Lambert-Eaton syndrome antibodies: reaction with membranes from a small cell lung cancer xenograft.
Lambert-Eaton myasthenic syndrome (LEMS) is a paraneoplastic autoimmune disorder caused by an IgG-mediated reduction in number of presynaptic voltage-gated calcium channels (VGCC) at the neuromuscular junction. In at least 50% of cases, the stimulus for antibody production may be VGCC on small cell lung cancer (SCLC). In this study membranes isolated from a human small cell lung cancer xenograft (Mar), that bound [3H]PN200-110, a VGCC antagonist, were subjected to Western blotting using plasma from 12 LEMS patients and eight controls. Although one band recognised by 3/12 LEMS IgGs might be associated with the VGCC, a number of other proteins were recognised both by LEMS plasma, and by plasma from patients with other disorders. The results illustrate the difficulties found using Western blotting with autoimmune plasma to identify specific polypeptides in a crude antigen preparation.
Chester
K A
KA
Department of Neurological Science, Royal Free Hospital School of Medicine, London, U.K.
Lang
B
B
Gill
J
J
Vincent
A
A
Newsom-Davis
J
J
D000328:Adult; D000368:Aged; D000818:Animals; D000937:Antigen-Antibody Reactions; D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000032:analysis* / Q000276:immunology; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels; D018288:Carcinoma, Small Cell / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007118:Immunoassay; D008175:Lung Neoplasms / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D008297:Male; D051379:Mice; D008819:Mice, Nude; D008875:Middle Aged; D009368:Neoplasm Transplantation; D009468:Neuromuscular Diseases / Q000276:immunology*; D011978:Receptors, Nicotinic / Q000032:analysis; D013577:Syndrome; D014183:Transplantation, Heterologous
D001323:Autoantibodies; D001324:Autoantigens; D015220:Calcium Channels; D011978:Receptors, Nicotinic; D002118:Calcium