Piacentini G L, Vicentini L, Mazzi P, Chilosi M, Martinati L, Boner A L
Clinica Pediatrica, Università di Verona, Italy.
Clin Exp Allergy. 1998 May;28(5):561-7. doi: 10.1046/j.1365-2222.1998.00260.x.
Asthma is characterized by bronchial hyperresponsiveness (BHR), bronchial mucosa inflammation and airway epithelial damage.
This study was designed to evaluate the effect of mite avoidance on bronchial epithelial shedding in asthmatic children sensitized to Dermatophagoides.
The percentages of airway epithelial cells and eosinophil have been counted in samples obtained by hypertonic saline-induced sputum before and after a period of antigen avoidance in an Alpine environment (1756 m). The degree of bronchial hyperresponsiveness to methacholine was also evaluated.
After avoidance the median (lower, Q1, and upper, Q3, quartile) percentage of epithelial cells in the sputum decreased significantly from 3.50 [0.50;6.98] to 0 [0;0.5] (P=0.012) and eosinophil percentage decreased from 1 [0;5.25] to 0 [0,1.5] (P<0.05). Median (Q1,Q3) PC20 increased significantly from 2.75 [1.53;7.5] to 3.25 [1.65;15.25] mg/ mL (P=0.038). After 3 weeks of re-exposure to mite the epithelial median (Q1,Q3) percentage raised to 3.90 [1.5;6] (P = 0.027), eosinophils to 1.5 [0;3.00] (NS) and PC20 was 5.25 [1.68;14.50] (NS).
Exposure to house dust mite antigen can induce airway epithelial shedding even in subjects with low eosinophil airway infiltration, thus supporting the idea that epithelial damage in asthmatics sensitized to Dermatophagoides may be due to a proteolytic activity of the mite major antigens.
哮喘的特征为支气管高反应性（BHR）、支气管黏膜炎症和气道上皮损伤。
本研究旨在评估避免接触螨对致敏于尘螨的哮喘儿童支气管上皮脱落的影响。
在海拔1756米的高山环境中，于一段抗原回避期前后，对通过高渗盐水诱导痰液获取的样本中的气道上皮细胞和嗜酸性粒细胞百分比进行计数。还评估了对乙酰甲胆碱的支气管高反应性程度。
回避后，痰液中上皮细胞的中位数（下限、第一四分位数Q1和上限、第三四分位数Q3）百分比从3.50 [0.50；6.98]显著降至0 [0；0.5]（P = 0.012），嗜酸性粒细胞百分比从1 [0；5.25]降至0 [0，1.5]（P < 0.05）。中位数（Q1，Q3）PC20从2.75 [1.53；7.5]显著增加至3.25 [1.65；15.25]毫克/毫升（P = 0.038）。再次接触螨3周后，上皮细胞中位数（Q1，Q3）百分比升至3.90 [1.5；6]（P = 0.027），嗜酸性粒细胞升至1.5 [0；3.00]（无统计学意义），PC20为5.25 [1.68；14.50]（无统计学意义）。
即使在嗜酸性粒细胞气道浸润较低的受试者中，接触屋尘螨抗原也可诱导气道上皮脱落，从而支持以下观点：致敏于尘螨的哮喘患者的上皮损伤可能归因于螨主要抗原的蛋白水解活性。
