Inflammatory phenotype of Crohn's disease: common and challenging
T.S. Fil, I.G. Bakulin, V.V. Petrenko
North Western State Medical University named after I.I. Mechnikov, St. Petersburg, Russian Federation
Aim: to evaluate pathomorphosis of non-stricturing non-penetrating (inflammatory) phenotype of Crohn's disease (CD) in the Russian population.
Materials and Methods: a single-center retrospective cohort study with prospective assessment of outcomes was conducted. The selection was carried out among patients stayed in the Gastroenterology Department, North Western State Medical University named after I.I. Mechnikov, in 2019–2026. Primary medical documents confirming the history (e. g., discharge records, test results) were a prerequisite for enrollment. Medical history, as well as physical and instrumental data were evaluated.
Results: among patients with an inflammatory phenotype of Crohn's disease, the onset was reported in 172 women (52.3%) and 157 men (47.7%). Subsequently, 136 (41.34%) out of 329 patients with an onset of an inflammatory phenotype of Crohn's disease demonstrated the phenotype transformation into a phenotype associated with strictures, fistulas, periproctitis, etc. 100 (30.4%) patients with mild activity and an inflammatory phenotype of Crohn's disease at onset had to underwent genetically engineered biological therapy (GEBT). In addition, it is compelling to note the discrepancy between clinical presentation and endoscopic activity of the inflammatory phenotype of Crohn's disease. In particular, an endoscopic examination revealed ulcers in 43% of patients with mild clinical activity and an inflammatory phenotype of CD.
Conclusion: in terms of routine practice, it should be borne in mind that CD is disease that requires a whole range of instrumental and laboratory examination methods during diagnosis, follow-up care and monitoring of patients. This resulted from a common discrepancy between clinical and endoscopic activity of CD, very likely complications and subsequent transformation of the initial phenotype. Moreover, timely assessment of the CD phenotype transformation often cannot be based on physical data and requires a comprehensive set of instrumental examinations.
Keywords: inflammatory bowel diseases, Crohn's disease, Crohn's disease complications, inflammatory phenotype of Crohn's disease, phenotype transformation.
For citation: Fil T.S., Bakulin I.G., Petrenko V.V. Inflammatory phenotype of Crohn's disease: common and challenging. Russian Medical Inquiry. 2026;10(9):636–642 (in Russ.). DOI: 10.32364/2587-6821-2026-10-9-7
About the authors:
Tatiana S. Fil — C. Sc. (Med.), Head of the Gastroenterology Department, Gastroenterologist at the Clinic named after Peter the Great, North Western State Medical University named after I.I. Mechnikov; 41, Kirochnaya str., St. Petersburg, 191015, Russian Federation; ORCID iD 0000-0002-2859-4942
Igor G. Bakulin — Dr. Sc. (Med.), Professor, Head of the Department of Propaedeutics of Internal Diseases, Gastroenterology, and Dietetics named after S.M. Ryss, North Western State Medical University named after I.I. Mechnikov; 41, Kirochnaya str., St. Petersburg, 191015, Russian Federation; ORCID iD 0000-0002-6151-2021
Valentin V. Petrenko — C. Sc. (Med.), Gastroenterologist at the Gastroenterology Department at the Clinic named after Peter the Great; Teaching Assistant at the Department of Propaedeutics of Internal Diseases, Gastroenterology, and Dietetics named after S.M. Ryss, North Western State Medical University named after I.I. Mechnikov; 41, Kirochnaya str., St. Petersburg, 191015, Russian Federation; ORCID iD 0000-0001-9168-0184
Contact information: Tatiana S. Fil, e-mail: fts-88@mail.ru
Financial Disclosure: no authors have a financial or property interest in any material or method mentioned.
There is no conflict of interest.
Received 02.07.2026.
Revised 27.07.2026.
Accepted 19.08.2026.
