Early Initiation of Biologics and Disease Outcomes in Adults and Children With Inflammatory Bowel Diseases: Results From the Epidemiology Group of the Nationwide Israeli Inflammatory Bowel Disease Research Nucleus Cohort

BACKGROUND & AIMS

In this nationwide study, we explored whether early initiation of biologics is associated with improved outcomes in children and adults with Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

All patients diagnosed with CD or UC in Israel (2005-2020) were included in the Epidemiology Group of the Israeli Inflammatory Bowel Disease Research Nucleus cohort, encompassing 98% of the population. We compared disease duration at biologics initiation (ie, 0-3 months, >3-12 months, >1-2 years, and >2-3 years) using the cloning, censoring, and weighting by inverse probabilities method to emulate a target trial, adjusting for time-varying confounders and selection bias.

RESULTS

Of the 34,375 included patients (of whom 5240 [15%] were children), 7452 of 19,264 (39%) with CD and 2235 of 15,111 (15%) with UC received biologics. In CD, by 10 years postdiagnosis, the probability of CD-related surgery decreased gradually but modestly with earlier initiation of biologics; a significant difference was noted between >2-3 years (31%) and 0-3 months (18%; P = .02; number needed to treat, 7.7), whereas there was no difference between the 0-3-month and >3-12-month periods. The 10-year probability of steroid dependency for the 0-3-month period (19%) differed both from the >2-3-year (31%; P < .001) and 1-2-year periods (37%; P < .001). In UC, no significant differences in colectomy or steroid dependency rates were observed between the treatment initiation periods. Similar trends were noted in the pediatric population.

CONCLUSIONS

Very early initiation of biologics was not associated with some outcomes except for a modest risk reduction of surgery and steroid dependency for CD, which requires confirmation in future studies. In UC, early introduction of biologics was not associated with reduced risk of colectomy or steroid dependency.

Durability of the First Biologic in Children and Adults With Ulcerative Colitis: A Nationwide Study from the epi-IIRN

BACKGROUND

In this nationwide study, our objective was to compare the durability of first-line biologics in ulcerative colitis (UC), categorized into monotherapy and combotherapy with immunomodulators.

METHODS

We utilized data from the nationwide epi-IIRN cohort from 2005 to 2020. Durability was defined as consistent treatment without surgery. Comparisons were based on stringent propensity score-matching.

RESULTS

We included 15 111 patients with UC, of whom 2322 (15%) received biologics, with a median follow-up of 7.0 years (interquartile range, 3.8-11.0). The durability rate was similar between pediatric-onset and adults after 1 and 5 years from initiation of treatment (72% and 43% vs 71% and 43%, respectively; P = .8). Durability of adalimumab vs infliximab after 1 or 5 years was similar, whether prescribed as monotherapy (65%/46% vs 63%/33%, respectively; n = 182 matched pairs, P = .3) or combotherapy (78%/56% vs 91%/58%, respectively; n = 46 matched pairs, P = .4). Durability of infliximab was higher as combotherapy (85%/50%) vs monotherapy (69%/42%; n = 174 matched pairs, P = .007), while it was similar for adalimumab (80%/52% vs 74%/52%; n = 53 matched pairs, P = .4). The durability rate was similar for vedolizumab monotherapy (77%/56%) compared with adalimumab monotherapy (69%/52%; n = 125 matched patients, P = .1), and infliximab monotherapy (73%/55% vs 62%/44%; n = 78 matched patients, P = .1). However, combotherapy of antitumor necrosis factors (TNFs) had longer durability than vedolizumab (85%/50% vs 75%/43%, respectively; n = 131 matched pairs, P = .02).

CONCLUSION

After 5 years of treatment, 43% of the patients with UC sustained their first biologic, with similar durability in pediatric and adult-onset onset disease. Anti-TNFs had similar durability to vedolizumab and superior durability when prescribed as combotherapy.

The epidemiology of inflammatory bowel diseases during the COVID-19 pandemic: comparison of two nationwide cohorts

BACKGROUND

We aimed to explore the epidemiology of inflammatory bowel diseases (IBD) in association with the COVID-19 pandemic in two countries with different lockdown policies.

METHODS

We utilized nationwide IBD cohorts in Israel and Sweden to explore the incidence of IBD during the pandemic compared to three years prior (2017- 2019). We examined temporal trends through the presence of inflection points by Joinpoint regression analysis and reported average monthly percentage changes (AMPC).

RESULTS

A total of 155,837 patients with IBD were included (Israel, 58,640; Sweden, 97,197). The annual incidence of IBD was stable until 2019 in both countries and since, it decreased in Israel (AAPC of -16.6% [95%CI -19.9% to -10.0%]) and remained stable in Sweden (AAPC of -3.5% [95%CI -11.6% to 3.7%]). When exploring the monthly incidence during the pandemic, in Israel the rate remained stable until November 2020 (AMPC 2.3% [95%CI -13.4% to 29.9%]) and then decreased sharply (AMPC -6.4% [95%CI-20.8% to 17.0%]) until February 2021 and -20.1% [95%CI -38.9% to -4.7%]) from February 2021), while in Sweden, which had a less stringent lockdown policy, it decreased slightly until July 2020 (AMPC -3.3% [95%CI -21.6% to 20.3%]), but increased thereafter (AMPC 13.6% [95%CI -12.6% to 27.0%]). The change of incidence rate in Sweden occurred mainly in elderly-onset patients, the only population with significant restrictions during the pandemic.

CONCLUSION

The incidence of IBD decreased during the pandemic in association with lockdowns, more so in Israel, which had more stringent policies. Future studies are needed to determine the long-term effect of the pandemic on IBD.

Outcomes in Adult Inflammatory Bowel Disease Clinical Trials: Assessment of Similarity Among Participants with Adolescent-Onset and Adult-Onset Disease

BACKGROUND AND AIMS

Most pediatric IBD studies are performed after medications are approved in adults and the majority of participants in these studies are adolescents. We hypothesized that adolescent-onset IBD is not fundamentally different than adult-onset IBD. If this is correct, the value of delaying access to novel drugs in adolescents becomes questioned.

METHODS

Data from 11 randomized, double-blind, placebo-controlled adult phase 2 and 3 trials of 4 biologics were analyzed. Participants were categorized as having adolescent- or adult-onset disease (diagnosed 12 to <18, or ≥18 years). Multivariable modelling explored the association between age at diagnosis and response to treatment after adjustment for disease duration, extent, and severity at baseline. Data from dose arms were pooled to evaluate similarity of therapeutic response between adolescent- and adult-onset IBD within the same trial (not between doses or across trials). Ratios of odds ratios between the two groups were evaluated.

RESULTS

Data from 6,283 study participants (2,575 with Crohn's disease [CD], 3,708 with ulcerative colitis [UC]) were evaluated. Of 2,575 study participants with CD, 325 were 12-<18 years old at diagnosis; 836 participants (32.4%) received placebo. Of 3,708 participants with UC, 221 were 12-<18 years old at diagnosis; 1,212 (33%) were receiving placebo. The majority of the ratios of ORs were within two-fold, suggesting that responses in adolescent and adult-onset participants are generally similar.

CONCLUSION

Data presented lend support for extrapolating efficacy of biologics from adults to adolescents with IBD, which would facilitate earlier labeling and patient access.

Predictors of Complicated Disease Course in Adults and Children With Crohn's Disease: A Nationwide Study from the epi-IIRN

BACKGROUND

Since data on predictors of complicated Crohn's disease (CD) from unselected populations are scarce, we aimed to utilize a large nationwide cohort, the epi-IIRN, to explore predictors of disease course in children and adults with CD.

METHODS

Data of patients with CD were retrieved from Israel's 4 health maintenance organizations, whose records cover 98% of the population (2005-2020). Time-to-event modeled a complicated disease course, defined as CD-related surgery, steroid-dependency, or the need for >1 class of biologics. Hierarchical clustering categorized disease severity at diagnosis based on available laboratory results.

RESULTS

A total of 16 659 patients (2999 [18%] pediatric-onset) with 121 695 person-years of follow-up were included; 3761 (23%) had a complicated course (750 [4.5%] switched to a second biologic class, 1547 [9.3%] steroid-dependency, 1463 [8.8%] CD-related surgery). Complicated disease was more common in pediatric- than adult-onset disease (26% vs 22%, odds ratio, 1.3; 95% confidence interval [CI], 1.2-1.4). In a Cox multivariate model, complicated disease was predicted by induction therapy with biologics (hazard ratio [HR], 2.1; 95% CI, 1.2-3.6) and severity of laboratory tests at diagnosis (HR, 1.7; 95% CI, 1.2-2.2), while high socioeconomic status was protective (HR, 0.94; 95% CI, 0.91-0.96). In children, laboratory tests predicted disease course (HR, 1.8; 95% CI, 1.2-2.5), as well as malnutrition (median BMI Z score -0.41; 95% CI, -1.42 to 0.43 in complicated disease vs -0.24; 95% CI, -1.23 to 0.63] in favorable disease; P < .001).

CONCLUSIONS

In this nationwide cohort, CD course was complicated in one-fourth of patients, predicted by laboratory tests, type of induction therapy, socioeconomic status, in addition to malnutrition in children.

Fatigue in pediatric inflammatory bowel diseases: A systematic review and a single center experience

OBJECTIVES

We aimed to review the literature on fatigue in pediatric inflammatory bowel diseases (PIBD), to explore how it is measured, and approximate its rate in an inception pediatric cohort.

METHODS

Studies on fatigue were systematically reviewed and selected by two authors. Next, we retrieved the two fatigue-related questions of the IMPACT-III questionnaire at 4 and 12 months after diagnosis from a prospectively maintained cohort of PIBD patients, each scoring 0-100 (lower scores imply more fatigue), and 44 healthy controls.

RESULTS

The systematic review identified 14 studies reporting fatigue in children, of which nine had fatigue as the primary outcome and only two provided rates of fatigue. No standalone index was identified for measuring fatigue specifically for PIBD. Of 80 children included in the inception cohort, 62 (78%) scored an average of ≤75 on the two IMPACT-III questions (approximating at least mild fatigue), 26 (33%) scored ≤50 (at least moderate fatigue) and nine (11%) scored ≤25 (severe fatigue). In comparison, only four (9%) healthy children scored at least moderate fatigue (p = 0.007). Fatigue rates at 12 months were only slightly and nonsignificantly lower. Fatigue of any severity was reported in 92% children with active disease versus 63% of those in clinical remission (p = 0.01).

CONCLUSION

Literature reporting on fatigue in PIBD is scarce, and no PIBD-specific tool is available to measure fatigue. In our cohort, fatigue-related questions were frequently scored low in children with IBD, mainly among children with active disease but also during clinical remission.

Prevalence and Outcomes of No Treatment Versus 5-ASA in Ulcerative Colitis: A Nationwide Analysis From the epi-IIRN

BACKGROUND

Data regarding patients with ulcerative colitis (UC) not receiving maintenance treatment are scarce. In this nationwide study, we aimed to explore the frequency and long-term outcomes of untreated patients with UC vs treated patients.

METHODS

We retrieved data from Israel's Health Maintenance Organizations, covering 98% of the population. No maintenance treatment (NMT) was defined as lack of treatment during the period from 3 to 6 months from diagnosis, allowing at most 3 months for induction treatment.

RESULTS

A total of 15 111 patients have been diagnosed with UC since 2005, of whom 4410 (29%) have had NMT, with 36 794 person-years of follow-up. NMT was more likely in adults (31%) and in elderly-onset UC (29%) than in pediatric-onset UC (20%; P < .001) and decreased from 38% in 2005 to 18% in 2019 (P < .001). The probability of remaining without treatment was 78%, 49%, and 37% after 1, 3, and 5 years from diagnosis, respectively. In propensity score-matched analysis of 1080 pairs of treated (93% with 5-aminosalicylic acid) and untreated patients, outcomes were comparable for time to biologics (P = .6), surgery (P = .8), steroid dependency (P = .09), and hospitalizations (P = .2). Multivariable modeling indicated that failing NMT was less likely in adults or elderly-onset patients who received at most rectal therapy or antibiotics as induction therapy.

CONCLUSIONS

Nowadays, 18% of patients with UC do not receive maintenance therapy, of whom half remain without treatment after 3 years. Matched pairs of patients on NMT and 5-aminosalicylic acid, representing the mildest patients of the latter, had similar outcomes. Prospective studies are needed to further explore the role of NMT in UC.

Dual Biologic or Small Molecule Therapy in Refractory Pediatric Inflammatory Bowel Disease (DOUBLE-PIBD): A Multicenter Study from the Pediatric IBD Porto Group of ESPGHAN

BACKGROUND

Current data on dual biologic therapy in children are limited. This multicenter study aimed to evaluate the effectiveness and safety of dual therapy in pediatric patients with inflammatory bowel disease (IBD).

METHODS

A retrospective study from 14 centers affiliated with the Pediatric IBD Interest and Porto Groups of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition. Included were children with IBD who underwent combinations of biologic agents or biologic and small molecule therapy for at least 3 months. Demographic, clinical, laboratory, endoscopic, and imaging data were collected. Adverse events were recorded.

RESULTS

Sixty-two children (35 Crohn's disease, 27 ulcerative colitis; median age 15.5 [interquartile range, 13.1-16.8] years) were included. They had all failed previous biologic therapies, and 47 (76%) failed at least 2 biologic agents. The dual therapy included an anti-tumor necrosis factor agent and vedolizumab in 30 children (48%), anti-tumor necrosis factor and ustekinumab in 21 (34%) children, vedolizumab and ustekinumab in 8 (13%) children, and tofacitinib with a biologic in 3 (5%) children. Clinical remission was observed in 21 (35%), 30 (50%), and 38 (63%) children at 3, 6, and 12 months, respectively. Normalization of C-reactive protein and decrease in fecal calprotectin to <250 µg/g were achieved in 75% and 64%, respectively, at 12 months of follow-up. Twenty-nine (47%) children sustained adverse events, 8 of which were regarded as serious and led to discontinuation of therapy in 6.

CONCLUSIONS

Dual biologic therapy may be effective in children with refractory IBD. The potential efficacy should be weighed against the risk of serious adverse events.

Durability of the First Biologic in Patients with Crohn's Disease: A Nationwide Study from the epi-IIRN

BACKGROUND

In this nationwide study we aimed to compare the durability of the first initiated biologic in Crohn's disease [CD], stratified by monotherapy and combotherapy.

METHODS

We used data from the epi-IIRN cohort, which includes 98% of the Israeli inflammatory bowel disease population [2005-2020]. Durability was defined as consistent treatment without surgery or added medications [except for combination therapy with thiopurines or methotrexate]. All comparisons were based on stringent propensity-score matching and paired time-to-event analyses.

RESULTS

A total of 19 264 patients with CD were included, of whom 7452 [39%] received biologics with a median follow-up of 6.8 years (interquartile range [IQR] 3.6-10.7). Time to biologics decreased gradually from 6.7 years [IQR 2.7-10.4] in 2005 to 0.2 years [0.07-0.23] in 2020. The durability of the first biologic after 1 and 3 years was higher with adalimumab monotherapy [88%/61%] than vedolizumab monotherapy [81%/59%; n = 394 matched patients, p = 0.04] and similar between infliximab monotherapy and vedolizumab monotherapy [65%/43%; n = 182 matched patients, p = 0.1]. Durability was higher in adalimumab monotherapy vs infliximab monotherapy [83%/62% vs 71%/48% at 1/3 years; p <0.001] and it was similar in adalimumab monotherapy vs infliximab combotherapy [87%/63% vs 80%/58%, respectively; p = 0.1]. Durability was higher in combotherapy compared with monotherapy for both infliximab [85%/64% vs 67%/43%, respectively; n = 496 matched pairs, p <0.001], and adalimumab [93%/76% vs 82%/62%, respectively; n = 540 matched pairs, p <0.001].

CONCLUSION

Durability of the first biologic in CD was highest for adalimumab monotherapy. Combotherapy further increased the durability of adalimumab and infliximab. Unless otherwise indicated, our data may support using anti-tumour necrosis factors [TNFs] as first-line biologics in CD, particularly adalimumab if monotherapy is advised.

Durability of Adalimumab and Infliximab in Children With Crohn's Disease: A Nationwide Comparison From the epi-IIRN Cohort

BACKGROUND

In a nationwide cohort, we aimed to compare the durability of infliximab and adalimumab as first biologic treatment in children with Crohn's disease (CD), stratified as combotherapy or monotherapy.

METHODS

We used data from the epi-IIRN cohort that includes all patients with inflammatory bowel diseases in Israel. Durability was defined as consistent treatment without surgery or treatment escalation. All comparisons followed stringent propensity-score matching in Cox proportional hazard models.

RESULTS

Of the 3487 children diagnosed with CD since 2005, 2157 (62%) received biologics (1127 [52%] infliximab, 964 [45%] adalimumab and 52 [2%] vedolizumab as first biologic), representing a higher proportion than that among adults diagnosed during the same time period (5295 of 15 776 [34%]; P < .001). Time from diagnosis to initiation of biologic was shorter in pediatric-onset compared with adult-onset disease (median time during the last 3 years was 2.7 months [interquartile range 1.2-5.4] vs 5.2 months [2.6-8.9]; P < .001). The durability of adalimumab monotherapy after 1 and 5 years from initiation of treatment was better than infliximab monotherapy (79%/54% vs 67%/37%, respectively; n = 452 matched children; hazard ratio [HR], 1.7; 95% confidence interval [CI], 1.3-2.3; P < .001), while in those treated with combotherapy, durability was similar (94%/66% with infliximab vs 90%/54% with adalimumab; n = 100; HR, 1.7; 95% CI, 0.9-3.3; P = .1). Durability was higher in children treated with infliximab combotherapy vs infliximab monotherapy (87%/45% vs 75%/39%; n = 440; HR, 1.4; 95% CI, 1.1-1.8; P = .01). The durability of adalimumab monotherapy was similar to infliximab combotherapy (83%/53% vs 89%/56%, respectively; n = 238; HR, 0.9; 95% CI, 0.7-1.2; P = .4).

CONCLUSION

Our results support using adalimumab monotherapy as a first-line biologic in children with CD. When infliximab is used, combotherapy may be advantageous over monotherapy.

Residence in Peripheral Regions and Low Socioeconomic Status Are Associated With Worse Outcomes of Inflammatory Bowel Diseases: A Nationwide Study From the epi-IIRN

BACKGROUND

Timely access to quality medical care impacts patient outcomes in inflammatory bowel disease (IBD). In a nationwide study from the epidemiology group of the Israeli IBD research nucleus we aimed to assess the impact of residence and socioeconomic status (SES) on disease outcomes.

METHODS

We utilized data from the 4 health maintenance organizations in Israel, representing 98% of the population. Regions were defined as central, northern and southern; SES was graded from lowest to highest (from 1 to 4) as per Israel Central Bureau of Statistics. The primary outcome was steroid dependency, with secondary outcomes of surgeries and biologic therapy use.

RESULTS

A total of 28 216 IBD patients were included: 15 818 (56%) Crohn's disease (CD) and 12 398 (44%) ulcerative colitis; 74%, 12% and 14% resided in central, southern, and northern Israel, respectively (SES 1: 21%, SES 4: 12%). Lower SES was associated with steroid dependency (20% in SES 1 vs 12% in SES 4 in CD; P < .001; and 18% vs 12% in ulcerative colitis; P < .001), and higher surgery rates (12% vs 7%; P < .001, and 1.4% vs 0.7%; P = .115, respectively). There were higher steroid dependency and CD surgery rates in peripheral vs central regions. In multivariable models, both SES and peripheral region were independently associated with poorer outcomes.

CONCLUSIONS

We found that lower SES and peripheral residence were associated with deleterious outcomes in IBD. This should be considered by policymakers and should encourage strategies for improving outcomes in populations at risk.

Mpox in people with past infection or a complete vaccination course: a global case series

BACKGROUND

Since May, 2022, a large global outbreak of human mpox (formerly known as monkeypox) has predominantly affected men who have sex with men. The strain responsible, Clade IIb, has mutated substantially from precursors originating from the 2017-18 outbreak in Nigeria. Immunity to smallpox, another orthopoxvirus, via previous infection or vaccination provides lifelong immunity. However, since the 2022 mpox outbreak, recent clusters were described in individuals with presumed immunity through recent infection or vaccination. We aim to describe the epidemiological and clinical characteristics of mpox in individuals with past infection or vaccination to improve the understanding of this disease in the setting of previous immunity.

METHODS

In this global case series, international collaborators from nine countries provided data on individuals with PCR-confirmed mpox after documented previous infection or vaccination between May 11, 2022, and June 30, 2023. We excluded cases that could not confirm vaccination status or cases with partial immunisation or any doses received before the current multi-national mpox outbreak (cutoff date May 1, 2022). Data were collected via a case report spreadsheet that reported on dates of infection and vaccination, route of immunisation, demographic characteristics, clinical findings, HIV status, concomitant sexually transmitted infections, and markers of disease severity (mpox severity score system). We describe case epidemiology, clinical course, and mpox severity scores; all analyses were descriptive.

FINDINGS

We report mpox infections in 37 gay and bisexual men who have sex with men: seven individuals had mpox reinfections, 29 individuals had mpox infections that occurred after two appropriately spaced Modified Vaccinia Ankara-Bavarian Nordic vaccine courses, and one individual had an infection that met the criteria for both reinfection and infection after vaccination. The median age of individuals was 36 years (IQR 30-45; range 21-58). Those with natural immunity after initial infection had a shorter disease course with less mucosal disease upon reinfection than with their initial infection. Infections post-vaccination were characterised by few lesions, little mucosal disease, and minimal analgesia requirements; two people received oral tecovirimat. Overall, there were no deaths, no bacterial superinfections, and all individuals were managed in the ambulatory clinic with one hospital admission for a necrotising neck lesion.

INTERPRETATION

The epidemiology of people with mpox reinfection or infection post-vaccination was similar to other published cohorts during the 2022 outbreak-predominantly young, sexually active gay and bisexual men who have sex with men. Clinical features and outcomes of repeat infection and infection after vaccination appear to be less clinically severe than those described in 2022 case literature. Specifically, compared with the 2022 case series, these individuals in the present study had fewer confluent lesions, less mucosal involvement, reduced analgesia requirement, and fewer admissions. Natural immunity and vaccine-induced immunity are not fully protective against mpox infection. However, in this small series both disease duration and severity appear to be reduced.

FUNDING

None.

Inflammatory bowel disease among first generation immigrants in Israel: A nationwide epi-Israeli Inflammatory Bowel Disease Research Nucleus study

BACKGROUND

Israel has a high rate of Jewish immigration and a high prevalence of inflammatory bowel disease (IBD).

AIM

To compare IBD prevalence in first-generation immigrants vs Israel-born Jews.

METHODS

Patients with a diagnosis of IBD as of June 2020 were included from the validated epi-IIRN (Israeli IBD Research Nucleus) cohort that includes 98% of the Israeli population. We stratified the immigration cohort by IBD risk according to country of origin, time period of immigration, and age group as of June 2020.

RESULTS

A total of 33544 patients were ascertained, of whom 18524 (55%) had Crohn's disease (CD) and 15020 (45%) had ulcerative colitis (UC); 28394 (85%) were Israel-born and 5150 (15%) were immigrants. UC was more prevalent in immigrants (2717; 53%) than in non-immigrants (12303, 43%, P < 0.001), especially in the < 1990 immigration period. After adjusting for age, longer duration in Israel was associated with a higher point prevalence rate in June 2020 (high-risk origin: Immigration < 1990: 645.9/100000, ≥ 1990: 613.2/100000, P = 0.043; intermediate/low-risk origin: < 1990: 540.5/100000, ≥ 1990: 192.0/100000, P < 0.001). The prevalence was higher in patients immigrating from countries with high risk for IBD (561.4/100000) than those originating from intermediate-/low-risk countries (514.3/100000; P < 0.001); non-immigrant prevalence was 528.9/100000.

CONCLUSION

Lending support to the environmental effect on IBD etiology, we found that among immigrants to Israel, the prevalence of IBD increased with longer time since immigration, and was related to the risk of IBD in the country of origin. The UC rate was higher than that of CD only in those immigrating in earlier time periods.

Outcomes and endpoints of postoperative recurrence in Crohn's Disease: systematic review and consensus conference

BACKGROUND

Outcomes after ileocolonic resection in Crohn's Disease (CD) are heterogeneous and a clear definition of postoperative recurrence remains to be determined. Our Endpoints Working Group of the International Organization for the study of Inflammatory Bowel Disease (IOIBD) aimed to standardize postoperative outcomes, to discuss which endpoints should be used for postoperative clinical trials and to define those which could be used in trials or registries.

METHODS

Based on a systematic review of the literature, recommendations and statements were drafted and sent to all IOIBD members for a first round of voting. Recommendations and statements were revised based on the voters' comments during a consensus hybrid conference open to all IOIBD members. If no agreement was reached after 2 rounds of voting, the statement was excluded.

RESULTS

In the systematic review, 3,071 manuscripts were screened, of which 434 were included. Sixteen recommendations were identified, of which 11 were endorsed. Recommendations and statements include that endoscopy remains the gold standard and should be used as a short-term primary endpoint in both observational cohorts and randomized controlled trials. Clinical symptoms classically used in clinical trials for luminal CD are not reliable in this specific situation. For that reason, longer term endpoints should be based on the evidence of macroscopic inflammation assessed by imaging techniques, endoscopy or reflected by the presence of complications.

CONCLUSIONS

Agencies recommend the use of clinical evaluations, as in the case of luminal CD, and do not recognize primary endpoints based solely on endoscopy. This consensus has led to agreement on the need to define postoperative endoscopy- and/or imaging-based endpoints.

Factors Associated with Virological Failure in First-Line Antiretroviral Therapy in Patients Diagnosed with HIV-1 between 2010 and 2018 in Israel

Despite the progress in contemporary antiretroviral therapy (ART) and the continuous changes in treatment guidelines, virological failure (VF) is still an ongoing concern. The goal of this study was to assess factors related to VF after first-line ART. A longitudinal cohort retrospective study of individuals on first-line ART diagnosed with HIV-1 in 2010-2018 and followed-up for a median of two years was conducted. Demographics, baseline and longitudinal CD4 counts, treatment regimens, adherence and VF were recorded. The Cox proportional hazards regression and mixed models were used. A cohort of 1130 patients were included. Overall, 80% were males and 62% were Israeli-born individuals. Compared to individuals diagnosed in 2010-2014, when treatment was initiated according to CD4 levels, those diagnosed in 2015-2018 were older and had lower baseline CD4 counts. VF was recorded in 66 (5.8%) patients. Diagnosis with CD4 <200 cells/mmᶟ with AIDS-defining conditions (HR = 2.75, 95%CI:1.52-4.97, p < 0.001) and non-integrase strand transfer inhibitor regimens (non-INSTI, HR = 1.80, 95%CI:1.01-3.24, p = 0.047) increased VF risk. No impact of baseline resistance was observed. We concluded that the early detection of HIV-1 infection and usage of INSTI-based regimens are recommended to reduce VF.

Precision medicine in monogenic inflammatory bowel disease: proposed mIBD REPORT standards

Owing to advances in genomics that enable differentiation of molecular aetiologies, patients with monogenic inflammatory bowel disease (mIBD) potentially have access to genotype-guided precision medicine. In this Expert Recommendation, we review the therapeutic research landscape of mIBD, the reported response to therapies, the medication-related risks and systematic bias in reporting. The mIBD field is characterized by the absence of randomized controlled trials and is dominated by retrospective observational data based on case series and case reports. More than 25 off-label therapeutics (including small-molecule inhibitors and biologics) as well as cellular therapies (including haematopoietic stem cell transplantation and gene therapy) have been reported. Heterogeneous reporting of outcomes impedes the generation of robust therapeutic evidence as the basis for clinical decision making in mIBD. We discuss therapeutic goals in mIBD and recommend standardized reporting (mIBD REPORT (monogenic Inflammatory Bowel Disease Report Extended Phenotype and Outcome of Treatments) standards) to stratify patients according to a genetic diagnosis and phenotype, to assess treatment effects and to record safety signals. Implementation of these pragmatic standards should help clinicians to assess the therapy responses of individual patients in clinical practice and improve comparability between observational retrospective studies and controlled prospective trials, supporting future meta-analysis.

Thiopurines Have Longer Treatment Durability than Methotrexate in Adults and Children with Crohn's Disease: A Nationwide Analysis from the epi-IIRN Cohort

BACKGROUND

Thiopurines and methotrexate have long been used to maintain remission in Crohn's disease [CD]. In this nationwide study, we aimed to compare the effectiveness and safety of these drugs in CD.

METHODS

We used data from the epi-IIRN cohort, including all patients with CD diagnosed in Israel. Outcomes were compared by propensity-score matching and included therapeutic failure, hospitalisations, surgeries, steroid dependency, and adverse events.

RESULTS

Of the 19264 patients diagnosed with CD since 2005, 3885 [20%] ever received thiopurines as monotherapy and 553 [2.9%] received methotrexate. Whereas the use of thiopurines declined from 22% in 2012-2015 to 12% in 2017-2020, the use of methotrexate remained stable. The probability of sustaining therapy at 1, 3, and 5 years was 64%, 51%, and 44% for thiopurines and 56%, 30%, and 23% for methotrexate, respectively [p <0.001]. Propensity-score matching, including 303 patients [202 with thiopurines, 101 with methotrexate], demonstrated a higher rate of 5-year durability for thiopurines [40%] than methotrexate [18%; p <0.001]. Time to steroid dependency [p = 0.9], hospitalisation [p = 0.8], and surgery [p = 0.1] were comparable between groups. These outcomes reflect also shorter median time to biologics with methotrexate (2.2 [IQR 1.6-3.1 years) versus thiopurines (6.6 [2.4-8.5]; p = 0.02). The overall adverse events rate was higher with thiopurines [20%] than methotrexate [12%; p <0.001], including three lymphoma cases in males, although the difference was not significant [4.8 vs 0 cases/10 000 treatment-years, respectively; p = 0.6].

CONCLUSION

Thiopurines demonstrated higher treatment durability than methotrexate but more frequent adverse events. However, disease outcomes were similar, partly due to more frequent escalation to biologics with methotrexate.

Medical concept embedding of real-valued electronic health records with application to inflammatory bowel disease

Deep learning approaches are gradually being applied to electronic health record (EHR) data, but they fail to incorporate medical diagnosis codes and real-valued laboratory tests into a single input sequence for temporal modeling. Therefore, the modeling misses the existing medical interrelations among codes and lab test results that should be exploited to promote early disease detection. To find connections between past diagnoses, represented by medical codes, and real-valued laboratory tests, in order to exploit the full potential of the EHR in medical diagnosis, we present a novel method to embed the two sources of data into a recurrent neural network. Experimenting with a database of Crohn's disease (CD), a type of inflammatory bowel disease, patients and their controls (~1:2.2), we show that the introduction of lab test results improves the network's predictive performance more than the introduction of past diagnoses but also, surprisingly, more than when both are combined. In addition, using bootstrapping, we generalize the analysis of the imbalanced database to a medical condition that simulates real-life prevalence of a high-risk CD group of first-degree relatives with results that make our embedding method ready to screen this group in the population.

Association of Antibiotic Use with Durability of Biologic Agents in Inflammatory Bowel Disease: a Report from the epi-IIRN

BACKGROUND

Different antibiotic classes were reported to have variable effects on immunogenicity towards anti-tumour necrosis factor [TNF] agents. However, the impact of antibiotic administration on biologic treatment durability was not investigated. We aimed to assess the association between antibiotic treatment and persistence of different classes of biologic therapy in inflammatory bowel disease [IBD] patients.

METHODS

Data from the epi-IIRN, a nationwide registry of all Israeli IBD patients were analysed. All patients who filled a prescription of either infliximab, adalimumab, vedolizumab, or ustekinumab, were included. Treatment cessation was defined as drug discontinuation of at least 6 months. Macrolides, cephalosporins, fluoroquinolones, and penicillins with beta-lactamase inhibitors were selected as primary exposure variables. Survival analysis was performed using marginal structural models for each drug separately.

RESULTS

In all 13 513 IBD patients, with a total of 39 600 patient-years, were included. Significant differences of overall treatment persistence were demonstrated, with highest persistence rates for ustekinumab and the lowest for infliximab treatment. Macrolides were found to be significantly associated with reduced risk of infliximab cessation (adjusted hazard ratio [aHR] 0.72, 95% CI 0.62-0.89]. Fluoroquinolones and cephalosporins were associated with an elevated risk of adalimumab treatment cessation [aHR 1.33, 95% CI 1.22-1.46; and aHR 1.20, 95% CI 1.08-1.34, respectively]. No significant effects of the studied antibiotics were observed in ustekinumab and vedolizumab users.

CONCLUSIONS

Specific antibiotic classes are associated with duration of anti-TNF treatment, but not with durability of vedolizumab or ustekinumab treatments. Further research is required to study the effect of specific antibiotics on response to biologics.

Thiopurines Maintenance Therapy in Children With Ulcerative Colitis: A Multicenter Retrospective Study

BACKGROUND AND AIMS

Thiopurines are an established treatment for pediatric ulcerative colitis (UC). However, data regarding safety and efficacy are lacking. We aimed to determine short and long-term outcome following thiopurines use in children with UC.

METHODS

We conducted a retrospective review of children (2-18 years) with UC treated with thiopurines between January 2008 and January 2019 at 7 medical centers in Israel. The primary outcome was corticosteroid (CS)-free clinical remission at week 52 following thiopurines initiation without the need for rescue therapy (infliximab, calcineurin inhibitors, or colectomy).

RESULTS

A total of 133 children were included [median age at diagnosis of 12.4 (interquartile range 11.0-15.8) years, 30 (23%) left-sided colitis, 113 (85%) with moderate or severe disease at diagnosis]. At diagnosis 58 patients (44%) were treated with 5-aminosalicylates and 72 (54%) with CS. Sixty patients (45%) received thiopurines as 1st line maintenance therapy. Seventy-four patients (56%) had CS-free clinical remission at week 52 without rescue therapy. Predictors of clinical remission were not identified. In a sub-analysis among patients with steroid-responsive moderate to severe UC, 59 (55%) patients achieved this outcome. The likelihood of remaining free of rescue therapy among thiopurines-treated patients was 83%, 62%, 45%, and 37% at 1, 2, 3, and 4 years, respectively.

CONCLUSION

More than half of children with UC starting thiopurines without previous or concomitant biologic therapy have CS-free clinical remission at 52 weeks later without the need for rescue therapy. Thiopurines are effective in pediatric UC and could be considered prior to biologics.

Outcome of Very Early Onset Inflammatory Bowel Disease Associated With Primary Sclerosing Cholangitis: A Multicenter Study From the Pediatric IBD Porto Group of ESPGHAN

BACKGROUND

Whether primary sclerosing cholangitis related to inflammatory bowel disease (PSC-IBD) diagnosed before 6 years (ie, VEO-IBD) has a distinct phenotype and disease course is uninvestigated. We aimed to analyze the characteristics and natural history of VEO-PSC-IBD, compared with early and adolescent-onset PSC-IBD.

METHODS

This is a multicenter, retrospective, case-control study from 15 centers affiliated with the Porto and Interest IBD group of ESPGHAN. Demographic, clinical, laboratory, endoscopic, and imaging data were collected at baseline and every 6 months. Inflammatory bowel disease-related (clinical remission, need for systemic steroids and biologics, and surgery) and PSC-related (biliary and portal hypertensive complications, need for treatment escalation and liver transplantation, cholangiocarcinoma, or death) outcomes were compared between the 2 groups.

RESULTS

Sixty-nine children were included, with a median follow-up of 3.63 years (interquartile range, 1-11): 28 with VEO-PSC-IBD (23 UC [82%], 2 IBD-U [7%] and 3 [11%] CD), and 41 with PSC-IBD (37 UC [90%], 3 IBDU [7.5%] and 1 [2.5%] CD). Most patients with UC presented with pancolitis (92% in VEO-PSC-UC vs 85% in PSC-UC, P = .2). A higher number of patients with VEO-PSC-IBD were diagnosed with PSC/autoimmune hepatitis overlap syndrome than older children (24 [92%] vs 27 [67.5%] PSC-IBD, P = .03), whereas no other differences were found for PSC-related variables. Time to biliary strictures and infective cholangitis was lower in the VEO-PSC-IBD group (P = .01 and P = .04, respectively), while no difference was found for other outcomes. No cases of cholangiocarcinoma were reported.

CONCLUSIONS

Primary sclerosing cholangitis related to inflammatory bowel disease has similar baseline characteristics whether diagnosed as VEO-IBD or thereafter. A milder disease course in terms of biliary complications characterizes VEO-PSC-IBD.

Incidence, Management, and Outcomes of Very Early Onset Inflammatory Bowel Diseases and Infantile-Onset Disease: An Epi-IIRN Study

BACKGROUND & AIMS

In this nationwide study from the Israeli Inflammatory Bowel Disease Research Nucleus, we aimed to describe the incidence of very early onset inflammatory bowel diseases (VEOIBDs) with a focus on infantile-onset disease and to compare management and disease course with older children.

METHODS

Data were retrieved from the 4 Israeli Health Maintenance Organizations covering 98% of the population. Pediatric-onset IBD was categorized as follows: adolescent onset (10 to <18 y), early onset (6 to <10 y), VEOIBD (0 to <6 y), toddler onset (2 to <6 y), and infantile onset (<2 y).

RESULTS

A total of 5243 children with 35,469 person-years of follow-up evaluation, were diagnosed with IBD during 2005 to 2020: 4444 (85%) with adolescent onset, 548 (10%) with early onset, and 251 (4.8%) with VEOIBD, of whom 81 (1.5%) had infantile onset. The incidence of pediatric-onset IBD increased from 10.8 per 100,000 in 2005 to 15.3 per 100,000 in 2019 (average annual percentage change, 2.8%; 95% CI, 2.2%-3.4%), but that of VEOIBD remained stable (average annual percentage change, 0%; 95% CI, -2.5% to 2.6%). The infantile-onset and toddler-onset groups were treated less often with biologics (36% and 35%, respectively) vs the early onset (57%) and adolescent-onset groups (53%; P < .001). The time to steroid dependency was shorter in infantile-onset (hazard ratio [HR], 2.1; 95% CI, 1.5-2.9) and toddler-onset disease (HR, 1.6; 95% CI, 1.2-2.0) vs early onset and adolescent-onset disease, but time to hospitalizations, time to surgery, and growth delay were worse only in infantile-onset disease. In a multivariable model, infantile-onset patients had a higher risk for surgery (HR, 1.4; 95% CI, 1.1-1.9) and hospitalization (HR, 1.7; 95% CI, 1.2-2.4) than the toddler-onset group.

CONCLUSIONS

The incidence of VEOIBD remained stable. Infantile-onset IBD had worse outcomes than older children, while toddler onset had mostly similar outcomes, despite less frequent use of biologics.

Gut Microbiome Composition Is Associated With Future Onset of Crohn's Disease in Healthy First-Degree Relatives

BACKGROUND & AIMS

The cause of Crohn's disease (CD) is unknown, but the current hypothesis is that microbial or environmental factors induce gut inflammation in genetically susceptible individuals, leading to chronic intestinal inflammation. Case-control studies of patients with CD have cataloged alterations in the gut microbiome composition; however, these studies fail to distinguish whether the altered gut microbiome composition is associated with initiation of CD or is the result of inflammation or drug treatment.

METHODS

In this prospective cohort study, 3483 healthy first-degree relatives (FDRs) of patients with CD were recruited to identify the gut microbiome composition that precedes the onset of CD and to what extent this composition predicts the risk of developing CD. We applied a machine learning approach to the analysis of the gut microbiome composition (based on 16S ribosomal RNA sequencing) to define a microbial signature that associates with future development of CD. The performance of the model was assessed in an independent validation cohort.

RESULTS

In the validation cohort, the microbiome risk score (MRS) model yielded a hazard ratio of 2.24 (95% confidence interval, 1.03-4.84; P = .04), using the median of the MRS from the discovery cohort as the threshold. The MRS demonstrated a temporal validity by capturing individuals that developed CD up to 5 years before disease onset (area under the curve > 0.65). The 5 most important taxa contributing to the MRS included Ruminococcus torques, Blautia, Colidextribacter, an uncultured genus-level group from Oscillospiraceae, and Roseburia.

CONCLUSION

This study is the first to demonstrate that gut microbiome composition is associated with future onset of CD and suggests that gut microbiome is a contributor in the pathogenesis of CD.

Difficult-to-treat inflammatory bowel disease: results from an international consensus meeting

Many patients with inflammatory bowel disease (IBD) have persistent symptoms and disease activity despite the best available medical or surgical treatments. These patients are commonly referred to as having difficult-to-treat IBD and need additional therapeutic strategies. However, the absence of standard definitions has impeded clinical research efforts and comparisons of data. Under the guidance of the endpoints cluster of the International Organization for the Study of Inflammatory Bowel Disease, we held a consensus meeting to propose a common operative definition for difficult-to-treat IBD. 16 participants from 12 countries voted on 20 statements covering various elements of difficult-to-treat IBD, such as failure of medical and surgical treatments, disease phenotypes, and specific complaints from patients. "Agreement" was defined as at least 75% consensus. The group agreed that difficult-to-treat IBD is defined by the failure of biologics and advanced small molecules with at least two different mechanisms of action, or postoperative recurrence of Crohn's disease after two surgical resections in adults, or one in children. In addition, chronic antibiotic-refractory pouchitis, complex perianal disease, and comorbid psychosocial complications that impair disease management also qualified as difficult-to-treat IBD. Adoption of these criteria could serve to standardise reporting, guide enrolment in clinical trials, and help identify candidates for enhanced treatment strategies.

Humoral and Cellular Immune Responses of People Living With Human Immunodeficiency Virus After 3 Doses of Messenger RNA BNT162b2 Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine: A Prospective Cohort Study

Background

Recent studies have shown good serological and cellular immune responses in people living with human immunodeficiency virus (PLWH) after receipt of 2 doses of messenger RNAA (mRNA) severe acute respiratory syndrome coronavirus 2 vaccine. Data are missing regarding the response after 3 vaccine doses.

Methods

We followed up a group of PLWH who received 3 doses of the mRNA BNT162b2 vaccine and for whom data of humoral immune response after 2 vaccine doses were available. Patients provided a blood sample 4-6 months after the booster dose. The aim of the study was to measure the serological and cellular response after the third dose and to evaluate factors associated with the vaccine response.

Results

Fifty patients have provided a serum sample for serological evaluation after the booster. The anti-receptor-binding domain (RBD) immunoglobulin (Ig) G titers were higher after the booster with a median delta of 3240 arbitrary units/mL. The median CD4+ T-cell count was 660/μL (interquartile range, 515-958/μL) and had no influence on the antibody level. Factors associated with lower delta included higher CD8+ T-cell count (P = .02) and longer time between the third dose and the blood test (P = .01). Higher anti-RBD IgG titer after the second vaccine (P = .03), as well as a longer interval between second and third doses (P = .031) were associated with higher delta. There was no increase in the median number of activated interferon γ+ and tumor necrosis factor α+ CD4+ T cells after the booster (n = 8).

Conclusions

The anti-RBD IgG level after 3 doses of mRNA BNT162b2 vaccine was higher than the level after 2 doses, suggesting additional value of the booster. Cellular response did not further increase after a booster.

Prospective Validation of the Lémann Index in Children: A Report From the Multicentre Image Kids Study

BACKGROUND

The Lémann Index [LI] and the recently updated LI are tools for measuring structural bowel damage in adults with Crohn's disease [CD] but have not been evaluated in children. We aimed to validate the updated LI in the prospective multicentre ImageKids study of paediatric CD.

METHODS

We included children with CD undergoing magnetic resonance enterography [MRE], pelvic magnetic resonance imaging [MRI] and ileocolonoscopy. Half were followed for 18 months, when MRE was repeated. Serum was collected for fibrosis-related proteomic markers. The LI was calculated by central readers from the MRE, ileocolonoscopy, physical examination and surgical data. Reliability and construct validity were assessed at baseline, while responsiveness and test-retest reliability were explored longitudinally.

RESULTS

In total, 240 children were included (mean age, 14.2 ± 2.5 years; median disease duration, 2.2 years [interquartile range, IQR 0.25-4.42]; median baseline LI, 4.23 [IQR 2.0-8.8]). The updated LI had excellent inter-observer reliability (interclass correlation coefficient [ICC] = 0.94, 95% confidence interval [CI] 0.92-0.95) but poor, although statistically significant, correlation with radiologist and gastroenterologist global assessments of damage and with serum proteomic levels of fibrotic markers [rho = 0.15-0.30, most p < 0.05]. The updated LI had low discriminative validity for detecting damage (area under the receiver operating characteristic curve [AUC-ROC] 0.69, 95% CI 0.62-0.75). In 116 repeated MREs, responsiveness was suboptimal for differentiating improved from unchanged disease [AUC-ROC 0.58, 95% CI 0.45-0.71]. Test-retest reliability was high among stable patients [ICC = 0.84, 95% CI 0.72-0.91].

CONCLUSION

Overall, the updated LI had insufficient psychometric performance for recommending its use in children. An age-specific index may be needed for children with shorter disease duration than typical adult cohorts.

Validation of predictive models for disease outcomes in paediatric ulcerative colitis: A multicentre prospective inception cohort

BACKGROUND

Several studies proposed models to predict disease outcomes in paediatric ulcerative colitis (UC), notably PROTECT, Schechter and PIBD-ahead, but none have been validated by external cohorts.

AIM

To explore these models in a prospective multicentre inception cohort.

METHODS

Children newly diagnosed with UC in 17 centres were followed at disease onset and 3 and 12 months thereafter, as well as at last visit. Outcomes included steroid-free remission (SFR) and acute severe colitis (ASC).

RESULTS

Of the 223 included children, 74 (34%), 97 (43%) and 52 (23%) presented with mild, moderate and severe disease respectively. SFR rate was 35% at 3 months and 47% at 12 months (62% of those with mild disease at diagnosis vs. 41% in moderate-severe disease; p = 0.01). Thirty-six (16%) children developed ASC during the first month after diagnosis, and 53 (24%) during the first year. The AUC of the PROTECT model for predicting SFR at 3 and 12 months were 0.78 [95% CI 0.65-0.92] and 0.57 [95% CI 0.47-0.66] respectively. The sensitivity/specificity/PPV/NPV of Schechter's criteria to predict sustained SFR (SSFR) at 12 months was 50%/60%/35%/74%. ASC was predicted only by the PUCAI score at diagnosis and at 3 months.

CONCLUSIONS

The PROTECT model had a good predictive utility for SFR at 3 months, but not at 12 months. The other predictive models did not achieve sufficient accuracy, and all were far from that reported in the original studies. This highlights the necessity for external validation of any prediction model prior to its implementation in clinical practice.

Development and Validation of the TUMMY-UC: A Patient-Reported Outcome for Pediatric Ulcerative Colitis

BACKGROUND & AIMS

The TUMMY-UC is a patient-reported outcome measure for pediatric ulcerative colitis (UC) with an observer-reported outcome version for children aged <8 years. It includes eight items selected by concept elicitation interviews. We aimed to finalize the TUMMY-UC by cognitive interviews (stage 2) and to evaluate the index for its psychometric properties (stage 3).

METHODS

The TUMMY-UC items were first finalized during 129 cognitive debriefing interviews. Then, in a prospective, multicenter validation study, 84 children who underwent colonoscopy or provided stool for calprotectin completed the TUMMY-UC and various measures of disease activity. Assessments were repeated after 7 and 21 days for evaluating reliability and responsiveness.

RESULTS

During stage 2, the items were formatted with identical structure to ensure conceptual equivalence and weighted based on ranking of importance. In stage 3, the TUMMY-UC total score had excellent reliability in repeated assessments (intraclass correlation coefficient, 0.90; 95% confidence interval, 0.84-0.94). It also had moderate to strong correlations with all constructs of disease activity: r = 0.70 with UC endoscopic index of severity, r = 0.63 with the IMPACT-III questionnaire, r = 0.43 with calprotectin, r = 0.80 with the Pediatric Ulcerative Colitis Activity Index, r = 0.75 with global assessment of disease activity, and r = 0.46 with C-reactive protein (all P < .015). The index had excellent discrimination of disease activity, with a score of <9 defining remission (area under the receiver operating characteristic curve, 0.95; 95% confidence interval, 0.93-0.99). The ΔTUMMY-UC showed high responsiveness and differentiated well between children who experienced changed from those with no change.

CONCLUSIONS

The TUMMY-UC, constructed from patient-reported outcome and observer-reported outcome versions, is a reliable, valid and responsive index that can be now used in practice and clinical trials.

Paediatric Inflammatory Bowel Disease: A Multi-Stakeholder Perspective to Improve Development of Drugs for Children and Adolescents

BACKGROUND AND AIMS

Despite recent approvals for new drugs to treat adults with Crohn's disease or ulcerative colitis, there are only two approved advanced treatment options [infliximab and adalimumab] for children with inflammatory bowel disease [IBD]. There are many potential new therapies being developed for adult and paediatric IBD. Moreover, regulatory agencies in both the European Union and USA have processes in place to support the early planning and initiation of paediatric studies. Nevertheless, unacceptable delays in approvals for use of drugs in children persist, with an average 7-year gap, or longer, between authorization of new IBD drugs for adults and children.

METHODS

A 2-day virtual meeting was held during April 14-15, 2021 for multi-stakeholders [clinical academics, patient community, pharmaceutical companies and regulators] to discuss their perspectives on paediatric drug development for IBD.

RESULTS

The multi-stakeholder group presented, discussed and proposed actions to achieve expediting the approval of new drugs in development for paediatric IBD.

CONCLUSIONS

Collaborative action points for all stakeholders are required to make progress and facilitate new drug development for children with IBD.

Global survival trends for brain tumors, by histology: analysis of individual records for 556,237 adults diagnosed in 59 countries during 2000-2014 (CONCORD-3)

BACKGROUND

Survival is a key metric of the effectiveness of a health system in managing cancer. We set out to provide a comprehensive examination of worldwide variation and trends in survival from brain tumors in adults, by histology.

METHODS

We analyzed individual data for adults (15-99 years) diagnosed with a brain tumor (ICD-O-3 topography code C71) during 2000-2014, regardless of tumor behavior. Data underwent a 3-phase quality control as part of CONCORD-3. We estimated net survival for 11 histology groups, using the unbiased nonparametric Pohar Perme estimator.

RESULTS

The study included 556,237 adults. In 2010-2014, the global range in age-standardized 5-year net survival for the most common sub-types was broad: in the range 20%-38% for diffuse and anaplastic astrocytoma, from 4% to 17% for glioblastoma, and between 32% and 69% for oligodendroglioma. For patients with glioblastoma, the largest gains in survival occurred between 2000-2004 and 2005-2009. These improvements were more noticeable among adults diagnosed aged 40-70 years than among younger adults.

CONCLUSIONS

To the best of our knowledge, this study provides the largest account to date of global trends in population-based survival for brain tumors by histology in adults. We have highlighted remarkable gains in 5-year survival from glioblastoma since 2005, providing large-scale empirical evidence on the uptake of chemoradiation at population level. Worldwide, survival improvements have been extensive, but some countries still lag behind. Our findings may help clinicians involved in national and international tumor pathway boards to promote initiatives aimed at more extensive implementation of clinical guidelines.

Preoperative clear fluid fasting and endoscopy-measured gastric fluid volume in children

BACKGROUND

In light of new recommendations to shorten clear fluid fasting time before anesthesia, our study aimed at exploring residual fluid volume in the stomach after different fasting times. We intended to perform direct endoscopic aspiration of stomach contents under vision, as part of routine gastroscopy assessment. Hereby we would be able to quantify true residual gastric fluid volume and acidity in children and measure their correlation with fasting times.

METHODS

The study was performed as a single-center, prospective study in pediatric perioperative day care at a university-affiliated tertiary care center. Aspiration of gastric fluid contents was performed in anesthetized children aged 1-18 years undergoing an elective gastroscopy. Recorded data included patient fast time, last meal content, last clear fluid content, and aspirated gastric volume and pH, as well as patient characteristics.

RESULTS

We included 253 gastroscopies, performed in 245 children. Mean fasting time for clear fluids was 6.9 h (range 1 h 40 min - 18 h 35 min) (SD 4.5). Mean age was 9.8 years (SD 5.1) and mean body weight was 33.2 kg (SD 18.7). Mean residual gastric volume was 12 mL (0-90) (SD 13.5) or 0.34 mL/kg (SD 0.37) and mean pH was 1.5 (SD 0.9). No significant correlation was observed between clear fluid fasting time and the child's residual gastric fluid volume per kg body weight (r = -.103, p = .1), nor between clear fluid fasting time and the pH of the residual gastric fluid (r = -.07, p = .3). In more than half of the patients the residual gastric volume was less than 10 mL, unrelated to fasting time.

CONCLUSIONS

In children undergoing gastroscopy, we could not demonstrate any association between clear fluid fasting time and the child's residual gastric fluid volume per kg body weight. Since we did not see a clinically relevant association between clear fluids fasting time and gastric residual volume, this study may support the recommendation to shorten clear fluids fasting time.

5-aminosalicylate maintenance is not superior to no maintenance in patients with newly diagnosed Crohn's disease-A nationwide cohort study

BACKGROUND

5-aminosalicylates (5-ASA) are widely used in Crohn's disease (CD) despite guidelines advising otherwise. We aimed to assess in nationwide study the outcomes of first-line 5-ASA maintenance therapy (5-ASA-MT) compared with no maintenance treatment (no-MT) in patients with newly diagnosed CD.

METHODS

We utilised data from the epi-IIRN cohort, including all patients with CD diagnosed in Israel between 2005 and 2020. Propensity score (PS) matching was utilised to compare outcomes in the 5-ASA-MT versus no-MT groups.

RESULTS

Of the 19,264 patients diagnosed with CD, 8610 (45%) fulfilled the eligibility criteria (3027 [16%] received 5-ASA-MT and 5583 [29%] received no-MT). Both strategies declined over the years; 5-ASA-MT from 21% of CD patients diagnosed in 2005 to 11% in 2019 (p < 0.001) and no-MT from 36% to 23% (p < 0.001). The probability of maintaining therapy at 1, 3 and 5 years from diagnosis: 5-ASA-MT-78%, 57% and 47% and no-MT-76%, 49% and 38% respectively (p < 0.001). PS analysis successfully matched 1993 pairs of treated and untreated patients and demonstrated comparable outcomes of time to: biologic (p = 0.2), steroid dependency (p = 0.9), hospitalisation (p = 0.5) and CD-related surgery (p = 0.1). Rates of acute kidney injury (5.2% vs. 3.3%; p < 0.001) and pancreatitis (2.4% vs. 1.8%; p = 0.03) were higher in the 5-ASA-MT group compared with the no-MT group but after PS matching the rates of adverse events were similar.

CONCLUSION

First-line 5-ASA monotherapy was not superior to no-MT but associated with a slightly higher rates of adverse events, while both strategies have declined over the years. These findings suggest that a subset of patients with mild CD may be offered a watchful waiting approach.

A198 THE LONG-TERM IMPACT OF ENVIRONMENTAL EXPOSURES ON HOST HEALTH AND THE RISK FACTORS OF CROHN'S DISEASE

Background

Several environmental factors are associated with Crohn’s disease (CD) in large case-control studies; however, it is not clear how these factors maybe be influenced by age of exposure and if they are related to alterations in pre-disease biological markers of CD risk.

Purpose

To investigate the association between environmental factors in different age groups with future risk of CD onset and assess their relation to other pre-disease biomarkers.

Method

We used an environmental risk assessment questionnaire (ERA) to collect information from healthy first-degree relatives(FDR) of CD enrolled in the CCC-GEM project. ERA was a multi-item questionnaire querying 69 questions under 7 section headings: background, cultural/ethnic, smoking history, medical history, family history, environmental history and pet history. For the environmental and pet sections, current and historical (<1, 2-4, 5-15 years old) data was captured at the time of recruitment. We used Cox proportional hazard models to identify exposures associated with future CD onset. Next, we used regression models to identify the relationship of exposures with biological factors associated with CD risk previously identified by our group i.e.: i) intestinal permeability using urinary fractional excretion of lactulose to mannitol ratio (LMR) with LMR≥0.025 defined as abnormal; ii) subclinical inflammation using fecal calprotectin (FCP) with FCP≥100µg/g; and iii) fecal microbiome composition and diversity using 16S rDNA sequencing. Two-sided p<0.05 (or false discovery rate corrected p<0.05) were considered significant.

Result(s)

A total of 4289 FDRs were recruited, 47% were male, median recruitment age was 17.0 years[6-35]. After a median follow-up of 5.6-years (IQR=3.42-8.67), 86 FDRs developed CD. Living with a dog between age 5-15 (Hazard Ratio (HR)=0.61; 95% confidence interval (CI)=0.39-0.95), and a large family size (>3) in the first year of life (HR=0.41; 95% CI=0.22-0.89) were protective against CD onset. Conversely, having a bird at time of survey (HR=2.84; CI=1.37-5.90), and having a sibling with CD (HR=2.07; 95% CI=1.18-3.63) were risk factors for CD onset. We found that owning a dog between age of 5-15 (Odd Ratio(OR)=0.77, 95% CI=0.65-0.90) was significantly associated with LMR, nine taxa bacterial and higher chao1 diversity index. Having a bird at time of survey was significantly associated with FCP (OR=2.04, 95% CI=1.33-3.11). There was no association between large family size and having a CD sibling with gut microbiome, FCP or LMR.

Conclusion(s)

The study identified four environmental factors associated with future development of CD. Among them, exposure to dogs during early life was protective against CD onset and might be explained by its association with normal gut permeability and microbiome. We also identified that having a bird at recruitment increased risk of CD onset which might be mediated by an increase in subclinical inflammation.

Submitted on behalf of the CCC-GEM consortium

Disclosure of Interest

None Declared

A39 HEALTHY FIRST-DEGREE RELATIVES FROM MULTIPLEX FAMILIES VERSUS SIMPLEX HARBOR A HIGHER RISK OF DEVELOPING CROHN'S DISEASE AND ARE ASSOCIATED WITH SUBCLINICAL INFLAMMATION AND ALTERED MICROBIOME COMPOSITION

Background

Healthy individuals within families with multiple affected members (multiplex families) with Crohn’s disease (CD) have a notably high risk of developing CD. No large prospective pre-disease cohort has assessed differences in preclinical intestinal inflammation, permeability, fecal microbiome, and genetics in healthy at-risk subjects from multiplex families.

Purpose

We aimed to assess differences in subclinical gut inflammation, genetic risk, gut barrier function, and fecal microbiota composition between first-degree relatives (FDRs) from families with 2 or more affected members (multiplex) and families with only one affected member (simplex). Also, we aimed to assess the risk of future CD onset in subjects from multiplex versus simplex families.

Method

We utilized the GEM Project cohort of healthy FDRs of CD patients. Subclinical gut inflammation was assessed using fecal calprotectin (FCP) at recruitment. Gut barrier function was assessed using the lactulose-to-mannitol ratio (LMR). For assessment of the CD-related genetic risk, CD-polygenic risk scores (CD-PRS) were calculated. Microbiome composition was assessed by sequencing fecal 16S ribosomal RNA. Generalized estimating equations logistic regression and LEfSe (PMID: 21702898) were used to assess the associations between multiplex status and different outcomes. A Cox proportional hazards model was used to assess time-related risk of future onset of CD.

Result(s)

4385 subjects were included. Median age was 17 [IQR 12-24] years, 52.9% were female, 69.4% were siblings and 30.6% were offspring. 4052 (92.4%) and 333 (7.6 %) were simplex and multiplex subjects, respectively. After adjusting for age, sex, family size, and relation to proband, multiplex status was significantly associated with higher baseline FCP (p=0.038), but was not associated with either baseline LMR or CD-PRS (p=0.19 and p=0.33, respectively).

We found no significant differences in alpha diversity (Shannon index) (p=0.57) between simplex and multiplex subjects. Beta diversity analysis assessed by the Bray-Curtis dissimilarity index did not reveal significant differences (R2=3e-04, p=0.607). The genera Eisenbergiella, Eggerthellaceae uncultured, and Morganella, were significantly more abundant in multiplex subjects, whereas Lachnospira, Sutterella, Lachnospiraceae_NK4A136_group, and Lachnospiraceae_UCG_004 less abundant.

The risk of CD onset was significantly higher in multiplex subjects. In multivariable analysis, multiplex status at recruitment was associated with increased risk of CD onset (adjusted HR 3.41, 95% CI 1.70-6.87, p=0.00055), after adjusting for demographics, FCP, LMR, and CD-PRS.

Conclusion(s)

Multiplex status compared to simplex is associated with a 3.4-fold increased risk of CD onset, a higher FCP, and fecal bacterial composition. A comprehensive assessment of environmental factors that increase CD risk in multiplex families remains to be elucidated in future studies.

Disclosure of Interest

None Declared

Future Exploration of the Outer Heliosphere and Very Local Interstellar Medium by Interstellar Probe

A detailed overview of the knowledge gaps in our understanding of the heliospheric interaction with the largely unexplored Very Local Interstellar Medium (VLISM) are provided along with predictions of with the scientific discoveries that await. The new measurements required to make progress in this expanding frontier of space physics are discussed and include in-situ plasma and pick-up ion measurements throughout the heliosheath, direct sampling of the VLISM properties such as elemental and isotopic composition, densities, flows, and temperatures of neutral gas, dust and plasma, and remote energetic neutral atom (ENA) and Lyman-alpha (LYA) imaging from vantage points that can uniquely discern the heliospheric shape and bring new information on the interaction with interstellar hydrogen. The implementation of a pragmatic Interstellar Probe mission with a nominal design life to reach 375 Astronomical Units (au) with likely operation out to 550 au are reported as a result of a 4-year NASA funded mission study.

Immune response and barrier dysfunction-related proteomic signatures in preclinical phase of Crohn's disease highlight earliest events of pathogenesis

OBJECTIVE

The measure of serum proteome in the preclinical state of Crohn's disease (CD) may provide insight into biological pathways involved in CD pathogenesis. We aimed to assess associations of serum proteins with future CD onset and with other biomarkers predicting CD risk in a healthy at-risk cohort.

DESIGN

In a nested case-control study within the Crohn's and Colitis Canada Genetics Environment Microbial Project (CCC-GEM) cohort, which prospectively follows healthy first-degree relatives (FDRs), subjects who developed CD (n=71) were matched with four FDRs remaining healthy (n=284). Using samples at recruitment, serum protein profiles using the Olink Proximity Extension Assay platform was assessed for association with future development of CD and with other baseline biomarkers as follows: serum antimicrobial antibodies (AS: positive antibody sum) (Prometheus); faecal calprotectin (FCP); gut barrier function using the fractional excretion of lactulose-to-mannitol ratio (LMR) assay.

RESULTS

We identified 25 of 446 serum proteins significantly associated with future development of CD. C-X-C motif chemokine 9 (CXCL9) had the highest OR with future risk of CD (OR=2.07 per SD, 95% CI 1.58 to 2.73, q=7.9e-5), whereas matrix extracellular phosphoglycoprotein had the lowest OR (OR 0.44, 95% CI 0.29 to 0.66, q=0.02). Notably, CXCL9 was the only analyte significantly associated with all other CD-risk biomarkers with consistent direction of effect (FCP: OR=2.21; LMR: OR=1.67; AS: OR=1.59) (q<0.05 for all).

CONCLUSION

We identified serum proteomic signatures associated with future CD development, reflecting potential early biological processes of immune and barrier dysfunction.

Multi-item Measures for Pediatric Inflammatory Bowel Diseases: The ABCs of All Those Acronyms

With the recent acceptance of multiple treatment goals for inflammatory bowel diseases (IBD), it becomes increasingly important to accurately quantify the measurable concepts. These include patient-reported symptoms, intestinal damage, mucosal activity, transmural inflammation, and histologic appearance, as well as quality of life, disability, and other patient-centered attributes. Standardized indices which show sufficient validity, reliability, and responsiveness to change are not only mandatory for implementing the treat-to-target approach but are also critical for assessing the effectiveness of emerging medications in clinical trial settings. Some concepts can be accurately assessed through the use of existing measurement tools used for adults (e.g. capsule endoscopy, ultrasonic, endoscopic, and histologic scoring) while others may be age-specific. Although several pediatric indices and scales are well established (e.g. IMPACT questionnaire, PCDAI, and PUCAI), recent years have seen the development of newer indices for children, including the MINI to predict endoscopic healing in Crohn's disease, MRI indices that measure inflammation (i.e. PICMI) and perianal disease (i.e. PEMPAC), and patient-reported outcome measures in ulcerative colitis (i.e. TUMMY-UC), upper gastrointestinal inflammatory score (i.e. UGI-SES-CD), simplified endoscopic mucosal assessment score for Crohn's disease (SEMA-CD), and the parent-completed IMPACT questionnaire (i.e. IMPACT-III-P). Despite these advances, quantifiable pediatric IBD-specific tools are still lacking for disability and fatigue. In this review, we provide a contemporary, clinically-focused overview of the indices that a pediatric gastroenterologist can use to quantify disease status.

Outcomes, dosing, and predictors of vedolizumab treatment in children with inflammatory bowel disease (VEDOKIDS): a prospective, multicentre cohort study

BACKGROUND

Scarce data are available on the use of vedolizumab in children with inflammatory bowel disease (IBD). We aimed to evaluate the safety, effectiveness, and dosing of vedolizumab to induce remission of IBD.

METHODS

VEDOKIDS was a paediatric, multicentre, prospective cohort study done in 17 centres in six countries. We report the 14-week outcomes as the first analyses of the planned 3-year follow-up of the VEDOKIDS cohort. Children (aged 0-18 years) with IBD who had commenced vedolizumab were followed up at baseline and at 2, 6, and 14 weeks. Children were managed according to local prescribing practices without standardisation of dosing or criteria for escalation, but the study protocol suggested dosing of 177 mg/m² body surface area (up to 300 mg maximum). The primary outcome was steroid-free and exclusive enteral nutrition-free remission at 14 weeks, analysed according to the intention-to-treat principle. Serum samples were taken for analysis of drug concentration and faecal calprotectin at baseline, and at 2, 6, and 14 weeks. Adverse events were recorded in real time and classified as severe or non-severe and related or unrelated to vedolizumab. This study is registered with ClinicalTrials.gov, NCT02862132.

FINDINGS

Between May 19, 2016, and April 1, 2022, 142 children (76 [54%] girls and 66 [46%] boys; mean age 13·6 years [SD 3·6]) were enrolled. 65 (46%) children had Crohn's disease, 68 (48%) had ulcerative colitis, and nine (6%) had unclassified IBD (those with unclassified IBD were analysed with the ulcerative colitis group). 32 (42% [95% CI 30-54]) of 77 children with ulcerative colitis and 21 (32% [23-45]) of 65 children with Crohn's disease were in steroid-free and exclusive enteral nutrition-free remission at 14 weeks. Median drug concentrations at week 14 were higher in children with ulcerative colitis than in those with Crohn's disease (11·5 μg/mL [IQR 5·5-18·1] vs 5·9 μg/mL [3·0-12·7]; p=0·006). In children who weighed less than 30 kg, the optimal drug concentration associated with steroid-free and exclusive enteral nutrition-free clinical remission was 7 μg/mL at week 14 (area under the curve 0·69 [95% CI 0·41-0·98]), corresponding to a dose of 200 mg/m² body surface area or 10 mg/kg. 32 (23%) of 142 children reported at least one adverse event, the most common were headache (five [4%]), myalgia (four [3%]), and fever (three [2%]). None of the adverse events were classified as severe, and only two (1%) patients discontinued treatment due to adverse events.

INTERPRETATION

Vedolizumab showed good safety and effectiveness at inducing remission in children with IBD at 14 weeks, especially those with ulcerative colitis. Vedolizumab should be considered in children when other approved drug interventions for IBD are unsuccessful. In children who weigh less than 30 kg, vedolizumab should be dosed by the child's body surface area (200 mg/m²) or weight (10 mg/kg).

FUNDING

The European Crohn's and Colitis Organization, the European Society for Paediatric Gastroenterology Hepatology and Nutrition, and Takeda.

Development of a multimodal machine-learning fusion model to non-invasively assess ileal Crohn's disease endoscopic activity

BACKGROUND AND OBJECTIVE

Recurrent attentive non-invasive observation of intestinal inflammation is essential for the proper management of Crohn's disease (CD). The goal of this study was to develop and evaluate a multi-modal machine-learning (ML) model to assess ileal CD endoscopic activity by integrating information from Magnetic Resonance Enterography (MRE) and biochemical biomarkers.

METHODS

We obtained MRE, biochemical and ileocolonoscopy data from the multi-center ImageKids study database. We developed an optimized multimodal fusion ML model to non-invasively assess terminal ileum (TI) endoscopic disease activity in CD from MRE data. We determined the most informative features for model development using a permutation feature importance technique. We assessed model performance in comparison to the clinically recommended linear-regression MRE model in an experimental setup that consisted of stratified 2-fold validation, repeated 50 times, with the ileocolonoscopy-based Simple Endoscopic Score for CD at the TI (TI SES-CD) as a reference. We used the predictions' mean-squared-error (MSE) and the receiver operation characteristics (ROC) area under curve (AUC) for active disease classification (TI SEC-CD≥3) as performance metrics.

RESULTS

121 subjects out of the 240 subjects in the ImageKids study cohort had all required information (Non-active CD: 62 [51%], active CD: 59 [49%]). Length of disease segment and normalized biochemical biomarkers were the most informative features. The optimized fusion model performed better than the clinically recommended model determined by both a better median test MSE distribution (7.73 vs. 8.8, Wilcoxon test, p<1e-5) and a better aggregated AUC over the folds (0.84 vs. 0.8, DeLong's test, p<1e-9).

CONCLUSIONS

Optimized ML models for ileal CD endoscopic activity assessment have the potential to enable accurate and non-invasive attentive observation of intestinal inflammation in CD patients. The presented model is available at https://tcml-bme.github.io/ML_SESCD.html.

Barriers and Facilitators of Hepatitis C Care in Persons Coinfected with Human Immunodeficiency Virus

Hepatitis C virus (HCV) and human immunodeficiency virus (HIV) are often co-transmitted. Viral coinfection results in worse outcomes. Persons who inject drugs (PWIDs) face barriers to medical treatment, but HCV treatment is indicated and effective even with ongoing active drug use. We aimed to assess access to HCV care and treatment results in patients coinfected with HIV-HCV. This is a real-world retrospective single-center study of patients followed in the HIV clinic between 2002 and 2018. Linkage to care was defined as achieving care cascade steps: (1) hepatology clinic visit, (2) receiving prescription of anti-HCV treatment, and (3) documentation of sustained virologic response (SVR). Of 1660 patients with HIV, 254 with HIV-HCV coinfection were included. Only 39% of them achieved SVR. The rate limiting step was the engagement into hepatology care. Being a PWID was associated with ~50% reduced odds of achieving study outcomes, active drug use was associated with ~90% reduced odds. Older age was found to facilitate treatment success. Once treated, the rate of SVR was high in all populations. HCV is undertreated in coinfected young PWIDs. Further efforts should be directed to improve access to care in this marginalized population.

The association of Inflammatory Bowel Disease with Celiac Disease and Celiac Autoimmunity in children and adults: A nationwide study from the epi-IIRN

BACKGROUND AND AIMS

Given the paucity of population-based data on the association between inflammatory bowel diseases (IBD), celiac disease (CeD) and celiac autoimmunity (CeA) we aimed to study the associations in a nationwide study.

METHODS

Utilizing health administrative data for all four health maintenance organizations in Israel, covering 98% of the population, we explored the prevalence of CeD in children and adults with IBD versus non-IBD matched controls. CeD was defined by three ICD-9 codes and CeA by positivity for tissue transglutaminase antibodies.

RESULTS

In total, 34,375 IBD patients (56% Crohn's disease [CD] and 44% ulcerative colitis [UC]) were compared with 93,603 non-IBD controls. Among IBD patients, 319 (0.93%) had CeD versus 294 (0.31%) non-IBD controls (odds ratio [OR]=2.97 [95%CI 2.54-3.48]; p<0.001). CeA was identified in 575 (1.67%) IBD patients vs. 158 (0.17%) controls (OR=10.06 [95%CI 8.43-12], p<0.001). The prevalence of CeD was higher in pediatric-onset IBD (87/5,243 [1.66%]) than adult-onset IBD (232/29,132 [0.79%]; p<0.001). CD patients had a higher prevalence of CeD (229/19,264 [1.19%]) than UC patients (90/15,111 [0.56%]; OR=2.01 [95%CI 1.57-2.56]; p<0.001). The diagnosis of CeD preceded the diagnosis of IBD in 241/319 cases (76%). The time to treatment escalation was shorter in patients with both IBD and CeD than in patients with IBD without CeD (p=0.017).

CONCLUSION

CeD and CeA are more prevalent in IBD patients, especially in pediatric-onset IBD and in CD. The diagnosis of CeD usually precedes that of IBD. Having CeD is associated with more intensified treatment for IBD.

The Modified Mucosal Inflammation Noninvasive Index and Endoscopic Remission in Adults With Crohn's Disease

The Mucosal Inflammation Noninvasive Index is a validated noninvasive tool to assess endoscopic remission in pediatric Crohn’s disease. In this study, we evaluated a modified version of the Mucosal Inflammation Noninvasive Index on adult cohorts to explore its validly in adult Crohn’s disease.

Development, Validation, and Evaluation of the Pediatric Inflammatory Crohn's Magnetic Resonance Enterography Index From the ImageKids Study

BACKGROUND & AIMS

Cross-sectional imaging is important in the assessment of transmural inflammation in Crohn's disease (CD). Small bowel involvement is often more extensive in pediatric CD, requiring a panentering measuring tool. We undertook to develop a magnetic resonance enterography (MRE)-based index that would measure inflammation in all segments of the intestine, without rectal contrast.

METHODS

Children with CD underwent ileocolonoscopy and MRE and half were prospectively followed for 18 months when MRE was repeated. Item generation and reduction were performed by a Delphi panel of pediatric radiologists, a systematic literature review, a cross-sectional study of 48 MREs, and a steering committee. Formatting and weighting were performed using multivariate modeling adjusted by a steering committee. MREs were read locally and centrally. Reliability, validity, and responsiveness were determined using several clinimetric and psychometric approaches.

RESULTS

Thirty items were initially generated and reduced to 5 using regression analysis on 159 MREs: wall thickness, wall diffusion weighted imaging, ulcerations, mesenteric edema, and comb sign. In the validation cohort of 81 MREs, the weighted global PICMI correlated well with the radiologist global assessment (r = 0.85; P < .001) and with the simple endoscopic score in a subsample with ileocolonic disease (r = 0.63; P < .001). Interobserver and test-retest reliability were high (interclass correlation coefficients, 0.84; 95% confidence interval [CI], 0.79-0.87; and 0.81, 95% CI, 0.65-0.90, respectively; both P < .001). Excellent responsiveness was found at repeated visits (n = 116 MREs; area under the receiver operating characteristic curve 0.96; 95% CI, 0.93-0.99). Transmural healing was defined as PICMI ≤10 and response as a change of >20 points with excellent discriminative validity (area under the receiver operating characteristic curve = 0.96; 95% CI, 0.93-0.99).

CONCLUSIONS

The PICMI is a valid, reliable, and responsive index for assessing transmural inflammation in pediatric CD. It scores the entire bowel length and does not require intravenous contrast or rectal enema and, therefore, is suitable for use in children. (ClinicalTrials.gov, Number: NCT01881490.).

Altered Gut Microbiome Composition and Function Are Associated With Gut Barrier Dysfunction in Healthy Relatives of Patients With Crohn's Disease

BACKGROUND & AIMS

The gut microbiome has been suggested to play a role in gut barrier hemostasis, but data are scarce and limited to animal studies. We therefore aimed to assess whether alterations in gut microbial composition and functional pathways are associated with gut barrier function in a cohort of healthy first-degree relatives of patients with Crohn's disease.

METHODS

We used the Crohn's and Colitis Canada Genetic Environmental Microbial (CCC-GEM) cohort of healthy first-degree relatives of patients with Crohn's disease. Gut barrier function was assessed using the urinary fractional excretion of lactulose-to-mannitol ratio (LMR). Microbiome composition was assessed by sequencing fecal 16S ribosomal RNA. The cohort was divided into a discovery cohort (n = 2472) and a validation cohort (n = 655). A regression model was used to assess microbial associations with the LMR. A random forest classifier algorithm was performed to assess microbial community contribution to barrier function.

RESULTS

Individuals with impaired barrier function (LMR >0.025) had reduced alpha-diversity (Chao1 index, P = 4.0e-4) and altered beta-diversity (Bray-Curtis dissimilarity index, R² = 0.001, P = 1.0e-3) compared with individuals with an LMR ≤0.025. When taxa were assessed individually, we identified 8 genera and 52 microbial pathways associated with an LMR >0.025 (q < 0.05). Four genera (decreased prevalence of Adlercreutzia, Clostridia UCG 014, and Clostridium sensu stricto 1 and increased abundance of Colidextribacter) and 8 pathways (including decreased biosynthesis of glutamate, tryptophan, and threonine) were replicated in the validation cohort. The random forest approach revealed that the bacterial community is associated with gut barrier function (area under the curve, 0.63; P = 1.4e-6).

CONCLUSIONS

The gut microbiome community and pathways are associated with changes in gut barrier function. These findings may identify potential microbial targets to modulate gut barrier.