On auscultation there would be pleural friction rub. In the Arthus reaction, the immune complexes form in the vessel wall. Morphologically, polyarteritis nodosa resembles an Arthus reaction. No question asked. Case Three Image 1.
Hyperacute rejection occurs within minutes to hours after renal transplantation.
The mechanism is the presence of preformed antibodies against the graft antigens, which rapidly react with the endothelium when the vascular anastamoses are made. Endothelial damage by antibody and complement triggers thrombosis. When antibodies enter the graft, they encounter the donor endothelium, hence the reaction occurs primarily in the vasculature. These suggest severe ischemia and possibly coagulative necrosis of the cortex due to vascular thromboses. The pink area in the cortex where cell outlines are preserved is an area of coagulation necrosis.