Diverticulosis Is Associated With Internal Hemorrhoids on Colonoscopy: Possible Clues to Etiology

Hemorrhoids are a common but poorly understood gastrointestinal condition. Bowel habits and fiber consumption are frequently cited as risk factors for hemorrhoids, but research has been inconclusive. Recent genome-wide association studies (GWAS) have suggested an association between diverticular disease and hemorrhoids. We sought to investigate the association between colonic diverticulosis and internal hemorrhoids to validate the prediction from the GWAS

The Expression of LEC/CCL16, a Powerful Inflammatory Chemokine, is Upregulated in Ulcerative Colitis

Ulcerative colitis (UC) is a chronic inflammatory disease of unknown aetiology and pathogenesis. The presence in the colonic mucosa of reactive cells expressing proinflammatory cytokines and chemokines is associated with high levels of IL-10, an anti-inflammatory cytokine. Our aim was to investigate the role of IL-10 and the βchemokine LEC/CCL16 selectively up-regulated by IL-10 in inflammatory cell recruitment and cytokine and chemokine production during UC. We studied histologically, immunohistochemically and ultrastructurally colonic biopsies from 20 active UC patients and 10 control specimens taken far from any macroscopically detectable lesion in age and sex-matched patients with noninflammatory bowel disease. In active UC, immature dendritic cells (DCs) in the LP are associated with IL-10 in the T cell rich area. Furthermore, most of the LP-infiltrating macrophages strongly expressed LEC/CCL16, a chemokine upregulated by IL-10. To evaluate if LEC/CCL16 plays a role in the inflammatory reaction present in UC, we performed morphological studies in mice injected s.c. with syngeneic tumor cells engineered to produce LEC/CCL16. We found that the LEC protein locally released by LEC-gene-transfected tumor cells is a potent proinflammatory chemokine that induces the recruitment of a reactive infiltrate, and an angiogenic process mirroring that in human UC. In conclusion our data indicate that: 1) LEC is endowed with a powerful inflammatory activity and 2) upregulated in active UC, when IL-10 expression is elevated in a T cell rich area, 3) this upregulation can be seen as a pro-inflammatory pathway triggered by IL-10 in UC