A 33-year-old female is brought to Urgent Care by her husband who states his wife has gotten suddenly confused and complains of a severe headache. He also noticed large bruises on her legs which were not there yesterday. Only significant past medical history is that the patient developed herpes zoster 2 weeks ago and was given acyclovir for treatment. Physical exam revealed well developed female who is only oriented to person. Large areas of ecchymosis noted on both arms and legs. Stat CBC revealed a platelet count of 18,000/mm3, hemoglobin of 8 g/dl and hematocrit of 24%. The patient was immediately transported to the Emergency Room by Emergency Medical Services (EMS) where further work up demonstrated idiopathic thrombotic thrombocytopenic purpura (TTP).
Question:
What is the pathophysiology of TTP?