactive protein, fecal calprotectin, and co-primary end points of symptomatic remission and endoscopic response. In UC, there was consensus to use the 9-point Mayo Clinic Score, fecal urgency, Robarts Histopathology Index or Geboes Score, fecal calprotectin, and a composite primary end point including both symptomatic and endoscopic remission. Safety outcomes should be reported using the Medical Dictionary for Regulatory Activities. CONCLUSIONS: This multidisciplinary collaboration involving patients and clinical experts has produced the first core outcome set that can be applied to randomized controlled trials of CD and UC.

Increased Proportion of Colorectal Cancer in Patients With Ulcerative Colitis Undergoing Surgery in the Netherlands.

INTRODUCTION: The aim of the current study was to assess whether there is an indication shift for surgery in patients with ulcerative colitis (UC) from refractory disease to malignant degeneration over the past 3 decades. METHODS: All patients with histologically confirmed UC who underwent a colorectal resection between 1991 and 2020 were extracted from the nationwide Dutch Pathology Registry. The primary outcome was the proportion of colorectal cancer (CRC) in the colon specimens. Outcomes were compared between 3 periods (P1: 1991-2000, P2: 2001-2010, and P3: 2011-2020). RESULTS: Overall, 6,094 patients with UC were included of which 4,854 underwent a (procto)colectomy and 1,240 a segmental resection. In 1,031 (16.9%) patients, CRC was demonstrated in the pathological resection specimen after a median disease duration of 11 years (IQR 3.0-19.0). The proportion of CRC increased from 11.3% in P1, to 16.1% in P2, and 22.8% in P3 ( P < 0.001). Median disease duration at the time of resection increased from 4 years in P1, to 10 years in P2, and 17 years in P3 ( P < 0.001). The proportion of patients diagnosed with advanced malignancy (pT3/T4) (P1: 61.2% vs P2: 65.2% vs P3: 62.4%, respectively, P = 0.633) and lymph node metastasis (N+) (P1: 33.0% vs P2: 41.9% vs P3: 38.2%, respectively, P = 0.113) did not change over time. DISCUSSION: This nationwide pathology study demonstrated an increased proportion of surgery for CRC over the past 3 decades. We hypothesize that the expanding therapeutic armamentarium for UC leads to exhausting medical options and hence postponed colectomy. This, however, might be at the expense of an increased risk of CRC in the long term.

Disease activity in patients with immune-mediated inflammatory diseases after SARS-CoV-2 vaccinations.

For patients with immune-mediated inflammatory diseases (IMIDs), concerns exist about increased disease activity after vaccination. We aimed to assess changes in disease activity after SARS-CoV-2 vaccination in patients with IMIDs, and determine risk factors for increased disease activity. In this substudy of a prospective observational cohort study (Target-to-B!), we included patients with IMIDs who received a SARS-CoV-2 vaccine. Patients reported changes in disease activity on a five-point Likert scale every 60 days for up to twelve months after first vaccination. In case of self-reported increased activity, hospital records were screened whether the treating physician reported increased activity, and for potential intensification of immunosuppressive (ISP) treatment. Mixed models were used to study determinants for self-reported increased disease activity. In total, 2111 patients were included for analysis after primary immunization (mean age 49.7 years [SD 13.7], 1329/2111 (63.0%) female), from which 1266 patients for analysis after first additional vaccination. Increased disease activity at 60 days after start of primary immunization was reported by 223/2111 (10.6%). In 96/223 (43.0%) the increase was confirmed by the treating physician and in 36/223 (16.1%) ISP treatment was intensified. Increased disease activity at seven to 60 days after additional vaccination, was reported by 139/1266 (11.0%). Vaccinations were not temporally associated with self-reported increased disease activity. Conversely, increased disease activity before first vaccination, neuromuscular disease, and multiple sclerosis were associated. Altogether, self-reported increased disease activity after vaccination against SARS-CoV-2 was recorded in a minority of patients and was generally mild. Moreover, multivariate analyses suggest that disease related factors, but not vaccinations are the major determinants for self-reported increased disease activity.

Primary SARS-CoV-2 infection in patients with immune-mediated inflammatory diseases: long-term humoral immune responses and effects on disease activity.

BACKGROUND: Patients with immune-mediated inflammatory diseases (IMIDs) on immunosuppressants (ISPs) may have impaired long-term humoral immune responses and increased disease activity after SARS-CoV-2 infection. We aimed to investigate long-term humoral immune responses against SARS-CoV-2 and increased disease activity after a primary SARS-CoV-2 infection in unvaccinated IMID patients on ISPs. METHODS: IMID patients on active treatment with ISPs and controls (i.e. IMID patients not on ISP and healthy controls) with a confirmed SARS-CoV-2 infection before first vaccination were included from an ongoing prospective cohort study (T2B! study). Clinical data on infections and increased disease activity were registered using electronic surveys and health records. A serum sample was collected before first vaccination to measure SARS-CoV-2 anti-receptor-binding domain (RBD) antibodies. RESULTS: In total, 193 IMID patients on ISP and 113 controls were included. Serum samples from 185 participants were available, with a median time of 173 days between infection and sample collection. The rate of seropositive IMID patients on ISPs was 78% compared to 100% in controls (p < 0.001). Seropositivity rates were lowest in patients on anti-CD20 (40.0%) and anti-tumor necrosis factor (TNF) agents (60.5%), as compared to other ISPs (p < 0.001 and p < 0.001, respectively). Increased disease activity after infection was reported by 68 of 260 patients (26.2%; 95% CI 21.2-31.8%), leading to ISP intensification in 6 out of these 68 patients (8.8%). CONCLUSION: IMID patients using ISPs showed reduced long-term humoral immune responses after primary SARS-CoV-2 infection, which was mainly attributed to treatment with anti-CD20 and anti-TNF agents. Increased disease activity after SARS-CoV-2 infection was reported commonly, but was mostly mild. TRIAL REGISTRATION: NL74974.018.20, Trial ID: NL8900. Registered on 9 September 2020.

Assessing Disease Activity in Pediatric Crohn's Disease Using Ultrasound: The Pediatric Crohn Disease Intestinal Ultrasound Score.

OBJECTIVES: Currently, there is no consensus on how to score Crohn disease (CD) activity assessed by intestinal ultrasound (IUS) in children. This study aimed to design an easy-to-use IUS score for disease activity in pediatric CD. METHODS: Children undergoing ileo-colonoscopy for CD assessment underwent IUS the day before ileo-colonoscopy, assessed with simple endoscopic score for CD (SES-CD). IUS features were compared to the SES-CD on segmental level. Multiple regression analyses, separately for terminal ileum (TI) and colon, were done to assess predictors of disease activity and to develop a model. RESULTS: In 74 CD patients (median 15 years, 48% female), 67 TI and 364 colon segments were assessed. Based on receiver operating characteristics curves, bowel wall thickness (BWT) was categorized into low [1 point: 2-3 mm (TI) and 1.6-2 mm (colon)], medium [2 points: 3.0-3.7 mm (TI) and 2.0-2.7 mm (colon)], and high [3 points: >3.7 mm (TI) and >2.7 mm (colon)]. In TI, only BWT was retained in the model [high BWT: odds ratio (OR) 11.50, P < 0.001]. In colon, BWT (high BWT: OR 8.63, P < 0.001) and mesenteric fat (1 point: OR 3.02, P < 0.001) were independent predictors. A pediatric Crohn disease IUS score (PCD-US) cut-off of 1 resulted in a sensitivity of 82% (95% confidence interval, CI: 65%-93%) and 85% (95% CI: 80%-89%) and a cut-off of 3 in a specificity of 88% (72%-97%) and 92% (87%-96%) for TI and colon, respectively. Inter-observer agreement was moderate for TI and colon ( K : 0.42, K : 0.49, respectively). CONCLUSIONS: The PCD-US score is an easy-to-use and reliable score to detect or rule out CD activity on segmental level in children. External validation is needed before applying this score in clinical practice.

Early Combined Immunosuppression Reduces Complications in Long-standing Crohn's Disease: A Post Hoc Analysis of REACT.

Crohn's disease (CD) can lead to bowel damage, stricturing, and obstruction thereby resulting in surgery and hospitalization. The Randomized Evaluation of an Algorithm for Crohn's Treatment (REACT) trial showed that early combined immunosuppression (ECI) with symptom-based treatment escalation for 24 months resulted in a lower risk of surgery, hospitalization, or CD-related complications compared with conventional management (CM).1 Treatment earlier in the disease course may be associated with reduced risk of complications compared with later initiation, although data are sparse.2 We performed a post hoc analysis of REACT to evaluate the impact of baseline disease duration on surgery, hospitalization, or CD-related complications in patients treated with ECI compared with CM.

Modeling Endoscopic Improvement after Induction Treatment With Mesalamine in Patients With Mild-to-Moderate Ulcerative Colitis.

BACKGROUND & AIMS: Endoscopic improvement is an important treatment target for mild-to-moderate ulcerative colitis (UC). However, early endoscopic evaluation is not always feasible. We aimed to develop a clinical decision support tool to discriminate patients who have achieved endoscopic improvement from those with more severe inflammation following mesalamine induction therapy. METHODS: We performed a post-hoc analysis of data from a phase 3 non-inferiority trial of 726 adults with mild-to-moderate UC treated with mesalamine. Multivariable logistic regression modeling determined associations between candidate variables and endoscopic improvement (Mayo endoscopic subscore=0-1 according to blinded central reading) at Week 8. Internal model validation was performed using bootstrap resampling. A clinical decision support tool was developed to stratify patients into low, intermediate, and high probability groups for endoscopic improvement. RESULTS: Variables associated with endoscopic improvement at Week 8 included 50% reduction in fecal calprotectin from baseline (odds ratio [OR] 2.64, 95% CI:, 1.81, 3.85), reduction in rectal bleeding (OR 1.79 per point reduction, 95% CI: 1.35, 2.39), and improvement in physician global assessment (OR 2.32 per point improvement, 95% CI: 1.88, 2.85). The baseline Geboes score (OR 0.74 per grade, 95% CI: 0.65, 0.85) and prolonged disease duration (OR 0.95 per year, 95% CI: 0.92, 0.98) were negatively associated with endoscopic improvement. This model strongly discriminated endoscopic improvement in the development dataset (area under the curve [AUC] 0.84, 95% CI: 0.81, 0.87) and during validation (AUC 0.83). CONCLUSIONS: We developed and validated a clinical decision support tool that has good discriminative performance for induction of endoscopic improvement in patients with mild-to-moderate UC treated with mesalamine. ClinicalTrials.gov Registration: NCT01903252.

Responsiveness of Magnetic Resonance Enterography Indices for Evaluation of Luminal Disease Activity in Crohn's Disease.

BACKGROUND & AIMS: Magnetic resonance enterography (MRE) is having an increasing role in Crohn's disease; however, fully validated indices are needed. We evaluated the responsiveness of 4 MRE indices in luminal Crohn's disease. METHODS: Paired MRE images (pretreatment and post-treatment at weeks 12 or 14) from 41 patients were scored by 3 blinded radiologists. Disease activity was scored for 4 MRE indices (magnetic resonance index of activity [MaRIA], simplified MaRIA, London index, and London extended index) and a 100-mm visual analog scale (VAS) of overall disease activity. The criterion for change was an improvement by at least one half of an SD in the VAS after treatment. Responsiveness was evaluated using the standardized effect size (SES). Longitudinal validity was evaluated using correlations between changes in MRE index scores and disease activity measures including endoscopy and the VAS. RESULTS: The SES was 1.17 (95% CI, 0.56-1.77) for the simplified MaRIA, 0.98 (95% CI, 0.42-1.55) for the MaRIA, 0.95 (95% CI, 0.38-1.51) for the London extended index, and 0.85 (95% CI, 0.31-1.39) for the London index. The simplified MaRIA was significantly more responsive than the London index (ΔSES, 0.32; 95% CI, 0.05-0.58) but not the MaRIA (ΔSES, 0.18; 95% CI, -0.01 to 0.38) or the London extended index (ΔSES, 0.22; 95% CI, -0.05 to 0.50). Correlations with endoscopy (simplified MaRIA: r = 0.72) were not different from correlations with the VAS (London extended index: r = 0.70). CONCLUSIONS: Evaluated MRE indices showed moderate-to-large responsiveness and are suitable for use in clinical trials. The simplified MaRIA may be preferred because of its responsiveness and nonreliance on gadolinium administration.

Efficacy and Safety of Continued Treatment With Mirikizumab in a Phase 2 Trial of Patients With Ulcerative Colitis.

BACKGROUND & AIMS: Mirikizumab is an antibody against the p19 subunit of interleukin 23 that has demonstrated clinical efficacy and was well tolerated following 12 weeks of induction treatment in a phase 2 trial of patients with moderate to severe ulcerative colitis. We present results of the open-label extended induction period in patients who did not initially respond to treatment with mirikizumab. METHODS: This study was a continuation of I6T-MC-AMAC, a double-blind trial, performed at 75 sites in 14 countries, in which patients with moderate to severe ulcerative colitis were randomly assigned to 12 weeks induction therapy with 50 mg, 200 mg, or 600 mg mirikizumab or placebo. Patients without a clinical response (a 9-point decrease in Mayo subscore of ≥2 points and ≥35% from baseline and either a decrease of rectal bleeding subscore of ≥1 or a rectal bleeding subscore of 0 or 1) at week 12 were offered the opportunity to participate in an open-label, extended induction study for another 12 weeks, in which they received either 600 mg intravenous mirikizumab (n = 20) or, following a protocol amendment, 1000 mg intravenous mirikizumab (n = 64) every 4 weeks. At week 24, patients with a clinical response continued the extension maintenance period and received 200 mg subcutaneous mirikizumab. Endpoints included clinical remission (Mayo subscores of 0 for rectal bleeding, 0 or 1 with a 1-point decrease from baseline), clinical response, endoscopic remission (Mayo endoscopic subscore of 0), or endoscopic improvement (endoscopic subscore of 0 or 1), at study weeks 24 and 52. Data were analysed for patients who received mirikizumab or placebo during the induction phase of the study. RESULTS: Among participants who did not respond to induction mirikizumab, 50.0% of those who received the 12-week extension of 600 mg mirikizumab and 43.8% who received the extension of 1000 mg mirikizumab achieved a clinical response; 15.0% and 9.4% achieved clinical remission, respectively. Endoscopic improvement was achieved by 20.0% of subjects in the 600 mg mirikizumab group and 15.6% subjects in the 1000 mg mirikizumab group. Among initial nonresponders to mirikizumab who had clinical response at study week 24 and continued into maintenance therapy, 65.8% maintained the clinical response, 26.3% achieved clinical remission, and 34.2% had endoscopic improvement at week 52. No new safety concerns were identified. CONCLUSIONS: Extended doses of mirikizumab (600 mg and 1000 mg) for an additional 12 weeks produce a clinical response in up to 50% of patients who did not have a clinical response to 12 weeks of induction doses (50 mg, 200 mg, or 600 mg). Most of the responders to the extended doses maintained clinical response for up to 52 weeks. Clinicaltrials.gov no: NCT02589665.

Prediction of Relapse After Anti-Tumor Necrosis Factor Cessation in Crohn's Disease: Individual Participant Data Meta-analysis of 1317 Patients From 14 Studies.

BACKGROUND & AIMS: Tools for stratification of relapse risk of Crohn's disease (CD) after anti-tumor necrosis factor (TNF) therapy cessation are needed. We aimed to validate a previously developed prediction model from the diSconTinuation in CrOhn's disease patients in stable Remission on combined therapy with Immunosuppressants (STORI) trial, and to develop an updated model. METHODS: Cohort studies were selected that reported on anti-TNF cessation in 30 or more CD patients in remission. Individual participant data were requested for luminal CD patients and anti-TNF treatment duration of 6 months or longer. The discriminative ability (concordance-statistic [C-statistic]) and calibration (agreement between observed and predicted risks) were explored for the STORI model. Next, an updated prognostic model was constructed, with performance assessment by cross-validation. RESULTS: This individual participant data meta-analysis included 1317 patients from 14 studies in 11 countries. Relapses after anti-TNF cessation occurred in 632 of 1317 patients after a median of 13 months. The pooled 1-year relapse rate was 38%. The STORI prediction model showed poor discriminative ability (C-statistic, 0.51). The updated model reached a moderate discriminative ability (C-statistic, 0.59), and included clinical symptoms at cessation (hazard ratio [HR], 2.2; 95% CI, 1.2-4), younger age at diagnosis (HR, 1.5 for A1 (age at diagnosis ≤16 years) vs A2 (age at diagnosis 17 - 40 years); 95% CI, 1.11-1.89), no concomitant immunosuppressants (HR, 1.4; 95% CI, 1.18-172), smoking (HR, 1.4; 95% CI, 1.15-1.67), second line anti-TNF (HR, 1.3; 95% CI, 1.01-1.69), upper gastrointestinal tract involvement (HR, 1.3 for L4 vs non-L4; 95% CI, 0.96-1.79), adalimumab (HR, 1.22 vs infliximab; 95% CI, 0.99-1.50), age at cessation (HR, 1.2 per 10 years younger; 95% CI, 1-1.33), C-reactive protein (HR, 1.04 per doubling; 95% CI, 1.00-1.08), and longer disease duration (HR, 1.07 per 5 years; 95% CI, 0.98-1.17). In subanalysis, the discriminative ability of the model improved by adding fecal calprotectin (C-statistic, 0.63). CONCLUSIONS: This updated prediction model showed a reasonable discriminative ability, exceeding the performance of a previously published model. It might be useful to guide clinical decisions on anti-TNF therapy cessation in CD patients after further validation.