Point-of-care gastrointestinal ultrasound in inflammatory bowel disease: An accurate alternative for disease monitoring

Background and Aim

Point‐of‐care ultrasound (POCUS) is a noninvasive alternative to ileocolonoscopy for monitoring disease activity in inflammatory bowel disease (IBD) but is underutilized in practice. Accuracy data are needed to engender clinician confidence in POCUS and increase uptake. The aim of this study was to evaluate the accuracy of POCUS compared to ileocolonoscopy in detecting active disease and extent in patients with IBD.

Methods

A prospective, blinded study was performed at a single tertiary center in South Australia between May 2017 and May 2018. Consecutive patients with a formal diagnosis of IBD who underwent both POCUS and ileocolonoscopy within 30 days of one another, performed to evaluate IBD disease activity, were eligible for participation. The accuracy of POCUS compared to ileocolonoscopy was assessed using sensitivity, specificity, and Cohen's kappa coefficient analyses.

Results

A total of 74 patients were included in the final analysis, 35 (47%) of whom had Crohn's disease and 39 (53%) ulcerative colitis; 37 subjects (50%) underwent a POCUS and ileocolonoscopy on the same day. POCUS demonstrated 91% sensitivity and 83% specificity for detecting endoscopically active IBD, correlating with a positive predictive value (PPV) of 89%, a negative predictive value (NPV) of 86%, and a kappa coefficient of 0.74 (88%). POCUS defined disease extent with 87% sensitivity and 81% specificity, correlating with a PPV of 85% and NPV of 83% and a kappa coefficient of 0.70 (85%).

Conclusion

POCUS is accurate in defining disease activity and extent in IBD compared to ileocolonoscopy. POCUS represents an appealing, noninvasive alternative to ileocolonoscopy for monitoring disease activity in IBD.

Gastrointestinal ultrasound in inflammatory bowel disease care: Patient perceptions and impact on disease-related knowledge

Background and Aim

Objective monitoring of disease activity is integral to therapeutic decision-making in inflammatory bowel disease (IBD). Data are sparse on patients' perspectives of tools used to monitor disease activity in IBD. To evaluate patients' perspectives of gastrointestinal ultrasound (GIUS) performed during routine IBD clinical care, along with its impact on IBD-specific knowledge.

Methods

Patients with a formal diagnosis of IBD who underwent GIUS at two tertiary IBD services between March 2017 and January 2019 participated in this prospective study. Participants completed a questionnaire measuring the acceptability, tolerability, and usefulness of GIUS using a visual analogue scale (VAS) from 0 (disagree) to 10 (strongly agree). Comparative acceptability of IBD monitoring tools and the impact of GIUS on IBD-specific knowledge was measured.

Results

A total of 121 participants completed the questionnaire, with a mean age of 42 years (range 17-78), 54 (45%) males, and 79 (65%) Crohn's disease patients. In the overall population, GIUS was scored as highly acceptable for monitoring IBD (mean 9.20 ± 1.37) compared to colonoscopy (7.94 ± 2.30), stool sampling (8.17 ± 1.96), blood sampling (8.87 ± 1.62), and imaging (8.67 ± 1.60); P < 0.01 for each comparison. GIUS caused little patient discomfort (1.88 ± 1.83), and 98 (81%) participants ranked GIUS as their preferred IBD monitoring tool. GIUS also improved patients' overall IBD-specific knowledge (VAS IBD-specific knowledge 7.96 ± 1.92), including their understanding of the need for medical therapy and disease extent.

Conclusion

GIUS is a highly acceptable and well-tolerated tool for monitoring disease activity in IBD patients. GIUS is preferred by patients and enhances IBD-specific knowledge.

Cells, cytokines and inflammatory bowel disease: a clinical perspective

Ulcerative colitis and Crohn's disease are chronic inflammatory disorders of the GI tract. Although the disorders can usually be distinguished on clinical and pathological criteria, there are similarities in natural history and response to therapy. The purpose of this article is to examine the inflammatory infiltrate in both disorders and the cytokine profiles in intestinal mucosa and peripheral blood. For both disorders, the predominant cells in inflamed mucosa are neutrophils and lymphocytes positive for CD4. There are also increases in the number of B cells, macrophages, dendritic cells, plasma cells, eosinophils and perhaps mast cells. Cytokine levels and cytokine expression are also similar for both disorders, with increases in TNF-α and IFN-γ consistent with a Th1 response. As inflammation occurs in a microbial environment, one possibility is that the nature of the inflammatory response is largely independent of initiating factors. One concept that might be useful is that of initiating cells and cytokines and effector cells and cytokines. Persuasive evidence exists for a defect in phagocytic cells in Crohn's disease, perhaps with the expansion of a subset of activated macrophages. There are also possible links to natural killer cells and changes in the regulation of IL-8 and perhaps IL-22. For ulcerative colitis, the cellular events are less clear, but natural killer T cells may be important as initiating cells, and there is some evidence for upregulation of cytokines involved in Th2 responses, including IL-4 and IL-13. For both disorders, proinflammatory cytokines include TNF-α, IL-12, IL-23, and perhaps IL-17 and IFN-γ. Research challenges include the identification, activation and function of subsets of inflammatory cells, as well as new ways to terminate the inflammatory response.