Since chocolate truffles are made through a recipe, it would depend on the chef who created the truffles to determine whether those truffles are gluten free. Gluten is found in wheat, rye, barley, yeast and malt among other ingredients. So, it would depend if the chef used flour that contains one of these grains. Many chocolate truffles that you buy in the store can be gluten free.
Recipes can also be altered with other ingredients in order to make them gluten free. Some chocolates contain gluten and so the truffles might have gluten in them. It is important for the person to check the label for the common ingredients that contain gluten. Usually, these people with celiac disease know what to look for.