# Interleukin Signatures as Prognostic Biomarkers in Ulcerative Colitis: From Immune Pathways to Clinical Prediction

## TL;DR

This paper reviews how interleukin patterns can serve as biomarkers for microscopic inflammation in ulcerative colitis, offering a better understanding of disease progression beyond clinical symptoms.

## Contribution

The paper synthesizes evidence showing that interleukin signatures reflect distinct immunopathologic states in UC, providing a new framework for assessing disease activity.

## Key findings

- IL-23-driven pathways correlate with severe histologic inflammation and resistance to healing.
- IL-10 signaling is linked to histologic remission and mucosal healing.
- Downstream ILs like IL-6 and IL-17A mediate tissue injury from immune imbalance.

## Abstract

Ulcerative colitis (UC) is a chronic immune-mediated inflammatory disease characterized by substantial heterogeneity in histologic activity, which is frequently uncoupled from clinical symptoms and endoscopic findings. Persistent microscopic inflammation is increasingly recognized as a critical determinant of relapse, therapeutic failure, and long-term disease outcomes, underscoring the need for molecular frameworks that align directly with tissue-level immune dysregulation. Interleukins (ILs) represent central regulators of mucosal immunity in UC, integrating innate and adaptive immune responses that govern epithelial injury and resolution. In this narrative review, we synthesize mechanistic, translational, genetic, and clinical evidence examining IL networks associated with histologic disease activity and persistence. Particular emphasis is placed on IL-23-driven inflammatory pathways, which consistently align with histologic severity, sustained microscopic inflammation, and resistance to immune resolution. In contrast, preserved IL-10-mediated regulatory signaling characterizes histologic remission and effective mucosal healing, whereas its insufficiency permits ongoing tissue-level inflammation. Downstream effector ILs, including IL-6, IL-1β, IL-8, and IL-17A, are discussed as mediators translating upstream immune imbalance into neutrophil recruitment and epithelial injury. Throughout this review, the term “prognostic” is used to denote alignment with histologic disease behavior rather than validated prediction of clinical outcomes. Collectively, the evidence supports the concept that coordinated IL patterns reflect distinct immunopathologic states underlying microscopic inflammation in UC, providing a biologically coherent framework for interpreting histologic activity and disease persistence beyond symptom-based assessment.