Endoscopy 2015; 47(08): 760
DOI: 10.1055/s-0034-1392534
Letters to the editor
© Georg Thieme Verlag KG Stuttgart · New York

Reply to Villanacci et al.

Marietta Iacucci
,
Xianyong Gui
,
Subrata Ghosh
Further Information

Publication History

Publication Date:
30 July 2015 (online)

We appreciate the comments of Villanacci et al. [1], as we believe that this discussion will be useful to the readers of Endoscopy. We completely agree that a detailed histological scoring system is designed for research purpose only, and it is particularly suitable for a study of mucosal healing because it is expected to reflect the minor residual histological changes. It is too complex for daily routine practice. Our study was designed to establish that even patients with a Mayo endoscopic subscore of 0 have subtle endoscopic and histological abnormalities, the significance of which remains to be established. A simple histological scoring scheme suitable for daily diagnostic work-up would likely miss many subtle histological abnormalities of both active and inactive disease.

The major aspects involved in the histological evaluation of inflammatory bowel disease, as pointed out by Villanacci et al., are the common changes that are indicative of obvious active ulcerative colitis but usually absent in mild, quiescent, ulcerative colitis. An excellent example of this type of simpler scheme is the Harpaz system, which was included in our study. All other similar clinically oriented schemes reported in the literature appear to have limitations. Although a simple descriptive scheme, as suggested by Villanacci et al., would be easier for clinicians to understand, it would not provide the full histopathological significance and summarizing categories of minor histological changes.

It is also true that several histological scoring systems already exist in the literature, but most of them do not meet the needs of a mucosal healing study, which requires analysis and classification of the various mild residual histological abnormalities, especially those subtle abnormalities in cases that appear to be healed endoscopically. In view of the fact that there is still no universally accepted definition of histological remission and no consensus on the best way to assess disease activity, our work may provide valuable and helpful information. It is certainly not our conclusion that our scoring system is the best; we simply intended to develop a system that can cover, comprehensively, all of the possible histological changes in the wide spectrum of inflammatory bowel disease pathology and categorize them in a meaningful way (i. e. extent of abnormality, degree of active and chronic inflammatory cell infiltrates, presence or absence of architecture distortion of crypts/glands, and integrity of surface and crypt epithelium). Furthermore, we attempted to identify the histological components that are most relevant to the mucosal healing process and to disease recurrence.

Importantly, the use of electronic virtual chromoendoscopy allowed us to demonstrate that some of these histological abnormalities are detectable by advanced endoscopic imaging techniques and are well correlated with the endoscopic findings. Our study is of value, therefore, given that these electronic techniques are increasingly being incorporated into endoscopes.

All of the scoring schemes – endoscopic or histological – bear some degree of subjectivity and interobserver variation. As stated recently by an international group [2], “valid, reliable, responsive, and predictive histological scoring systems are needed” in the future. Our scoring system also awaits further validation through multicenter collaboration. Ultimately, we all hope to find a universally accepted and standardized index of histological assessment of ulcerative colitis.

 
  • References

  • 1 Villanacci V, Antonelli E, Salemme M et al. Assessing mucosal healing in ulcerative colitis: the simpler, the better. Endoscopy 2015; 47: 759
  • 2 Mosli MH, Feagan BJ, Sandborn WJ et al. Histologic evaluation of ulcerative colitis: a systematic review of disease activity indices. Inflamm Bowel Dis 2014; 20: 564-575