Morita Shinya, Nakamaru Yuji, Fukuda Atsushi, Fujiwara Keishi, Suzuki Masanobu, Hoshino Kimiko, Honma Aya, Homma Akihiro
Department of Otolaryngology - Head and Neck Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
Otol Neurotol. 2022 Mar 1;43(3):e337-e343. doi: 10.1097/MAO.0000000000003431.
This study aimed to quantify the cell-free deoxyribonucleic acid (DNA), citrullinated-histone H3 (cit-H3)-DNA complex, and myeloperoxidase (MPO)-DNA complex as extracellular trap cell death (ETosis)-derived products in the middle ear fluid, and to identify diagnostic biomarkers for the discrimination of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (OMAAV) from eosinophilic otitis media (EOM).
Prospective study.
Tertiary referral center.
OMAAV patients were eligible for inclusion in this analysis. Patients with EOM were examined as controls.
All samples were obtained from the middle ear fluid in patients with OMAAV or EOM. The fluid samples were aspirated from the middle ear through the anterior-inferior portion of the tympanic membrane using a 1-ml tuberculin syringe with a 24- or 26-gauge needle under a microscope.
The levels of cell-free DNA, cit-H3-DNA complex and MPO-DNA complex in the fluid samples were quantified using an enzyme-linked immunosorbent assay.
Patients with OMAAV showed significantly higher levels of MPO-DNA complex compared to patients with EOM, regardless of the serum ANCA status at the time of sampling (p < 0.001 and p < 0.001, respectively). Meanwhile, there were no significant differences in the values of cell-free DNA or cit-H3-DNA complex between the OMAAV and EOM patients.
The findings of this study suggest that the detection and quantification of MPO-DNA complex in the otitis media fluid can be utilized to discriminate OMAAV, especially in cases of eosinophilic granulomatosis with polyangiitis, from EOM regardless of the serum ANCA status. It should be noted that it is possible for cell-free DNA and cit-H3-DNA complex in fluid samples to be derived from dead cells other than neutrophils that undergo ETosis.
本研究旨在对中耳积液中作为细胞外诱捕网细胞死亡（ETosis）衍生产物的游离脱氧核糖核酸（DNA）、瓜氨酸化组蛋白H3（cit-H3）-DNA复合物和髓过氧化物酶（MPO）-DNA复合物进行定量分析，并确定用于区分抗中性粒细胞胞浆抗体（ANCA）相关性血管炎（OMAAV）和嗜酸性中耳炎（EOM）的诊断生物标志物。
前瞻性研究。
三级转诊中心。
OMAAV患者符合纳入本分析的条件。将EOM患者作为对照进行检查。
所有样本均取自OMAAV或EOM患者的中耳积液。在显微镜下，使用带有24号或26号针头的1毫升结核菌素注射器，通过鼓膜前下部从中耳抽取液体样本。
采用酶联免疫吸附测定法对液体样本中游离DNA、cit-H3-DNA复合物和MPO-DNA复合物的水平进行定量分析。
与EOM患者相比，OMAAV患者的MPO-DNA复合物水平显著更高，无论采样时血清ANCA状态如何（分别为p<0.001和p<0.001）。同时，OMAAV患者和EOM患者的游离DNA或cit-H3-DNA复合物值无显著差异。
本研究结果表明，检测和定量分析中耳积液中的MPO-DNA复合物可用于区分OMAAV和EOM，尤其是在伴有嗜酸性肉芽肿性多血管炎的情况下，无论血清ANCA状态如何。需要注意的是，液体样本中的游离DNA和cit-H3-DNA复合物可能来自经历ETosis的中性粒细胞以外的死亡细胞。
