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.