Longer Colonoscopy Withdrawal Time Is Associated With the Detection of Visible Dysplasia in Patients With Inflammatory Bowel Disease.

Background: Colonoscopy withdrawal time (CWT) of at least 6-9 minutes is the minimum time needed for adequate adenoma detection in the general population. The ideal CWT in patients with inflammatory bowel disease (IBD) has not been determined. We aimed to identify the optimal CWT associated with the detection of visible dysplasia in patients with IBD. Methods: This is a retrospective study from 1/1/2017 to 9/1/2022 of adult patients with IBD in endoscopic healing undergoing surveillance via high-definition white light colonoscopy. The primary outcome was the association of CWT with visible dysplasia detection. Results: A total of 259 patients (mean age 56 ±â€…14.8 years; 51.3% female, 68% with ulcerative colitis; 8.9% with primary sclerosing cholangitis) underwent 330 colonoscopies. Patients with visible dysplasia were more likely to be older (P < .001) and have a personal history of visible dysplasia (P < .001) and invisible dysplasia (P = .023). The mean CWT was significantly longer in the visible dysplasia group at 26 minutes (interquartile range [IQR] 20-38.5) vs. 21 minutes (IQR 15-28) in procedures without visible dysplasia (P < .001). On multivariable analysis, increased age (P < .001), increased CWT (P = .001), and personal history of visible dysplasia (P = .013) were independently associated with the detection of visible dysplasia. A CWT of ≥15 minutes (odds ratio [OR] 2.71; 95% confidence interval [CI], 1.11-6.6; P = .02] and not ≥9 minutes (OR 2.57; 95% CI, 0.33-20.2; P = .35) is significantly associated with detection of visible dysplasia. Conclusions: For patients with IBD undergoing surveillance via high-definition white light colonoscopy, the mean CWT was independently associated with the detection of visible dysplasia.

Probabilistic risk assessment of residential exposure to electric arc furnace steel slag using Bayesian model of relative bioavailability and PBPK modeling of manganese.

Electric arc furnace (EAF) slag is a coproduct of steel production used primarily for construction purposes. Some applications of EAF slag result in residential exposures by incidental ingestion and inhalation of airborne dust. To evaluate potential health risks, an EAF slag characterization program was conducted to measure concentrations of metals and leaching potential (including oral bioaccessibility) in 38 EAF slag samples. Arsenic, hexavalent chromium, iron, vanadium, and manganese (Mn) were identified as constituents of interest (COIs). Using a probabilistic risk assessment (PRA) approach, estimated distributions of dose for COIs were assessed, and increased cancer risks and noncancer hazard quotients (HQs) at the 50th and 95th percentiles were calculated. For the residents near slag-covered roads, cancer risk and noncancer HQs were <1E - 6 and 1, respectively. For residential driveway or landscape exposure, at the 95th percentile, cancer risks were 1E - 6 and 7E - 07 based on oral exposure to arsenic and hexavalent chromium, respectively. HQs ranged from 0.07 to 2 with the upper bound due to ingestion of Mn among children. To expand the analysis, a previously published physiologically based pharmacokinetic (PBPK) model was used to estimate Mn levels in the globus pallidus for both exposure scenarios and further evaluate the potential for Mn neurotoxicity. The PBPK model estimated slightly increased Mn in the globus pallidus at the 95th percentile of exposure, but concentrations did not exceed no-observed-adverse-effect levels for neurological effects. Overall, the assessment found that the application of EAF slag in residential areas is unlikely to pose a health hazard or increased cancer risk.

Impact of COVID-19 Treatment on Real-World Outcomes in Inflammatory Bowel Disease.

BACKGROUND: While there are multiple safe and effective agents for COVID-19 treatment, their impact in inflammatory bowel disease (IBD) remains uncertain. AIMS: Our objective was to assess the effects of these therapies on both IBD and COVID outcomes. METHODS: A single-center retrospective study of adult patients with IBD who contracted COVID-19 between 12/2020 and 11/2022 was performed. Patients were stratified by COVID-19 treatment (antivirals and/or intravenous antibodies) vs no therapy. The primary outcome was the development of severe COVID-19 infection, defined by need for supplemental oxygen, corticosteroids and/or antibiotics, or hospitalization. Secondary outcomes included rates of withholding advanced IBD therapy (defined as biologic agents or small molecules) and of post-COVID-19 IBD flare. RESULTS: Of 127 patients with COVID-19 infection, 70% were on advanced therapies, 35% received COVID-19 treatment, and 15% developed severe COVID-19. Those treated for COVID-19 were more likely to be on corticosteroids [odds ratio (OR) 4.61, 95% confidence interval (CI) 1.72-12.39, p = 0.002] or advanced IBD therapies (OR 2.78, 95% CI 1.04-7.43, p = 0.041). After adjusting for age, race, sex, corticosteroid use, obesity, COVID-19 vaccination status, and severe COVID-19 infection, those treated for COVID-19 were more likely to have IBD therapy held (OR 6.95, 95% CI 1.72-28.15, p = 0.007). There was no significant difference in rates of post-COVID-19 IBD flares or severe COVID-19 infection. There were no COVID-related deaths. CONCLUSIONS: Patients with IBD on advanced therapies were frequently treated for acute COVID-19. Although COVID-19 treatment was associated with temporary withholding of IBD therapy, it did not result in increased IBD flares.

Use of physiologically based pharmacokinetic modeling to support development of an acute (24-hour) health-based inhalation guideline for manganese.

The toxicokinetics of manganese (Mn) are controlled through homeostasis because Mn is an essential element. However, at elevated doses, Mn is also neurotoxic and has been associated with respiratory, reproductive, and developmental effects. While health-based criteria have been developed for chronic inhalation exposure to ambient Mn, guidelines for short-term (24-h) environmental exposure are also needed. We reviewed US state, federal, and international health-based inhalation toxicity criteria, and conducted a literature search of recent publications. The studies deemed most appropriate to derive a 24-h guideline have a LOAEL of 1500 µg/m3 for inflammatory airway changes and biochemical measures of oxidative stress in the brain following 90 total hours of exposure in monkeys. We applied a cumulative uncertainty factor of 300 to this point of departure, resulting in a 24-h guideline of 5 µg/m3. To address uncertainty regarding potential neurotoxicity, we used a previously published physiologically based pharmacokinetic model for Mn to predict levels of Mn in the brain target tissue (i.e., globus pallidus) for exposure at 5 µg/m3 for two short-term human exposure scenarios. The PBPK model predictions support a short-term guideline of 5 µg/m3 as protective of both respiratory effects and neurotoxicity, including exposures of infants and children.

Early Flexible Sigmoidoscopy Improves Clinical Outcomes in Acute Severe Ulcerative Colitis.

Objectives: Guidelines recommend performing a flexible sigmoidoscopy in patients hospitalized with acute severe ulcerative colitis (ASUC). However, it is unclear if time to sigmoidoscopy affects relevant clinical outcomes. We aimed to assess the impact of early sigmoidoscopy on clinical outcomes using a well-characterized cohort of patients with ASUC. Methods: This is a single-center, retrospective study of all patients hospitalized with ASUC from January 1, 2012 to November 1, 2021. Early sigmoidoscopy was defined as occurring within 72 hours of admission while delayed sigmoidoscopy was defined as occurring >72 hours after admission. Primary outcomes were cumulative days of intravenous (IV) corticosteroid (CS) use, length of hospital stay, and colectomy rates. Secondary outcomes were time to infliximab (IFX) rescue and inpatient opioid medication use. Results: A total of 112 patients hospitalized with ASUC who underwent sigmoidoscopy were included in the analysis. Eighty-seven patients (78%) had early sigmoidoscopy and 25 (22%) had delayed sigmoidoscopy. Patients in the early sigmoidoscopy group were exposed to significantly fewer days of IV CS (4.5 vs 9.2 days; P < .001), had shorter hospital stays (6.4 vs 19.3 days; P < .001), and shorter time to IFX rescue (3.5 vs 6.4 days; P = .004). Rates of colectomy in the early and delayed sigmoidoscopy groups were 17% versus 28%, respectively (P = .23). Longer time to sigmoidoscopy was associated with a 16% increased risk of colectomy (HR = 1.16, P = .002). Conclusions: In this well-characterized cohort, early sigmoidoscopy in ASUC was associated with favorable clinical outcomes. These findings highlight the benefits of early sigmoidoscopy in patients with ASUC. Larger prospective studies are needed to corroborate these findings.

Manganese relative oral bioavailability in electric arc furnace steel slag is influenced by high iron content and low bioaccessibility.

Electric arc furnace (EAF) slag is a rock-like aggregate produced with carbon steel and used for construction, including residential ground cover. It is enriched with manganese (Mn) and other metals, including iron (Fe), but because metals are bound in mineral matrices, in vitro bioaccessibility (BA) is limited. We conducted a relative bioavailability (RBA) study using F344 rats to assess Mn RBA from EAF slag ingestion, compared with Mn in diet. Mn and Fe were measured in liver, and Mn in lung and striatum, the target tissue of the brain. Mn levels in each tissue were fit by dose-to-tissue concentration (D-TC) curves. The D-TC relationship was the most highly significant for the linear model using liver Mn, and the RBA was 48%. The D-TC relationship in lung showed a positive slope for chow, but that for EAF slag was slightly negative, and the RBA was 14%. In comparison, the striatum D-TC remained relatively constant, supporting that homeostasis was maintained. Increased Fe was observed in the liver of EAF slag-dosed groups, suggesting that Mn absorption was inhibited by the high Fe content of slag. Lung and striatum D-TC curves demonstrated that systemic delivery of Mn from EAF slag ingestion is limited and support an RBA of 14% for risk assessment. Although Mn levels in slag are elevated compared with health-based screening guidelines, this study supports that incidental ingestion of Mn in EAF slag is unlikely to pose a neurotoxicity hazard due to homeostatic controls, low BA, and high Fe content.

Assessment of Inflammatory Bowel Disease Training Among Gastroenterology Fellows.

In this multicenter survey study, we found that many gastroenterology fellows lacked confidence and desired a "moderate to a lot more" training in important inflammatory bowel disease management domains.

Impact of thiopurine dose in anti-tumor necrosis factor combination therapy on outcomes in inflammatory bowel disease.

Background: Combination therapy with thiopurines and anti-tumor necrosis factor (TNF) is superior to monotherapy in Crohn's disease (CD) and ulcerative colitis (UC). The optimal dose of thiopurines in combination therapy remains unclear. We investigated the impact of thiopurine dose in combination therapy on outcomes in inflammatory bowel disease (IBD). Methods: This was a single-center, retrospective study of patients with IBD treated with thiopurine and anti-TNF combination therapy between 1/2012 and 11/2020. A therapeutic dose of thiopurines was defined as ≥1 mg/kg for 6-mercaptopurine and ≥2 mg/kg for azathioprine. The primary outcome was anti-drug antibody (ADA) formation in patients on a therapeutic thiopurine dose vs. a lower thiopurine dose group. Secondary outcomes included steroid-free clinical remission, endoscopic healing (absence of ulcers/erosions in CD and Mayo endoscopic score ≤1 for UC), and normal serum C-reactive protein (CRP) in patients who were on combination therapy. Results: A total of 108 patients were included (median age 31.5 years; 58.3% male). A therapeutic dose of thiopurine was used in 19%. In the therapeutic thiopurine dose group, 23.8% developed ADA vs. 29.9% (P=0.58) in the lower dose group. No significant differences were noted between the therapeutic and lower dose thiopurine groups in terms of steroid-free clinical remission (57.1% vs. 60.9%, P=0.75), endoscopic healing (55% vs. 60%, P=0.69), and normal CRP (52.4% vs. 52.9%, P=0.27). Conclusion: In our cohort of patients with IBD on anti-TNF combination therapy, thiopurine dose was not associated with significant differences in anti-TNF immunogenicity and clinical outcomes.

Outcomes of immunomodulator and advanced therapies for primary sclerosing cholangitis-associated inflammatory bowel disease.

BACKGROUND: Inflammatory bowel disease (IBD) coexists in up to 80% of patients with primary sclerosing cholangitis (PSC). The aim of this study is to investigate the outcomes of immunomodulator (IMM)/advanced therapies for the treatment of PSC-IBD. METHODS: This was a single-center, retrospective study of patients with PSC from 1 January 2012 to 1 April 2021. Adult patients (age ≥ 18 years) with PSC-IBD were included. Primary outcomes were rates and predictors of IMM/advanced therapies to treat PSC-IBD. Secondary outcomes included rates of cholangitis, PSC-IBD clinical remission, and endoscopic healing. RESULTS: A total of 106 patients with PSC were reviewed and 72 (68%) with confirmed PSC-IBD were included in the study. The median age was 48 years (IQR, 33-59.5) and 69.4% were male. Overall, 28 patients (38.9%) required IMM/advanced therapies to treat PSC-IBD (22 biologic/small molecule therapy and six thiopurine monotherapy). Patients in the IMM/advanced therapies group were more likely to have small bowel involvement (32.1% vs. 4.6%; P = 0.002). In the IMM/advanced therapies group, clinical remission was achieved in 78.6% but endoscopic healing in only 50%. The rate of acute ascending cholangitis was 42.9% in the IMM/advanced therapies group compared with 31.8% in the non-IMM/advanced therapies group (P = 0.34). CONCLUSION: In our cohort, up to a third of patients with PSC-IBD required IMM/advanced therapies with only 50% of these patients achieving endoscopic healing. The use of IMM/advanced therapies was not associated with a higher risk of cholangitis, but larger studies are needed to investigate the risk with different classes of advanced therapies.

Effect of obesity on vedolizumab response in inflammatory bowel disease.

Background: Vedolizumab is used in inflammatory bowel disease (IBD), administered as a non-weight-based fixed dose. A higher body mass index (BMI) is associated with lower serum vedolizumab levels, but it is unclear whether it is associated with an unfavorable response to vedolizumab. We examined the relationship between BMI and the need for dose escalation, and the overall response to vedolizumab in IBD patients. Methods: This was a single-center, retrospective study of IBD patients who received vedolizumab between 1st July 2014 and 1st September 2020. The primary outcome was need for vedolizumab dose escalation or discontinuation. Secondary outcomes were steroid-free clinical remission (SFCR), endoscopic remission, and normal serum C-reactive protein (CRP). Outcomes were compared between patients with BMI <30 kg/m2 (non-obese) or ≥30 kg/m>2 (obese). Results: 190 patients were included, with a median follow-up time of 21 months. Median age was 37 years, 50.5% were male, and median BMI was 24.8 kg/m2 (75.3% of patients had BMI <30 kg/m2). Vedolizumab was dose-escalated in 48.9% of the obese group vs. 42% of the non-obese group (P=0.4). Vedolizumab was discontinued in 31.9% of the obese group vs. 53.2% of the non-obese group (P=0.01). The rate of CRP normalization was significantly lower in the obese group (46.2% vs. 66%, P=0.03). SFCR and endoscopic remission rates were not significantly different between the groups. Conclusions: Obesity was not associated with higher rates of vedolizumab dose escalation. However, it was associated with lower rates of vedolizumab discontinuation and CRP normalization, but not SFCR or endoscopic remission.

Immune Checkpoint Inhibitor-associated Diarrhea and Colitis: A Systematic Review and Meta-analysis of Observational Studies.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have transformed the management of advanced malignancies but are associated with diarrhea and colitis. The objective of our systematic review and meta-analysis was to determine the incidence and outcomes of ICI-associated diarrhea and colitis. Bibliographic databases were searched through August 13, 2019, for observational studies of ICI therapy reporting the incidence and/or treatment of diarrhea or colitis. The primary outcome was ICI-associated diarrhea and colitis. Meta-analyses were performed with random-effects models. Twenty-five studies (N=12,661) were included. All studies had a high risk of bias in at least 1 domain. The overall incidence of diarrhea/colitis was 12.8% [95% confidence interval (CI), 8.8-18.2, I2=96.5]. The incidence was lower in patients treated with anti-programmed cell death 1/programmed death-ligand 1 (4.1%, 95% CI, 2.6-6.5) than in those treated with anti-cytotoxic T-cell lymphocyte-associated antigen 4 (20.1%, 95% CI, 15.9-25.1). The remission of diarrhea and/or colitis was higher in patients treated with corticosteroids plus biologics (88.4%, 95% CI, 79.4-93.8) than in those treated with corticosteroids alone (58.3%, 95% CI, 49.3-66.7, Q=18.7, P<0.001). ICI were permanently discontinued in 48.1% of patients (95% CI, 17.8-79.1). ICI were restarted after temporary interruption in 48.6% of patients (95% CI, 18.2-79.4) of whom 17.0% (95% CI, 6.4-30.0) experienced recurrence. Real-world incidence of ICI-associated diarrhea/colitis exceeds 10%. These events lead to permanent ICI discontinuation in just over 50% of patients, while <20% have recurrence of symptoms if ICI are resumed. Further studies are needed to identify patients who would benefit from early treatment with biologics as well as appropriate patients to resume ICI therapy.

Inhalation cancer risk assessment for environmental exposure to hexavalent chromium: Comparison of margin-of-exposure and linear extrapolation approaches.

Hexavalent chromium [Cr(VI)] exists in the ambient air at low concentrations (average upperbound ~0.1 ng/m3) yet airborne concentrations typically exceed EPA's Regional Screening Level for residential exposure (0.012 ng/m3) and other similar benchmarks, which assume a mutagenic mode of action (MOA) and use low-dose linear risk assessment models. We reviewed Cr(VI) inhalation unit risk estimates developed by researchers and regulatory agencies for environmental and occupational exposures and the underlying epidemiologic data, updated a previously published MOA analysis, and conducted dose-response modeling of rodent carcinogenicity data to evaluate the need for alternative exposure-response data and risk assessment approaches. Current research supports the role of non-mutagenic key events in the MOA, with growing evidence for epigenetic modifiers. Animal data show a weak carcinogenic response, even at cytotoxic exposures, and highlight the uncertainties associated with the current epidemiological data used in risk assessment. Points of departure from occupational and animal studies were used to determine margins of exposure (MOEs). MOEs range from 1.5 E+3 to 3.3 E+6 with a median of 5 E+5, indicating that current environmental exposures to Cr(VI) in ambient air should be considered of low concern. In this comprehensive review, the divergent results from default linear and MOE assessments support the need for more relevant and robust epidemiologic data, additional mechanistic studies, and refined risk assessment strategies.

AGA technical review on the medical management of moderate to severe luminal and perianal fistulizing Crohn's disease

The incidence and prevalence of Crohn's disease (CD) is rising globally. Patients with moderate to severe CD are at high risk for needing surgery and hospitalization and for developing disease-related complications, corticosteroid dependence, and serious infections. Optimal management of outpatients with moderate to severe luminal and/or fistulizing (including perianal) CD often requires the use of immunomodulator (thiopurines, methotrexate) and/or biologic therapies, including tumor necrosis factor-α antagonists, vedolizumab, or ustekinumab, either as monotherapy or in combination (with immunomodulators) to mitigate these risks. Decisions about optimal drug therapy in moderate to severe CD are complex, with limited guidance on comparative efficacy and safety of different treatments, leading to considerable practice variability. Since the last iteration of these guidelines published in 2013, significant advances have been made in the field, including the regulatory approval of 2 new biologic agents, vedolizumab and ustekinumab. Therefore, the American Gastroenterological Association prioritized updating clinical guidelines on this topic. To inform the clinical guidelines, this technical review was completed in accordance with the GRADE (Grading of Recommendations Assessment, Development and Evaluation) framework. The review addressed the following focused questions (in adult outpatients with moderate to severe luminal CD): overall and comparative efficacy of different medications for induction and maintenance of remission in patients with or without prior exposure to tumor necrosis factor-α antagonists, comparative efficacy and safety of biologic monotherapy vs combination therapy with immunomodulators, comparative efficacy of a top-down (upfront use of biologics and/or immunomodulator therapy) vs step-up treatment strategy (acceleration to biologic and/or immunomodulator therapy only after failure of mesalamine), and the role of corticosteroids and mesalamine for induction and/or maintenance of remission. Finally, in adult outpatients with moderate to severe fistulizing CD, this review addressed the efficacy of pharmacologic interventions for achieving fistula and the role of adjunctive antibiotics without clear evidence of active infection.

Novel and Emerging Therapies for Inflammatory Bowel Disease.

Inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease are chronic, relapsing and remitting disorders of intestinal inflammation with potential systemic manifestations. Despite the availability of current biologics, such as anti-tumor necrosis factor (anti-TNF), anti-integrins, anti-interleukins and small molecules such as tofacitinib, the rates of primary and secondary treatment failure remain high in IBD. This highlights the importance of continued development of new therapeutic targets and modifications of existing ones to improve the treatment response rates and to also improve the safety profile and tolerability of these medications. In this review we will discuss novel treatment target agents including selective janus kinase (JAK) inhibitors, anti-interleukin (IL) (IL-12/IL-23), leukocyte trafficking/migrating inhibitors (such as sphingosine-1-phosphate receptor modulator) and other small molecules currently in development.

AGA Technical Review on the Medical Management of Moderate to Severe Luminal and Perianal Fistulizing Crohn's Disease.

The incidence and prevalence of Crohn's disease (CD) is rising globally. Patients with moderate to severe CD are at high risk for needing surgery and hospitalization and for developing disease-related complications, corticosteroid dependence, and serious infections. Optimal management of outpatients with moderate to severe luminal and/or fistulizing (including perianal) CD often requires the use of immunomodulator (thiopurines, methotrexate) and/or biologic therapies, including tumor necrosis factor-α antagonists, vedolizumab, or ustekinumab, either as monotherapy or in combination (with immunomodulators) to mitigate these risks. Decisions about optimal drug therapy in moderate to severe CD are complex, with limited guidance on comparative efficacy and safety of different treatments, leading to considerable practice variability. Since the last iteration of these guidelines published in 2013, significant advances have been made in the field, including the regulatory approval of 2 new biologic agents, vedolizumab and ustekinumab. Therefore, the American Gastroenterological Association prioritized updating clinical guidelines on this topic. To inform the clinical guidelines, this technical review was completed in accordance with the GRADE (Grading of Recommendations Assessment, Development and Evaluation) framework. The review addressed the following focused questions (in adult outpatients with moderate to severe luminal CD): overall and comparative efficacy of different medications for induction and maintenance of remission in patients with or without prior exposure to tumor necrosis factor-α antagonists, comparative efficacy and safety of biologic monotherapy vs combination therapy with immunomodulators, comparative efficacy of a top-down (upfront use of biologics and/or immunomodulator therapy) vs step-up treatment strategy (acceleration to biologic and/or immunomodulator therapy only after failure of mesalamine), and the role of corticosteroids and mesalamine for induction and/or maintenance of remission. Finally, in adult outpatients with moderate to severe fistulizing CD, this review addressed the efficacy of pharmacologic interventions for achieving fistula and the role of adjunctive antibiotics without clear evidence of active infection.

The Impact of Inflammatory Bowel Disease Clinic On-site Vaccination Services.

Background: Despite being susceptible to vaccine-preventable diseases, patients with inflammatory bowel disease (IBD) have low vaccination rates. The aims of this study are to examine the rates of vaccine discussion and completion among patients of an IBD clinic that offers on-site vaccinations. Methods: This is a retrospective study from March 1, 2019 to February 1, 2020 comparing vaccination discussion and completion rates for patients with IBD who visited 2 clinics-1 that offers on-site vaccination (Clinic A) and 1 that does not (Clinic B). Both clinics are staffed by the same IBD physicians and utilize an identical IBD vaccine checklist. Results: A total of 356 patients were included (64.6% Crohn's, 31.7% ulcerative colitis, 1.1% indeterminate colitis, and 2.5% pouchitis). Overall vaccine discussion rate was 77.6% in Clinic A vs 70.9% in Clinic B (P = .15). Herpes zoster (HZ), pneumococcal, and tetanus-diphtheria-pertussis (Tdap) vaccine discussion rates were higher in Clinic A compared to Clinic B (17.8% vs 5%, P < .001, 56.3% vs 43.4%; P = .01, and 41.4% vs 21.4%, P < .001), respectively. Influenza vaccine completion and hepatitis A immunization rates were higher in Clinic A compared to Clinic B (67.8% vs 47.8%, P < .001 and 36.2% vs 22.5%, P = .005), respectively. A numerically higher percentage of patients completed the pneumococcal, HZ, and hepatitis B vaccination in Clinic A, but this difference did not reach statistical significance. Conclusions: IBD clinic on-site vaccination services enhanced vaccine discussion and completion rates. IBD clinics should offer on-site vaccination services as part of the comprehensive care of the IBD patient.