Microheterogeneity of anti-myelin-associated glycoprotein antibodies.
Antibodies to the myelin-associated glycoprotein (MAG) are implicated in the pathogenesis of an acquired demyelinating polyneuropathy. We studied IgM affinity to MAG in 18 patients with anti-MAG antibodies. Binding of sera was tested for anti-MAG immunoreactivity in central nervous system (CNS) by ELISA and in CNS and peripheral nervous system (PNS) by Western blot analysis. Furthermore, immunohistochemical characterization of IgM binding on sural nerve tissue was investigated using the indirect peroxidase method. Western blot analysis revealed that all sera detected MAG in central myelin, but only eight in peripheral myelin. Anti-MAG-IgM-ELISA-titers correlated significantly (p<0.0001) with PNS-Western blot results. By indirect immunoperoxidase immunohistochemistry, 12 sera stained myelin sheaths, while 6 sera showed no staining. These results demonstrate considerable variations in antibody binding strength to MAG between PNS myelin and CNS myelin. The relevance of these differences for the pathogenesis of the neuropathy and clinical impairment remains to be demonstrated.
Fluri
Felix
F
Department of Clinical Neurology, University Hospitals Basel, Petersgraben 4, Switzerland. flurif@uhbs.ch
Ferracin
Fabrizia
F
Erne
Beat
B
Steck
Andreas J
AJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood / Q000378:metabolism*; D002493:Central Nervous System Diseases / Q000276:immunology; D004594:Electrophysiology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018992:Myelin-Associated Glycoprotein / Q000097:blood / Q000276:immunology* / Q000378:metabolism*; D010265:Paraproteinemias / Q000276:immunology
D001323:Autoantibodies; D007075:Immunoglobulin M; D018992:Myelin-Associated Glycoprotein