fava beans

Q. How is the anemia in G6PD deficiency self-limiting? Does it mean the anemia is short-lived?

A. When new red cells are formed, they have a lot of G6PD in them. As they age, there’s lots of nasty stuff formed during cell metabolism, and the G6PD gets used up. By the end of the cell’s lifespan, there’s less G6PD around (but still enough, in a person without G6PD, to handle all the nasty metabolites that are formed).

In a patient with G6PD, the red cells don’t have as much G6PD to begin with (and by the end of their lifespan, there’s very little G6PD around at all). If a person with G6PD deficiency eats a bunch of fava beans, or ingests some other oxidant, the red cells (particularly those that are older) will have a hard time handling the nasty substances that are formed, and the patient will get an anemia characterized by bite cells. However, the new red cells that get released into the circulation will have at least some G6PD, and they’ll be better equipped to handle the oxidant. As each new wave of red cells appears, the anemia becomes less and less severe, until finally it disappears (assuming the ingestion is a one-time, defined event, and not a ongoing occurrence). So yes, it does mean the anemia is short-lived – and that it goes away on its own without additional therapy. If it’s really severe, the patient may need supportive therapy – red cell transfusions, for example – but that’s just to help get the patient through the crisis.

Gorgeous image of fava beans by Andrew Huff (http://www.flickr.com/photos/51035597898@N01/499585508/), under cc license.