Comparison of the prevalence of glutamic acid decarboxylase (GAD65) and gliadin antibodies (AGA) in a randomly selected adult Estonian population

We aimed to test the hypothesis that gluten might be associated with the de velopment of islet cell autoimmunity. A random sample of 200 persons (87 ma les, mean age 42.4 years) from Estonia including one patient with type I di abetes mellitus was studied. IgG-type glutamic acid decarboxylase (GAD65) a ntibodies were determined using radioligand-binding assay and IgG/IgA-type gliadin antibodies (AGA) by enzyme-linked immunosorbent assay. Generic HLA- DRB1* alleles were analyzed using a polymerase chain reaction. Although our results revealed the highest GAD65Ab index and a high IgA-type AGA in a pe rson with diabetes, no correlation between GAD65Ab and AGA values was revea led among the other 199 persons (p > 0.05). There were also no differences between test values among persons with and without different HLA-DRB1* alle les (p > 0.05). In the GAD65Ab assay, one person (0.5%; 95% Cl: 0-1.5) out of 199 exceeded the 99(th) centile of the GAD65Ab index. In summary, the pr esent study does not confirm the possibility that there is a relationship b etween the immune reactivity against GAD65 and gliadin, at least in persons without type I DM.