Myasthenia gravis muscle antibodies examined by ELISA: IgG and IgM antibodies characterize different patient subgroups.
Sera from 90 myasthenia gravis (MG) patients were examined for antibodies against skeletal muscle citric acid extract (CA) antigens by ELISA and indirect haemagglutination (IHA). 31% (ELISA) and 24% (IHA) of the sera were positive, and the results of the two tests were in good agreement. 18 of 28 patients positive in ELISA had IgG CA-antibodies, 10 had IgM and 3 IgA CA-antibodies. The patients with IgG antibodies had a high mean age of MG disease onset, and 9/14 thymectomized patients had a thymoma. Patients with IgM CA-antibodies had a much lower age of onset and 4/5 thymectomized patients had thymus hyperplasia. IgM antibody positive patients had a long disease duration, indicating that they produce IgM antibodies for an indefinite period of time without switching to IgG antibody production.
Hofstad
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H
Broegelmann Research Laboratory for Microbiology, University of Bergen, Norway.
Ulvestad
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E
Gilhus
N E
NE
Matre
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R
Aarli
J A
JA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001284:Atrophy; D001323:Autoantibodies / Q000032:analysis*; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D007075:Immunoglobulin M / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000276:immunology*; D009132:Muscles / Q000276:immunology*; D009157:Myasthenia Gravis / Q000175:diagnosis / Q000276:immunology*; D013945:Thymoma / Q000175:diagnosis / Q000276:immunology; D013950:Thymus Gland / Q000473:pathology; D013952:Thymus Hyperplasia / Q000175:diagnosis / Q000276:immunology; D013953:Thymus Neoplasms / Q000175:diagnosis / Q000276:immunology
D001323:Autoantibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D009124:Muscle Proteins