Objective: To quantify the expression of elafin mRNA in peripheral blood in patients with inflammatory bowel disease (IBD) and to explore its value in assessment of the activity and severity of IBD.
Methods: From July 1 2015 to August 15 2015, 23 patients with IBD admitted to Peking University First Hospital were selected, including 15 cases with ulcerative colitis (UC) and 8 cases with Crohn's disease (CD). Among those, 5 cases were in remission (UC 3, CD 2), 6 cases were mild active (UC 3, CD 3), 3 cases were moderate active (UC 1, CD 2), and 9 cases were severe active (UC 8, CD 1). A total of 21 healthy individuals were selected as the control group. Peripheral blood samples of IBD patients and healthy controls were collected. The expression of elafin mRNA in peripheral blood leukocytes was detected by fluorescence quantitative real-time PCR. Mann-Whitney test was performed for comparison between the two groups. The correlation between the expression of elafin mRNA in peripheral blood and IBD activity score was analyzed by Pearson correlation analysis after transformation of variables.
Results: The median expression of elafin mRNA in peripheral blood leukocytes in IBD group and control group was 0.005 8 (0.000 2, 0.043 5) and 0.015 3 (0.002 1, 0.175 8), respectively, with no significant difference (P>0.05). However, in the active IBD patients it was lower than that in the controls (0.004 6 (0.000 2, 0.034 8) vs 0.015 3 (0.002 1, 0.175 8), P<0.05) and also lower than that in the remission patients(0.004 6 (0.000 2, 0.034 8) vs 0.023 1 (0.012 6, 0.043 5), P<0.05); in the active UC patients it was lower than that in the controls(0.003 7 (0.000 2, 0.027 0) vs 0.015 3 (0.002 1, 0.175 8), P<0.05). The expression of elafin mRNA in peripheral blood was negatively correlated with modified Mayo score in UC patients (r=-0.513, P<0.05) and with the Crohn's Disease Activity Index (CDAI) of Best score in CD patients (r=-0.889, P<0.05).
Conclusion: The expression of elafin mRNA in peripheral blood in active IBD patients is decreased, which may be correlated with the activity of IBD, and negatively correlated with corresponding disease activity score, suggesting that it may play a protective role in IBD and may be helpful in predicting disease activity.