To evaluate the predictive effect of vitamin D on clinical outcomes of infliximab treated Crohn’s disease patients in western China

Background and aim To evaluate predictors of clinical outcomes in infliximab(IFX) treated CD patients in western China, and provide evidence for future treatment optimization. Methods This study adopted retrospective investigation method, collected the clinical data of patients in the database of CD patients in Chongqing General Hospital during 2022.07-2023.07. The clinical data of CD patients at baseline and the endpoint(the seventh IFX treatment, 38 weeks)were collected.The baseline variables of IFX treated patients with regard to clinical remission(Crohn's Disease Activity Index(CDAI)<150) at endpoint were assessed, and the correlation of serum vitamin D(Vit-D) levels before initiating IFX therapy and CDAI at week 38 were analyzed. Results 60 patients with CD treated with IFX were included, Vit-D deficient rate was 51.7% at baseline, 81.7% of patients achieved clinical remission and 66.7% achieved endoscopic remission at week 38 after IFX treatment. Vit-D level at baseline were one of the independent predictors of clinical remission in CD patients after IFX treatment (P < 0.05). ROC curve analysis showed that when Vit-D concentration was 15.81ng/ml, the area under the curve was 0.711 (95%CI: 0.523–0.899, P = 0.03), the sensitivity and specificity was 81.6% and 63.6%. Vit-D level in normal BMI, smoking, combine with IMM subgroup had independent predictive value of CDAI at endpoint (P < 0.05). Conclusion Baseline Vit-D level were one of the independent predictors of clinical remission in CD patients after IFX treatment, which has predictive value on CDAI before the seventh IFX treatment, especially in normal Body Mass Index, smoking, combine with immunosuppressant subgroup.