Antibodies to active zone protein ERC1 in Lambert-Eaton myasthenic syndrome.

Abstract

Lambert-Eaton myasthenic syndrome (LEMS) is characterized by fluctuating muscle weakness and autonomic dysfunction. In 90% of the LEMS patients the disease is associated with auto-antibodies against the voltage-gated calcium channels (VGCC). Several auto-immune responses against other antigenic targets have been described to (co)-occur in LEMS patients. To identify new LEMS associated small cell lung cancer (SCLC) markers immunoprecipitation with a SCLC cell line was performed. We discovered strong immunoreactivity against the 120 kDa large ERC1 protein in one tumor-negative VGCC-positive LEMS patient. A recombinant ELISA assay and a cellular assay expressing GFP-tagged full length ERC1 were used to confirm the presence of auto-antibodies against ERC1 in this patient. Additional testing of 58 LEMS patients including 9 VGCC auto-antibody negative LEMS patients, 48 myasthenia gravis patients, 84 control patients with other diseases and 12 healthy controls revealed no other cases. ERC1 is therefore a new, but rare, antigen in LEMS.

• Authors: Maartje G Huijbers, Alexander F Lipka, Marko Potman, Paul J Hensbergen, Maarten J Titulaer, Erik H Niks, Silvère M van der Maarel, Rinse Klooster, Jan J Verschuuren
• Journal: Human immunology (Hum Immunol) Vol. 74 Issue 7 Pg. 849-51 (Jul 2013) ISSN: 1879-1166 [Electronic] United States
• PMID: 23583364 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Chemical References

• Adaptor Proteins, Signal Transducing
• Autoantibodies
• Autoantigens
• Calcium Channels
• ERC1 protein, human
• Nerve Tissue Proteins

Topics

• Adaptor Proteins, Signal Transducing (immunology)
• Adult
• Autoantibodies (blood)
• Autoantigens (immunology, isolation & purification)
• Calcium Channels (immunology)
• Cell Line
• Humans
• Lambert-Eaton Myasthenic Syndrome (complications, immunology)
• Lung Neoplasms (complications, immunology)
• Male
• Nerve Tissue Proteins (immunology)
• Small Cell Lung Carcinoma (complications, immunology)