Capsule endoscopy is a useful diagnostic test for assessing active small-bowel Crohn’s disease in patients with suggestive clinical symptoms but normal imaging, an Australian study suggests.

The Melbourne researchers say their findings support the integration of panenteric Crohn’s capsule endoscopy into the diagnostic algorithm for patients with known or suspected disease, given the potential to achieve earlier diagnosis and classify more accurately active disease.

Their study involved 22 patients with established or suspected Crohn’s disease referred from two tertiary IBD centres between January 2021 and August 2022. Patients with abnormal magnetic resonance enterography were excluded from the study.

All patients had undergone an ileocolonoscopy within 12 months preceding capsule endoscopy, with no active colonic Crohn’s disease observed.

Only 21 patients were included in the final analysis due to one patient failing the capsule endoscopy procedure – which involved the PillCam Crohn’s capsule to the caecum with water plus simethicone (80 mg) – due to delayed capsule transit.

For the 48% of participants with suspected Crohn’s disease (median age 37.5, 60% female), the most common symptom was abdominal pain, while the 52% with a diagnosis (median age 52, 73% female) most commonly had diarrhoea.

An elevated FC (>50 μg/g) was the most frequent abnormal biomarker.

Findings published in JGH Open [link here] showed that 86% of the cohort had evidence of active small-bowel Crohn’s disease (LS > 135) based on endoscopy.

Of the 11 patients with a pre-existing diagnosis of Crohn’s disease, 82% had a change in Montreal classification, with all nine patients with known Crohn’s disease adding L4 disease to their pre- existing Montreal classification, the authors said.

Overall, 57% of patients were classified to L1 + L4 disease, 9.5% to L3 + L4 disease, and 9.5% to isolated L1 disease following capsule endoscopy.

At six months following the procedure, almost all patients (94%) had clinician-directed modification to their therapy. Of these patients, 94% received a course of corticosteroid (either budesonide or prednisolone), 39% started on a thiopurine, and 44% on a biologic agent (adalimumab, ustekinumab or infliximab).

Of those already on a biologic, one patient was switched to ustekinumab from vedolizumab, and another had the frequency of vedolizumab increased.

Findings also revealed a significant improvement from baseline across a range of measures at six months in the 18 patients with active disease confirmed by capsule endoscopy. These included HBI (median: from 7 to 4), serum CRP (median: from 4.7 to 1.95 mg/L), and serum albumin (median: from 38 to 39.5 g/L).

There was also a significant improvement in self-reported health-related quality of life and a significant reduction in the impact that symptoms had on the ability to perform non-employment/regular activities before and after capsule endoscopy.

There were no significant changes in plasma haemoglobin, serum ferritin, and faecal calprotectin, said the authors from Box Hill Hospital and Monash University.

They said while ileocolonoscopy and magnetic resonance enterography remained the standard of care, these tools might “fail to capture activity in those with more subtle and/or non-stricturing, non-penetrating phenotypes of small-bowel Crohn’s disease”.

“This study has demonstrated the clear benefits of performing capsule endoscopy in this clinical context, where there is a high index of clinical suspicion based upon symptoms, abnormal biochemistry, and/or faecal calprotectin,” they wrote.

“Another valuable aspect of performing capsule endoscopy in this context was exemplified by the finding that 15 patients in this cohort were reclassified as having Montreal L4 disease location (i.e., upper gastrointestinal disease, including the proximal two-thirds of the ileum) with capsule endoscopy.

“This is highly important, as Crohn’s disease with L4 location tends to be more refractory to medical treatment and is more likely require surgery for the management of Crohn’s disease than other phenotypes and locations of Crohn’s disease. Hence, accurate classification with capsule endoscopy potentially allows for earlier introduction, or escalation, of therapy to prevent complications of untreated small-bowel disease.”

The authors mentioned the small sample size of patients and the single capsule endoscopy image reader as two of several limitations of the study.

Some of the authors have received funding from pharmaceutical companies. The project itself also received funding support from Janssen Pharmaceuticals.