The clinical spectrum of TTP can vary widely; however, the vast majority if not all patients will present with severe thrombocytopenia (platelet count <30 x10^9/L), evidence of microangiopathic hemolytic anemia (including schistocytes on peripheral smear, elevated LDH, indirect hyperbilirubinemia, low haptoglobin, and elevated plasma free hemoglobin) along with potential evidence of end organ damage. Here, HP is linked to thrombotic thrombocytopenic purpura.