A novel antineuronal antibody in stiff-man syndrome.
Two-thirds of stiff-man syndrome (SMS) patients harbor an autoantibody specific for a 64-kD species of glutamic acid decarboxylase (GAD), the rate-limiting enzyme in GABA synthesis. We assayed SMS antisera from two patients with SMS for the presence of anti-GAD antibodies using Western blot, immunohistochemical, and enzymatic analyses. Both SMS antisera recognized an 80-kD antigen present in human and rat neuronal extracts, and failed to recognize the 64-kD GAD species. Immunohistochemistry demonstrated neuronal binding identical to that reported with anti-GAD antibodies. Both sera depleted GAD activity from brain extracts. Our analysis indicates that these SMS antisera differ from previously reported SMS antisera by recognizing a novel 80-kD antigen, and suggests that they contain antibodies directed against either a species of GAD different in size from the 64-kD enzyme, or a protein that co-immunoprecipitates with GAD.
Darnell
R B
RB
Department of Neurology and Neuroscience, New York Hospital-Cornell Medical Center, New York.
Victor
J
J
Rubin
M
M
Clouston
P
P
Plum
F
F
D000328:Adult; D000368:Aged; D000818:Animals; D001323:Autoantibodies / Q000032:analysis*; D015153:Blotting, Western; D004576:Electromyography; D005074:Evoked Potentials, Visual; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D008297:Male; D051381:Rats; D016750:Stiff-Person Syndrome / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis / Q000276:immunology*; D013552:Swine
D001323:Autoantibodies; D005968:Glutamate Decarboxylase