Impaired agglutination of IgM resulting from non-enzymatic glycation in diabetes mellitus

Non-enzymatic glycation of circulating immunoglobulin G, A and M, measured by boronic acid affinity chromatography was found to be significantly increased in diabetes mellitus. The mean value of glycated IgM was already high in the control group: 49.58% (±10.3% SD) and increased up to a mean value of 61.00% (±8.5%) in the diabetic group. Similarly IgG and IgA glycation was significantly higher in the diabetic group than in controls: IgG 21.6% (±3.4%) vs. 14.1% (±2.9%; P < 0.01); IgA 14.7% (±4.9%) vs. 7.7% (±1.3%; P < 0.01).