Most of anti-glycolipid IgG-antibodies associated to neurological disorders occur without their IgM counterpart

• Published in: Journal of biomedical science 2019-09, Vol.26 (1), p.67-67, Article 67
• Main Authors: Lardone, Ricardo Dante, Irazoqui, Fernando José, Nores, Gustavo Alejandro
• Format: Article
• Language: English
• Subjects: Anti-ganglioside IgG-antibodies; Antibodies; Antibodies, Anti-Idiotypic - blood; Antibody response; Argentina; Autoimmunity; Bacteria; Binding sites; Blood groups; Chromatography; Diagnosis; Discordance; Disorders; Displays (Marketing); Gangliosides; Glycan; Glycolipid; Glycolipids; Glycolipids - immunology; Human behavior; Humans; IgG/IgM discordance; Immune response; Immune response (humoral); Immune system; Immunoglobulin G; Immunoglobulin M; Immunoglobulin M - blood; Immunoglobulins; Immunology; Immunoreactivity; Lipids; Membrane lipids; Nervous system diseases; Nervous System Diseases - immunology; Neurological diseases; Neurological disorder; Neurological disorders; Plant lipids; Polysaccharides; Risk factors; Thin layer chromatography
• ISSN: 1423-0127; 1021-7770; 1423-0127
• DOI: 10.1186/s12929-019-0562-5

Different neurological disorders frequently display antibodies against several self-glycans. Increasing evidence supports their pathogenic role; however, far less is known about their origin. Meanwhile, antibodies recognizing non-self glycans appear in normal human serum during immune response to bacteria. Using high performance thin layer chromatography-immunostaining, we comparatively evaluated humoral immune response (IgG and IgM immunoreactivity) against glycolipids carrying self-glycans (GM3/GM2/GM1/GD1a/GD1b/GD3/GT1b/GQ1b) and non-self glycans (Forssman/GA1/"A" blood group/Nt7) in sera from 383 patients with neurological disorders along with 87 healthy controls. In contrast to no healthy controls having anti-self glycan IgG antibodies, one-fifth of patients' sera had anti-self glycan IgG antibodies: remarkably, 60% of these occurred without IgM antibodies of the same specificity. Contrary to this unusual fact (anti-self glycan IgG occurrence without simultaneous presence of IgM having the same specificity ~ IgG/IgM discordance), all IgG antibodies against non-self glycans occurred simultaneously with their IgM antibody counterpart (i.e. 0% discordance). When analyzed closer, the IgG/IgM discordance frequency for anti-self glycans exhibited a dual trend: below 40% for IgG antibodies against GM2, GM1 and GD1b, and greater than 53% for IgG antibodies against the remaining self glycans. Interestingly, this discordance behavior was common to several different neurological disorders. Classic immunology principles indicate this anti-self glycan IgG/IgM discordance should not occur in an antibody response; its unusual presence is discussed within the "binding site drift hypothesis" context, where anti-self glycan IgG antibodies could originate from pre-existing IgG recognizing structurally-related non-self glycans.