Serum and Histologic Eosinophilia as a Predictive Biomarker of Response to Mirkizumab in Ulcerative Colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease that causes painful symptoms and can significantly impact quality of life. Doctors often use powerful medications, including biological drugs (commonly called biologics), which are produced using living systems such as microorganisms or animal cells, to control inflammation. However, not all patients respond well to these treatments.

This study aims to investigate whether levels of a type of white blood cell called eosinophils, measured in blood and tissue samples, might help predict which patients with UC are more likely to respond to mirikizumab, a newer medication that targets a specific part of the immune system called interleukin 23 (IL-23). By blocking IL-23, mirikizumab reduces immune activation and inflammation.

The researchers will analyze both single time points and changes in eosinophil levels over time (a longitudinal analysis) to explore whether higher levels at the beginning of treatment or reductions during treatment are associated with better outcomes. The goal is to determine whether eosinophils could serve as an early sign of treatment success, helping doctors better personalize UC therapy in the future.