Faculty Bibliography

BACKGROUND:We aimed to characterize patients with inflammatory bowel disease (IBD) and novel coronavirus disease 2019 (COVID-19). METHODS:We performed a case series of patients with IBD and confirmed or highly suspected COVID-19 to assess rates of severe outcomes. RESULTS:We identified 83 patients with IBD with confirmed (54%) or highly suspected (46%) COVID-19. The overall hospitalization rate was 6%, generally comprising patients with active Crohn's disease or older men with comorbidities, and 1 patient expired. DISCUSSION/CONCLUSIONS:In this series of patients with IBD, severe outcomes of COVID-19 were rare and comparable to similarly aged individuals in the general population.

BACKGROUND & AIMS/OBJECTIVE:Restorative proctocolectomy with ileal pouch-anal anastomosis is a surgical procedure in patients with ulcerative colitis refractory to medical therapies. Pouchitis, the most common complication, is inflammation of the pouch of unknown etiology. To define how the intestinal immune system is distinctly organized during pouchitis, we analyzed tissues from patients with and without pouchitis and from patients with ulcerative colitis using single-cell RNA sequencing (scRNA-seq). METHODS:We examined pouch lamina propria CD45+ hematopoietic cells from intestinal tissues of ulcerative colitis patients with (n=15) and without an ileal pouch-anal anastomosis (n=11). Further in silico meta-analysis was performed to generate transcriptional interaction networks and identify biomarkers for patients with inflamed pouches. RESULTS:In addition to tissue-specific signatures, we identified a population of IL1B/LYZ+ myeloid cells and FOXP3/BATF+ T cells that distinguish inflamed tissues which we further validated in other single cell RNA-seq datasets from IBD patients. Cell type specific transcriptional markers obtained from single-cell RNA-sequencing was used to infer representation from bulk RNA sequencing datasets, which further implicated myeloid cells expressing IL1B and S100A8/A9 calprotectin as interacting with stromal cells, and Bacteroidiales and Clostridiales bacterial taxa. We found that non-responsiveness to anti-integrin biologic therapies in ulcerative colitis patients was associated with the signature of IL1B+/LYZ+ myeloid cells in a subset of patients. CONCLUSIONS:Features of intestinal inflammation during pouchitis and ulcerative colitis are similar, which may have clinical implications for the management of pouchitis. scRNA-seq enables meta-analysis of multiple studies, which may facilitate the identification of biomarkers to personalize therapy for IBD patients.

BACKGROUND AND AIMS/OBJECTIVE:Gastrointestinal infections have been linked to changes in the composition and function of gut microbiome and development of inflammatory bowel diseases. We therefore sought to examine the relationship between gastroenteritis and risk of microscopic colitis (MC). METHODS:We conducted a case-control study of all adult MC patients diagnosed between 1990-2016 in Sweden matched to up to 5 general population controls according to age, sex, calendar year, and county. Cases of MC were identified using SNOMED codes from the ESPRESSO study, a cohort of gastrointestinal pathology reports from all 28 pathology centers in Sweden. We used logistic regression modeling to estimate adjusted odds ratios (aORs) and 95% CIs. RESULTS:Through December of 2016, we matched 13,468 MC cases to 64,479 controls. The prevalence of previous diagnosed gastrointestinal infection was 7.5% among MC patients which was significantly higher than in controls (3.0%, Pcomparison <0.001). After adjustment, gastroenteritis was associated with an increased risk of MC (aOR 2.63; 95%CI=2.42-2.85). Among specific pathogens, Clostridioides difficile (aOR 4.39, 95%CI=3.42-5.63), Norovirus (aOR 2.87, 95%CI=1.66-4.87) and Escherichia species (aOR 3.82, 95%CI=1.22-11.58) but not Salmonella species were associated with an increased risk of MC. The association between gastrointestinal infections and risk of MC was stronger for collagenous subtype (aOR 3.23, 95% CI 2.81-3.70) as compared to lymphocytic colitis (aOR = 2.51, 95% CI 2.28-2.76, Pheterogeneity = 0.005). The associations remained significant after adjustment for immune-mediated conditions and polypharmacy and when compared to unaffected siblings. CONCLUSION/CONCLUSIONS:In a nationwide study, we found that gastrointestinal infection, particularly Clostridioides difficile is associated with an increased risk of subsequent MC.

BACKGROUND:There are concerns that individuals with chronic immune-mediated diseases are at increased risk of COVID-19 and related severe adverse outcome, including intensive care admission or death. We aimed to explore the absolute and relative risk of severe COVID-19 in inflammatory bowel disease (IBD). METHODS:This population-based cohort study used nationwide registers in Sweden, with 67,292 individuals with a diagnosis of IBD 1969-2017 (Crohn's disease, n = 21,599; ulcerative colitis: n = 43,622; IBD-unclassified: n = 2071) and alive on 1 February 2020. Patients with IBD were matched to up to five controls from the general population (n = 297,910). Cox regression estimated hazard ratios (HRs) for (i) hospital admission with laboratory-confirmed COVID-19 as the primary diagnosis, and (ii) severe COVID-19 (composite outcome consisting of (a) COVID-19 intensive care admission, or (b) death from COVID-19 or (c) death within 30 days of COVID-19 hospital admission), were calculated. Analyses were conditioned on age, sex, calendar period, and county and adjusted for other comorbidities. RESULTS:Between 1 February and 31 July 2020, 179 (0.27%) IBD patients and 500 (0.17%) general population controls were admitted to hospital with COVID-19 (adjusted HR [aHR] = 1.43; 95% CI = 1.19-1.72). The corresponding numbers for severe COVID-19 was 65 (0.10%) and 183 (0.06%; aHR = 1.11; 95% CI = 0.81-1.52). Adjusted HRs were similar in Crohn's disease and ulcerative colitis. In a propensity score-matched model taking comorbidity into account until 2016, the increased risk for COVID-19 hospital admission remained (aHR = 1.32; 1.12-1.56), but there was no increased risk of severe COVID-19 (aHR = 1.12; 0.85-1.47). CONCLUSIONS:While individuals with IBD were more likely to be admitted to hospital for COVID-19 than the general population, the risk of severe COVID-19 was not higher.

OBJECTIVE:Crohn's disease (CD) is associated with increased risk of small bowel cancer (SBC), but previous studies have been small. We aimed to examine the risk of incident SBC and death from SBC in patients with inflammatory bowel disease (IBD). DESIGN/METHODS:In a binational, population-based cohort study from Sweden and Denmark of patients with IBD during 1969-2017 and matched reference individuals from the general population, we evaluated the risk of incident SBC and death from SBC. Cox regression was used to estimate adjusted hazard ratios (aHRs). RESULTS:We identified 161 896 individuals with IBD (CD: 47 370; UC: 97 515; unclassified IBD: 17 011). During follow-up, 237 cases of SBC were diagnosed in patients with IBD (CD: 24.4/100 000 person-years; UC: 5.88/100 000 person-years), compared with 640 cases in reference individuals (2.81/100 000 person-years and 3.32/100 000 person-years, respectively). This corresponded to one extra case of SBC in 385 patients with CD and one extra case in 500 patients with UC, followed up for 10 years. The aHR for incident SBC was 9.09 (95% CI 7.34 to 11.3) in CD and 1.85 (95% CI 1.43 to 2.39) in UC. Excluding the first year after an IBD diagnosis, the aHRs for incident SBC decreased to 4.96 in CD and 1.69 in UC. Among patients with CD, HRs were independently highest for recently diagnosed, childhood-onset, ileal and stricturing CD. The relative hazard of SBC-related death was increased in both patients with CD (aHR 6.59, 95% CI 4.74 to 9.15) and patients with UC (aHR 1.57; 95% CI 1.07 to 2.32). CONCLUSION/CONCLUSIONS:SBC and death from SBC were more common in patients with IBD, particularly among patients with CD, although absolute risks were low.

Background: Ustekinumab has been recently approved for the treatment of moderately to severely active ulcerative colitis (UC). The registry trials for ustekinumab in UC demonstrated efficacy and safety, but data on real-world outcomes are limited. We describe the effectiveness and safety of ustekinumab in patients with UC from 2 US tertiary inflammatory bowel disease centers. Methods: Patients with moderately to severely active UC treated with ustekinumab at NYU Langone Health (New York, New York) and University of Chicago Medical Center (Chicago, Illinois) between January 2016 and March 2020 were retrospectively included. The primary outcome was clinical remission at 3 and 12 months, defined as a partial Mayo score of ≤2, with a combined rectal bleeding and stool frequency subscore of ≤1. Results: Sixty-six UC patients were included. Ninety-two percent of patients had prior exposure to biologics or tofacitinib. Forty-three percent and 45% of patients achieved clinical remission by 3 and 12 months, respectively. Anti-TNF nonresponse and endoscopic Mayo score of 3 were negative predictors of clinical remission. Thirty-three percent of those followed for a year achieved concurrent endoscopic and histologic healing, which was significantly associated with lower partial Mayo score (P < 0.01) and lower stool frequency (P = 0.02). Serious adverse events occurred in 4 (6%) patients (3 UC exacerbations, 1 vasculitis). Conclusions: In this cohort of mostly biologic-refractory UC patients, treatment with ustekinumab achieved remission in nearly half of them at 12 months, and was associated with an overall favorable safety profile. These results are modestly better than the pivotal trials.

The inflammatory bowel diseases (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), are chronic, progressive, inflammatory conditions of the gastrointestinal tract. Imbalance in the gut microbial community, or dysbiosis, and the subsequent immune response, represent the critical relationship between genetic susceptibility, microbes, and environment factors, that result in IBD. Gastrointestinal pathogens - a common cause of dysbiosis - have been implicated as an environmental trigger in new onset IBD, as well as flare of existing IBD. In this article, we systematically review clinical data regarding the association between specific gastrointestinal pathogens and IBD. Numerous bacteria, viruses, fungi, and parasites have been implicated in the pathogenesis of IBD, and exacerbations of existing disease. In this article, we will also specifically discuss the less recognized microbes that have an inverse association with IBD, including certain bacterial pathogens, such as Helicobacter pylori, and parasites, such as Trichuris species. Future prospective and experimental studies are required to establish causality and clarify potential mechanisms of enteric pathogens in modifying the risk and course of IBD.