There is a really interesting new paper on corn and celiac.
This paper carefully identifies fragments of corn gluten (zein) that could potentially bind to HLA-DQ2 and HLA-DQ8 in a subset of people with celiac disease. They removed all the gluten IgA antibodies from sera of some celiac volunteers and found some antibodies to corn zein were still present. They carefully tracked down what the antibodies were binding to, using mass spectrometry, and found the antibodies were recognizing poorly digested peptides from corn zein. This is similar to gluten, where the most immunogenic peptides are the ones that are not fully digested. Some computer work supported that the peptides would bind best to DQ2.5, and that they are similar but not identical to wheat gluten fragments.
The reaction is NOT a cross-reaction to corn. Let me repeat that lest there is any confusion. THIS IS NOT A CROSS-REACTION TO CORN. It is a completely separate set of anti-zein antibodies in some teens and adults with celiac disease. Interestingly, two of the five corn-sensitive people were still sick gluten-free. They don't mention in the paper if they got well off corn.
First, if you're feeling OK, don't freak out about corn. Corn is still safe for most celiacs. Only 5 out of 24 people they tested had the antibodies. Also, the corn antibodies don't tend to show up in kids suggesting that corn is not inflammatory like wheat. There is no evidence for corn causing celiac in someone who grows up without wheat. The authors suggest that a person needs to be untreated celiac for a while for the corn antibodies to show up.
There have been flaws in little bit of other corn research that has been done (like the one with 80 ppm gluten in their cornmeal), but this seems to be really solid study. It does raise a lot of questions though. Did the people who were still sick recover off corn? Is corn processed by TTG, triggering autoimmunity? Do the corn epitopes the authors identified stimulate T-cells? Can corn cause TTG antibodies to stay elevated in people with anti-zein IgA? If so, can corn trigger villous atrophy in people who have the anti-zein IgA?
This is extremely important for those of you who are gluten-free and still not well, or potentially being diagnosed with refractory celiac disease. We always tell people to eliminate casein. It's looking like we should also be suggesting people try a period of time eliminating corn (which is unfortunately even harder than eliminating gluten or casein).