Abstract: In order to study the pathological characteristics of lungs in severe acute respiratory syndrome (SARS) and the expression of nuclear factor kappa B (NF-κB) in lungs, investigate the relationship between the activation of NF-κB and damage of lungs, HE staining and immuno-histochemical staining (SP methods) were used to study 3 lungs of autopsy cases of SARS.Antibody against NF-κB p65 was used for immunohistochemical studies.The pathological changes were diffuse pulmonary interstitial inflammation and alveolar damages with apoptosis and desquamation of pneumocytes in alveolar spaces, hyaline-membrane formation, wider alveolar walls and predominant lymphocyte and mononuclear inflammatory infiltrates.Immunoreactivity to NF-κBp65 were all positive and located in plasma and nuclei of pneumocytes, macrophages and lymphocytes.This study indicates that the lungs of patients with SARS show acute injury, NF-κB plays an important role in it.

Key words: severe acute respiratory syndrome, pneumonia tissue, NF-κB