Intestinal Ultrasound in Severe Ulcerative Colitis Treated With Intravenous Cyclosporine

Background: Intestinal ultrasound (IUS) is a non-invasive real-time monitoring tool that allows serial assessment in severe ulcerative colitis (UC). A recent study showed that reduction in bowel wall thickness by > 20% by 48±24h in patients with severe UC receiving intravenous corticosteroids predicted treatment response at one week. However, evidence of short-term follow-up with IUS in rescue therapy for UC is scarce. We aimed to describe IUS utility in patients hospitalized with severe UC treated with intravenous cyclosporine. Methods: This is a retrospective observational study in a single tertiary IBD center from February 2023 to September 2023. Hospitalized patients with severe UC monitored with IUS (SAMSUNG HM70 EVO) during the treatment with intravenous cyclosporine were extracted. Clinical information and IUS parameters including BWT and modified Limberg score (mLimberg) at baseline and at day 3 after cyclosporine therapy were collected. Results: Six patients monitored with IUS treated with intravenous cyclosporine were identified, with a median (IQR) Simple Clinical Colitis Activity Index of 8 (6-11) and Mayo endoscopic subscore of 3 in five patients (one patient scored 2). Four patients were exposed to more than two biologics, and the median albumin level was 2.6 (2.1-3.0) g/dL at baseline. The median BWT in the sigmoid was 4.9 (3.3-5.2) mm, and the median modified Limberg score was 1.5 (1.0-3.0). Among four patients with available data of serial IUS follow-up at day 3, the median reduction of sigmoid BWT in three patients who required colectomy during admission was 0.5 (0.45-0.5) mm (7.7% reduction). Conversely, the reduction of BWT in a patient who successfully responded to cyclosporine was 1 mm (30.3% reduction). In three patients who required colectomy, mLimberg median reduction was 0 (-0.5-0). For the patient with cyclosporine response, the mLimberg score remained 1. Conclusions: In patients with severe UC, we demonstrate the value of IUS in assessing disease activity and therapy response in real-time. Incorporation of IUS in hospitalized patients treated with intravenous cyclosporine may predict treatment response, however, prospective studies with a larger sample size and other induction therapies are needed and underway.