Astrocytic and neuronal biochemical markers in the sera of subjects with diabetes mellitus

To determine if clinical diabetes is associated with disruption of the blood-brain barrier (BBB) and/or brain injury, enzyme-linked immunoassays and Western blots were used to measure serum levels of S100B, NSE and their auto-antibodies in type 1 and type 2 diabetic subjects. Serum S100B concentrations in type 2 diabetic subjects, but not in type 1 diabetic subjects, were significantly lower than those found in healthy controls. There were no significant differences in serum NSE levels of either type I or type 2 diabetics compared to healthy controls. However, there was a significant increase in antibodies to NSE in both type I and type 2 diabetic subjects compared to controls, whereas diabetics and controls had equally very low levels of anti S 100B auto-antibodies. These studies suggest that diabetes in humans may be associated with alterations in the BBB integrity that allow the emergence of antibodies against neuronal antigens. (C) 2004 Elsevier Ireland Ltd. All rights reserved.