Laitinen A, Laitinen L A
Department of Anatomy, University Central Hospital, Helsinki, Finland.
Allergy Proc. 1994 Nov-Dec;15(6):323-8. doi: 10.2500/108854194778816436.
Appreciation of the early damage that occurs to the respiratory epithelium has been limited by the use of autopsy specimens from fatally stricken asthmatics as a source of representative specimens. The use of bronchoscopy to obtain specimens from patients early in the course of their asthma has allowed a new understanding of the evolution of pathological changes that occur in asthma. Newly diagnosed, mild asthmatics have been shown to have bronchial goblet cell hyperplasia in addition to increased numbers of mast cells and eosinophils in the respiratory epithelium, and increased eosinophil granule protein deposition within the lamina propria. Endothelial gaps in postcapillary venules are greater in asthmatic airways, suggesting that increased plasma transudation may contribute to the known epithelial cell shedding characteristic of asthma attacks. Asthmatic inflammation, even early in the course of the disease, includes vascular permeability changes, inflammatory cell infiltration, epithelial cell shedding, and goblet cell hyperplasia, replacing the normal ciliated epithelium. Current investigation evaluating the effects of asthmatic inflammation on epithelial cell attachment to each other and to the extracellular matrix molecules regulated by adhesion glycoproteins will likely enhance further the understanding of the pathological changes that occur within the asthmatic airway.
对呼吸道上皮早期损伤的认识一直受到限制，这是因为以往使用来自因哮喘致死患者的尸检标本作为代表性标本来源。利用支气管镜在哮喘病程早期从患者身上获取标本，使得人们对哮喘中发生的病理变化演变有了新的认识。研究表明，新诊断出的轻度哮喘患者除了呼吸道上皮中肥大细胞和嗜酸性粒细胞数量增加外，还存在支气管杯状细胞增生，并且固有层内嗜酸性粒细胞颗粒蛋白沉积增加。哮喘气道中毛细血管后微静脉的内皮间隙更大，这表明血浆渗出增加可能导致哮喘发作时已知的上皮细胞脱落特征。即使在疾病早期，哮喘炎症也包括血管通透性改变、炎性细胞浸润、上皮细胞脱落和杯状细胞增生，从而取代正常的纤毛上皮。目前正在进行的研究评估哮喘炎症对上皮细胞彼此之间以及对由黏附糖蛋白调节的细胞外基质分子附着的影响，这可能会进一步加深对哮喘气道内发生的病理变化的理解。
