[Immunohistochemical investigation of lungs with severe acute respiratory syndrome].

ABSTRACT

OBJECTIVE: To investigate the roles of different cells in the pulmonary lesions in the severe acute respiratory syndrome (SARS) patients. METHODS: The monoclonal antibodies of CD8, CD20, CD34, LCA, CD56, CD68, and AE1/AE3 are used to demonstrate the different cells in the lung specimens of SARS patients in order to study the patterns of cell responses in this new disease. Meanwhile the HE stained slides were also carefully studied to compare with the results of immunohistochemical staining. RESULTS: The number of capillaries increased and the capillaries clearly outlined the contour of alveolar wall from beginning to early stage of organization, the number of lymphocytes decreased sharply while the number of macrophage remarkably increased, together with proliferation of type II pneumocytes. The numbers of blood vessels decreased in the fibrotic and consolidated lung tissue, and the vessel cavities enlarged, losing the normal contour of alveolar septa. CONCLUSIONS: The lesions in the lung from SARS patients are consisted of the tissue reaction to the inflammatory injury, including extensive exudation, capillary proliferation, fibrosis, and obvious infiltration of macrophages which may play a key role in the pathogenesis of pulmonary lesions of SARS.