[Expression and significance of severe acute respiratory syndrome associated coronavirus (SARS-CoV)-X4 protein in lungs of SARS patients].

Tan, Ya-xia; Chen, Tao; Zhong, Shu-qing; Li, Yi-min; Chen, Ying-yu; Qiu, Xiao-yan; Mo, Xiao-ning; Song, Quan-sheng; Gan, Qi-ni; Gu, Ying-ying; Mo, Hong-ying; Luo, Wei; He, Xin-ming; Liu, Mu-chang; Zhong, Nan-shan

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.