I was told that maltodextrin, regardless of it's source is "Gluten Free". That Gluten is a protein, and maltodextrin is a sugar. That the reason some celiacs react to maltodextrin, specifically derived from wheat, is because many celiacs are also intolerant of other wheat products. So that, some celiacs and gluten intolerant people, are ok and others are not, it depends what else they're allergic to.
If you react to maltodextrin, the suggestion would be that unless its contaminated by something else, you may just simply be intolerant or sensitve to wheat products, as well as gluten.