Intestinal ultrasound proved its mettle against endoscopy for analyzing treatment response and remission in patients with ulcerative colitis (UC) followed in a small prospective Dutch study.
Bowel wall thickness (BWT) was the most important parameter in assessing treatment response, reported Krisztina Gecse, MD, PhD, of the University of Amsterdam, and colleagues in Gastroenterology.
In their study of 27 consecutive patients with moderate to severe UC starting on tofacitinib (Xeljanz), measuring BWT at baseline and 8 weeks on intestinal ultrasound demonstrated moderate to strong correlation with two endoscopic scoring indices — the endoscopic Mayo score (EMS) and the UC endoscopic index of severity (UCEIS) — in both the sigmoid and descending colon:
- EMS: Spearman’s ρ=0.68 for sigmoid (P<0.0001) and ρ=0.76 for descending (P<0.0001)
- UCEIS: ρ=0.73 (P<0.0001) and ρ=0.74 (P<0.0001), respectively
BWT on intestinal ultrasound in the sigmoid colon moderately correlated with the Robarts Histopathology Index (RHI; ρ=0.49, P=0.002).
Median BWT in the sigmoid colon was significantly lower for patients who achieved endoscopic improvement (1.8 vs 4.5 mm, P<0.0001) or remission (1.4 vs 4.0 mm, P=0.016), Gecse and coauthors found. And decreases in BWT were more pronounced in those with endoscopic response (-58.1% vs -13.4%, P=0.018).
“We have demonstrated that intestinal ultrasound, and in particular BWT as a single most important parameter, is highly accurate in identifying segmental endoscopic remission, endoscopic improvement, and response when compared to globally utilized endoscopic scoring indices,” Gecse and colleagues wrote. “It is even able to detect microscopic treatment response in patients UC.”
Multivariable regression analysis found that the most accurate BWT cut-off values were: ≤2.8 mm for endoscopic remission, with an area under the receiver operating characteristic curve (AUC) of 0.87 (95% CI 0.74-1.00, P=0.006); and ≤3.9 mm for endoscopic improvement, with an AUC of 0.92 (95% CI 0.82-1.00, P<0.0001).
And the researchers reported that a BWT reduction of 32% for endoscopic response in the sigmoid colon detected response with a 71% sensitivity and 90% specificity.
“Furthermore, we demonstrated that the submucosa was the most responsive layer for endoscopic response and remains significantly thickened when endoscopic remission or endoscopic improvement are not reached,” the researchers wrote.
Endoscopy remains the gold standard for diagnosing UC and for disease monitoring, but it is expensive, invasive, and requires bowel preparation.
Though intestinal ultrasound is used in other parts of the world as a non-invasive method for assessing inflammatory bowel disease, the modality is not widely available in the U.S., noted Adam C. Ehrlich, MD, MPH, of Temple University in Philadelphia, who was not involved in the study.
“This early study suggests that intestinal ultrasound may be used to assess response to therapy in ulcerative colitis patients,” Ehrlich told MedPage Today. “If born out in additional studies, this strengthens the argument for adoption of intestinal ultrasound in the U.S., as it is a relatively easy and inexpensive way to assess therapeutic response in real time.”
From October 2018 to August 2020, Gecse and colleagues enrolled 30 adult patients with moderate to severe UC, as evidenced by an EMS of 2 or more in at least one segment of the colon. Median patient age was 35.5 years and 60% were women. Average body mass index was 24, and the average disease duration was 78 months.
Patients were included if they underwent a complete colonoscopy or flexible sigmoidoscopy at baseline and started on tofacitinib within days of their endoscopy. All but three completed follow-up and were included in the analysis. Intestinal ultrasound was also conducted at baseline and at 8 weeks, but on alternative days, with a mean time of 5.6 days between each modality. Image readers were blinded. Two biopsies were obtained during endoscopy for 22 patients.
Half of the patients were on concomitant corticosteroids. Nearly all had previously received aminosalicylates (90%) and corticosteroids (90%), and 70% had also received thiopurines. All patients had a Lichtiger score of 6 or above, and all but one had a simple clinical colitis activity index score of 4 or greater. At baseline, 89% had a pathological BWT of 4.0 mm or greater in the sigmoid colon, and 64% had a BWT of 3.0 mm or greater in the distal colon.
The authors acknowledged limitations to the data, including the small number of participants and short follow-up. Findings may also only be generalizable to those treated with tofacitinib.
Gecse reported funding from AbbVie, Arena Pharmaceuticals, Celltrion, Ferring, Galapagos, Gilead, Immunic Therapeutics, Janssen Pharmaceuticals, Novartis, Pfizer, Samsung Bioepis, Takeda, and Tillotts. Coauthors disclosed numerous relationships with industry entities.