Page 738 - Hematology_ Basic Principles and Practice ( PDFDrive )

Chapter 44 Red Blood Cell Enzymopathies 625

type I b5R deficiency have cyanosis but a normal life expectancy, 4. Cortazzo JA, Lichtman AD: Methemoglobinemia: a review and recom-
whereas the pan-deficient type II b5R patients usually succumb in mendations for management. J Cardiothorac Vasc Anesth 28:1055–1059,
childhood. 2014.
Critical review of common causes and management of acute toxic
methemoglobinemia.
Therapy 5. Grace RF, Zanella A, Neufeld EJ, et al: Erythrocyte pyruvate kinase
deficiency: 2015 status report. Am J Hematol 90:825–830, 2015.
Offending agents in cases of acquired methemoglobinemia should be A summary of current understanding and management of clinical and
discontinued. No other therapy may be required in an asymptomatic metabolic features of pyruvate kinase deficiency.
patient. However, if the patient is symptomatic or if methemoglobin 6. Ho HY, Cheng ML, Chiu DT: Glucose-6-phosphate dehydrogenase—
levels are greater than 20%, specific therapy is indicated. Methy- beyond the realm of red cell biology. Free Radic Res 48:1028–1048, 2014.
lene blue, 1–2 mg/kg intravenously over 5 minutes, is an effective Focus on basic science of glucose-6-phosphate dehydrogenase.
treatment for patients with methemoglobinemia because NADPH 7. Koralkova P, van Solinge WW, van Wijk R: Rare hereditary red blood
formed in the pentose shunt can rapidly reduce this dye to leu- cell enzymopathies associated with hemolytic anemia—pathophysiology,
komethylene blue in a reaction catalyzed by NADPH diaphorase. clinical aspects, and laboratory diagnosis. Int J Lab Hematol 36:388–397,
Leukomethylene blue, in turn, nonenzymatically reduces methemo- 2014.
globin to hemoglobin. An exception to the efficacy of this treatment A critical review of rarer red cell enzymes.
exists in those patients who are G6PD deficient. In these patients, 8. Luzzatto L, Seneca E: G6PD deficiency: a classic example of pharmacoge-
methylene blue would not only fail to give the desired effect on netics with on-going clinical implications. Br J Haematol 164:133–201,
methemoglobin levels but might compound the situation by induc- 2014.
ing an acute hemolytic episode. If methylene blue is contraindicated, Critical review of G6PD deficiency.
ascorbic acid can be given. Patients with G6PD deficiency and acute 9. Prchal JT, Gregg XT: Red cell enzymes. Hematology Am Soc Hematol Educ
methemoglobinemia have been successfully treated with exchange Program 19–23, 2005.
transfusion. Hyperbaric oxygen has also been used in severe cases of Summary of red cell enzyme defects in descending order of their clinical
methemoglobinemia. importance.
The cyanosis in hereditary b5R deficiency is of cosmetic signifi- 10. van Wijk R, van Solinge WW: The energy-less red blood cell is lost:
cance only but can be treated with methylene blue or ascorbic acid, erythrocyte enzyme abnormalities of glycolysis. Blood 106:4034–4042,
both of which facilitate the reduction of methemoglobin through 2005.
alternate pathways. However, this therapy has no effect on the neu- This review focuses on the impact of energy metabolism of erythrocyte and
rologic and other systemic defects seen in type II b5R deficiency. its pathophysiology.
11. van Zwieten R, Verhoeven AJ, Roos D: Inborn defects in the antioxidant
systems of human red blood cells. Free Radic Biol Med 67:377–386,
SUGGESTED READINGS 2014.
A critical review of defects in the antioxidant system of red cells.
1. Balasubramaniam S, Duley JA, Christodoulou J: Inborn errors of 12. Viprakasit V, Ekwattanakit S, Riolueang S, et al: Mutations in Kruppel-
purine metabolism: clinical update and therapies. J Inherit Metab Dis like factor 1 cause transfusion-dependent hemolytic anemia and per-
37:687–698, 2014. sistence of embryonic globin gene expression. Blood 123:1586–1595,
Purine metabolism reviewed with implications for erythrocyte toxicity. 2014.
2. Beutler E: Red cell metabolism: a manual of biochemical methods, ed 3, An unusual cause of pyruvate kinase deficiency.
1984, Grune & Stratton. 13. van Solinge WW, van Wijk R: Erythrocyte enzyme disorders. In
Manual of assays for red cell enzymes and red cell metabolic intermediates. Kaushansky K, Lichtman MA, Prchal JT, editors: Williams manual of
3. Borron SW, Bebarta VS: Asphyxiants. Emerg Med Clin North Am hematology, ed 9, New York, 2015, McGraw Hill, pp 689–724.
33:89–115, 2015. Review of red cell enzymes with extensive bibliography of original and recent
Review of methemoglobinemia and other conditions impairing oxygen articles.
delivery.