Anemia can be caused by metabolic RBC disorders (thanks to haematologica.org for this image) that interferes with the integrity of the red blood cell membrane.One of the more important enzyme deficiencies is the glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency), dealt with under this link.
Briefly, the red blood cell has it’s own metabolism that involves an important enzyme, glucose-6-phosphate dehydrogenase that is absolutely essential for a normal RBC function. If this enzyme is partially of totally absent, the membrane of the red blood cells cannot be maintained and red blood cells break up. They also do not last the normal 120 days, but are used up earlier. This results in a breakdown of the RBC’s , hemolytic anemia and an enlargement of the spleen as the spleen filters out fragments of RBC’s and aged RBC’s.
Hemolysis can occur in those afflicted with this enzyme deficiency following a fever (viral or bacterial) and also with diabetic acidosis, which occurs when diabetes is poorly controlled.
Interestingly, there is also a vulnerability of the red blood cells to certain drugs that are mentioned under the above link. Briefly, some of the more important drugs are salicylates and sulfonamides, but some are also very sensitive to fava beans. As this metabolic RBC disorder is an X-linked disorder, it is more common in black males than females as females have a second X chromosome that can compensate for missing G6PD function. There are also more than 100 mutant forms of this enzyme that have been found within the population that translates into various degrees of severity.
References:
1. The Merck Manual: Hemolytic anemia
2. Noble: Textbook of Primary Care Medicine, 3rd ed., Mosby Inc. 2001
3. Goldman: Cecil Medicine, 23rd ed., Saunders 2007: Chapter 162 – APPROACH TO THE ANEMIAS
