Objective To investigate the expression of serum Elabela and leucine-rich-alpha-2-glycoprotein-1(LRG1)in ulcerative colitis(UC)patients and their correlation with disease activity index(DAI).Methods A total of 98 patients with UC admitted to Yuncheng Central Hospital from January to December 2022 were selected as the UC group,including 62 patients in active stage and 36 patients in remission stage.According to the severity of the disease,these patients were divided into mild group(n=26),moderate group(n=43)and severe group(n=29).In addition,these patients were grouped into gradeⅠ group(n=25),grade Ⅱ group(n=40)and grade Ⅲ group(n=33)based on the endoscopic activity index(EAI).According to the mucosal healing condition under endoscopy,these patients were divided into the healed group(n=65)and the unhealed group(n=33).Another 51 patients with colonic polyps were selected as control group 1,and 50 healthy individuals were selected as control group 2.Serum Elabela and LRG1 levels were detected by enzyme-linked immunosorbent assay(ELISA).Pearson method was used to analyze the correlation between serum Elabela,LRG1 levels and DAI in UC patients.Receiver operating characteristic(ROC)curve was applied to analyze the predictive value of serum Elabela and LRG1 for endoscopic mucosal healing.Results The levels of Elabela(4.77±1.36 ng/ml)and LRG1(352.12±39.45 ng/ml)in UC group were higher than those in control group 1(2.51±0.53 ng/ml,121.02±21.06 ng/ml)and control group 2(2.35±0.42 ng/ml,120.35±23.49 ng/ml),and the differences were statistically significant(t= 11.410～39.000,all P＜0.05).The levels of Elabela(5.26±0.54 ng/ml)and LRG1(370.42±12.49 ng/ml)in the active group were higher than those in the remission group(3.93±0.42 ng/ml,320.60±8.47 ng/ml),and the differences were statistically significant(t=12.705,21.242,all P＜0.05).The levels of Elabela(5.89±0.20 ng/ml)and LRG1(369.92±16.59 ng/ml)in the severe group were higher than those in the moderate groups(4.51±0.67 ng/ml,356.12±18.75 ng/ml)and mild groups(3.95±0.21 ng/ml,325.65±10.14 ng/ml),and the differences were statistically significant(t=3.205～35.077,all P＜0.05).The levels of Elabela(5.80±0.18 ng/ml)and LRG1(369.16±13.47 ng/ml)in grade Ⅲ group were higher than those in grade Ⅱ group(4.49±0.35 ng/ml,355.46±16.34 ng/ml)and grade Ⅰgroup(3.86±0.16 ng/ml,324.15±8.71 ng/ml),and the differences were statistically significant(t= 3.854～48.725,all P＜0.05).The levels of Elabela(5.12±0.42 ng/ml)and LRG1(367.12±14.27 ng/ml)in unhealed group were higher than those in healed group(4.08±0.37 ng/ml,322.57±10.35 ng/ml),and the differences were statistically significant(t=12.043,15.917,all P＜0.05).The serum levels of Elabela and LRG1 in UC patients were positively correlated with EAI and ESR(r=0.602,0.298;0.576,0.302,all P＜0.05),but negatively correlated with hemoglobin level(r=-0.351,-0.334,all P＜0.05).The area under the curve predicted by the combination of serum Elabela and LRG1 for endoscopic mucosal healing was 0.926(95%CI:0.880～0.958),was higher than the 0.803(95%CI:0.741～0.856)and 0.783(95%CI:0.720～0.838)predicted by Elabela and LRG1 alone,and the difference was statistically significant(Z=4.101,4.228,all P＜0.05).Conclusion The serum levels of Elabela and LRG1 in UC patients increased,and they were related to the increase of DAI and worsening of the condition.Testing serum Elabela and LRG1 can provide a reference for evaluating mucosal healing under UC endoscopy.