How can patients receive blood transfusions without an iron overload?

Blood and Fe loading. It's impossible to get blood transfusions and not have the iron accumulate, unless someone is having ongoing bleeding (which then makes you lose iron). There are several iron-removing (or chelating) drugs available now, like Desferal (which is given IV or subcutaneously) and Exjade (which is given orally). These are very effective at removing iron if the patient is compliant with taking them.