Intestinal ultrasound (IUS) findings correlate strongly with endoscopy results in patients with ulcerative colitis (UC), with treatment responses detected as soon as 8 weeks after starting tofacitinib, a longitudinal prospective study has found.
IUS accurately detected improvements and remission across a variety of scoring methodologies, suggesting that it may be a cost-effective, noninvasive alternative to endoscopic monitoring, reported lead author Floris de Voogd, MD, of Amsterdam University Medical Centers, and colleagues.
“Endoscopy is generally considered as the gold standard for the diagnosis and follow-up of patients with UC,” the investigators wrote in Gastroenterology. “However, endoscopy is an invasive and costly modality and therefore less attractive to perform frequently during the disease course.”
Whereas noninvasive fecal biomarkers are a more economical method of monitoring inflammation and treatment responses, they fail to characterize disease extent and fall short in detecting early endoscopic responses, the investigators added.
The present study aimed to determine if IUS could offer more clinical insight by measuring bowel wall thickness. Thirty patients were enrolled with moderate to severe UC, all with an endoscopic Mayo score of at least 2. Twenty-seven of these patients were evaluable through follow-up, having undergone both IUS and endoscopy at baseline and 8 weeks after starting tofacitinib.
At both time points, IUS findings correlated significantly with endoscopic Mayo score (EMS), UC endoscopic index for severity, and Robarts Histopathology Index, with correlation coefficients of 0.68, 0.73, and 0.49, respectively. Remission according to EMS was defined as a score of 0, and improvement was defined as a score of 1 or less.
Patients with EMS improvement showed lower median bowel wall thickness in the sigmoid colon after 8 weeks of treatment than did patients without improvement (1.8 mm vs. 4.5 mm; P < .0001); patients who were in EMS remission after 8 weeks also had lower median bowel wall thickness of the sigmoid colon (1.4 mm vs. 4.0 mm; P = .016).
The investigators also sought to define cutoff values for bowel wall thickness. The most accurate cutoff values for identifying endoscopic remission and improvement were 2.8 mm (area under the receiver operating curve, 0.87; 95% confidence interval, 0.74-1.00; P = .006) and 3.9 mm (AUROC, 0.92; 95% CI, 0.82-1.00; P < .0001), respectively. Treatment response was best identified by a 32% threshold reduction in thickness (AUROC, 0.87; 95% CI, 0.74-1.00; P = .002).
“Intestinal ultrasound, with bowel wall thickness as the single most important parameter is accurate to determine treatment response to tofacitinib in patients with moderate-severe UC when compared against endoscopy,” the investigators concluded.
Michael Dolinger, MD, MBA, assistant professor of pediatrics and the associate pediatric gastroenterology fellowship program director at the Icahn School of Medicine at Mount Sinai, New York, said the study is noteworthy because it is the first of its kind to show that IUS can accurately monitor treatment responses in UC.
“This study is what we’re looking for now, and in the future,” Dr. Dolinger said in an interview. “We’re looking for noninvasive biomarkers to predict early responses so that we know as clinicians ... if our medicines are working or if we need to pivot and switch effectively.”
For patients, this can mean feeling better quicker while reducing burden of care, he added.
“We can use this study to predict patient responses without having to potentially rescope them in 8 weeks using a 5-minute point-of-care test in the clinic,” Dr. Dolinger said. “It’s huge to be able to say that for patients with colitis, and to provide reassurance that not only are they potentially feeling better, but the medicine is working to change and heal their bowel wall really quickly as well.”
Dr. Dolinger speaks from clinical experience. Over the past 2 years, he and his colleagues at Mount Sinai have been implementing IUS for patients with both UC and Crohn’s disease.
“It’s become part of our standard of care,” Dr. Dolinger said. “This is now emerging in the United States and will soon take hold. There is a lot of interest.”
Dr. Dolinger is one of just a few American physicians credentialed by the International Bowel Ultrasound Group, an organization based out of Europe, Israel, and Canada. Formalized training and certification are necessary, Dr. Dolinger noted, to ensure that this new clinical approach maintains consistency as it is rolled out across the United States.
“We have the unique opportunity to do something from the ground up quickly, but also correctly, meaning that we can train everyone to speak the same language and do the same standardized exams so that all the findings and research are relatable,” Dr. Dolinger said.
He advised interested physicians to contact their local inflammatory bowel disease center to find out if training is available, and if it is, devoting “a lot of time” to the learning process.
“If you’re going to use this potentially as a clinical decision-making tool without using other invasive procedures, you really want to make sure what you’re doing is accurate and correct,” Dr. Dolinger said.
The investigators disclosed relationships with AbbVie, Merck, Takeda, and others. Dr. Dolinger disclosed a relationship with NeuroLogica, a subsidiary of Samsung Electronics.