Correlation between soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) expression and endoscopic activity in inflammatory bowel diseases

Background: Recently, a triggering receptor expressed on myeloid cells-1 was shown to be upregulated in the intestines of patients with inflammatory bowel diseases. Aims: To investigate the relationship between serum soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) level and endoscopic activity in patients with inflammatory bowel diseases. Methods: A total of 85 patients with ulcerative colitis and 34 patients with Crohn's disease were prospectively enrolled. Endoscopic disease activity was determined using the Mayo score and the Simplified Endoscopic Activity Score for Crohn's disease. Results: In ulcerative colitis, sTREM-1 level was correlated more strongly with the endoscopic activity (r=0.498) than the C-reactive protein level (r = 0.386) or erythrocyte sedimentation rate (r=0.272), although not superior to the partial Mayo score (r=0.611). Moreover, only sTREM-1 was correlated significantly with the endoscopic activity irrespective of the disease extent. In Crohn's disease, the Simplified Endoscopic Activity Score for Crohn's disease was correlated with both the C-reactive protein level (r=0.585) and erythrocyte sedimentation rate (r=0.474), but not with sTREM-1 level (r=0.097). Conclusions: In ulcerative colitis, sTREM-1 level was correlated most closely with the endoscopic disease activity among serum biomarkers, but was not superior to the clinical activity index. Our results suggest that sTREM-1 level may represent a complementary marker for the assessment of endoscopic activity in ulcerative colitis, but not in Crohn's disease.