Baba Shintaro, Kondo Kenji, Suzukawa Maho, Ohta Ken, Yamasoba Tatsuya
Department of Otolaryngology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan; Department of Otolaryngology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.
Department of Otolaryngology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Ann Allergy Asthma Immunol. 2017 Aug;119(2):120-128. doi: 10.1016/j.anai.2017.05.019. Epub 2017 Jun 19.
Chronic rhinosinusitis with nasal polyps (CRSwNP) has been categorized into 2 subtypes in the Asian population: eosinophilic chronic rhinosinusitis (ECRS; similar to CRSwNP in Western countries) and non-ECRS (characterized by inflammation dominated by T-helper cell type 1). The pathogenesis of CRSwNP and the role of mast cells are poorly understood.
To investigate the distribution, phenotypes, and immunoglobulin E (IgE) positivity of mast cells in these 2 subtypes of CRSwNP.
We collected nasal tissue from patients with CRSwNP and control subjects. The mRNA for mast cell proteases tryptase and chymase was measured using real-time polymerase chain reaction, and the distribution of each type of protease-positive mast cell was examined using immunohistochemistry and immunofluorescence. IgE distribution on mast cells was determined using double-immunofluorescent staining for IgE and tryptase.
Expression of tryptase mRNA was significantly increased in nasal polyps from patients with the 2 subtypes of CRSwNP compared with controls. Immunohistochemistry showed increased numbers of tryptase-positive mast cells in the epithelium, glands, and submucosa of ECRS polyps, whereas the number of tryptase- and chymase-positive mast cells was increased in the glands and submucosa of non-ECRS polyps. IgE-positive mast cells were abundant in the epithelial, glandular, and submucosal regions of ECRS polyps but few were detected in non-ECRS polyps.
The present study demonstrates that the distribution, subtype population, and IgE positivity of mast cells is different between ECRS and non-ECRS nasal polyps. Our results suggest a role for IgE-mediated mast cell activation in the pathogenesis of ECRS.
在亚洲人群中，伴鼻息肉的慢性鼻-鼻窦炎（CRSwNP）已被分为2种亚型：嗜酸性粒细胞性慢性鼻-鼻窦炎（ECRS，类似于西方国家的CRSwNP）和非ECRS（以1型辅助性T细胞主导的炎症为特征）。CRSwNP的发病机制以及肥大细胞的作用尚不清楚。
研究这2种CRSwNP亚型中肥大细胞的分布、表型及免疫球蛋白E（IgE）阳性情况。
我们收集了CRSwNP患者和对照者的鼻组织。采用实时聚合酶链反应检测肥大细胞蛋白酶类胰蛋白酶和糜蛋白酶的mRNA，并通过免疫组织化学和免疫荧光检查每种蛋白酶阳性肥大细胞的分布。使用IgE和类胰蛋白酶的双重免疫荧光染色确定肥大细胞上IgE的分布。
与对照组相比，2种CRSwNP亚型患者鼻息肉中类胰蛋白酶mRNA的表达显著增加。免疫组织化学显示，ECRS息肉的上皮、腺体和黏膜下层中类胰蛋白酶阳性肥大细胞数量增加，而非ECRS息肉的腺体和黏膜下层中类胰蛋白酶和糜蛋白酶阳性肥大细胞数量增加。IgE阳性肥大细胞在ECRS息肉的上皮、腺体和黏膜下层区域丰富，但在非ECRS息肉中检测到的很少。
本研究表明，ECRS和非ECRS鼻息肉中肥大细胞的分布、亚型群体及IgE阳性情况不同。我们的结果提示IgE介导的肥大细胞激活在ECRS发病机制中起作用。
