RESUMO
OBJECTIVE: To investigate the significance of severe acute respiratory syndrome associated coronavirus (SARS-CoV)-X4 protein expression in lungs of patients with SARS. METHODS: Pathological features of the lungs from 4 SARS patients were examined and the expression of SARS-CoV-X4 protein in the lungs was evaluated with immunohistochemical staining using specific antibodies against protein X4. RESULTS: Microscopically, all lungs from 4 cases showed edema, erythrocyte and fibrin exudates in the alveoli, hyperplasia of alveolar epithelium, necrosis, hyaline membrane formation and fibroblast foci. Immunohistochemical stains showed a strong positivity of X4 protein in denudation cells, vascular endothelial cells and also erythrocytes and neutrophils in the alveoli of the lung tissues from the 4 cases. CONCLUSIONS: Expression of SARS-CoV-X4 protein in the lungs may be involved in the pathogenesis and progression of SARS.
