Clinical Value Of The Systemic Immune-inflammatory Index For Assessing The Severity Of Ulcerative Colitis

Objective:Ulcerative colitis(UC)is a chronic,non-specific inflammatory disease occurring in the colorectal mucosa.Non-invasive indicators of the severity of UC patients were mainly based on fecal calferin,complete blood cell count,etc.Systemic immune inflammation index(SII)is an objective marker to assess the balance between host systemic inflammation and immune response,and high levels of SII may lead to the proliferation and metastasis of tumors in patients with rectal cancer,gastric cancer,pancreatic cancer and other tumors.In recent years,with the deepening of research,SII was found to be somewhat predictive of the severity of UC patients,but there are very few related studies.This study aimed to retrospectively analyze the clinical value of the SII for assessing the severity of UC.Methods:A total of 224 UC patients and 224 healthy controls who presented to Qingdao University Affiliated Hospital from February 2014 to October 2021 as the study subjects.Gender,age,body mass index(BMI),hemoglobin(Hb),platelets(PLT),neutrophils(NEU),lymphocytes(LYM),monocytes(MONO),neutrophil to lymphocyte ratio(NLR),platelet to lymphocyte ratio(PLR),lymphocyte to monocyte ratio(LMR),and SII were compared between the two groups.Modified Truelove and Witts score(TWC),Mayo endoscopic score(MES),the Degree of Ulcerative Colitis Burden of Luminal Inflammation(DUBLIN)and the Ulcerative Colitis Endoscopic Index of Severity(UCEIS)were used to evaluate UC disease activity,and the disease extension was assessed by Montreal classification.Chi-square test,the Mann-Whitney U test,Kruskal-Wallis test and Spearman correlation analysis were used to compare the differences in SII,NLR,PLR,LMR,and the correlation with UC severity or disease extension.The diagnostic efficiency of SII,NLR,PLR,and LMR in predicting severity UC was assessed by the receiver operating characteristic(ROC)and multivariate logistic regression.Results:1.In UC and control groups,the mean age was all 49.5(37-62)years,the male-female ratio was 1:0.85 and 1:0.88,respectively,and the mean height was 1.68(1.6-1.73)m and1.67(1.6-1.73)m,respectively.There was no statistical difference in sex,age and height between the two groups(P>0.05).Compared with the control group,BMI,PLT,NEU,MONO,NLR,PLR,LMR,SII were significantly increased,and Hb,LYM,LMR were markedly decreased,with statistically significant differences(P<0.001).2.SII levels were no statistically significant difference between UC and control groups(P>0.05).Comparing control group,SII levels in UC group were significantly higher by sex,age and BMI(P<0.001).SII in control group was not statistically different between BMI groups(P>0.05),while SII in UC group was statistically different between BMI groups(P<0.05).Further pairwise comparisons showed that SII had a significant difference between low weight,normal weight and super-weight,respectively(P<0.05).3.SII showed no statistical difference between E1,E2 and E3 groups(P>0.05),and a significant difference between DUBLIN and UCEIS groups(P>0.001).SII showed statistical differences between mild,moderate and severe groups of TWC and MES.Further pairwise comparison found that the differences between mild,moderate,moderate and severe groups were statistically significant difference(P<0.001).4.SII,NLR,and PLR of UC patients were positively correlated with TWC,MES,DUBLIN,and UCEIS scores(r=0.405～0.633,P<0.001).LMR of UC patients and TWC,MES,DUBLIN,and UCEIS scores appear in a obvious negative correlation(r=-0.301～-0.391,P<0.001).SII,NLR,PLR and LMR were no correlation with Montreal classification(r=-0.001～0.098,P>0.05).5.ROC curves were used to compare the predictive value of SII,NLR,PLR,and LMR for moderate and severe UC of TWC scores.AUC of SII,NLR,PLR,and LMR were0.84,0.78,0.79,and 0.74,respectively.SII had the largest predictive value with an optimal cut-off value of 618.98×10~9/L,with corresponding sensitivity and specificity of 78.57%and 83.33%,respectively.6.Comparing the predictive value of SII,NLR,PLR and LMR for moderate to severe UC of MES score by ROC curve,the AUC of SII,NLR,PLR and LMR were 0.78,0.71,0.75and 0.72,respectively.SII had the largest predictive value with its best cut-off value of696.19×10~9/L with corresponding sensitivity and specificity of 70.92%and 85.71%,respectively.7.For comparison of the predictive value of SII,NLR,PLR,LMR for moderate and severe UC of UCEIS score by ROC curve,AUC of SII,NLR,PLR and LMR were0.74,0.68,0.72,and 0.69,respectively.SII had the largest predictive value with the optimal threshold value of 618.98×10~9/L,corresponding sensitivity and specificity of 72.86%and80.00%,respectively.8.Comparing the predictive value of SII,NLR,PLR,and LMR for moderate to severe UC of DUBLIN score using ROC curve,AUC of SII,NLR,PLR,and LMR were0.76,0.72,0.71,and 0.68,respectively.SII having the largest predictive value and optimal critical value of 738.91×10~9/L,with corresponding sensitivity and specificity of 74.56%and 69.09%,respectively.9.The multivariate Logistic analysis showed that SII was a significant independent predictive risk factor for moderate to severe UC(OR=1.002,95%CI=1.001-1.003,P<0.05).Conclusions:1.SII,NLR,and PLR were significantly higher in UC and positively correlated with UC severity,while LMR was significantly decreased in UC and negatively correlated with disease severity.SII,NLR,PLR,and LMR can be used as monitoring indicators of disease severity.2.SII,NLR,PLR,and LMR showed high clinical value in TWC,MES,UCEIS,and DUBLIN in predicting UC severity,among which SII had the highest predictive value.3.SII showed significant positive associations with TWC,MES,UCEIS,and DUBLIN,with the highest correlation with TWC.SII is not only closely associated with the endoscopic severity of UC,but also with the clinical severity.4.SII is an independent risk factor for UC severity.5.SII increases with the decrease of BMI,which indicates the malnutrition of the body.