Researchers have reported an association between endothelial cell clusters and submucosal scarring in fibrostenosing Crohn’s disease, based on histopathologic analysis of intestinal tissue.
Crohn’s disease can progress to a fibrostenosing phenotype characterized by bowel wall thickening and narrowing of the gut lumen. Submucosal scarring, or fibrosis, is a defining feature of this process, but the structural and cellular contributors are not fully established.
In this study, investigators examined resection specimens using histology, immunohistochemistry, and spatial analysis. They focused on lymphoid aggregates – organized collections of immune cells commonly seen in inflamed bowel tissue – and assessed their relationship to fibrotic changes.
A subset of lymphoid aggregates was found to contain clusters of endothelial cells, identified using endothelial markers. These clusters appear as discrete cellular groupings within or adjacent to lymphoid aggregates and are distinct from surrounding blood vessels.
Spatial analysis, using single-cell RNA sequencing, showed that lymphoid aggregates with endothelial clusters were more frequently located near areas of submucosal fibrosis. Aggregates without these features were less consistently associated with fibrotic regions. Quantitative assessment indicated that endothelial-containing aggregates were associated with higher fibrosis scores in adjacent tissue.
The presence of endothelial clusters alongside fibrosis suggests a potential interaction between immune organization, vascular changes, and tissue remodeling. Hence, identification of lymphoid aggregates with endothelial clusters may provide additional context when evaluating specimens from patients with suspected fibrostenosing Crohn’s disease.
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