1. Decreased CD3+CD56+ Natural Killer T Lymphocytes and Increased Human Leukocyte Antigen-DR+ Cells in the Inflamed Area of Pouchitis in Ulcerative Colitis Patients.
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Iwamuro M, Tanaka T, Takahara M, Inokuchi T, and Hiraoka S
- Abstract
Background: Pouchitis is an inflammatory condition that affects the ileal pouch during ileal pouch-anal anastomosis surgery. Despite its clinical significance, precise immunological mechanisms underlying pouchitis remain unclear. This study aimed to investigate the lymphocyte profile in the ileal pouch of patients with pouchitis compared to those with familial adenomatous polyposis (FAP) and ulcerative colitis without pouchitis using flow cytometry and immunohistochemical techniques., Methods: We prospectively analyzed endoscopic biopsy specimens from the ileal pouches of 15 patients and categorized them into three groups: FAP, ulcerative colitis with an inflammation-free pouch (UC-I), and ulcerative colitis with ulcers and/or erosions in the pouch (UC-UE). Flow cytometry was used to assess various T-lymphocyte markers, including cluster of differentiation (CD) 4, CD8, CD56, and human leukocyte antigen (HLA)-DR. Immunohistochemistry was performed to visualize the spatial distribution of CD3+, CD56+, and HLA-DR+ cells in the pouch mucosa., Results: We observed significantly reduced CD56+/CD3+ and CD8+/CD3+ ratios in the UC-UE group compared to those in the FAP group, indicating a disruption in natural killer T-cell populations. Immunohistochemical analysis revealed that the spatial distribution of lymphocytes differed among the non-inflamed mucosa, dense lymphocyte infiltration, and lymphoid follicles, with these components frequently intermingling. CD56 + cells were less abundant in areas with dense lymphocyte infiltration, whereas HLA-DR+ cells were more abundant., Conclusion: Our study revealed a decrease in CD56+ natural killer T cells and an increase in HLA-DR+-activated T cells in areas with dense lymphocyte infiltration, suggesting an association between these cells and pouchitis in ulcerative colitis. The distinct patterns observed in non-inflamed mucosa, areas with dense lymphocyte infiltration, and lymphoid follicles underscore the need for further analyses of these three segments to elucidate the immunological mechanisms underlying pouchitis., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Ethics Committee of Okayama University Hospital, Okayama, Japan issued approval 2203-039. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: This study was partially supported by JSPS KAKENHI (grant number: JP22K07962). Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Iwamuro et al.)
- Published
- 2024
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