The Diagnostic and Clinical Utility of the Myeloperoxidase-DNA Complex as a Biomarker in Otitis Media With Antineutrophil Cytoplasmic Antibody-associated Vasculitis.

Abstract

This prospective study aimed to evaluate the diagnostic and clinical utility of the myeloperoxidase (MPO)-DNA complex as a NETosis-derived product in the middle ear fluid of patients with otitis media with antineutrophil cytoplasmic antibody-associated vasculitis (OMAAV). Prospective study. Tertiary referral center. Twenty-two patients diagnosed with OMAAV. Collection of the fluid samples from middle ear. The levels of the MPO-DNA complex in the fluid samples were quantified using an enzyme-linked immunosorbent assay. Patients with both systemic and localized forms of OMAAV showed significantly higher levels of the MPO-DNA complex compared to the controls (p < 0.001 and p = 0.002, respectively). In particular, they showed significantly higher levels of MPO-DNA complex compared to the controls, regardless of serum antineutrophil cytoplasmic antibody status (p < 0.001 and p < 0.001, respectively) or immunosuppressive therapy (p < 0.001 and p < 0.001, respectively) at the time of sampling. An optical density cutoff value of 0.16 at 405 nm according to the receiver operating characteristic curve showed a sensitivity of 86.4%, specificity of 95.5%, positive predictive value of 95.0% and negative predictive value of 87.5% for the diagnosis of OMAAV. Significant positive correlations were observed between the levels of MPO-DNA complex and the values for air conduction - (r = 0.49, p = 0.022) and bone conduction - pure tone average thresholds (r = 0.45, p = 0.035). The detection and quantification of the MPO-DNA complex in the otitis media fluid may aid in providing a definite diagnosis as well as predicting the activity and severity of OMAAV.