RBC enzyme defects

on 4.3.09 with 0 comments

  • RBCs can’t handle oxidative damages as well

  • Can come about from abnormalities in the hexose shunt or in glutathione metabolism

  • The most frequent cause is G6PD decrease

    • G6PD-A- is found in 10% of American blacks and causes mild hemolysis with exposure to oxidants like quinacrine, sulfonamides, etc

    • G6PD-Mediterranean produces more severe hemolysis

    • Both are X-linked; gene persistence through anti-malarial effect

    • Pitting of Heinz bodies (little clusters of altered Hb) from affected RBCs by the RES leads to the formation of schizocytes (“bite cells”), spherocytes, and eventual hemolysis

    • A diagnosis may be suggested by a (+) Heinz body stain (crystal violet, which stains denatured Hb) and confirmed by measuring G6PD levels

  • Other enzymopathies include deficiencies of pyruvate kinase, hexokinase, and glutathione synthetase

Category: Medical Subject Notes , Pathology Notes



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