A 35-year-old woman presents with confusion, fever, and dark urine. Vital signs show temperature 38.9°C, blood pressure 108/72 mmHg, heart rate 102/min, respirations 18/min, and SpO2 98% on room air. Examination reveals diffuse petechiae. Laboratory studies show hemoglobin 8.1 g/dL, platelets 19,000/mm³, creatinine 1.9 mg/dL, and elevated lactate dehydrogenase. Peripheral smear demonstrates schistocytes. PT and PTT are normal. She denies recent antibiotic use. Which of the following best explains the pathogenesis?
- A)Autoantibody against ADAMTS13 causing large von Willebrand multimersGABARITO
- B)Defect in glycoprotein Ib mediated platelet adhesion
- C)Consumption of fibrinogen from tissue factor activation
- D)Immune destruction of platelets after heparin exposure
- E)Deficiency of factor VIII due to inherited mutation
Explicação
Autoantibody against ADAMTS13 causing large von Willebrand multimers is correct. TTP is characterized by thrombocytopenia, microangiopathic hemolytic anemia, neurologic symptoms, renal dysfunction, and fever with normal coagulation studies. Failure to cleave l... Ver explicação completa e trilha adaptativa →