A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Voltage-Gated Calcium Channel (VGCC) Type N Antibody
Test Code93882
CPT Codes
86596
Preferred Specimen
1 mL serum
Minimum Volume
0.5 mL
Transport Container
Plastic screw-cap vial
Transport Temperature
Frozen
Specimen Stability
Room temperature: 48 hours
Refrigerated: 48 hours
Frozen: 60 days
Refrigerated: 48 hours
Frozen: 60 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Grossly lipemic • Grossly icteric samples • Turbid • Bacterial contamination
Methodology
Radioimmunoassay (RIA)
FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Setup Schedule
Set up: Tues, Thurs; Report available: 8-15 days
Reference Range
<54 pmol/L
Clinical Significance
N-type calcium channel antibodies are more highly associated with primary lung cancer than P/Q-type. One or all of the autoantibodies in the myasthenia gravis (MG)/LEMS evaluation can occur with neoplasia without evidence of neurological impairment. One or both calcium channel antibodies (P/Q and N) can occur with paraneoplastic and idiopathic cerebellar ataxia, encephalomyeloneuropathies, and autonomic neuropathy. Classical symptoms of LEMS include proximal muscle weakness, fatigability, dry mouth and impotence. When presentation is further complicated with oculobulbar weakness, these symptoms can easily be misinterpreted as MG. However, because VGCC antibodies are positive in only approximately 5% of MG patients, the measurement of these antibodies is very useful in distinguishing LEMS from MG.
Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA |
33608 Ortega Highway |
San Juan Capistrano, CA 92675-2042 |