Reply to van Gils et al.

We appreciate the opportunity to address the comments made by van Gils et al. concerning our e-video on confocal laser endomicroscopy (CLE) in protein-losing enteropathy (PLE).

Although CLE has been reported for the assessment of barrier dysfunction in patients with irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and other conditions, the severity of the impairment of the intestinal barrier can vary widely. Because of the risk associated with endoscopic entry in this patient with severe hypoproteinemia, we only inserted the colonoscope to observe this patient's colon and terminal ileum. During the examination, we observed a severity of fluorescence leakage that was far more significant than we had seen previously in patients with IBS or IBD. The use of CLE to assess barrier dysfunction was initially reported in patients with IBD [1]: with the development of a semiquantitative grading system called the Watson grade, which describes the amount of cell shedding and the intensity of the luminal fluorescein signal on single good-quality images from four separated fields of view of the terminal ileum. This grading system suggests that the severity of the gut barrier impairment using CLE is a core factor in the assessment process of the gut barrier [2] [3] [4]. Furthermore, the fluorescein leakage observed in the video and images of our patient that were shown in our e-video were only part of our examination video; similar leakage was observed in multiple spots, far more than were shown in the article.

Although the α₁-antitrypsin clearance examination was not conducted owing to inspection constraints, α₁-antitrypsin clearance is still only indirect evidence for the diagnosis of PLE. In this patient, the diagnosis of PLE was based on clinical symptoms, laboratory results, endoscopy, and imaging, with corresponding differential diagnoses excluded. Herein, CLE provides intuitive evidence of an impaired gut barrier. This is only a single case report and may be limited by the need for further research and additional cases.

Publication History

Article published online:
30 January 2024

• References

• 1 Kiesslich R, Duckworth CA, Moussata D. et al. Local barrier dysfunction identified by confocal laser endomicroscopy predicts relapse in inflammatory bowel disease. Gut 2012; 61: 1146-1153
• 2 Karstensen JG, Săftoiu A, Brynskov J. et al. Confocal laser endomicroscopy: a novel method for prediction of relapse in Crohnʼs disease. Endoscopy 2016; 48: 364-372
• 3 Chang J, Leong RW, Wasinger VC. et al. Impaired intestinal permeability contributes to ongoing bowel symptoms in patients with inflammatory bowel disease and mucosal healing. Gastroenterology 2017; 153: 723-731.e1
• 4 Lim LG, Neumann J, Hansen T. et al. Confocal endomicroscopy identifies loss of local barrier function in the duodenum of patients with Crohnʼs disease and ulcerative colitis. Inflamm Bowel Dis 2014; 20: 892-900