严重急性呼吸综合征的肺组织损伤病理改变

目的 观察严重急性呼吸综合征(SARS)死亡患者的肺部病变特点。方法 采用光镜、组织特殊染色对3例SARS死亡患者的肺组织进行了重点观察。采用兔抗-Fas、鼠抗-PCNA、鼠抗-CD83、CD4、CD8单克隆抗体，经免疫组织化学法对肺及肺门淋巴结等组织进行了检测。结果 肺脏的外观多呈红色或紫红色，镜下显示不同程度的间质渗出性或漏出性炎症和肺泡损伤，肺泡间隔内单个核细胞浸润，肺泡腔内有透明膜形成及凋亡脱落的Ⅱ型肺泡上皮细胞。一些肺泡毛细血管腔内可见纤维素性血栓形成，支气管动脉腔内有血栓栓塞。增宽的肺泡间隔内有纤维素沉积。3例肺泡腔内未见明显地巨细胞浸润。免疫组织化学检测显示，增殖细胞核抗原阳性细胞少见，Ⅱ型肺泡上皮细胞及肺泡间隔、肺门淋巴结内的单个核细胞有较多的Fas抗原表达；与慢性炎性淋巴结相比，SARS患者的肺门淋巴结内淋巴细胞结构破坏、淋巴细胞稀疏、数量明显减少，但CD83及CD8阳性细胞仍较多见，而CD4阳性淋巴细胞少见。脾脏也可观察到淋巴细胞数量的减少，白髓萎缩，出血坏死，表达CD4的阳性细胞减少。结论 严重的肺组织及免疫系统损伤可能导致SARS患者的死亡。

Pathological damage of lung in severe acute respiratory syndrome

Objective We report the pathological features of lung in the dead patients with severe acute respiratory syndrome (SARS). Methods Post-mortem lung and pulomonary hilar lymph nodes tissues of 3 patients dead from SARS were studied by histology and immuhistochemistry with rabbit anti-Fas polyclonal antibody, mouse anti-PCNA, mouse anti- CD83,mouse anti-CD4 and mouse anti-CD8 monoclonal antibodies. Results The surface of lung from 3 cases were shown red or purplish red color. Histopathological examination showed that diffuse interstitial exudative or leakage inflammation and alveolar damages with a pronounced increase of of monocytes in the interval at various levels of progression and severity. There were hyaline-membrane formation, desquamation and apoptosis of type-2 pneumocytes in alveolar spaces. Fibrin thrombus and thrombo-embolism could be found in blood capillary and bronchial artery respectively. We observed some fibrin deposition in alveoli interval. No obviously giant-cell infiltrate within the alveolar lumen. The positive cell of proliferative cell nuclear antigen (PCNA) was rare. Fas antigen were expressed in a lot of type-2 pneumocytes, monocytes of the interval and pulomonary hilar lymph nodes. Comparison with the lymph nodes of chronic inflammation, there were obviously disorganization and attenuation of lymphocyte in lymph nodes of SARS. The proportion of CD4 positive lymphocytes were rare, but CD83 and CD8 positive lymphocyte seemed no decreased, relatively. The seminal changes such as decreased lymphocytes ,white pulp atrophy,hemorrhage and necrosis,and decreased expression of lymphocytes for CD4 antigen could also observe in spleen. Conclusions Severe damages of lung and immunological system damages might lead to death of patients with SARS.