IgG from "seronegative" myasthenia gravis patients binds to a muscle cell line, TE671, but not to human acetylcholine receptor

Citation
F. Blaes et al., IgG from "seronegative" myasthenia gravis patients binds to a muscle cell line, TE671, but not to human acetylcholine receptor, ANN NEUROL, 47(4), 2000, pp. 504-510
Citations number
23
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurology,"Neurosciences & Behavoir
Journal title
ANNALS OF NEUROLOGY
ISSN journal
0364-5134 → ACNP
Volume
47
Issue
4
Year of publication
2000
Pages
504 - 510
Database
ISI
SICI code
0364-5134(200004)47:4<504:IF"MGP>2.0.ZU;2-2
Abstract
Antibodies to acetylcholine receptor (AChR) are found in 85% of patients wi th myasthenia gravis (seropositive MG [SPMG]) and are thought to be pathoge nic; but in 15% of MG patients, the standard immunoprecipitation test for a nti-AChR is negative (seronegative MG [SNMG]). Here, me used a novel approa ch, fluorescence-activated cell sorting analysis, to measure binding of SPM G and SNMG IgG antibodies to rhabdomyosarcoma cell lines that express human adult (TE671-epsilon) or fetal (TE671-gamma) AChR, and to human embryonic kidney (HEK) fibroblasts that express adult human AChR (HEK-AChR). We found that whereas most SPMG antibodies bind to all three cell fines, IgG from 8 of 15 SNMG sera/plasmas bind to the surface of both TE671 cell lines but n ot to HEK-AChR cells. These results indicate that SNMG antibodies bind to a muscle surface antigen that is not the AChR, which strongly supports previ ous studies that suggest that SNMG should be considered a distinct subtype of MG.