title: Impaired agglutination of IgM resulting from non-enzymatic glycation in diabetes mellitus.
abstract: 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 less than 0.01); IgA 14.7% (+/- 4.9%) vs. 7.7% (+/- 1.3%; P less than 0.01). To investigate how glycation would alter IgM function, serum proportions from diabetic patients with blood group O were separated into glycated and non-glycated fractions by affinity chromatography and, adjusted to the same concentrations, tested against group A1 erythrocytes. Agglutination, which is mainly an IgM-mediated reaction, was significantly lower in the glycated than in the non-glycated fraction of IgM. The correlation between glycation of IgM and the reduction of agglutination titres in the glycated fraction was significant (r = 0.88, P less than 0.001). We conclude that impaired IgM function may be caused by non-enzymatic glycation in diabetes mellitus with possible consequences for host resistance in the early phase of infection.
authors.affiliation: III. Med. Klinik und Poliklinik, Justus-Liebig-Universität, Giessen, F.R.G.
authors.forename: H P
authors.initials: HP
authors.lastname: Hammes
authors.forename: V
authors.initials: V
authors.lastname: Kiefel
authors.forename: H
authors.initials: H
authors.lastname: Laube
authors.forename: K
authors.initials: K
authors.lastname: Federlin
mesh_terms: D000371:Agglutination; D002846:Chromatography, Affinity; D003920:Diabetes Mellitus / Q000276:immunology*; D006031:Glycosylation; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D007074:Immunoglobulin G / Q000032:analysis*; D007075:Immunoglobulin M / Q000032:analysis*; D012016:Reference Values
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M