P129 Segmental loss of motility drives reduced small bowel function in limited cutaneous systemic sclerosis: a pilot magnetic resonance enterography study

Background/Aims Intestinal disease is the main driver of gastrointestinal (GI) related morbidity in Systemic Sclerosis (SSc), with loss of physiological motility postulated as the main pathologic culprit of lower GI involvement. However, standardized tools for quantifying GI dysmotility in SSc are lacking. Building on the growing experience employing magnetic resonance enterography (MRE) for the assessment of small bowel function in inflammatory bowel diseases (IBD), we implemented a quantitative imaging assessment of the small bowel for phenotyping of intestinal disease in SSc. Methods SSc patients with severe GI burden, defined by UCLA GIT2.0 total score >1 and ScleroID lower GI > 7 were invited to participate. MREs were performed following oral administration of 1 L of 2.5% mannitol solution to distend the bowel and provoke contractility. A CE marked tool, GI-Quant, generated motility heatmaps and enabled contractility analysis; values >200 motility units, considered normal based on IBD standards, were validated in local Healthy Control cohort. Single-slice segments exceeding the lower limit of normal were quantified and visualised, the others classified as hypomotile. Summary scores were extracted from 2D small-bowel ROI. Mean/median global scores and percent below lower limit of normal (200 mu) were analysed using Wilcoxon rank-sum test (R version 4.5.1). Results 12 patients with severe reported GI burden (8 lcSSc) were enrolled in this pilot study. Motility scores were significantly different between patients and HC [median (IQR) GIQuant score 214.00 (173.25-258.50) vs 303.00 (296.00-314.25) respectively, (p = 0.018)]. LcSSc patients had worse overall motility than dcSSc with same patient reported burden [181.50 (154.00-258.5)] vs [248.50 (228.50-271.7)]. Distribution of GIQuant was bimodal in SSc and driven by a variable amount of hypomotile small bowel [median (IQR) 89.02% (72.51%-95.06%) vs 97.81% (97.10%-98.39%), p = 0.046]. All patients (5/12- 41.7%) with extensive segmental hypomotility had lcSSc. Conclusion This pilot study provides the first evidence that gut dysmotility in SSc is variable despite high patient reported GI burden and is driven by small bowel segments severely hypomotile rather than generalised dysmotility. A larger cohort is currently enrolling to extend these findings and identify clinical and demographic features linked with segmental loss of motility of the small bowel in SSc. Disclosure M. Minerba: None. R. Ross: None. S. Zahed Mohajerani: None. I. Naim: Other; Scientific Success Lead at Motilent, which developed the software used for this study. A. Bard: Other; Scientific Lead at Motilent, which developed the software used for this study. L. Bissell: None. G. Bandini: None. R. Giacomelli: None. A. Menys: Other; CEO at Motilent, which developed the software used for this study. F. Del Galdo: None.