In G6PD deficiency, exposure to oxidizing agents causes which type of hemolysis?

• A. Extravascular and intravascular hemolysis
• B. Intravascular hemolysis only
• C. Extravascular hemolysis only
• D. No hemolysis

Answer: (A)

Oxidative stress in G6PD deficiency damages hemoglobin and the red cell membrane because these cells cannot regenerate reduced glutathione without NADPH. The oxidative damage leads to Heinz bodies; damaged cells are cleared by the spleen (extravascular hemolysis) and, in some cases, lyse directly within the bloodstream (intravascular hemolysis). This dual path explains why exposure to oxidizing agents can cause both intravascular and extravascular hemolysis. Clinically, you might see markers of intravascular destruction like hemoglobinemia/hemoglobinuria alongside signs of extravascular clearance such as indirect hyperbilirubinemia and reticulocytosis, with a smear showing Heinz bodies or bite cells.