[Study on etiology and pathology of severe acute respiratory syndrome].
OBJECTIVE
To investigate the clinicopathologic characteristics of severe acute respiratory syndrome (SARS).


METHODS
Three autopsy cases were studied retrospectively. Routine HE stain was used to study all the cases. Part of the lung tissue specimens were studied further with Macchiavello's stain, viral inclusion body stain, reticulin and PAS stains, immunohistochemistry, thin sections with staining, light microscopy and transmission electronic microscope investigation.


RESULTS
The earliest symptom of all 3 cases was hyperpyrexia and followed by progressive dyspnea and appearance of lung field shadows in X rays findings. Pulmonary lesions included: bilateral and extensive consolidation, localized hemorrhage and necrosis, desquamative alveolitis and bronchitis, alveolar proliferation and desquamation, accumulation of protein exudates, mononuclear cells, lymphocytes, and plasma cells as well as hyaline membrane formation in alveoli and viral inclusion bodies were seen in the alveolus epithelial cells. The exudated organization tended to become glomeruloid organizing pneumonitis in a few avaoli. Lesions of the immune organs included: large patchy necrosis in the spleens and localized necrosis in the lymph nodes were seen. Bone marrow became restrained. There were lesions of systemic small vasculitis including edema of the perivascular tissue and vascular wall of the small veins with localized fibrinoid necrosis distributing in the heart, lungs, kidneys, adrenal glands and the striated muscles accompanying with mononuclear cells and lymphocytes infiltration. Thrombosis was seen in part of the small veins. In addition, there were also the systemic poisonous changes including: degeneration and necrosis of the parenchyma cells in lungs, liver, kidneys, heart and adrenals. Electronic microscopy demonstrated clusters of virus particles seen in the lung tissue.


CONCLUSIONS
SARS is a systemic disease. Lungs, immune system and systemic small vessels are the main target organs attacked by the virus. Extensive consolidation of lungs, formation of hyaline membrane to a large extent, respiratory distress and decrease of immune function are the main causes of death.
Ding
Yan-qing
YQ
Department of Pathology, Nanfang Hospital, the First Military Medical University, Guangzhou 510515, China. dyq@fimmu.com
Wang
Hui-jun
HJ
Shen
Hong
H
Li
Zu-guo
ZG
Geng
Jian
J
Han
Hui-xia
HX
Cai
Jun-jie
JJ
Li
Xin
X
Kang
Wei
W
Weng
De-sheng
DS
Lu
Yao-dan
YD
Yao
Kai-tai
KT
D000328:Adult; D002423:Cause of Death; D005260:Female; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D045169:Severe Acute Respiratory Syndrome / Q000209:etiology / Q000473:pathology*