- Lambert-Eaton Myasthenic Syndrome and Voltage-gated Calcium Channel Antibodies (VGCC Ab)
- VGCC Ab testing
- Technical Information
*Download the requisition onto a computer and open with Adobe Acrobat/Reader for a writeable PDF
Lambert-Eaton Myasthenic Syndrome and Voltage-gated Calcium Channel Antibodies
Lambert-Eaton Myasthenic Syndrome (LEMS) is an autoimmune, neuromuscular transmission disorder characterized by muscle weakness and fatigue. In LEMS, voltage-gated calcium channels (VGCC) located at nerve terminals are targeted by pathogenic autoantibodies, which prevent the influx of calcium and, in turn, inhibit the presynaptic release of acetylcholine into the neuromuscular junction in response to an action potential, consequently reducing the strength of muscle contraction. About 50 – 60% of LEMS patients have an underlying malignancy, most commonly small cell lung cancer (SCLC), and, therefore, is also regarded as a paraneoplastic syndrome. Measuring VGCC antibodies is clinically useful in differentiating between neuromuscular disease and a polyneuritis. VGCC antibody positivity suggests the presence SCLC and treatment of cancer may improve LEMS.
VGCC Ab Testing at the Neuro-Immunology Lab
The lab uses a radioimmunoassay kit that is FDA-approved for in vitro diagnostic used to semi-quantitatively measure antibodies to voltage-gated calcium channels in human serum.
Serum samples should be collected in SST tubes, clotted for a minimum of 30 minutes, centrifuged at 4°C, transferred to cryovials, and stored at 4°C prior to shipping.
Two (2) to five (5) ml of serum should be shipped according to IATA, ICAO and Canadian transportation goods regulation. Samples do not need to be frozen. Please courier your samples together with a completely filled out requisition (see “Lab Requisition” above). When applicable, the clinical information should be filled out by the referring physician (whom we will call or write in case of discrepant results).
Results will be faxed (please include a fax number on the requisition).
Ship samples to:
University of British Columbia Hospital
Room S-157, 2211 Wesbrook Mall
Vancouver, B.C, Canada
For all other inquiries, please contact us:
Lab Phone: (604) 822-7175
Office Phone: (604) 822-7696
Fax: (604) 822-0758