Simultaneous Assessment of Eosinophil Biomarkers in Eosinophilic Esophagitis Patients (original) (raw)

RATIONALE: Monitoring disease activity in eosinophilic esophagitis is challenging as there is a lack of validated tools to replace invasive procedure-based endoscopy and pathology evaluation. We aim to identify a profile of eosinophil surface biomarkers that will correlate with eosinophil activation and disease activity in eosinophilic esophagitis. Previous studies have demonstrated that expression of eotaxin in esophageal tissue is a prominent mediator for the recruitment and activation of eosinophils in eosinophilic esophagitis. METHODS: Peripheral blood eosinophils purified by density centrifugation and negative selection using AutoMACS were stimulated with eotaxin. In an effort to identify biomarkers that correlate with EoE disease activity, previously identified eosinophil surface proteins associated with activation or allergic diseases were selected for analysis by flow cytometry. This pilot experiment was designed to concurrently examine biomarkers including: alphaL, alphaM, beta1, and beta2 integrins, activated beta1 integrin (monitored by mAb N29), CCR3, CD40, CD44, CD66b, CRTH2 and P-selectin glycoprotein ligand-1 (PSGL-1) on eosinophils, as well as alphaIIb integrin and cell-surface-associated P-selectin as markers of associated platelets. RESULTS: Eotaxin stimulation of purified eosinophils upregulated surface protein expression of beta2, alphaM and alphaL integrins, and CD66b; while downregulating CRTH2, CCR3, and N29 signals. No major changes in the expression of the other biomarkers were observed. CONCLUSIONS: Eotaxin stimulation of eosinophils results in the upregulation or downregulation of several surface biomarkers. We expect that the modulation of the surface expression of these biomarkers will be observed and will correspond to changes in eosinophilic esophagitis disease activity.