An African American college student is planning a trip to South America. A week prior to departure he begins a course of antimalarial pills (Mefloquine) that you have given him while working at the...

An African American college student is planning a trip to South America. A week prior to departure he begins a course of antimalarial pills (Mefloquine) that you have given him while working at the university travel clinic. Several days later he begins feeling ill and comes back to see you. His labs are as follows: Hgb 10 g/dL, Hct 30%, MCV 87 fL, and reticulocytes are 8%. The peripheral smear shows bite cells. His blood is direct Coombs negative. What is the pathophysiology of his illness?

A. IgG autoantibodies bind RBCs and cause partial phagocytosis by macrophages.

B. IgM-drug complexes bind RBCs and cause complementmediated lysis.

C. Mechanical vascular damage causes RBC fragmentation.

D. Cold-mediated vasoocclusion of peripheral veins.

E. Oxidized Hgb precipitates in the RBC and causes phagocytosis by macrophages.