Eosinophil Extracellular Trap Remnants as Potential Biomarkers for the Diagnosis and Activity Assessment of Otitis Media Associated With Eosinophilic Granulomatosis With Polyangiitis and Eosinophilic Otitis Media.

OBJECTIVE

This study hypothesized that the expression levels of eosinophil extracellular traps (EETs) in middle ear lavage fluid and serum would correlate with various clinical parameters in otitis media associated with eosinophilic granulomatosis with polyangiitis (EGPA) and eosinophilic otitis media (EOM). The aim of this study was to evaluate the potential utility of EETs as diagnostic and monitoring tools for assessing disease activity and therapeutic response.

STUDY

DESIGN

Exploratory research.

SETTING

Two tertiary referral centers.

PATIENTS: EGPA and EOM patients were eligible for inclusion. Patients with chronic otitis media (COM) were examined as controls.

INTERVENTION: The middle ear lavage and blood samples were obtained from patients with EGPA, EOM, and COM.

MAIN OUTCOME MEASURES: The levels of cell-free deoxyribonucleic acid (DNA), citrullinated-histone H3 (cit-H3)-DNA complex, and eosinophil peroxidase (EPO)-DNA complex as EET remnants were quantified using an enzyme-linked immunosorbent assay.

RESULTS

Patients with EGPA and EOM showed significantly higher levels of EET remnants in the middle ear lavage compared with controls. In patients with EGPA and EOM, the levels of EET remnants in the middle ear lavage at post-treatment were significantly lower compared with those at pretreatment. Furthermore, the levels of EET remnants in the middle ear lavage were positively correlated with Lund-Mackay scores and temporal bone CT scores. It is noteworthy that EET remnants in the serum of patients with EGPA were found to be elevated and were positively correlated with peripheral blood eosinophil fraction and serum immunoglobulin E levels.

CONCLUSIONS

These preliminary findings suggest that EET remnants in the middle ear lavage may be potentially useful as biomarkers for the diagnosis and disease activity of otologic lesions in EGPA and EOM. It seems acceptable to measure the levels of EET remnants using blood samples in patients with EGPA.