Role of pan-T and Cytotoxic T Cells in the Pathogenesis of Adult Eosinophilic Esophagitis – A Single Institutional Study of 325 Patients
P Dhakras, D Patil, J Liao, HN Li, SM Rao, G-Y Yang. Northwestern University, Chicago, IL
Background: Eosinophilic esophagitis (EE) has evolved as a distinct clinic pathologic entity which is increasingly recognized by pathologists and gastroenterologists worldwide. The difference from pediatric EE (predominant due to allergy), is that only 1/3 of adult EE is in association with allergy and the etiology predominantly remains unknown.It has been shown that T cell and T regulatory cells (T reg) may be involved in the interaction with eosinophils and in that sense, may play a pivotal role in pathogenesis of eosinophilic esophagitis. This study is designed to characterize T cell-mediated inflammation in adult EE patients in comparison with reflux esophagitis and normal esophagus and explore the role of T cells in pathogenesis of EE.
Design: Large cohort of 325 patients with EE was analyzed which were classified as distal predominant type and diffuse type of EE according to pathologic diagnostic criteria.Concurrent infiltration of pan-T cell, cytotoxic T cells (CD8),CD4 T cells and T regulatory lymphocyte (Fox p3 labeled cells) was quantitatively analyzed immunohistochemically in the selected different types of EE biopsy specimens (n=20 for each type) in comparison with reflux esophagitis (n=10) and morphologically normal esophagus (n=5) with proper positive and negative controls. Average numbers of immunostaining-labeled T cells were counted for at least five high power fields in the areas of EE with highest eosinophil infiltration.
Results: Significant increase of pan T cells (CD3)and cytotoxic T cells (CD8) was observed in both distal predominant and diffuse types of EE as compared to normal and reflux esophagitis (P<0.05). The results showed there were average of 31.75+ 7.47 and 34.93+ 26.19 intraepithelial CD8 T cells, respectively in distal-predominant and diffuse type EE compared to 18.13+ 7.66 in normal esophagus and 22.60+ 14.20 in reflux esophagitis. But, there is no statistically significance for CD8 T cells between distal predominant and diffuse types of EE. Similar results were noted for CD3 labeled pan-T cells, with 37.35+ 7.45 in distal predominant, 39.38+9.30 in diffuse type.T regs (Foxp3 labeled cells) in EE showed marked difference in the ratio of CD3 to Treg cells between EE and normal esophagus.
Conclusions: We demonstrate that pan-T cell and cytotoxic T cells play an important role in the pathogenesis of EE.T cells would be also a biomarker to differentiate EE from reflux esophagitis and the role of T cell-mediated inflammation needs to be investigated further.
Monday, March 22, 2010 1:00 PM
Poster Session II # 72, Monday Afternoon