ADAMTS13 and Thrombocytopenia: Thrombocytopenia (45 × 109/L), Coombs negative hemolytic anemia (hemoglobin 7.9 g/dL; schistocytes 42‰, haptoglobin < 10 mg/dL; total serum bilirubin 2455 mg/dL; and acute renal failure (serum creatinine 1.95 mg/dL), ADAMTS13 antibodies were reduced but still positive (19.9 U/mL); ADAMTS13 activity was 14%