A 10-year-old boy is brought to the physician for a 4-day history of nosebleeds and bruising. Physical examination shows ecchymoses over the upper and lower extremities. He has no past medical history. Hemoglobin is 14 g/dL, WBCs 8,000/μL, and platelets 50,000/μL. Which of the following is most likely to be seen in this patient?
Antibodies against factor VIII
Impaired carboxylation
Molecular mimicry
Schistocytosis
Spherocytosis