Photographs of sections of adrenal and kidneys from baboons injected with sublethal doses of E coli and blocking anti-EPCR mAbs.

The organs were harvested at the time of impending death. The “early” changes (ie, changes in animals with relatively short survival) consist of prominent microthrombus formation in the subcapsular vessels (arrows) of the adrenals (A) and also in the renal glomeruli (arrow) (C). Note the extensive cortical hemorrhage in the adrenal gland (A) and the early ischemic/necrobiotic changes (karyopyknosis) in the proximal tubular epithelial cells (triangle) of the kidney (C). In B and D, the animals that had relatively long survival, widespread necrotic foci were apparent with associated polymorphonuclear leukocyte infiltrates in the adrenal cortex (B) and severe acute tubular necrosis involving the proximal tubules (P) of the kidney (D). The distal tubules (D) were well-preserved. Occasional mitotic figures of the proximal tubular epithelial cells are also seen as features of regeneration (arrow) (D). Note the lack of thrombi and hemorrhage in the “late” group (B and D).