What condition leads to the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure?

The condition characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure is hemolytic-uremic syndrome (HUS). HUS is primarily associated with infection by certain strains of Escherichia coli, particularly the Shiga toxin-producing E. coli (STEC), which can lead to significant endothelial damage.

In HUS, the microangiopathic hemolytic anemia occurs due to the destruction of red blood cells as they pass through the damaged small blood vessels. This damage also contributes to thrombocytopenia since the platelets aggregate at the sites of vascular injury, leading to their consumption. Acute renal failure arises from the direct effects of the toxins on renal endothelial cells, resulting in a collapse of the microvasculature and decreased glomerular filtration rate.

Understanding HUS in this context highlights how these three conditions are interconnected through the underlying pathophysiological processes triggered by the infectious agent and the resultant vascular damage.