Evaluating the predictive effect of vitamin D on clinical outcomes of infliximab-treated Crohn's disease patients in western China.

The aim was to evaluate predictors of clinical outcomes in infliximab (IFX)-treated Crohn's disease (CD) patients in western China and provide evidence for future treatment optimization. Our retrospective study included CD patients at Chongqing General Hospital from July 2022 to July 2023. Clinical data of CD patients at baseline and the endpoint (the seventh IFX treatment, 38 weeks) were collected. 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 was analyzed. Sixty patients with IFX-treated CD were included. The 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 of IFX treatment. Vit-D level at baseline was an independent predictors of clinical remission after IFX treatment (P < 0.05). Receiver operating characteristic curve analysis showed that when Vit-D concentration was 15.81 ng/ml, the area under the curve was 0.711 (95% CI 0.523-0.899, P = 0.03). The sensitivity and specificity were 81.6% and 63.6%, respectively. Vit-D level in the normal BMI, non-smoking, immunosuppressant-treated subgroup had independent predictive value for CDAI at endpoint (P < 0.05). Baseline Vit-D level predicted clinical remission in CD patients after IFX treatment, especially in those with normal body mass index, who do not smoke, and who take IFX in combination with immunosuppressants.