Histopathological and cytological examination of autopsy cases with multiple organ dysfunction syndromes.

To evaluate the role of small scavenger receptor A (SRA)-positive (SRA(+)) cells and large SRA(+) cells in the peripheral blood (PB) in the pathophysiological mechanisms underlying multiple organ dysfunction syndromes (MODS), 24 autopsy cases with MODS were examined. In addition to histopathological and immunohistochemical examination, cytokine levels of cardiac blood, the SRA index (number of small SRA(+) cells in 10 high power fields, upper limit <30), and appearance of large SRA(+) cells in PB were examined. The SRA index exceeded 30 in all cases. Large SRA(+) cells and tumor necrosis factor (TNF)-alpha(+) cells were detected in PB in all cases. Macrophage colony stimulating factor (M-CSF), interleukin (IL)-6 and IL-8 levels exceeded the normal level in all cases, and 18 and 15 cases had TNF-alpha and IL-1beta levels above the normal threshold, respectively. Lung injury and necrosis of cardiac myocyte were observed in all cases. Neutrophils and platelets accumulated in the capillaries of injured organs and endothelial cells were extensively injured. From these results, large SRA(+) cells differentiated from monocytes in PB were considered to play an important role in the development of MODS, and necrosis of cardiac myocytes together with lung injury might be the leading cause of death in MODS patients.