Oxidative injury of the red blood cells leading to heamolysis is associated with of the following clinical conditions?
Glucose-6-phosphate dehydrogenase catalyzes the initial step in the hexose monophosphate (HMP) shunt, oxidizing glucose-6-phosphate to 6- phosphogluconolactone and reducing nicotinamide adenine dinucleotide phosphate (NADP) to NADPH. The main function of the HMP shunt is to protect red blood cells against oxidative injury the production of NADPH. Red blood cells contain relatively high concentrations of reduced glutathione (GSH) which is protective against oxidant injury. The oxidants, such as super oxide anion (O2-) and hydrogen peroxide, are formed within red cells due to reactions of hemoglobin with oxygen and due to drugs or infections. They accumulate within red cells and cause oxidation of hemoglobin and other proteins leading to loss of function and cell death. The combined effect of HMP shunt to glutathione metabolism is responsible for protecting intracellular proteins from oxidative stress. G6PD deficiency results in hemolytic episodes related to altered HMP shunt and glutathione metabolism. The cells that over express G6PD are protected against oxidative injury.
G6PD deficiency
Hereditary spherocytosis
Sickle cell anemia
Hemophilia