Prediction of deep remission through serum TNF-α level at 1 year of treatment in pediatric Crohn’s disease

A pilot study investigated the cytokine profile (IL-6, TNF-α, IL-17 A, and IL-10) at diagnosis, affecting infliximab (IFX) trough levels (TLs) in pediatric patients with Crohn's disease (CD). In this follow-up study, we evaluated the changes in cytokine level changes after Crohn's disease treatment. Cytokines were re-measured after 1 year of treatment. infliximab trough levels and total anti-infliximab antibodies were also measured in patients who had started infliximab treatment. In total, 29 patients followed up for a year after moderate to severe Crohn's disease diagnosis from June 2020 to June 2021 were enrolled. The mean concentrations of all cytokines at one year were significantly lower than those at the time of diagnosis. IL-6, IL-17 A, and IL-10 concentrations at 1 year maintained their correlation with each other observed at diagnosis, unlike TNF-α following infliximab treatment. At 1 year, TNF-α concentration exhibited a negative correlation with infliximab trough levels (Pearson coefficient = -0.500, p = 0.009), and a positive correlation with anti-infliximab antibody titre (Pearson coefficient = 0.510, p = 0.018). The diagnostic capability of 1-year TNF-α concentration to predict achievement of deep remission had an area under the ROC of 0.802 (p = 0.008), with a TNF-α cut-off concentration set at 9.40 pg/mL. Decreased cytokine concentrations following Crohn's disease treatment reflected reduced inflammatory burden. Targeted medical intervention (infliximab) aimed at specific cytokines, such as TNF-α, led to the reduction of the corresponding cytokines. High TNF-α level post-treatment, combined with suboptimal infliximab trough levels and increased antibody formation, may contribute to deep remission failure in patients.