Abstract Objectives Whipple’s disease (WD) results from infection of the bacteria Tropheryma whipplei (TW). This disease is characterized by macrophage infiltration of intestinal mucosa and primarily affects Caucasian males. Genetic studies of host susceptibility are scarce. Nucleotide-binding oligomerization domain containing protein 2 (NOD2) is an innate immune sensor, resides mainly in monocytes/macrophages and contributes to defence against infection and inflammatory regulation. NOD2 mutations are associated with autoinflammatory diseases. We report the association of NOD2 mutations with TW and WD for the first time. Methods A multicentre, retrospective study of three patients with WD was conducted. Patients received extensive multidisciplinary evaluations and were cared for by the authors. NOD2 and its association with infection and inflammation were schematically represented. Results All patients were Caucasian men and presented with years of autoinflammatory phenotypes, including recurrent fever, rash, inflammatory arthritis, gastrointestinal symptoms and elevated inflammatory markers. All patients underwent molecular testing using a gene panel for periodic fever syndromes and were identified to carry NOD2 mutations associated with NOD2-associated autoinflammatory disease. Despite initially negative gastrointestinal evaluations, repeat endoscopy with duodenal tissue biopsy ultimately confirmed WD. After initial ceftriaxone and maintenance with doxycycline and/or HCQ, symptoms were largely controlled, though mild relapses occurred in follow-up. Conclusion Both NOD2 and TW/WD are intensively involved in monocytes/macrophages. WD is regarded as a macrophage disease. NOD2 leucin-rich repeat–associated mutations in monocytes/macrophages cause functional impairment of these cells and consequently may make the host susceptible for TW infection and WD, especially in the setting of immunosuppression.
S1421 Safety and Efficacy of Long-Term Treatment With Lirentelimab, A Monoclonal Antibody Against Siglec-8, in Patients With Eosinophilic Gastritis and/or Duodenitis
621 PL02.05 LONG-TERM TREATMENT OF PATIENTS WITH EOSINOPHILIC GASTRITIS AND/OR EOSINOPHILIC DUODENITIS WITH LIRENTELIMAB, A MONOCLONAL ANTIBODY AGAINST SIGLEC-8
Abstract Eosinophilic esophagitis (EoE), gastritis (EG), and/or duodenitis (EoD) are associated with accumulation and activation of eosinophils and mast cells in the esophagus, stomach, and/or duodenum, respectively. Lirentelimab (AK002), an antibody against siglec-8, depletes eosinophils and inhibits mast cells. We performed an open-label extension (OLE) study of subjects who completed ENIGMA (a randomized, double-blind, placebo-controlled phase 2 study of lirentelimab in adults with symptomatic, biopsy-confirmed EG and/or EoD, with or without EoE) to evaluate long-term responses. Methods Subjects who received 4 monthly infusions of lirentelimab or placebo during ENIGMA (n = 59) were eligible for the OLE; they received monthly, escalating doses of lirentelimab (0.3 or 1 mg/kg escalating to 3 mg/kg). Symptoms were assessed weekly using an electronic daily patient-reported outcome questionnaire and total symptom scores (TSS) were calculated. Patients underwent upper endoscopy with biopsy at screening and at the end of ENIGMA (day 99, week 16, blinded); in the OLE, endoscopies were performed on day 323 (30 weeks after the first dose in the OLE). Histopathology was assessed by a single pathologist. Results Fifty-eight subjects entered the OLE; 45 completed ≥52 weeks lirentelimab (including exposure during ENIGMA) and 29 completed 70 weeks. Mean TSS improved through week 70 (Figure 1). Subjects receiving 70 weeks lirentelimab (ENIGMA+OLE) had further improvements in TSS from baseline (mean reductions: 68% at weeks 29–30, 70% at weeks 51–52, 75% at weeks 69–70). Symptom scores (abdominal pain, nausea, vomiting, early satiety, appetite loss, abdominal cramping, bloating, diarrhea) decreased significantly from baseline. Treatment response was not associated with concomitant EoE. The most common adverse event was mild to moderate infusion-related reactions, usually with the first infusion. Conclusion In the OLE of the ENIGMA study, patients with EG and or EoD (with or without concomitant EoE) who received lirentelimab had sustained tissue eosinophil depletion and significant long-term symptom improvement. Symptoms continued to improve with duration of treatment. Lirentelimab appears to be a promising targeted treatment for EG and/or EoD.
Certolizumab Trough Levels and Antibodies in Crohn Disease: A Single-Center Experience
Abstract Background Certolizumab pegol (CZP) has been successfully used for the treatment of Crohn disease (CD); however, real-world data regarding the utility of CZP trough levels (CTLs) are lacking. We aimed to correlate CTL with CD outcomes and to determine frequency of CZP antibodies. Methods Retrospective evaluation of all CD patients on maintenance CZP with CTL obtained between 2016 and 2019. Outcomes included: median CTL, presence of anti-CZP antibodies, biochemical response (BR), clinical response (CR), radiologic response (RR), radiologic healing (RH), and mucosal healing (MH). Results Seventy-seven CD patients were included. Median CTL was 18.9 µg/mL (interquartile range, 7.6–35.4). Twenty-three patients (27.3%) had positive antibody levels, with lower median CTL compared to patients with no antibodies (0.0 vs 29.8; P < 0.0001). Median CTL levels were higher in patients with vs without CR (30.4 vs 10.3 µg/mL; P = 0.0015) and RR (29.6 vs 5.8 µg/mL; P = 0.006). CZP dosing at least every 2 weeks was associated with higher odds of achieving MH (odds ratio, 3.2; 95% confidence interval, 1.03–9.97). CTL resulted in change in clinical management in 62.7% of cases and presence of CMZ antibodies was associated with an odds ratio of 5.83 (95% confidence interval, 1.57–21.73) of change in management. Receiver operating characteristic curve and quartile analysis suggested that CTL >19 µg/mL is associated with increased rates of CR and RR. Conclusions Higher CTL was significantly associated with CR and RR. The rate of CZP antibodies was 27.3%. Our data suggest maintenance CTL of ≥19 µg/mL should be achieved in order to optimize outcomes in clinical practice.
Anti–Siglec-8 Antibody for Eosinophilic Gastritis and Duodenitis
1244 Symptomatic Patients Suspected of Eosinophilic Gastritis and/or Enteritis Have Elevated Mucosal Mast Cell Counts Without Eosinophilia: A New Diagnostic Entity?
INTRODUCTION: Eosinophilic gastrointestinal diseases (EGIDs) are a set of inflammatory diseases subclassified according to the site(s) of abnormal accumulation of eosinophils (eos) in the gastrointestinal (GI) tract such as eosinophilic esophagitis (EoE), gastroenteritis (EGE), and colitis. These conditions often decrease quality of life due to debilitating symptoms. While the pathogenesis of EGIDs is primarily thought to be driven by eos, there is increasing evidence for the involvement of mast cells (MCs). AIM: To characterize symptomatic patients (pts) with suspected EG/EGE who did not meet histopathologic entry criteria for mucosal eosinophilia for a Phase 2 randomized, double-blind, placebo-controlled study of AK002, an anti-Siglec-8 antibody. METHODS: To undergo screening endoscopy for this study, pts were required to report an average symptom score ≥3 (0 to 10 scale) for abdominal pain, nausea, and/or diarrhea on a daily patient-reported outcome questionnaire for ≥2 weeks and have no other known cause for GI symptoms. During the screening endoscopy, biopsies were systematically obtained from the stomach and duodenum, and read by a single pathologist. Eos counts (eos/hpf; hpf area = 0.237 mm 2 ) were assessed on H&E slides. To quantify MCs, immunohistochemistry for tryptase was performed. We quantified eos and MCs in the stomach and duodenum. Histopathologic entry criteria for the randomized study was ≥30 eos/hpf in 5 hpfs in the stomach (EG) and/or ≥30 eos/hpf in 3 hpfs in the duodenum (EGE). A literature review was conducted to determine normal MC counts in the GI tract. RESULTS: Eighty-eight pts underwent screening endoscopy based upon suspected EG/EGE and active symptoms, and 72 pts met histopathologic eos criteria. All pts whose eos did not meet entry criteria (n = 16) were found to have elevated MC counts (Figure 1; reported normal range = 12-19 MCs/hpf). In these pts, the mean gastric eos count was 6 eos/hpf in 5 hpfs and mean duodenal eos count was 15 eos/hpf in 3 hpfs. In contrast, these pts exhibited a mean gastric MC count of 47 MC/hpf in 5 hpfs and a mean duodenal MC count of 49 MC/hpf in 3 hpfs. Almost all symptomatic pts screened (87/88; 99%) had elevated MC counts. CONCLUSION: Data from this large randomized EG/EGE study showed that symptomatic pts with suspected EG/EGE had increased mucosal MCs with or without mucosal eosinophilia. These data suggest that MCs may play a role in pts with suspected EG/EGE and raise the possibility of a unique clinical presentation driven by MCs.
1161 Learning Styles and Burnout in Gastroenterology: Should Continuing Medical Education Be Changed to Accommodate all Learning Styles?
INTRODUCTION: Learning styles among gastroenterology providers have not been reported and may have implications in improving continuing medical education (CME). This study aims to 1) evaluate learning styles among gastroenterology providers participating in a board review course, 2) assess self-reported burnout, and 3) determine if demographic information, practice style, or burnout was associated with specific learning styles. METHODS: Participants at the 2018 Mayo GI and Hepatology Board Review Course had the opportunity to participate in an anonymous, survey-based study evaluating learning styles and burnout. Demographic and practice information, reason for participating in the course, questions regarding burnout and callousness, and the Kolb Learning Style Inventory (KLSI) (v3.1, Korn Ferry Hay Group, Boston, MA) were collected. Associations between demographic data, burnout, and learning styles were assessed using Fisher’s exact test. RESULTS: A total of 71 of 230 participants elected to participate and 47 completed the KLSI. Median age range was 41-50 years, 31 (43.7%) were female, and 60 (84.5%) had MD or DO degree. All regions of the United States were represented and 4 participants were from outside of the US. Reasons for participation included new certification (12.7%), recertification (45.1%), not passing prior board certification (4.2%), and general knowledge (38%). Burnout was noted by 27 (38%), callousness by 19 (26.8%), and both by 9 (12.7%). Kolb learning styles were diverging in 27.7%, assimilating in 31.9%, converging in 27.7%, and accommodating in 12.8%. There were no associations with demographics, practice type or reason for taking the course with specific learning styles; however, more frequent markers of burnout were associated with the accommodating learning style (50% burnout only, 33% callous only, and 16.7% reporting both; P = .03). CONCLUSION: All learning styles are represented at the studied board review course and are dispersed throughout ages, sex, geography, and practice style. This highlights the importance of a transition from lecture-based CME to more varied education modalities. Indices of self-reported burnout are seen frequently in this cohort, and seem to have increased association with the accommodating learning style. Future study with more participants is needed to further understand learning styles and burnout in gastroenterology providers, with the aim of improving CME.