This study investigates the pathogenesis of severe acute respiratory syndrome (SARS) by analyzing 18 autopsy cases and 22 confirmed SARS patients. The SARS virus was detected in multiple organs, including the respiratory tract, gastrointestinal tract, kidneys, brain, and lymphoid tissues. The virus infects various cell types, with immune cells and pulmonary epithelium being the main sites of injury. The study proposes a comprehensive theory of SARS pathogenesis, emphasizing immune and lung damage as key features. The SARS virus was found in the epithelial cells of the respiratory tract, the mucosa of the intestine, the epithelium of the renal distal tubules, the neurons of the brain, and macrophages in different organs. The virus was detected in a large number of circulating lymphocytes, monocytes, and lymphoid tissues. The study also found that SARS virus sequences were present in the spleen, lymph nodes, and lymphoid tissues of various organs. The virus was detected in the epithelial cells of the trachea, bronchi, and bronchioles, as well as in the mucosal and submucosal lymphoid tissues of the small and large intestines. The study found that the SARS virus infects and damages immune cells, particularly T lymphocytes, monocytes, and macrophages. The virus was detected in the blood, spleen, and lymph nodes of confirmed SARS patients. The study also found that the SARS virus was present in the kidneys, brain, and other organs. The virus was detected in the epithelial cells of the kidneys and in the neurons of the brain. The study found that the SARS virus was present in the digestive tract, with the most obvious lesions being the depletions of the submucosa lymphoid tissues. The study found that the SARS virus was present in the brain of all SARS autopsies, with signals confined to the cytoplasm of numerous neurons in the hypothalamus and cortex. The study also found that the SARS virus was present in the kidneys, with viral sequences localized to the epithelial cells of the renal distal tubules. The study found that the SARS virus was present in the digestive tract, with the most obvious lesions being the depletions of the submucosa lymphoid tissues. The study found that the SARS virus was present in the brain of all SARS autopsies, with signals confined to the cytoplasm of numerous neurons in the hypothalamus and cortex. The study also found that the SARS virus was present in the kidneys, with viral sequences localized to the epithelial cells of the renal distal tubules. The study found that the SARS virus was present in the digestive tract, with the most obvious lesions being the depletions of the submucosa lymphoid tissues. The study found that the SARS virus was present in the brainThis study investigates the pathogenesis of severe acute respiratory syndrome (SARS) by analyzing 18 autopsy cases and 22 confirmed SARS patients. The SARS virus was detected in multiple organs, including the respiratory tract, gastrointestinal tract, kidneys, brain, and lymphoid tissues. The virus infects various cell types, with immune cells and pulmonary epithelium being the main sites of injury. The study proposes a comprehensive theory of SARS pathogenesis, emphasizing immune and lung damage as key features. The SARS virus was found in the epithelial cells of the respiratory tract, the mucosa of the intestine, the epithelium of the renal distal tubules, the neurons of the brain, and macrophages in different organs. The virus was detected in a large number of circulating lymphocytes, monocytes, and lymphoid tissues. The study also found that SARS virus sequences were present in the spleen, lymph nodes, and lymphoid tissues of various organs. The virus was detected in the epithelial cells of the trachea, bronchi, and bronchioles, as well as in the mucosal and submucosal lymphoid tissues of the small and large intestines. The study found that the SARS virus infects and damages immune cells, particularly T lymphocytes, monocytes, and macrophages. The virus was detected in the blood, spleen, and lymph nodes of confirmed SARS patients. The study also found that the SARS virus was present in the kidneys, brain, and other organs. The virus was detected in the epithelial cells of the kidneys and in the neurons of the brain. The study found that the SARS virus was present in the digestive tract, with the most obvious lesions being the depletions of the submucosa lymphoid tissues. The study found that the SARS virus was present in the brain of all SARS autopsies, with signals confined to the cytoplasm of numerous neurons in the hypothalamus and cortex. The study also found that the SARS virus was present in the kidneys, with viral sequences localized to the epithelial cells of the renal distal tubules. The study found that the SARS virus was present in the digestive tract, with the most obvious lesions being the depletions of the submucosa lymphoid tissues. The study found that the SARS virus was present in the brain of all SARS autopsies, with signals confined to the cytoplasm of numerous neurons in the hypothalamus and cortex. The study also found that the SARS virus was present in the kidneys, with viral sequences localized to the epithelial cells of the renal distal tubules. The study found that the SARS virus was present in the digestive tract, with the most obvious lesions being the depletions of the submucosa lymphoid tissues. The study found that the SARS virus was present in the brain