Expression of CD34,VEGF and ICAM-1 in lungs of severe acute respiratory syndrome

Purpose To study the possible pathogenesis of severe acute respiratory syndrome(SARS)by comparing the protein expression of CD34,VEGF and ICAM-1 in SARS lungs with those in non-SARS lung injury.Methods Specimens,from 7 cases of diagnosed SARS and 6 non-SARS cases died with acute lung injury,were examined by routine HE and immunohistochemical stains of CD34,VEGF and ICAM-1,and then image analysis.Results The blood vessels in SARS lungs outlined the alveolus clearly,and its mean optical density(MOD)was 0.284 3±0.103 3,which was significantly greater than that of non-SARS lungs(0.129 7±0.007 3,P=0.007 4).The MOD of VEGF of the two groups had no statistical difference.The MOD of ICAM-1 in SARS lung was significantly increased in the cases without infectious morbidity(P=0.041 6).Conclusion The endothelial cells in SARS lungs are injured not so seriously as compared with those of infectious lung injury.The expression of ICAM-1 and VEGF is also different,which may reflect the characteristics of SARS lung injury and explain the clinical process of SARS partly.