Blood Eosinophil Beta1-Integrin Activation Correlates with Eosinophilic Esophagitis (EoE) Disease Activity

Abstract

RATIONALE: Hypereosinophilia is defined as a peripheral blood absolute eosinophil count (AEC) of >0.5 x10 9 /L, while severe hypereosinophilia is defined as an AEC of >1.5x10 9 /L. Much has been published on hypereosinphilia in the adult literature; however, there is limited literature on pediatric patients with hypereosinophilia (especially severe eosinophila) or hypereosinophilic syndrome (HES). The goal of this study was to characterize children with severe hypereosinophilia hospitalized in a tertiary care center. METHODS: We reviewed the charts of allergy/immunology consults performed from January 2013-April 2016 at Saint Louis Children's Hospital. Children were included in this study if their AEC was >1.5x10 9 at the time of the allergy/immunology consult. Data was collected on demographics, comorbidities, treatment, laboratory data, and clinical outcomes. Patients were sorted into diagnostic groups that included: overlap hypereosinophilic syndrome, allergic/atopy, hypereosinophilic syndrome myeloproliferative subtype, immunodeficiency, and unknown. RESULTS: We reviewed that chart of 289 inpatient consults and 13 met our inclusion criteria. Mean age at presentation was 19.5 months (range 1-49 months). Mean peak peripheral blood AEC was 5.5x10 9 /L (range 1800-12,524x10 9 /L). Four patients were found to have atopic driven eosinophilia, three with an underlying primary immunodeficiency, two with HES myeloproliferative variant, one with overlap HES. Four patients had an unknown etiology. Mortality in our cohort was 23%. CONCLUSIONS: Severe hypereosinophilia was the reason for 4.5% of inpatient Allergy/Immunology consults. A variety of reasons caused underlying eosinophilia. As many life threatening conditions were identified, prompt recognition of the underlying pathology is critical for proper treatment.

Heterogeneity of Intestinal Tissue Eosinophils: Potential Considerations for Next-Generation Eosinophil-Targeting Strategies

“…These "activated" eosinophils within circulation are more prone to arrest on endothelial-expressed VCAM-1 [39], and correlate with decreased lung function in subjects with mild asthma [40]. A similar scenario of activation of eosinophil-expressed β1 integrins appears to occur in EoE patients [41] and may correlate with disease activity [42]. Moreover, reports of two case studies demonstrated a higher percentage of CD274 + (PDL1) blood eosinophils in EoE with reduction back down to normal levels following successful treatment [43].…”