The systemic immune-inflammation index is superior to predicting clinical remission and relapse for ulcerative colitis patients treated with vedolizumab

Jing Yan ¹ Jun Wu ² Rongkun Wang ³ Pin Meng ² Ailing Liu ² Yonghong Xu ^2*

• ¹ Department of Gastroenterology, Qingdao Women and Children's Hospital, Qingdao, Shandong Province, China
• ² Department of Gastroenterology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, China
• ³ Department of Vascular Surgery, The Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, China

Background: Vedolizumab (VDZ), a novel biologic targeting α4β7 integrin, is safe and effective for the treatment of patients with ulcerative colitis (UC). The objective of this study was to compare the potential of the Platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), and systemic immune-inflammation index (SII) in predicting clinical remission and treatment failure in patients with moderate-tosevere UC on VDZ therapy and to explore the risk factors for treatment failure.Methods: Seventy-four UC patients treated with VDZ at our institution between December 1, 2020, and October 1, 2023, who had medical records were included in this study. We retrospectively collected baseline NLR, PLR, and SII values and assessed the predictive ability of the three indices for clinical remission and treatment failure using the receiver operating characteristic (ROC) curves.Results: Patients in the severe group (n=47) had significantly higher baseline PLR and SII values than those in the moderate group (n=27) (P<0.05). Patients with MES3 had significantly higher PLR and SII values than patients with MES2 (P<0.05). At 14 weeks after VDZ treatment, 28 patients obtained steroid-free clinical remission, whereas 46 did not. The area under the ROC curve (AUC) for SII was 0.659 for predicting clinical remission and exhibited the best predictive ability. Of the 52 patients who achieved long-term remission, 35 patients responded consistently to VDZ, whereas 17 patients experienced disease relapse. The SII, with an AUC of 0.793, showed the best predictive ability (sensitivity: 94.1%; specificity: 57.1%; cutoff value: 602.0). Cox regression analysis revealed that SII ≥602.0, was a potential predictor of relapse after VDZ treatment in UC patients (P=0.048, hazard ratio: 8.651; 95 % confidence interval: 1.017-73.593).The SII performed better than NLR and PLR in predicting clinical remission and relapse for UC patients on VDZ therapy. Moreover, patients with high SII may relapse after VDZ treatment and should be treated with caution.