Autoimmunity to GABAA-receptor-associated protein in stiff-person syndrome.
Publication/Presentation Date
12-1-2006
Abstract
Stiff-person syndrome (SPS) is an autoimmune neurological disorder characterized by autoantibodies to glutamic acid decarboxylase (GAD), the enzyme responsible for the synthesis of inhibitory neurotransmitter GABA. To search for biomarkers that distinguish SPS from other neurological disorders (OND), we used surface enhanced laser desorption/ionization-time of flight (SELDI-TOF) mass spectrometry to obtain proteomic profile of sera from 25 GAD-positive SPS patients and 25 controls. A significant decrease was found in the level of a protein corresponding to GABA(A)-receptor-associated protein (GABARAP), which is responsible for the stability and surface expression of the GABA(A)-receptor. Up to 70% of the SPS sera examined, compared with 10% of the controls, immunoprecipitated GABARAP protein. Antibodies raised against GABARAP immunostained neuronal cell bodies as well as axonal and dendritic processes, as visualized by confocal microscopy. In vitro experiments demonstrated that the IgG from GABARAP antibody-positive patients, but not control IgG, significantly inhibited the surface expression of GABA(A)-receptor. We conclude that GABARAP is a new autoantigen in SPS. Because the patients' IgG inhibits the expression of GABA(A)-receptors, the circulating antibodies could impair GABAergic pathways and play a role in the clinical symptomatology of SPS patients.
Volume
129
Issue
Pt 12
First Page
3270
Last Page
3276
ISSN
1460-2156
Published In/Presented At
Raju, R., Rakocevic, G., Chen, Z., Hoehn, G., Semino-Mora, C., Shi, W., Olsen, R., & Dalakas, M. C. (2006). Autoimmunity to GABAA-receptor-associated protein in stiff-person syndrome. Brain : a journal of neurology, 129(Pt 12), 3270–3276. https://doi.org/10.1093/brain/awl245
Disciplines
Business Administration, Management, and Operations | Health and Medical Administration | Management Sciences and Quantitative Methods
PubMedID
16984900
Department(s)
Administration and Leadership
Document Type
Article