Abstract:Objective To investigate the expression and significance of microRNA-215（miR-125) in intestinal mucosa and peripheral blood of elderly patients with ulcerative colitis. Methods Using retrospective analysis,98 elderly patients with ulcerative colitis were selected as the case group,and 86 elderly patients with colonic polyps were selected as the control group at the same time.The expression of miR-215 in intestinal mucosa and peripheral blood was measured by qRT-PCR,the proportion of CD44 and Th17 cells in peripheral blood to total lymphocyte was detected by flow cytometry,and the levels of IL-4,IL-10,IL-12,TNF-α and hs-CRP in peripheral blood were measured by ELISA. Results The levels of miR-215 in intestinal mucosa and peripheral blood in the case group were higher than those in the control group (all P<0.01).With the increase of the severity of ulcerative colitis(grad Ⅰ→grade Ⅱ→grade Ⅲ）,the levels of miR-215 in intestinal mucosa and in peripheral blood were gradually increased(all P<0.01).The levels of CD44,IL-4,IL-10,IL-12,TNF-α,hs-CRP and Th17 in the case group were significantly higher than those in the control group (all P<0.01).miR-215 in intestinal mucosa and in peripheral blood were positively correlated with CD44,IL-4,IL-8,IL-10,TNF-α,hs-CRP and Th17,respectively(P<0.05,P<0.01).High levels of intestinal mucosal miR-215 ［OR=2.49,95%CI(1.13-5.23),P=0.013］ and peripheral blood miR-215 ［OR=2.21,95%CI(1.06-4.55),P=0.016］were risk factors for ineffective treatment of ulcerative colitis in the elderly. Conclusions The expression level of miR-215 in intestinal mucosa and peripheral blood of elderly patients with ulcerative colitis is increased,and it was positively correlated with the severity of the disease.miR-215 may aggravate the progress of ulcerative colitis in the elderly by promoting the release of inflammatory factors.High level of miR-215 in intestinal mucosa and in peripheral blood are risk factors for ineffective treatment of the disease.