A Previously Healthy 32-Year-Old Man Is Brought to the Emergency

A previously healthy 32-year-old man is brought to the emergency department by his girlfriend 1 hour after having a seizure. Earlier that day, he also experienced a nosebleed that took 30 minutes to stop when applying pressure. He has had no sick contacts or history of epilepsy or other seizure disorder. He does not take any medications. He is confused and disoriented. His temperature is 39.1°C (102.4°F) , pulse is 106/min, respirations are 26/min, and blood pressure is 128/70 mm Hg. Examination shows pallor and scattered petechiae over the trunk and arms. Laboratory studies show hemoglobin of 8.9 g/dL with elevated reticulocyte count and a platelet count of 26,000/mm³.  Bleeding time is prolonged; prothrombin time and activated partial thromboplastin time are normal.  The peripheral blood smear shows schistocytes and reduced platelets with presence of giant forms.  Blood urea nitrogen is 46 mg/dL and serum creatinine is 2.3 mg/dL.  Urinalysis is positive for proteinuria and hematuria.  Which of the following is most likely to be seen on renal biopsy?

A) Collapse and sclerosis of glomerular tufts
B) Crescent-shaped mass of cellular proliferation and leukocytes
C) Diffuse proliferation and subepithelial immunoglobulin deposits
D) Mesangial IgA deposition and proliferation
E) Patchy necrosis of tubular epithelium and loss of basement membrane
F) Platelet-rich thrombi in glomeruli and arterioles