What condition is characterized by a deficiency in ADAMTS13 leading to decreased degradation of von Willebrand factor (vWF)?

Thrombotic Thrombocytopenic Purpura (TTP) is characterized by a deficiency in the enzyme ADAMTS13, which is responsible for cleaving von Willebrand factor (vWF). In a healthy individual, ADAMTS13 regulates the size of vWF multimers, thus modulating platelet aggregation and preventing excessive clotting. When ADAMTS13 is deficient or dysfunctional, there is an accumulation of large vWF multimers. This leads to increased platelet aggregation and the formation of excessive microthrombi, which can cause various symptoms such as thrombocytopenia, hemolytic anemia, and organ dysfunction due to blood vessel occlusion.

The direct link between the deficiency of ADAMTS13 and the impairment in vWF degradation is crucial for understanding TTP’s pathophysiology. This results in clinical manifestations such as purpura, neurological symptoms, and renal involvement, which are characteristic features of this condition.

In contrast, the other conditions listed are associated with different mechanisms and etiologies. Hemolytic Uremic Syndrome (HUS) typically involves a different pathophysiology often related to infection with Shiga toxin-producing E. coli. Idiopathic Thrombocytopenic Purp