Endoscopic visualization of the ileum mucosa in the early diagnosis of acute graft-versus-host response after allogeneic stem cell transplantation in children

Introduction. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a cell therapy method that is widely used in hematological malignancies, solid tumors, hemoglobinopathies, primary immunodeficiencies, and other congenital diseases. One of the serious complications after allo-HSCT is graft-versus-host disease (GVHD). Acute GVHD affects the skin, liver, and gastrointestinal (GI) tract. In this connection, endoscopic diagnosis acquires special importance in the comprehensive diagnosis of gastrointestinal GVHD. The aim of the work was to determine the relationship between the severity of the clinical course of acute GVHD, visualization of villous atrophy during ileocolonoscopy and morphological changes in the mucous membrane of the terminal ileum in children after allo-HSCT. Materials and methods. There was conducted a retrospective study including forty eight 9 months–8 years patients who underwent allo-HSCT between 2020 and 2023. Depending on the presence and severity of atrophy. All 48 children were divided into four groups: group 1 included 18 (37.5%) patients with signs of pronounced atrophy according to endoscopy; group 2 included 6 (12.5%) children with mild villous atrophy; Group 3 included 7 (14.6%) patients without atrophy, but with signs of ileitis; group 4 was formed by 17 (35.4%) children without signs of inflammation of the mucous membrane of the terminal ileum. All subjects underwent ileocolonoscopy using Pentax high-resolution endoscopes (Japan), with a biopsy of the mucous membrane of the colon and ileum. Statistical data processing was performed using IBM SPSS Statistics 23 software. Results. When comparing endoscopy data with the clinical picture, there was noted a tendency to identify a more severe degree of acute GVHD in children from groups 1 and 2 with endoscopic signs of villous atrophy. Acute grade 3 GVHD was diagnosed only in children with endoscopic signs of villous atrophy — in 16.7%. In the 3rd and 4th groups of patients, there was a tendency towards more frequent detection of acute GVHD grade 0, compared to children with signs of atrophy (25% versus 8.3%); however, the differences were statistically insignificant (p > 0.05). According to histology, in the majority of patients in groups 1 and 2 (21 out of 24/87.5%), ileoscopy revealed “false” villous atrophy. In the 3rd group, not a single child showed signs of atrophy confirmed histologically, which was consistent with expectations. In 13 out of 17 (76.5%) patients of the 4th group, histological examination showed no pronounced signs of inflammation. In 3 (17.6%) children of the 4th group there were no morphological changes in the ileal mucosa. Conclusion. The clinical significance of atrophy and the prognostic value of this criterion remain controversial, which indicates to the need for continued research in this area.