Antibodies to 125I-glutamic acid decarboxylase in patients with stiff man syndrome.
Antibodies to glutamic acid decarboxylase (GAD) are found in about 40% of patients with stiff man syndrome. A new assay involving immunoprecipitation of (125)I-glutamic acid decarboxylase was used to measure anti-GAD antibodies in 18 patients with stiff man syndrome. Of the eight serum samples from patients with stiff man syndrome, that had previously been found positive by immunoprecipitation of (35)S-GAD, seven were strongly positive with (125)I-GAD and one gave an equivocal result. Other serum samples from patients with stiff man syndrome and from controls were negative except one from a patient who had a thymoma, acquired neuromyotonia, and myasthenia gravis. Nine of 35 serum samples referred for testing were positive; in two of these the serum titre was 20-50 times higher than that in the CSF. This assay should prove useful in the diagnosis, management, and investigation of stiff man syndrome.
Vincent
A
A
Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, UK.
Grimaldi
L M
LM
Martino
G
G
Davenport
C
C
Todd
I
I
D000906:Antibodies / Q000097:blood* / Q000134:cerebrospinal fluid; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D016750:Stiff-Person Syndrome / Q000276:immunology*
D000906:Antibodies; D005968:Glutamate Decarboxylase