hematology and oncology
Thrombotic Thrombocytopenic Purpura (TTP)
Pathophysiology of TTP
Thrombotic thrombocytopenic purpura (similar to Hemolytic-Uremic Syndrome (HUS) [HUS]) involves nonimmunologic platelet destruction. Endothelial damage is common. Loose strands of platelets and fibrin are deposited in multiple small vessels and damage passing platelets and red blood cells (RBCs), causing significant thrombocytopenia and anemia (microangiopathic hemolytic anemia). Platelets are also consumed within multiple small thrombi, contributing to the thrombocytopenia. (VWF) thrombi localized primarily to arteriocapillary junctions, described as thrombotic microangiopathy. The brain, gastrointestinal tract, and kidneys are particularly likely to be affected. Although kidney involvement is often present on biopsy (if done), severe Acute Kidney Injury (AKI) is rare, unlike in HUS. The microthrombi do not include RBCs or fibrin (unlike thrombi in 