Background and Aim: Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder characterized by upper gastrointestinal symptoms and the presence of high numbers of eosinophils in the esophagus. Although eosinophils in the esophagus have been found to be activated in subjects with EoE, detailed studies of intracellular signaling pathways involved in the mechanism of activation of eosinophils in EoE have heretofore been limited. The aim of the study was to assess whether any surface molecules or transcription factors are activated in peripheral eosinophils in subjects with EoE.
Methods: Eosinophils and CD3+ lymphocytes were identified directly from 50 μL of whole blood of EoE and control subjects. Using Hi-FACS, levels of surface activation markers, including CD66b, and intracellular phosphoepitopes, including phosphorylated forms of signal transducer and activator of transcription (phospho-STAT) 1 and 6, were measured within each cell subset.
Results: Levels of surface CD66b as well as levels of intracellular phospho-STAT1 and phospho-STAT6 in peripheral blood eosinophils were significantly higher for untreated subjects with EoE vs healthy controls (P < 0.05). Levels of phospho-STAT1 and phospho-STAT6 in peripheral blood eosinophils were lower in subjects with EoE on therapy versus untreated subjects with EoE (P < 0.05).
Conclusions: Levels of phospho-STAT1 and phospho-STAT6, transcription factors involved in inflammatory processes, were both significantly higher in peripheral eosinophils from untreated (ie, newly diagnosed) subjects with EoE versus subjects with EoE on therapy, healthy controls. Blood-based measurements of CD66b and phospho-STAT levels in peripheral eosinophils may be beneficial for identifying EoE.
*Department of Pediatrics, USA
†Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
Received 8 July, 2010
Accepted 25 January, 2011
Address correspondence and reprint requests to Kari C. Nadeau, MD, PhD, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305 (e-mail: firstname.lastname@example.org).
Tammie Nguyen and Yael Gernez participated equally in this study.
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The study was supported by the Stanford Children's Health Research Project, Morgridge Fellowship (Gernez and Nadeau), the Stanford Immunity, Transplantation and Infectious Diseases Institute (Nadeau), the Cowan Family Gift Fund (Nadeau and Nguyen), the Stanford Dean's Fellowship (Gernez), Association Régionale d'Assistance Respiratoire à Domicile (Gernez), the Sidney and Skippy Franck Foundation (Tirouvanziam and Gernez), the Siegelman Fellowship Award at Stanford University School of Medicine (Fuentabella), and the Tissue and Transplant Engineering Award at Stanford University School of Medicine (Patel).
The authors report no conflict of interest.