Increasing shift from islet antibody positivity to diabetes

(HealthDay) -- There is an increase in both the prevalence and levels of islet antigen-2 and zinc transporter 8, as well as in autoantibodies, in newly diagnosed type 1 diabetes patients during a period of rising disease incidence, according to a study published in the March issue of Diabetes.

Anna E. Long, of the University of Bristol in the United Kingdom, and colleagues analyzed autoantibodies to insulin (IAA), glutamic acid decarboxylase (GADA), islet antigen-2 (IA-2A), and zinc transporter 8 (ZnT8A) by measurement with radioimmunoassay of sera collected from children and young adults with newly diagnosed type 1 diabetes between 1985 and 2002.

The researchers found that the prevalence of IA-2A and ZnT8A increased significantly over the period studied. This finding was accompanied by raised levels of IA-2A, ZnT8A, and IA-2β autoantibodies (IA-2βA). No changes were observed in IAA or GADA prevalence and levels.

"Increases in IA-2A, ZnT8A, and IA-2βA at diagnosis during a period of rising incidence suggest that the process leading to type 1 diabetes is now characterized by a more intense humoral autoimmune response," the authors write.