Personalized Risk Stratification of Residual Histologic Activity in IBD Using Circulating Cytokines.

Background

Persistent histologic inflammation may remain present in patients with inflammatory bowel disease (IBD) despite endoscopic remission. This study evaluated a clinically interpretable cytokine-based framework for risk stratification of residual histologic activity.

Methods

In this prospective cohort study, 59 patients with IBD undergoing colonoscopy were included. Primary analyses were restricted to patients with ulcerative colitis (UC) in endoscopic remission (n = 31). Histologic activity was assessed using the Geboes score. Serum interleukin-10 (IL-10), interleukin-23 (IL-23), and C-reactive protein (CRP) were measured prior to endoscopy. Receiver operating characteristic (ROC) analysis and ROC-derived thresholds were used to evaluate biomarker performance and construct a cytokine-based risk stratification framework.

Results

Among patients with UC in endoscopic remission, 14/31 (45.2%) demonstrated persistent histologic activity. IL-10 showed the strongest discriminatory performance for histologic activity (AUC 0.850), with a threshold < 3.9 pg/mL associated with sensitivity of 84.6% and specificity of 77.8%. Similar performance was observed using raw assay-reported IL-10 values (AUC 0.906). IL-23 showed limited overall discrimination (AUC 0.615). A combined IL-10/IL-23 framework stratified patients into progressively higher-risk subgroups, with histologic activity observed in 1/14 patients (7.1%) in the low-risk subgroup, 1/2 patients (50.0%) in the Intermediate A subgroup, 9/12 patients (75.0%) in the Intermediate B subgroup, and 3/3 patients (100%) in the high-risk subgroup (p < 0.001), although estimates for smaller subgroups should be interpreted cautiously. Reduced IL-10 levels were independently associated with histologic activity, whereas IL-23 primarily refined subgroup classification without substantially improving discrimination.

Conclusions

An exploratory cytokine-based framework incorporating IL-10 and IL-23 may support risk stratification of residual histologic activity in UC during endoscopic remission. Larger multicenter studies are required to validate these findings and define their clinical utility.