Pongdee, Thanai

Background: Mastocytic enterocolitis has been proposed as a cause of chronic diarrhea and abdominal pain, characterized by increased mast cells in gastrointestinal mucosal biopsies. However, its clinical significance remains uncertain. Methods: We present a case report of a patient identified to have high levels of mast cells on gastrointestinal biopsies. We then reviewed cases at Mayo Clinic where patients had >20 mast cells per high-power field (HPF) on gastrointestinal biopsies. Patients with alternative explanations for mast cell elevation, including systemic mastocytosis were excluded. We analyzed demographics, clinical presentations, pathology reports, serum and urine mast cell mediators, inflammatory markers, bone marrow biopsies, motility testing, and treatment responses. Results: We identified 42 patients (30 female and 12 male) with elevated mast cells on biopsy (mean age: 41 y, range: 17 to 81). Mast cells were quantified using KIT (CD117) staining, with no abnormal clumping or morphology, and CD25 immunostaining was negative in all cases. Eosinophilic infiltration was absent in all but one case. Small intestinal bacterial overgrowth (SIBO) was found in 78% of patients tested. Treatments varied widely, with antihistamines and cromolyn being the most common. Among 21 patients with sufficient follow-up, only 5 (24%) reported partial or complete symptom improvement, while 76% experienced persistent symptoms. Conclusion: Routine assessment of mast cells on gastrointestinal biopsies is not supported by our findings. Elevated mucosal mast cells, in the absence of systemic mast cell disorders, may not indicate a distinct disease entity. Evaluation should focus on ruling out other inflammatory, allergic, infectious, and motility disorders, as well as SIBO. Further research is needed to determine the clinical significance of increased mucosal mast cells and their role in gastrointestinal symptomatology.

Objectives/Goals: Community-based practices have limited research opportunities for providers. As a rural community-based health system, Mayo Clinic Health System (MCHS) sought to create intramural funding mechanisms to help early-stage researchers conduct pilot research so they are more competitive to compete for more robust extramural funding opportunities. Methods/Study Population: We created a Research Seed Grant Program infrastructure across our four MCHS regions (Southwest and Southeast Minnesota, Northwest and Southwest Wisconsin). This model program featured an initial research funding announcement call based on 6 prioritized programs (AI Validation & Stewardship, Cancer, Health Equity, Population Health, Rural Health, Learning Healthcare System [LHS]), with submissions uploaded to a central electronic repository. Proposal review and ranking was organized on a regional basis, with ranking of all proposals by at least 2 clinical scientist reviewers according to the NIH domain-specific framework (i.e., 1.0 best > 9.0 worst). Awards were competitively selected by conformity to prioritized research areas and through ranking of most competitive overall application scores. Results/Anticipated Results: For our inaugural RFA, we received 55 grant application submissions across the MCHS regions. Fifteen of the most highly ranked applications were selected for awards on a per region basis, providing direct funding as well as protected investigator research time of 10% for up to six months. The selected projects address several research priorities including improving access, reducing health disparities, improving behavioral health in our communities, increasing cancer screening and prevention, and community-based pragmatic trials and interventions. Outcomes from these now completed pilot projects remain pending at this time. Funding for this seed grant program was supported by philanthropy, Mayo Clinic Research Administration, Mayo Clinic Comprehensive Cancer Center, and the Mayo Clinic CCaTS Rural Core. Discussion/Significance of Impact: We present this framework for a LHS-focused Seed Grant program model for consideration of adoption by other national/international LHS. Future plans include tracking of outcome metrics (e.g., published peer review articles, extramural grant applications) of this initial cycle and future expansion of this program to support the goals of our LHS.