# Determining the Treatment Strategy for Refractory Ulcerative Colitis Using Prostaglandin E-major Urinary Metabolite (PGE-MUM) Measurement

## TL;DR

A 14-year-old boy with severe ulcerative colitis was successfully treated with mirikizumab after high PGE-MUM levels suggested a specific immune response.

## Contribution

This case demonstrates how PGE-MUM measurement can guide targeted treatment in refractory ulcerative colitis.

## Key findings

- High PGE-MUM levels indicated a Th17-like cytokine profile in a patient with severe ulcerative colitis.
- Treatment with mirikizumab led to remission in a patient unresponsive to steroids and infliximab.
- PGE-MUM measurement proved useful in selecting appropriate anti-cytokine therapy.

## Abstract

Prostaglandin E-major urinary metabolite (PGE-MUM) is a valuable biomarker reflecting the cytokine profile. We encountered a case of a 14-year-old boy with pan-colitis-type ulcerative colitis who was unresponsive to steroids and infliximab. The patient’s clinical symptoms gradually deteriorated and surgical treatment was strongly considered because anti-inflammatory therapy was unlikely to be effective. PGE-MUM levels were markedly elevated, indicating a T-helper 17 (Th17)-like cytokine profile. Because an antibody against interleukin 23 (IL-23) was presumed to be effective, the patient was treated with mirikizumab, after which he achieved remission. In the present case, measurement of PGE-MUM levels was useful in selecting anti-cytokine treatments for severe ulcerative colitis.