A low IgA in a young child is to be expected. On the Celiac.com site, there is a reference that IgA levels don't reach adult levels until a person is 16 years old, and that IgA is only 1/5 an adults at 2 years of age. http://www.celiac.com/cgi-bin/webc.cgi/st_prod.html?p_prodid=16&p_catid=2&sid=91hH9H0WWJj330z-19102080399.5f There are many sites with gluten- free, casein- free diets- http://www.gfcfdiet.com/Beginningthediet.htm states that the urine has high levels of peptides (in people using this diet/ autistic spectrum). Peptides contain Nitrogen, and may have been detected on Tyler's tests. Another good place to look is http://www.gfcfdiet.com/Beginningthediet.htm http://autismndi.com/ has articles in the 'news' section
