What Causes Thrombotic Thrombocytopenic Purpura?
A lack of activity in the ADAMTS13 enzyme (a type of protein in the blood) causes thrombotic thrombocytopenic purpura (TTP). The ADAMTS13 gene controls the enzyme, which is involved in blood clotting. Not having enough enzyme activity causes platelets to clump together and form blood clots. In TTP, when blood clots form, the result is fewer platelets in the blood. This can cause bleeding into the skin (purpura), prolonged bleeding from cuts, and internal bleeding. It also can cause small blood clots to form suddenly throughout the body, including in the brain and kidneys. TTP also can cause red blood cells to break apart faster than the body can replace them. This leads to hemolytic anemia.
