藻酸盐对家兔肺组织的免疫损伤作用

目的：建立藻酸盐免疫性肺炎动物模型，研究藻酸盐对肺组织的致病作用；以探讨细菌生物被膜对呼吸系统的致病机制。方法：本实验用乙醇沉淀法提取细菌藻酸盐；A组用生理盐水作对照，B组、C组分别用海藻藻酸盐、细菌藻酸盐免疫家兔。比较三组家兔的体温、血象及血循环免疫复合物(CIC)水平；比较支气管肺泡灌洗液(BALF)细菌计数；观察肺组织的病理改变。结果：两种藻酸盐免疫组家兔的血CIC水平皆较处理前及生理盐水对照组显著增高，BALF培养无细菌生长。经两种藻酸盐免疫后皆出现细支气管旁淋巴细胞浸润、淋巴小结形成及细支气管管腔狭窄等病理改变。结论：海藻藻酸盐和细菌藻酸盐都能导致家兔肺组织非感染性免疫损伤，其主要病理改变为细支气管旁淋巴细胞浸润及淋巴小结形成；这种免疫损伤是呼吸道生物被膜病的致病机制之一。

The immunic damage effect of alginate in rabbit lung tissue

Objective To establish models of alginate immune pneumonia in rabbits; The pathogenic role of alginate on lung tissue was studied; To explore the pathogenic merchanism of biofilm on respiratory system. Methods Bacterial alginate was extracted with ethanol precipitation method. Rabbits of group A were challenged by saline and can be the control group. Rabbits of group B and C were immunized with seaweed alginate and bacterial alginate respectively. The body temperature,peripheral blood cells and the serum level of circulating immune complex (CIC) were measured after challenge. Bacteria in bronchoalveolar lavage fluid (BALF) were incubated and the colonies were counted. The pathogenic changes of lung tissue were observed under microscopy.Results: the serum CIC levels were increased significantly in B and C groups, and there were little bacterial colonies in BALF of all groups. Under light microscope, the lymphocyte accumulation and lymphoid follicles around the bronchiolus in all alginate immunized groups were observed,and the narrowing of bronchiolus was also observed. Conclusion Both seaweed alginate and bacterial alginate could cause uninfectional pneumonia in rabbits. Alginate can cause inflammatory reaction and pathological changes in rabbits lung which are mainly peribronchilar lymphocyte infiltration and lymphoid follicles formed around the bronchiolus. The immunic injury is one of the pathogenic merchanisms in airway biofilm disease.