Intestinal ultrasound should be considered a useful disease-monitoring tool in a point-of-care setting and can be used to assess short-term treatment response in patients with ulcerative colitis (UC), according to research published in Gut.

Between November 2015 and March 2018, German researchers conducted the TRUST (TRansabdominal Ultrasonography of the bowel in Subjects with IBD To monitor disease activity) prospective, observational study evaluating the use of intestinal ultrasound as a means of closely monitoring patients with UC through routine medical care.

Adults with a proctosigmoiditis, left-sided colitis, or pancolitis in clinical relapse and ≥18 years of age at baseline were consecutively enrolled in the study. At all visits, patients underwent large bowel segment evaluation via intestinal ultrasound.

The total study cohort included 253 patients with active UC (defined as Short Clinical Colitis Activity Index [SCCAI] ≥5) from 42 German IBD-specialized centers, of whom 88.5% were included in the statistical analysis, or the modified intent-to-treat population. Within this group, half of all patients had left-sided colitis and half had pancolitis.

Within 12 weeks, investigators noted a significant decrease in the percentage of patients with increased bowel wall thickness in the sigmoid colon (89.3% to 38.6%, 35.4%, and 32% at weeks 2, 6, and 12, respectively) and the descending colon (83% to 42.9%, 43.4%, and 37.6% at weeks 2, 6, and 12, respectively). Improvements in colon doppler signal were noted by week 2 and were maintained up to week 12 in both the sigmoid and descending colons.

The researchers also noted a significant reduction in the percentage of patients with additional abnormal intestinal ultrasound parameters, including mesenteric fibrofatty proliferation, mesenteric lymphadenopathies, ascites, loss of bowel wall stratification, and loss of haustration.

To assess the primary end point — the proportion of patients with bowel wall thickness normalization with clinical response (SCCAI decrease of ≥3 points) — researchers examined data from the 178 patients who completed the week 12 visit. Those with normalization of bowel wall thickness in the sigmoid or descending colon had higher clinical response rates compared with those without bowel wall thickness normalization (90.5% vs 68.9% and 96.4% vs 68.8%). Patients who responded also demonstrated a significant reduction in quantitative bowel wall thickness compared with nonresponders.

In terms of SCCAI and fecal calprotectin correlation, no significant difference in SCCAI was noted at baseline; however, at weeks 2, 6, and 12, patients with fecal calprotectin levels <250 μg/g demonstrated a significantly lower SCCAI (1.33±1.03, 1.91±1.99, and 1.79±2.88) compared with patients with fecal calprotectin levels ≥250 μg/g (5.05±2.15, 4.56±3.13, and 4.08±3.54).

Overall, fecal calprotectin normalization was more frequent in patients with bowel wall thickness normalization in the sigmoid or descending colon compared with patients without bowel wall thickness normalization at 12 weeks (48.9% vs 22.2% and 50% vs 25%).

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Study limitations included the lack of a currently defined gold standard for UC, including endoscopy, medication changes among the patient population, and potential interobserver and interequipment variability in the intestinal ultrasound.

“Our findings give rise to the assumption that monitoring [bowel wall thickness] alone has the potential to predict therapeutic response,” the researchers concluded, adding that future prospective studies are necessary to determine the value of intestinal ultrasound in the prediction of short- and long-term UC responses and outcomes.

Disclosure: This clinical trial was supported by AbbVie. Please see the original reference for a full list of authors’ disclosures.

References

Maaser C, Petersen F, Helwig U, et al; on behalf of the German IBD Study Group and the TRUST&UC study group. Intestinal ultrasound for monitoring therapeutic response in patients with ulcerative colitis: Results from the TRUST&UC study [published online December 20, 2019]. Gut. doi: 10.1136/gutjnl-2019-319451