Early-life exposures and the microbiome: implications for IBD prevention.

The early-life period is one of microbiome establishment and immune maturation. Early-life exposures are increasingly being recognised to play an important role in IBD risk. The composition of functions of the gut microbiome in the prenatal, perinatal, and postnatal period may be crucial towards development of health or disease, including IBD, later in life. We herein present a comprehensive summary of the interplay between early-life factors and microbiome perturbations, and their association with risk of IBD. In addition, we provide an overview of host and external factors in early life that are known to impact gut microbiome maturation and exposures implicated in IBD risk. Considering the emerging concept of IBD prevention, we propose strategies to minimise maternal and offspring exposure to potentially harmful variables and recommend protective measures during pregnancy and the postpartum period. This holistic view of early-life factors and microbiome signatures among mothers and their offspring will help frame our current understanding of their importance towards IBD pathogenesis and frame the roadmap for preventive strategies.

Impact of prenatal and postnatal maternal IBD status on offspring's risk of IBD: a population-based cohort study.

OBJECTIVE: In utero exposure to maternal inflammation may impact immune system development and subsequent risk of disease. We investigated whether a maternal diagnosis of IBD before childbirth is linked to a higher risk of IBD in offspring compared with a diagnosis after childbirth. Further, we analysed paternal IBD status for comparison. DESIGN: Using Danish health registers, we identified all individuals born in Denmark between 1997 and 2022 and their legal parents, as well as their IBD status. Cox proportional hazards regression analyses adjusted for calendar period and mode of delivery were used to estimate offspring IBD risk by maternal and paternal IBD status before and after childbirth. RESULTS: Of 1 290 358 children, 10 041 (0.8%) had mothers with IBD diagnosis before childbirth and 9985 (0.8%) had mothers with IBD diagnosis after childbirth. Over 18 370 420 person-years, 3537 individuals were diagnosed with IBD. Offspring of mothers with IBD before childbirth had an adjusted HR of IBD of 6.27 (95% CI 5.21, 7.54) compared with those without maternal IBD, while offspring of mothers with IBD after childbirth had an adjusted HR of 3.88 (95% CI 3.27, 4.60). Corresponding adjusted HRs were 5.26 (95% CI 4.22, 6.56) among offspring with paternal IBD before childbirth and 3.73 (95% CI 3.10, 4.50) for paternal IBD after childbirth. CONCLUSION: Offspring had a greater risk of IBD when either parent was diagnosed before childbirth rather than later, emphasising genetic predisposition and environmental risk factors rather than maternal inflammation in utero as risk factors for IBD.

Specific gut pathobionts escape antibody coating and are enriched during flares in patients with severe Crohn's disease.

OBJECTIVE: Patients with Crohn's disease (CD) exhibit great heterogeneity in disease presentation and treatment responses, where distinct gut bacteria and immune interactions may play part in the yet unresolved disease aetiology. Given the role of antibodies in the barrier defence against microbes, we hypothesised that gut bacterial antibody-coating patterns may influence underlying disease-mediated processes. DESIGN: Absolute and relative single and multicoating of gut bacteria with IgA, IgG1, IgG2, IgG3 and IgG4 in patients with CD and healthy controls were characterised and compared with disease activity. IgG2-coated and non-coated taxa from patients with severe CD were identified, profiled for pathogenic characteristics and monitored for enrichment during active disease across cohorts. RESULTS: Patients with severe CD exhibited higher gut bacterial IgG2-coating. Supervised clustering identified 25 bacteria to be enriched in CD patients with high IgG2-coating. Sorting, sequencing and in silico-based assessments of the virulent potential of IgG2-coated and bulk stool bacteria were performed to evaluate the nature and pathogenicity of IgG2-coated and non-coated bacteria. The analyses demonstrated IgG2-coating of both known pathogenic and non-pathogenic bacteria that co-occurred with two non-coated pathobionts, Campylobacter and Mannheimia. The two non-coated pathobionts exhibited low prevalence, rarely coincided and were strongly enriched during disease flares in patients with CD across independent and geographically distant cohorts. CONCLUSION: Distinct gut bacterial IgG2-coating was demonstrated in patients with severe CD and during disease flares. Co-occurrence of non-coated pathobionts with IgG2-coated bacteria points to an uncontrolled inflammatory condition in severe CD mediated via escape from antibody coating by two gut pathobionts.

Antibiotic Use in the 12 Months Prior to Ileal Pouch-Anal Anastomosis Increases the Risk for Pouchitis.

BACKGROUND & AIMS: Pouchitis is the most common complication after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC); however, clinical and environmental risk factors for pouchitis remain poorly understood. We explored the relationship between specific clinical factors and the incidence of pouchitis. METHODS: We established a population-based cohort of all adult persons in Denmark undergoing proctocolectomy with IPAA for UC from 1996-2020. We used Cox proportional hazard modeling to assess the impact of antibiotic, nonsteroidal anti-inflammatory drug (NSAID) exposure, and appendectomy on diagnosis of acute pouchitis in the first 2 years after IPAA surgery. RESULTS: Among 1616 eligible patients, 46% developed pouchitis in the first 2 years after IPAA. Antibiotic exposure in the 12 months before IPAA was associated with an increased risk of pouchitis (adjusted hazard ratio [aHR], 1.41; 95% confidence interval [CI], 1.22-1.64) after adjusting for anti-tumor necrosis factor alpha use and sex. Compared with persons without any antibiotic prescriptions in the 12 months before IPAA, the risk of pouchitis was increased in those with 1 or 2 courses of antibiotics in that period (aHR, 1.30; 95% CI, 1.11-1.52) and 3 or more courses (aHR, 1.77; 95% CI, 1.41-2.21). NSAID exposure in the 12 months before IPAA and appendectomy were not associated with risk of acute pouchitis (P = .201 and P = .865, respectively). CONCLUSIONS: In this population-based cohort study, we demonstrated that antibiotic exposure in the 12 months before IPAA is associated with an increased risk of acute pouchitis. Future prospective studies may isolate specific microbial changes in at-risk patients to drive earlier interventions.

Tumor Necrosis Factor Inhibitors in Inflammatory Bowel Disease and Risk of Immune Mediated Inflammatory Diseases.

BACKGROUND & AIMS: Tumor necrosis factor inhibitors (anti-TNF) are effective therapies for several immune-mediated inflammatory diseases (IMIDs). However, case reports have identified the paradoxical occurrence of IMIDs in patients treated with anti-TNF. We studied the risk of rheumatoid arthritis, psoriasis, and hidradenitis suppurativa after the initiation of anti-TNF therapy for inflammatory bowel disease (IBD). METHODS: We conducted 2 nationwide cohort studies comprising all patients with IBD in Denmark (2005-2018) and France (2008-2018). We obtained individual-level information on exposure to anti-TNF, diagnoses of IMIDs including rheumatoid arthritis, psoriasis, and hidradenitis suppurativa, and potential confounders from healthcare registers in the respective countries. We used Cox models to estimate hazard ratios (HRs) for the association between anti-TNF exposure and IMIDs and then pooled the estimates from the 2 cohorts. To test the robustness of our results, we performed an active comparator analysis of anti-TNF monotherapy vs azathioprine monotherapy. RESULTS: The Danish and French cohorts comprised 18,258 and 88,786 subjects with IBD, respectively, contributing a total of 516,055 person-years of follow-up. Anti-TNF was associated with an increased risk of rheumatoid arthritis, psoriasis, and hidradenitis suppurativa in both the Danish (HR, 1.66; 95% confidence interval [CI], 1.34-2.07) and the French cohort (HR, 1.78; 95% CI, 1.63-1.94), with a pooled HR of 1.76 (95% CI, 1.63-1.91). Anti-TNF was also associated with an increased risk of the outcomes when compared with azathioprine (pooled HR, 2.94; 95% CI, 2.33-3.70). CONCLUSIONS: In 2 nationwide cohorts of IBD patients, anti-TNF therapy was associated with an increased risk of rheumatoid arthritis, psoriasis, and hidradenitis suppurativa.

Early Ileocecal Resection for Crohn's Disease Is Associated With Improved Long-term Outcomes Compared With Anti-Tumor Necrosis Factor Therapy: A Population-Based Cohort Study.

BACKGROUND & AIMS: Early Crohn's disease (CD) treatment involves anti-tumor necrosis factor (TNF) agents, whereas ileocecal resection (ICR) is reserved for complicated CD or treatment failure. We compared long-term outcomes of primary ICR and anti-TNF therapy for ileocecal CD. METHODS: Using cross-linked nationwide registers, we identified all individuals diagnosed with ileal or ileocecal CD between 2003 and 2018 and treated with ICR or anti-TNF agents within 1 year of diagnosis. The primary outcome was a composite of ≥1 of the following: CD-related hospitalization, systemic corticosteroid exposure, CD-related surgery, and perianal CD. We conducted adjusted Cox's proportional hazards regression analyses and determined the cumulative risk of different treatments after primary ICR or anti-TNF therapy. RESULTS: Of 16,443 individuals diagnosed with CD, 1279 individuals fulfilled the inclusion criteria. Of these, 45.4% underwent ICR and 54.6% received anti-TNF. The composite outcome occurred in 273 individuals (incidence rate, 110/1000 person-years) in the ICR group and in 318 individuals (incidence rate, 202/1000 person-years) in the anti-TNF group. The risk of the composite outcome was 33% lower with ICR compared with anti-TNF (adjusted hazard ratio, 0.67; 95% confidence interval, 0.54-0.83). ICR was associated with reduced risk of systemic corticosteroid exposure and CD-related surgery, but not other secondary outcomes. The proportion of individuals on immunomodulator, anti-TNF, who underwent subsequent resection, or were on no therapy 5 years post-ICR was 46.3%, 16.8%, 1.8%, and 49.7%, respectively. CONCLUSION: These data suggest that ICR may have a role as first-line therapy in CD management and challenge the current paradigm of reserving surgery for complicated CD refractory or intolerant to medications. Yet, given inherent biases associated with observational data, our findings should be interpreted and applied cautiously in clinical decision making.

Breastfeeding Duration Is Not Associated With Offspring Inflammatory Bowel Disease Risk in Three Population-Based Birth Cohorts.

BACKGROUND & AIMS: Breastfeeding is critical for offspring health and development. Although many observational studies report a protective effect between breastfeeding and inflammatory bowel disease (IBD), the relationship is not well-understood. METHODS: We used prospectively collected data from 3 population-based birth cohorts (Danish National Birth Cohort, Norwegian Mother, Father, and Child Cohort, and All Babies in Southeast Sweden) and cross-linked national registers to ascertain the impact of breastfeeding duration on offspring IBD risk in each country, using adjusted Cox proportional regression analyses. We performed meta-analyses to determine pooled estimates. RESULTS: We included 148,737 offspring and 169,510 offspring in analyses of exclusive and any breastfeeding duration, respectively. During median follow-up of 16.3-22.3 years, between 1996 and 2021, 543 offspring were diagnosed with IBD. In each country, there was no association between exclusive breastfeeding duration and offspring IBD risk after adjusting for birth year (Denmark), offspring sex, parental IBD status, maternal education, smoking during pregnancy, age at delivery, mode of delivery, preterm birth, and small for gestational age. The pooled adjusted hazard ratio for IBD was 1.24 (95% confidence interval, 0.94-1.62; Q = 0.16, I2 = 0.0%) and 1.02 (95% confidence interval, 0.85-1.21; Q = 1.45, I 2= 0.0%) among offspring breastfed exclusively for ≥6 months and <4 months, respectively, compared with 4-5 months. Similarly, we found null associations in pooled analyses of any breastfeeding duration and IBD, subtypes Crohn's disease and ulcerative colitis, as well as in cohort-specific analyses. CONCLUSIONS: In prospectively collected data from 3 population-based birth cohorts, the duration of exclusive or any breastfeeding was not associated with offspring IBD risk.

Infant Ustekinumab Clearance, Risk of Infection, and Development After Exposure During Pregnancy.

BACKGROUND: Evidence on ustekinumab safety in pregnancy is gradually expanding, but its clearance in the postnatal period is unknown. The aim of this study was to investigate ustekinumab concentrations in umbilical cord blood and rates of clearance after birth, as well as how these correlate with maternal drug concentrations, risk of infection, and developmental milestones during the first year of life. METHODS: Pregnant women with inflammatory bowel disease were prospectively recruited from 19 hospitals in Denmark and the Netherlands between 2018 and 2022. Infant infections leading to hospitalization/antibiotics and developmental milestones were assessed. Serum ustekinumab concentrations were measured at delivery and specific time points. Nonlinear regression analysis was applied to estimate clearance. RESULTS: In 78 live-born infants from 76 pregnancies, we observed a low risk of adverse pregnancy outcomes and normal developmental milestones. At birth, the median infant-mother ustekinumab ratio was 2.18 (95% confidence interval, 1.69-2.81). Mean time to infant clearance was 6.7 months (95% confidence interval, 6.1-7.3 months). One in 4 infants at 6 months had an extremely low median concentration of 0.015 µg/mL (range 0.005-0.12 µg/mL). No variation in median ustekinumab concentration was noted between infants with (2.8 [range 0.4-6.9] µg/mL) and without (3.1 [range 0.7-11.0] µg/mL) infections during the first year of life (P = .41). CONCLUSIONS: No adverse signals after intrauterine exposure to ustekinumab were observed with respect to pregnancy outcome, infections, or developmental milestones during the first year of life. Infant ustekinumab concentration was not associated with risk of infections. With the ustekinumab clearance profile, live attenuated vaccination from 6 months of age seems of low risk.

Antibiotic use as a risk factor for inflammatory bowel disease across the ages: a population-based cohort study.

BACKGROUND: There is an increasing incidence of inflammatory bowel disease (IBD) for which environmental factors are suspected. Antibiotics have been associated with development of IBD in earlier generations, but their influence on IBD risk in adults is uncertain. OBJECTIVE: To assess the impact of antibiotic exposure, including dose-response, timing and antibiotic class, on the risk of IBD in all individuals aged ≥10 years. DESIGN: Using Denmark nationwide registries, a population-based cohort of residents aged ≥10 years was established between 2000 and 2018. Incidence rate ratios (IRRs) for IBD following antibiotic exposure were calculated using Poisson regression. RESULTS: There were a total of 6 104 245 individuals, resulting in 87 112 328 person-years of follow-up, and 52 898 new cases of IBD. Antibiotic exposure was associated with an increased risk of IBD as compared with no antibiotic exposure for all age groups, although was greatest among individuals aged 40-60 years and ≥60 years (age 10-40 years, IRR 1.28, 95% CI 1.25 to 1.32; age 40-60 years, IRR 1.48, 95% CI 1.43 to 1.54; age ≥60 years, IRR 1.47, 95% CI 1.42 to 1.53). For all age groups a positive dose-response was observed, with similar results seen for both ulcerative colitis and Crohn's disease. The highest risk of developing IBD was seen 1-2 years after antibiotic exposure, and after use of antibiotic classes often prescribed to treat gastrointestinal pathogens. CONCLUSION: Antibiotic exposure is associated with an increased risk of IBD, and was highest among individuals aged 40 years and older. This risk increased with cumulative antibiotic exposure, with antibiotics targeting gastrointestinal pathogens and within 1-2 years after antibiotic exposure.

Risk of Recurrent Acute Arterial Events Associated With Thiopurines and Anti-Tumor Necrosis Factor in Inflammatory Bowel Diseases.

BACKGROUND & AIMS: Patients with inflammatory bowel disease (IBD) are at increased risk of acute arterial events. Treatment with anti-tumor necrosis factor (anti-TNF) agents has been associated with a protective effect against the first occurrence of acute arterial events, but the impact of treatment with anti-TNF in patients with a previous history of acute arterial events remains unclear. We assessed the effect of anti-TNF and thiopurines on the risk of recurrent acute arterial events in patients with IBD in a nationwide cohort. METHODS: Based on the French nationwide health insurance database, patients with IBD and a previous history of an acute arterial event were followed up from January 1, 2009, until December 31, 2018. The risk of acute arterial event recurrence associated with anti-TNF and thiopurine exposure was assessed using marginal structural Cox proportional hazard models adjusted for baseline and time-varying covariates. RESULTS: A total of 27,185 patients were included. During 121,822 person-years (median follow-up period, 4.0 y), 6865 recurrent acute arterial events occurred (incidence rate per 1000 person-years, 56.4; 95% CI, 55.0-57.7). Exposure to both anti-TNF and thiopurines were associated with a decreased risk of recurrent acute arterial events compared with the absence of exposure to either treatment (hazard ratio, 0.75; 95% CI, 0.63-0.90 and hazard ratio, 0.76; 95% CI, 0.66-0.88, respectively). CONCLUSIONS: In a nationwide cohort study of patients with IBD and a previous history of an acute arterial event, exposure to both anti-TNF and thiopurines were associated with a decreased risk of recurrent acute arterial events.

Increasing Incidence of Pouchitis Between 1996 and 2018: A Population-Based Danish Cohort Study.

BACKGROUND & AIMS: Current knowledge regarding the epidemiology of pouchitis is based on highly selected, mostly single-center, patient cohorts. Our objective was to prospectively determine the population-based incidence of pouchitis in patients with ulcerative colitis in the first 2 years after ileal pouch-anal anastomosis and analyze time trends of the incidence of pouchitis. METHODS: Using national registries, we established a population-based cohort of all Danish patients undergoing proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis between 1996 and 2018. The primary outcome was the development of pouchitis within the first 2 years after surgery, evaluated by time period. We used Kaplan-Meier and Cox proportional hazard modeling to evaluate the time to development of pouchitis. RESULTS: Overall, 1664 patients underwent an ileal pouch-anal anastomosis. The cumulative incidence of pouchitis in the 2 years after ileal pouch-anal anastomosis increased throughout the study period, from 40% in the period from 1996 to 2000 (95% CI, 35%-46%) to 55% in the period from 2015 to 2018 (95% CI, 48%-63%). Patients undergoing surgery between 2015 and 2018 also showed an increased risk of pouchitis compared with the earliest study period (1996-2000) after adjusting for sex, age, and socioeconomic status (hazard ratio, 1.57; 95% CI, 1.20-2.05). CONCLUSIONS: This population-based study showed a 15% absolute and 38% relative increase in the incidence of pouchitis among patients undergoing surgery between 1996 and 2018, with the greatest cumulative incidence of pouchitis shown in the most recent era (2015-2018). The striking increase in the incidence of pouchitis highlights the need for further research into causes and prevention of pouchitis.

Comparative Risk of Serious Infections With Biologic Agents and Oral Small Molecules in Inflammatory Bowel Diseases: A Systematic Review and Meta-Analysis.

BACKGROUND & AIMS: Safety is a key consideration when choosing advanced therapies (biologic agents and oral small-molecule inhibitors/modulators) in patients with inflammatory bowel diseases (IBDs). We performed a systematic review and meta-analysis comparing the risk of serious infections with advanced therapies in active comparator studies. METHODS: Through a systematic search until February 28, 2022, we included 20 head-to-head studies comparing risk of serious infections with tumor necrosis factor α (TNFα) antagonists, vedolizumab, ustekinumab, tofacitinib, filgotinib, and ozanimod in patients with IBD. We performed random-effects meta-analysis comparing different advanced therapies. RESULTS: No significant difference was observed in the risk of serious infections between vedolizumab vs TNFα antagonists in all patients with IBD (17 cohorts: odds ratio [OR], 0.84; 95% CI, 0.68-1.04), with moderate heterogeneity (I2 = 37%); on subgroup analysis, vedolizumab was associated with a lower risk of serious infections in patients with ulcerative colitis (11 cohorts: OR, 0.68; 95% CI, 0.56-0.83; I2 = 0%), but not in Crohn's disease (CD) (9 cohorts: OR, 1.03; 95% CI, 0.78-1.35; I2 = 42%). Age, sex, prior biologic exposure, and use of biologic monotherapy did not influence this association. In patients with CD, ustekinumab was associated with a lower risk of serious infections vs TNFα antagonists (3 cohorts: OR, 0.49; 95% CI, 0.25-0.93; I2 = 16%) and vs vedolizumab (3 cohorts: OR, 0.40; 95% CI, 0.17-0.93; I2 = 67%). Few studies compared other advanced therapies. CONCLUSIONS: Vedolizumab may offer net benefit over TNFα antagonists in patients with ulcerative colitis, but not in CD. Ustekinumab may offer net benefit over TNFα antagonists and vedolizumab in patients with CD.

The Rising Burden of Inflammatory Bowel Disease in Denmark Over Two Decades: A Nationwide Cohort Study.

BACKGROUND & AIMS: Shifts in epidemiological stages of inflammatory bowel disease (IBD) carry implications toward understanding IBD etiology and managing clinical care. We conducted a temporal analysis of the epidemiology of IBD between 1995 and 2016 in the Danish nationwide cohort. METHODS: We used the Danish registers to obtain data on demographics and IBD-related outpatient and inpatient contacts between 1995 and 2016. IBD diagnosis was defined as having ≥2 registrations related to Crohn's disease (CD) or ulcerative colitis (UC) within a 2-year period. We estimated overall and annual incidence rates and prevalence of CD and UC standardized with respect to age and sex. RESULTS: A total of 47,830 individuals met the criteria for IBD diagnosis, of which 33% were diagnosed with CD and 67% with UC. Between 1995 and 2016, the incidence rate (95% confidence interval) per 100,000 person-years rose from 9.1 (8.3-10.0) to 17.8 (16.8-19.0) for CD, and from 21.0 (19.8-22.3) to 28.4 (27.0-29.8) for UC. The highest increase in CD and UC incidence rates occurred in children and young adults, respectively. The prevalence of IBD doubled from 1995 to 2016; the greatest increase (2.5-fold) was in UC prevalence among individuals aged >40 years. During this period, the median age of the IBD population increased by 6 to 7 years. CONCLUSIONS: In Denmark, the incidence and prevalence of IBD have increased during the last 2 decades. The IBD population is shifting toward an older age. These findings have implications towards understanding environmental shifts as well as preparing health care systems for an aging IBD population.

Has the Incidence of Inflammatory Bowel Disease Peaked? Evidence From the Population-Based NorDIBD Cohort 1978-2020.

INTRODUCTION: While the incidence of inflammatory bowel disease (IBD) is rising globally, it has been suggested to stabilize in westernized countries, but this has not yet been shown in exhaustive and large cohorts. We generated an IBD cohort in North Denmark (NorDIBD) of 6,158 patients with IBD diagnosed from 1978 to 2020, based on all recorded and verified IBD diagnoses in the region. While describing the establishment of this cohort, we aimed to present the accurate incidence and prevalence of IBD over 4 decades. METHODS: The NorDIBD cohort covered all pediatric and adult patients with an IBD diagnosis dated between January 1, 1978, and December 31, 2020, and living in North Denmark, hence forming an unselected population-based patient cohort. IBD incidence rates between 1978 and 2020 and IBD point prevalences between 2003 and 2020 were calculated. RESULTS: We observed a 4-fold increase in the incidence of IBD from 11.5 per 100,000 persons (95% confidence interval [CI] 8.4-14.6) in the year 1978 to 51.3/100,000 (95% CI 45.5-57.1) in the year 2014, whereas in 2020, this rate stabilized. The overall prevalence of IBD more than doubled from 2003 to 2020, from 424 (95% CI 407-443) in 2003 to 872 (95% CI 849-896) IBD cases per 100,000 persons in 2020. DISCUSSION: Our population-based NorDIBD cohort suggests stabilizing of the incidence of IBD in Denmark, whereas the prevalence continues to rise. Because the data represent a 10% sample of the entire Danish IBD population, we believe that data can be extrapolated to the IBD population in general and used for healthcare planning.

Medication-Wide Study: Exploring Medication Use 10 Years Before a Diagnosis of Inflammatory Bowel Disease.

INTRODUCTION: There is growing interest in the prediagnostic phase of inflammatory bowel disease (IBD) and in the overlap of IBD with other diseases. We described and compared use of any prescription medication between individuals with and without IBD in a 10-year period preceding diagnosis. METHODS: Based on cross-linked nationwide registers, we identified 29,219 individuals diagnosed with IBD in Denmark between 2005 and 2018 and matched to 292,190 IBD-free individuals. The primary outcome was use of any prescription medication in years 1-10 before IBD diagnosis/matching date. Participants were considered as medication users if they redeemed ≥1 prescription for any medication in the World Health Organization Anatomical Therapeutic Chemical (ATC) main groups or subgroups before diagnosis/matching. RESULTS: The IBD population had a universally increased use of medications compared with the matched population before IBD diagnosis. At 10 years before diagnosis, the proportion of users was 1.1-fold to 1.8-fold higher in the IBD population in 12 of 14 ATC main groups of medication ( P -value < 0.0001). This applied across age, sex, and IBD subtypes, although it was the most pronounced for Crohn's disease (CD). Two years before diagnosis, the IBD population had a steep increase in medication use for several organ systems. When analyzing therapeutic subgroups of medication, the CD population exhibited 2.7, 2.3, 1.9, and 1.9 times more users of immunosuppressants, antianemic preparations, analgesics, and psycholeptics, respectively, than the matched population 10 years before diagnosis ( P -value < 0.0001). DISCUSSION: Our findings demonstrate universally increased medication use years before IBD, especially CD, diagnosis and indicates multiorgan involvement in IBD.

Less prevalent use of biologics for inflammatory bowel disease in patients from Non-Academic hospitals - a Danish register-based study of a region with 580,000 citizens.

INTRODUCTION: Biologic therapy is widely used for inflammatory bowel disease (IBD) and may decrease surgery rates. However, it remains uncertain if there is unwarranted geographic variation in access to biologic therapy. The aim of the study was to explore if all patients had equal access to biologic therapy in the North Denmark Region. METHODS: A cross-sectional register-based study of use of biologics, hospital contacts and surgery among all IBD patients having a hospital contact in the geographically well-defined North Denmark Region during 2016-2018. ICD-10 diagnosis codes, hospital contacts and procedure codes were retrieved from the region's hospital registry. The population is served by an Academic Hospital and two Non-Academic Hospitals constituting three referral areas (according to postal codes). RESULTS: In total, 2371 patients with ulcerative colitis (UC) and 1383 patients with Crohn's disease (CD) had a hospital contact in the region during 2016-2018. Compared to patients from the Academic Hospital, patients from the Non-Academic Hospitals experienced a lower incidence of biologic therapy for UC IRR 0.786 (0.621: 0.994), as well as for CD IRR 0.912 (0.781: 1.065). The incidence of bowel related hospital contacts were higher in patients from Non-Academic hospitals for both UC IRR 1.318 (1.207: 1.438) and CD IRR 1.165 (0.915: 1.483). CONCLUSIONS: Patients with IBD living in a referral area to a Non-Academic Hospital in the North Denmark Region are less likely to receive biologics. This was associated with an increased prevalence of IBD related surgical procedures.

Risk of anorectal cancer in patients with Crohn's disease and perianal fistula: a nationwide Danish cohort study.

AIM: Patients with Crohn's disease (CD) often suffer from perianal fistulizing disease. Their risk of anorectal cancer remains uncertain. We aimed to examine the long-term risk of anorectal cancer in a population-based cohort of CD patients with anorectal fistula. METHOD: Our study population covered all individuals (n = 7 987 520) aged 15+ years living in Denmark from 1978 to 2018. We identified all patients with CD and anorectal fistula in the Danish National Patient Register (NPR) and 50 matched noninflammatory bowel disease (IBD) individuals from the general population. Using Cox regression analyses, we examined the risk of anorectal cancer in CD fistula patients versus non-IBD individuals. All patients with CD were identified using codes from the International Classification of Diseases and their data extracted from the NPR. The main outcome measure was cases of anorectal cancer. RESULTS: A total of 2786 CD patients with anorectal fistula and 139 300 non-IBD individuals were followed for 1 553 917 person-years. During follow-up, anorectal cancer was observed in 19 CD patients (0.68%) and 340 non-IBD individuals (0.24%), corresponding to a 2.9-fold increased hazard ratio (HR) of anorectal cancer in CD fistula patients (95% CI 1.80-4.53), with a particularly high risk of anal cancer (HR 15.13, 95% CI 6.88-33.31) and a mean time from CD fistula diagnosis to anorectal cancer of 6.7 (SD 6.5) years. The risk was slightly higher in women than men and had no apparent relation to treatment with tumour necrosis factor-α inhibitors. Sensitivity analyses using CD nonfistula patients for comparison revealed similar results. Individual data on smoking and infection with human papilloma virus were not available. CONCLUSION: Patients with CD and anorectal fistula have a three-fold increased risk of anorectal cancer compared with the general population. The number needed to surveil to detect one case of anorectal cancer in this patient population was 2160 patients per year in patients with long-standing fistula (>6 years).

Shared environment and colorectal cancer: A Nordic pedigree registry-based cohort study.

Risk of colorectal cancer (CRC) increases in relatives of patients with CRC. The extent to which this is attributable to genetic predisposition or shared environment is unclear. We explored this question using nationwide cohorts from Denmark, Finland and Sweden. From 1977 to 2013, we identified 359 879 individuals with a CRC diagnosis and 2 258 870 of their relatives who we followed for CRC incidence. We calculated standardized incidence ratios (SIR) and 95% confidence intervals (CI) for CRC in individuals with an affected relative. We used nationwide household and pedigree data along with national SIR estimates to calculate risk ratios (RR) for the contribution of shared household environment, childhood environment and genetic relationship to CRC risk in those with an affected relative. SIR of CRC was increased for individuals with an affected relative, across all countries and ages. For those with an affected parent, the SIR was 1.65 (95% CI: 1.61-1.69), 1.98 (95% CI: 1.87-2.09), for those with an affected sibling and 2.14 (95% CI: 1.84-2.49) for those with an affected halfsibling. In those <65 years old, shared childhood (RR: 1.41, 95% CI: 1.26-1.57) and household (RR: 2.08, 95% CI: 1.25-3.46) environments were significantly greater contributors to familial risk of CRC than genetics (RR: 0.88, 95% CI: 0.53-1.46). This large-scale Nordic population-based study of excess risk of CRC among relatives of those with CRC addresses the difficult disentangling of shared environment from genetic predisposition in the heritability of CRC. We found shared environment to be the most important contributor to CRC risk.

Early-Life Mebendazole Exposure Increases the Risk of Adult-Onset Ulcerative Colitis: A Population-Based Cohort Study.

INTRODUCTION: According to the hygiene hypothesis, exposure to parasites may protect against inflammatory bowel disease (IBD). Our aim was to examine the risk of IBD with childhood exposure to mebendazole, a broad-spectrum antihelminthic agent. METHODS: We conducted a population-based cohort study using prospectively collected historical data of all individuals born in Denmark between 1995 and 2018. We identified mebendazole exposure at age younger than 18 years and during early life (younger than 5 years). We performed adjusted Cox proportional hazards regression analysis to determine the risk of IBD, ulcerative colitis (UC), and Crohn's disease with mebendazole exposure after adjusting for potential confounders. RESULTS: Of 1,520,290 individuals in the cohort, 615,794 had childhood or adolescence mebendazole exposure. One thousand five hundred fifty-five and 1,499 individuals were subsequently diagnosed with pediatric-onset and adult-onset IBD, respectively. On multivariable analysis, mebendazole exposure at age younger than 18 years did not affect pediatric-onset or adult-onset IBD risk (adjusted hazard ratio [aHR] 0.97, 95% confidence interval [CI] 0.87, 1.07, and 1.08, 95% CI 0.97, 1.19, respectively). On limiting mebendazole exposure to age younger than 5 years while there was no association with pediatric-onset IBD (aHR 0.98, 95% CI 0.87, 1.11), adult-onset IBD risk was increased (aHR 1.17, 95% CI 1.04, 1.31). This increase in risk was driven by UC (aHR 1.32, 95% CI 1.12, 1.55), but not Crohn's disease (1.03, 95% CI 0.87, 1.22). DISCUSSION: Early-life mebendazole exposure is associated with an increase in the risk of adult-onset UC. These findings suggest the importance of early-life exposures in shaping the risk of IBD later in life.

The effect of immunosuppressants on the prognosis of SARS-CoV-2 infection.

BACKGROUND: Immunosuppression may worsen severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We conducted a nationwide cohort study of the effect of exposure to immunosuppressants on the prognosis of SARS-CoV-2 infection in Denmark. METHODS: We identified all SARS-CoV-2 test-positive patients from February 2020 to October 2020 and linked healthcare data from nationwide registers, including prescriptions for the exposure (immunosuppressant drugs). We estimated relative risks of hospital admission, intensive care unit (ICU) admission and death (each studied independently up to 30 days from testing) with a log-linear binomial regression adjusted for confounders using a propensity score-based matching weights model. RESULTS: A composite immunosuppressant exposure was associated with a significantly increased risk of death (adjusted relative risk 1.56 (95% CI 1.10-2.22)). The increased risk of death was mainly driven by exposure to systemic glucocorticoids (adjusted relative risk 2.38 (95% CI 1.72-3.30)), which were also associated with an increased risk of hospital admission (adjusted relative risk 1.34 (95% CI 1.10-1.62)), but not of ICU admission (adjusted relative risk 1.76 (95% CI 0.93-3.35)); these risks were greater for high cumulative doses of glucocorticoids than for moderate doses. Exposure to selective immunosuppressants, tumour necrosis factor inhibitors or interleukin inhibitors was not associated with an increased risk of hospitalisation, ICU admission or death, nor was exposure to calcineurin inhibitors, other immunosuppressants, hydroxychloroquine or chloroquine. CONCLUSIONS: Exposure to glucocorticoids was associated with increased risks of hospital admission and death. Further investigation is needed to determine the optimal management of coronavirus disease 2019 (COVID-19) in patients with pre-morbid glucocorticoid usage, specifically whether these patients require altered doses of glucocorticoids.