# Novel endoluminal parameters for predicting primary loss of response in Crohn’s disease: a multi-center study

## TL;DR

This study introduces new imaging parameters, particularly effective luminal diameter, to predict which Crohn’s disease patients will not respond to ustekinumab treatment.

## Contribution

The study introduces effective luminal diameter (EffLD) as a novel predictor of ustekinumab response in Crohn’s disease using cardiovascular imaging software.

## Key findings

- Effective luminal diameter (EffLD) emerged as an independent predictor of ustekinumab response with an AUC of 0.858.
- Endoluminal CT enterography parameters showed significant differences between primary loss of response and non-PLR groups.
- Cardiovascular imaging software was successfully applied to quantify intestinal parameters in Crohn’s disease.

## Abstract

Approximately 30% of patients with Crohn’s disease (CD) experience primary loss of response (PLR) to ustekinumab. However, studies integrating imaging parameters to predict PLR remain limited. This study aimed to quantify endoluminal and intestinal wall parameters using computed tomography enterography (CTE) and assess their predictive value for PLR to ustekinumab.

This multicenter study analyzed 466 intestinal segments from 161 patients with CD between March 2020 and May 2024. A national survey identified 10 CTE parameters for evaluating disease activity and predicting PLR. Logistic regression models were used to assess predictive performance in a validation cohort.

Ten CTE parameters related to lesion characterization—including length, luminal narrowing, and bowel wall thickness—were defined, with newly introduced metrics, including length, area, effective luminal diameter (EffLD), mean bowel wall thickness, and stenosis. A total of 352 baseline and 114 follow-up segments from 161 patients across six centers were analyzed to assess changes following ustekinumab treatment. Paired analysis across all patients showed significant improvements in eight parameters (p < 0.001); in contrast, unpaired comparisons between PLR and non-PLR groups revealed significant differences in six parameters (p < 0.001), with greater improvements in the non-PLR group. EffLD emerged as an independent predictor of ustekinumab response, with an AUC of 0.858 and an accuracy of 0.780 in the validation cohort.

Novel endoluminal parameters, particularly EffLD, provide a detailed characterization of intestinal lesions in inflammatory bowel disease and exhibit strong predictive value for PLR in ustekinumab-treated patients with CD.

This study first applied cardiovascular imaging software to quantify endoluminal CT enterography parameters, establishing effective luminal diameter as a novel, clinically applicable predictor of ustekinumab response in Crohn’s disease.

Cardiovascular imaging software can facilitate image analysis in Crohn’s disease.Endoluminal CT enterography parameters predict primary loss of response in Crohn’s disease.Effective luminal diameter independently predicts ustekinumab response.

Cardiovascular imaging software can facilitate image analysis in Crohn’s disease.

Endoluminal CT enterography parameters predict primary loss of response in Crohn’s disease.

Effective luminal diameter independently predicts ustekinumab response.