RESUMEN
Objective Detecting the level of IDO and KYN in ulcerative colitis (UC) patients; using ROC curve to discuss their value in the diagnosis of patients with active UC. Methods 60 cases of UC group, 18 cases of dis-ease control group and 20 cases of healthy control group were included in the study. Immunohistochemical staining methods were used to detect the expression of IDO in colonic mucosa of UC, enzyme-linked immunosorbent (ELISA) methods were used to detect the serum levels of IDO, KYN and CRP, and the value with ROC curve method was analyzed. Results ① There was a positive correlation between IDO level and IDO expression (P<0.05). There was a positive correlation between KYN level and IDO expression (P<0.05). ②The levels of IDO and KYN in UC group were higher than those of disease control group and health control group (P<0.05). ③The levels of IDO and KYN in patients with active UC were significantly higher than that in patients with catabasis UC (P<0.01), and the levels increased with severity of inflammation. ④ The levels of IDO and KYN in active UC were positively related to disease activity and CRP levels (P<0.05). ⑤The IDO,KYN and CRP area under ROC curve were 0.976, 0.856 and 0.864;best cut-off point were 53.66 U/L, 2.34 nmol/L and 1.75 mg/ml;sensitiv-ity were 90.5%, 78.65% and 100.0%; specifity were 94.4%, 83.3% and 61.1%; Youden index were 0.839 2, 0.619 0 and 0.611 1. Conclusion The levels of IDO and KYN in serum can be used as an important index to judge the severity of UC. They have important value in the diagnosis of active UC . The value of IDO is higher than KYN and CRP.