Immune Dysregulation and Barrier Dysfunction in COVID-19 and Ulcerative Colitis: Shared Mechanisms and Comparative Insights

• Grant number: 25/12298-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Biological Sciences - Immunology - Cellular Immunology
• Principal Investigator: Cristina Ribeiro de Barros Cardoso
• Grantee: Ana Laura Cremonese Momm de Almeida
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 23/03257-4 - The interplay between SARS-CoV-2 infection and dysregulated gut immunity, AP.TEM

Abstract

COVID-19 remains a major concern for the global scientific community. The sequelae of SARS-CoV-2 infection, collectively referred to as "long COVID" or "post-acute COVID-19 syndrome (PACS)," affect multiple organ systems, including the respiratory and gastrointestinal tracts.Gastrointestinal manifestations are observed in both acute and long COVID, commonly presenting asdiarrhea, abdominal pain, and nausea. In this context, COVID-19 has been associated with disruptions in gut homeostasis, including microbiota dysbiosis, increased intestinal permeability, and exacerbated inflammation. Inflammatory bowel diseases (IBD), such as ulcerative colitis (UC), similarly involvedysregulated mucosal immune responses and elevated levels of proinflammatory cytokines. Given theoverlap in pathophysiological mechanisms, we hypothesize that systemic immune dysregulation observed in COVID-19 patients without preexisting IBD may mirror that seen in patients with UC, whether in active disease or remission. Then, this study aims to elucidate shared mechanisms of systemic inflammation and compromised gut mucosal immunity in COVID-19 and UC. To achieve this, plasma samples from acute and post-acute COVID-19 patients collected in Brazil prior to vaccination (already available) will be analyzed and compared to new samples from post-vaccination COVID-19 patients to be collected in 2025.In parallel, a well-characterized cohort of UC patients, including individuals with active disease and those in remission, will be evaluated. Plasma will be assessed for immunological and gut barrier integrity markers, and the cytokine profile of all groups will be analyzed and correlated with clinical data to uncovercommon immunopathogenic pathways shared by COVID-19 and UC. (AU)