Impaired colonic PCs reduce mucosal IgA in CD

Background & Aims: Secretory IgA (SIgA) is critical for the maintenance of the colonic mucosal barrier, preventing bacterial translocation and reducing the risk of chronic inflammation. Decades of research have revealed a dysregulated B-cell compartment and altered immunoglobulin secretion in Crohn's disease (CD), of yet unknown origin. To unravel the role of mucosal humoral immunity in CD pathogenesis, we aimed to provide an in-depth characterization of colonic plasma cell (PC) differentiation in patients with CD. Here, bulk RNA sequencing was performed for 12 non IBD and 7 Crohn's disease patients in remission.